Add issue creation and editing

TESTING.md

@@ -141,6 +141,21 @@ xcrun simctl launch booted de.rfc1437.gotcha
       selections persist independently per repository and status persists.
 - [ ] The issue-filter icon uses a neutral color for Open + All Milestones + no
       labels, and the app accent color whenever any non-default filter is set.
+- [ ] Tap the add button. **New Issue** appears as a native modal with Cancel
+      and Save, title and Markdown body fields, multi-select labels, a
+      single-select optional milestone, and an optional inline due-date picker.
+- [ ] In the new-issue body, enter headings, emphasis, a list, a link, and a
+      fenced code block. **Write** syntax-highlights the Markdown and **Preview**
+      renders it; switching repeatedly preserves the exact source text.
+- [ ] Save is disabled for an empty or whitespace-only title. Create issues with
+      no labels/milestone/due date and with multiple labels, a milestone, and a
+      due date; each new issue appears in the list and opens its detail.
+- [ ] Tap **Edit** on an issue. Change its title and Markdown body, replace and
+      clear labels, select and clear its milestone, and add, change, and remove
+      its due date. Save, refresh, and relaunch to verify every change persists.
+- [ ] Cancel both new and edited issues, including with the keyboard and date
+      picker visible. Nothing is saved, the modal dismisses normally, and the
+      issue list/detail remains usable with Dynamic Type and VoiceOver labels.
 - [ ] Open both an open and a closed issue. A green open or purple closed icon
       appears beside the title and VoiceOver announces the state; author
       metadata, Markdown body, and comments remain correct. Links and

crates/app/src/api.rs

@@ -9,8 +9,8 @@ use tokio::task::JoinSet;
 use crate::{
     diff,
     domain::{
-        HistoryCommit, HomeData, IssueDetails, MilestoneDetails, PullDetails, RepositoryData,
+        HistoryCommit, HomeData, IssueDetails, IssueDraft, IssueEditorData, MilestoneDetails,
-        Server,
+        PullDetails, RepositoryData, Server, api_date,
     },
     presentation::compact_date,
 };
@@ -430,6 +430,115 @@ pub async fn load_issue(
     })
 }
 
+pub async fn load_issue_editor(
+    server: &Server,
+    owner: &str,
+    repository: &str,
+    number: Option<i64>,
+) -> Result<IssueEditorData, String> {
+    let issue = async {
+        match number {
+            Some(number) => {
+                let client = Client::new(&server.url, Some(&server.token))
+                    .map_err(|error| error.to_string())?;
+                apis::issue_api::issue_get_issue(&client.configuration(), owner, repository, number)
+                    .await
+                    .map(Some)
+                    .map_err(|error| error.to_string())
+            }
+            None => Ok(None),
+        }
+    };
+    let (issue, labels, milestones) = tokio::try_join!(
+        issue,
+        load_labels(server, owner, repository),
+        load_milestones(server, owner, repository)
+    )?;
+    Ok(IssueEditorData {
+        issue,
+        labels,
+        milestones,
+    })
+}
+
+fn create_issue_option(draft: IssueDraft) -> models::CreateIssueOption {
+    models::CreateIssueOption {
+        body: Some(draft.body),
+        due_date: draft.due_date.map(api_date),
+        labels: Some(draft.label_ids),
+        milestone: draft.milestone_id,
+        ..models::CreateIssueOption::new(draft.title)
+    }
+}
+
+fn edit_issue_option(draft: &IssueDraft) -> models::EditIssueOption {
+    models::EditIssueOption {
+        body: Some(draft.body.clone()),
+        due_date: draft.due_date.map(api_date),
+        milestone: Some(draft.milestone_id.unwrap_or_default()),
+        title: Some(draft.title.clone()),
+        unset_due_date: draft.due_date.is_none().then_some(true),
+        ..models::EditIssueOption::new()
+    }
+}
+
+pub async fn create_issue(
+    server: &Server,
+    owner: &str,
+    repository: &str,
+    draft: IssueDraft,
+) -> Result<models::Issue, String> {
+    let client =
+        Client::new(&server.url, Some(&server.token)).map_err(|error| error.to_string())?;
+    apis::issue_api::issue_create_issue(
+        &client.configuration(),
+        owner,
+        repository,
+        Some(create_issue_option(draft)),
+    )
+    .await
+    .map_err(|error| error.to_string())
+}
+
+pub async fn edit_issue(
+    server: &Server,
+    owner: &str,
+    repository: &str,
+    number: i64,
+    draft: IssueDraft,
+) -> Result<models::Issue, String> {
+    let client =
+        Client::new(&server.url, Some(&server.token)).map_err(|error| error.to_string())?;
+    let configuration = client.configuration();
+    let issue = apis::issue_api::issue_edit_issue(
+        &configuration,
+        owner,
+        repository,
+        number,
+        Some(edit_issue_option(&draft)),
+    )
+    .await
+    .map_err(|error| error.to_string())?;
+    apis::issue_api::issue_replace_labels(
+        &configuration,
+        owner,
+        repository,
+        number,
+        Some(models::IssueLabelsOption {
+            labels: Some(
+                draft
+                    .label_ids
+                    .into_iter()
+                    .map(serde_json::Value::from)
+                    .collect(),
+            ),
+        }),
+    )
+    .await
+    .map_err(|error| error.to_string())?;
+    Ok(issue)
+}
+
 pub async fn load_pull(
     server: &Server,
     owner: &str,
@@ -845,4 +954,32 @@ mod tests {
         assert!(commits[4].bottom_lanes.is_empty());
         assert_eq!(commits[4].node_lane, Some(0));
     }
+
+    #[test]
+    fn builds_complete_create_and_edit_issue_requests() {
+        let create = create_issue_option(IssueDraft {
+            title: "Title".into(),
+            body: "**Body**".into(),
+            label_ids: vec![2, 3],
+            milestone_id: Some(5),
+            due_date: Some(1_709_164_800),
+        });
+        assert_eq!(create.title, "Title");
+        assert_eq!(create.body.as_deref(), Some("**Body**"));
+        assert_eq!(create.labels, Some(vec![2, 3]));
+        assert_eq!(create.milestone, Some(5));
+        assert_eq!(create.due_date.as_deref(), Some("2024-02-29T00:00:00Z"));
+
+        let edit = edit_issue_option(&IssueDraft {
+            title: "New".into(),
+            body: String::new(),
+            label_ids: Vec::new(),
+            milestone_id: None,
+            due_date: None,
+        });
+        assert_eq!(edit.title.as_deref(), Some("New"));
+        assert_eq!(edit.body.as_deref(), Some(""));
+        assert_eq!(edit.milestone, Some(0));
+        assert_eq!(edit.unset_due_date, Some(true));
+    }
 }

crates/app/src/domain.rs

@@ -139,6 +139,20 @@ pub struct IssueDetails {
     pub comments: Vec<models::Comment>,
 }
 
+pub struct IssueEditorData {
+    pub issue: Option<models::Issue>,
+    pub labels: Vec<models::Label>,
+    pub milestones: Vec<models::Milestone>,
+}
+
+pub struct IssueDraft {
+    pub title: String,
+    pub body: String,
+    pub label_ids: Vec<i64>,
+    pub milestone_id: Option<i64>,
+    pub due_date: Option<i64>,
+}
+
 pub struct MilestoneDetails {
     pub milestone: models::Milestone,
     pub issues: Vec<models::Issue>,
@@ -155,6 +169,49 @@ pub fn open_status() -> String {
     "open".into()
 }
 
+pub fn civil_from_days(days: i64) -> (i64, i64, i64) {
+    let days = days + 719_468;
+    let era = days.div_euclid(146_097);
+    let day_of_era = days - era * 146_097;
+    let year_of_era =
+        (day_of_era - day_of_era / 1_460 + day_of_era / 36_524 - day_of_era / 146_096) / 365;
+    let mut year = year_of_era + era * 400;
+    let day_of_year = day_of_era - (365 * year_of_era + year_of_era / 4 - year_of_era / 100);
+    let month_prime = (5 * day_of_year + 2) / 153;
+    let day = day_of_year - (153 * month_prime + 2) / 5 + 1;
+    let month = month_prime + if month_prime < 10 { 3 } else { -9 };
+    year += i64::from(month <= 2);
+    (year, month, day)
+}
+
+pub fn days_from_civil(mut year: i64, month: i64, day: i64) -> i64 {
+    year -= i64::from(month <= 2);
+    let era = year.div_euclid(400);
+    let year_of_era = year - era * 400;
+    let month_prime = month + if month > 2 { -3 } else { 9 };
+    let day_of_year = (153 * month_prime + 2) / 5 + day - 1;
+    let day_of_era = year_of_era * 365 + year_of_era / 4 - year_of_era / 100 + day_of_year;
+    era * 146_097 + day_of_era - 719_468
+}
+
+pub fn api_date(timestamp: i64) -> String {
+    let (year, month, day) = civil_from_days(timestamp.div_euclid(86_400));
+    format!("{year:04}-{month:02}-{day:02}T00:00:00Z")
+}
+
+pub fn parse_api_date(value: &str) -> Option<i64> {
+    let date = value.get(..10)?;
+    let mut parts = date.split('-');
+    let year = parts.next()?.parse().ok()?;
+    let month = parts.next()?.parse().ok()?;
+    let day = parts.next()?.parse().ok()?;
+    if parts.next().is_some() || !(1..=12).contains(&month) || !(1..=31).contains(&day) {
+        return None;
+    }
+    let days = days_from_civil(year, month, day);
+    (civil_from_days(days) == (year, month, day)).then_some(days * 86_400)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -179,4 +236,12 @@ mod tests {
             .is_active("open")
         );
     }
+
+    #[test]
+    fn issue_dates_round_trip_and_reject_invalid_dates() {
+        let leap_day = parse_api_date("2024-02-29T12:34:56Z").unwrap();
+        assert_eq!(api_date(leap_day), "2024-02-29T00:00:00Z");
+        assert_eq!(parse_api_date("2023-02-29T00:00:00Z"), None);
+        assert_eq!(parse_api_date("not-a-date"), None);
+    }
 }

crates/app/src/lib.rs

@@ -323,6 +323,66 @@ impl GotchaCore {
         ))
     }
 
+    pub async fn issue_editor(
+        &self,
+        owner: String,
+        repository: String,
+        number: Option<i64>,
+    ) -> Result<IssueEditorPage, GotchaError> {
+        let (owner, repository) = validate_repository(&owner, &repository)?;
+        if number.is_some_and(|number| number <= 0) {
+            return Err("Invalid issue number.".into());
+        }
+        Ok(issue_editor_page(
+            load_issue_editor(&self.server()?, owner, repository, number).await?,
+        ))
+    }
+
+    #[allow(clippy::too_many_arguments)]
+    pub async fn save_issue(
+        &self,
+        owner: String,
+        repository: String,
+        number: Option<i64>,
+        title: String,
+        body: String,
+        label_ids: Vec<i64>,
+        milestone_id: Option<i64>,
+        due_date: Option<i64>,
+    ) -> Result<i64, GotchaError> {
+        let (owner, repository) = validate_repository(&owner, &repository)?;
+        let title = title.trim();
+        if title.is_empty() {
+            return Err("Enter an issue title.".into());
+        }
+        if number.is_some_and(|number| number <= 0)
+            || milestone_id.is_some_and(|id| id <= 0)
+            || label_ids.iter().any(|id| *id <= 0)
+        {
+            return Err("Invalid issue editor selection.".into());
+        }
+        let label_ids: Vec<_> = label_ids
+            .into_iter()
+            .collect::<std::collections::BTreeSet<_>>()
+            .into_iter()
+            .collect();
+        let draft = IssueDraft {
+            title: title.into(),
+            body,
+            label_ids,
+            milestone_id,
+            due_date,
+        };
+        let server = self.server()?;
+        let issue = match number {
+            Some(number) => edit_issue(&server, owner, repository, number, draft).await?,
+            None => create_issue(&server, owner, repository, draft).await?,
+        };
+        issue
+            .number
+            .ok_or_else(|| "The saved issue has no number.".into())
+    }
+
     pub async fn milestones(
         &self,
         owner: String,
@@ -502,6 +562,18 @@ impl GotchaCore {
     }
 }
 
+fn validate_repository<'a>(
+    owner: &'a str,
+    repository: &'a str,
+) -> Result<(&'a str, &'a str), GotchaError> {
+    let owner = owner.trim();
+    let repository = repository.trim();
+    if owner.is_empty() || repository.is_empty() {
+        return Err("Select a repository first.".into());
+    }
+    Ok((owner, repository))
+}
+
 impl GotchaCore {
     fn server(&self) -> Result<Server, GotchaError> {
         let state = self.state.lock().unwrap();

crates/app/src/presentation.rs

@@ -3,8 +3,8 @@ use gotcha_gitea::models;
 use crate::{
     activity,
     domain::{
-        HistoryCommit, HomeData, IssueDetails, IssueFilter, MilestoneDetails, PullDetails,
+        HistoryCommit, HomeData, IssueDetails, IssueEditorData, IssueFilter, MilestoneDetails,
-        PullFilter, RepositoryData,
+        PullDetails, PullFilter, RepositoryData, civil_from_days, days_from_civil, parse_api_date,
     },
 };
 
@@ -67,6 +67,29 @@ pub struct IssuePage {
     pub comments: Vec<CommentRow>,
 }
 
+#[derive(Clone, uniffi::Record)]
+pub struct IssueEditorLabel {
+    pub id: i64,
+    pub name: String,
+    pub selected: bool,
+}
+
+#[derive(Clone, uniffi::Record)]
+pub struct IssueEditorMilestone {
+    pub id: i64,
+    pub title: String,
+    pub selected: bool,
+}
+
+#[derive(Clone, uniffi::Record)]
+pub struct IssueEditorPage {
+    pub title: String,
+    pub body: String,
+    pub due_date: Option<i64>,
+    pub labels: Vec<IssueEditorLabel>,
+    pub milestones: Vec<IssueEditorMilestone>,
+}
+
 #[derive(Clone, uniffi::Record)]
 pub struct IssueFilterOptions {
     pub milestones: Vec<String>,
@@ -457,6 +480,70 @@ pub fn issue_page(details: IssueDetails) -> IssuePage {
     }
 }
 
+pub fn issue_editor_page(data: IssueEditorData) -> IssueEditorPage {
+    let selected_labels: std::collections::BTreeSet<_> = data
+        .issue
+        .as_ref()
+        .and_then(|issue| issue.labels.as_deref())
+        .unwrap_or_default()
+        .iter()
+        .filter_map(|label| label.id)
+        .collect();
+    let selected_milestone = data
+        .issue
+        .as_ref()
+        .and_then(|issue| issue.milestone.as_ref())
+        .and_then(|milestone| milestone.id);
+    let mut labels: Vec<_> = data
+        .labels
+        .into_iter()
+        .filter_map(|label| {
+            let id = label.id?;
+            Some(IssueEditorLabel {
+                id,
+                name: label.name?,
+                selected: selected_labels.contains(&id),
+            })
+        })
+        .collect();
+    labels.sort_by_key(|label| label.name.to_lowercase());
+    let mut milestones: Vec<_> = data
+        .milestones
+        .into_iter()
+        .filter(|milestone| {
+            milestone.state.as_deref() != Some("closed") || milestone.id == selected_milestone
+        })
+        .filter_map(|milestone| {
+            let id = milestone.id?;
+            Some(IssueEditorMilestone {
+                id,
+                title: milestone.title?,
+                selected: Some(id) == selected_milestone,
+            })
+        })
+        .collect();
+    milestones.sort_by_key(|milestone| milestone.title.to_lowercase());
+    IssueEditorPage {
+        title: data
+            .issue
+            .as_ref()
+            .and_then(|issue| issue.title.clone())
+            .unwrap_or_default(),
+        body: data
+            .issue
+            .as_ref()
+            .and_then(|issue| issue.body.clone())
+            .unwrap_or_default(),
+        due_date: data
+            .issue
+            .as_ref()
+            .and_then(|issue| issue.due_date.as_deref())
+            .and_then(parse_api_date),
+        labels,
+        milestones,
+    }
+}
+
 pub fn pull_page(details: PullDetails) -> PullPage {
     let pull = &details.pull;
     let author = pull
@@ -840,31 +927,6 @@ fn heat_cells(data: &[models::UserHeatmapData]) -> (Vec<HeatCell>, i64) {
     (cells, contribution_count)
 }
 
-fn civil_from_days(days: i64) -> (i64, i64, i64) {
-    let days = days + 719_468;
-    let era = days.div_euclid(146_097);
-    let day_of_era = days - era * 146_097;
-    let year_of_era =
-        (day_of_era - day_of_era / 1_460 + day_of_era / 36_524 - day_of_era / 146_096) / 365;
-    let mut year = year_of_era + era * 400;
-    let day_of_year = day_of_era - (365 * year_of_era + year_of_era / 4 - year_of_era / 100);
-    let month_prime = (5 * day_of_year + 2) / 153;
-    let day = day_of_year - (153 * month_prime + 2) / 5 + 1;
-    let month = month_prime + if month_prime < 10 { 3 } else { -9 };
-    year += i64::from(month <= 2);
-    (year, month, day)
-}
-
-fn days_from_civil(mut year: i64, month: i64, day: i64) -> i64 {
-    year -= i64::from(month <= 2);
-    let era = year.div_euclid(400);
-    let year_of_era = year - era * 400;
-    let month_prime = month + if month > 2 { -3 } else { 9 };
-    let day_of_year = (153 * month_prime + 2) / 5 + day - 1;
-    let day_of_era = year_of_era * 365 + year_of_era / 4 - year_of_era / 100 + day_of_year;
-    era * 146_097 + day_of_era - 719_468
-}
-
 fn label_row(label: &models::Label) -> Option<LabelRow> {
     let name = label.name.as_deref()?.trim();
     let color = label.color.as_deref()?.trim().trim_start_matches('#');
@@ -1172,6 +1234,42 @@ mod tests {
         assert_eq!(page.state, "closed");
     }
 
+    #[test]
+    fn issue_editor_exposes_selected_metadata_and_due_date() {
+        let selected_label = models::Label {
+            id: Some(2),
+            name: Some("bug".into()),
+            ..Default::default()
+        };
+        let page = issue_editor_page(IssueEditorData {
+            issue: Some(models::Issue {
+                title: Some("Title".into()),
+                body: Some("Body".into()),
+                due_date: Some("2024-02-29T18:00:00Z".into()),
+                labels: Some(vec![selected_label.clone()]),
+                milestone: Some(Box::new(models::Milestone {
+                    id: Some(4),
+                    title: Some("Current".into()),
+                    state: Some("closed".into()),
+                    ..Default::default()
+                })),
+                ..Default::default()
+            }),
+            labels: vec![selected_label],
+            milestones: vec![models::Milestone {
+                id: Some(4),
+                title: Some("Current".into()),
+                state: Some("closed".into()),
+                ..Default::default()
+            }],
+        });
+
+        assert_eq!((page.title.as_str(), page.body.as_str()), ("Title", "Body"));
+        assert_eq!(page.due_date, Some(1_709_164_800));
+        assert!(page.labels[0].selected);
+        assert!(page.milestones[0].selected);
+    }
+
     #[test]
     fn builds_sorted_issue_filter_options() {
         let filter = IssueFilter {

ios/Generated/gotcha_core.swift

@@ -619,6 +619,8 @@ public protocol GotchaCoreProtocol: AnyObject, Sendable {
 
     func issue(owner: String, repository: String, number: Int64) async throws  -> IssuePage
 
+    func issueEditor(owner: String, repository: String, number: Int64?) async throws  -> IssueEditorPage
+
     func issueFilters(owner: String, repository: String) async throws  -> IssueFilterOptions
 
     func issueFiltersActive(owner: String, repository: String) throws  -> Bool
@@ -645,6 +647,8 @@ public protocol GotchaCoreProtocol: AnyObject, Sendable {
 
     func repositoryFile(owner: String, repository: String, path: String) async throws  -> RepositoryFilePage
 
+    func saveIssue(owner: String, repository: String, number: Int64?, title: String, body: String, labelIds: [Int64], milestoneId: Int64?, dueDate: Int64?) async throws  -> Int64
+
     func selectServer(index: UInt32) throws
 
     func servers()  -> [ServerRow]
@@ -841,6 +845,22 @@ open func issue(owner: String, repository: String, number: Int64)async throws  -
         )
 }
 
+open func issueEditor(owner: String, repository: String, number: Int64?)async throws  -> IssueEditorPage  {
+    return
+        try  await uniffiRustCallAsync(
+            rustFutureFunc: {
+                uniffi_gotcha_core_fn_method_gotchacore_issue_editor(
+                        self.uniffiCloneHandle(),FfiConverterString.lower(owner),FfiConverterString.lower(repository),FfiConverterOptionInt64.lower(number)
+                )
+            },
+            pollFunc: ffi_gotcha_core_rust_future_poll_rust_buffer,
+            completeFunc: ffi_gotcha_core_rust_future_complete_rust_buffer,
+            freeFunc: ffi_gotcha_core_rust_future_free_rust_buffer,
+            liftFunc: FfiConverterTypeIssueEditorPage_lift,
+            errorHandler: FfiConverterTypeGotchaError_lift
+        )
+}
+
 open func issueFilters(owner: String, repository: String)async throws  -> IssueFilterOptions  {
     return
         try  await uniffiRustCallAsync(
@@ -1037,6 +1057,22 @@ open func repositoryFile(owner: String, repository: String, path: String)async t
         )
 }
 
+open func saveIssue(owner: String, repository: String, number: Int64?, title: String, body: String, labelIds: [Int64], milestoneId: Int64?, dueDate: Int64?)async throws  -> Int64  {
+    return
+        try  await uniffiRustCallAsync(
+            rustFutureFunc: {
+                uniffi_gotcha_core_fn_method_gotchacore_save_issue(
+                        self.uniffiCloneHandle(),FfiConverterString.lower(owner),FfiConverterString.lower(repository),FfiConverterOptionInt64.lower(number),FfiConverterString.lower(title),FfiConverterString.lower(body),FfiConverterSequenceInt64.lower(labelIds),FfiConverterOptionInt64.lower(milestoneId),FfiConverterOptionInt64.lower(dueDate)
+                )
+            },
+            pollFunc: ffi_gotcha_core_rust_future_poll_i64,
+            completeFunc: ffi_gotcha_core_rust_future_complete_i64,
+            freeFunc: ffi_gotcha_core_rust_future_free_i64,
+            liftFunc: FfiConverterInt64.lift,
+            errorHandler: FfiConverterTypeGotchaError_lift
+        )
+}
+
 open func selectServer(index: UInt32)throws   {try rustCallWithError(FfiConverterTypeGotchaError_lift) {
         uniffiCallStatus in
     uniffi_gotcha_core_fn_method_gotchacore_select_server(
@@ -1750,6 +1786,188 @@ public func FfiConverterTypeHomePage_lower(_ value: HomePage) -> RustBuffer {
 }
 
 
+public struct IssueEditorLabel: Equatable, Hashable {
+    public var id: Int64
+    public var name: String
+    public var selected: Bool
+
+    // Default memberwise initializers are never public by default, so we
+    // declare one manually.
+    public init(id: Int64, name: String, selected: Bool) {
+        self.id = id
+        self.name = name
+        self.selected = selected
+    }
+
+
+
+
+}
+
+#if compiler(>=6)
+extension IssueEditorLabel: Sendable {}
+#endif
+
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+public struct FfiConverterTypeIssueEditorLabel: FfiConverterRustBuffer {
+    public static func read(from buf: inout (data: Data, offset: Data.Index)) throws -> IssueEditorLabel {
+        return
+            try IssueEditorLabel(
+                id: FfiConverterInt64.read(from: &buf),
+                name: FfiConverterString.read(from: &buf),
+                selected: FfiConverterBool.read(from: &buf)
+        )
+    }
+
+    public static func write(_ value: IssueEditorLabel, into buf: inout [UInt8]) {
+        FfiConverterInt64.write(value.id, into: &buf)
+        FfiConverterString.write(value.name, into: &buf)
+        FfiConverterBool.write(value.selected, into: &buf)
+    }
+}
+
+
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+public func FfiConverterTypeIssueEditorLabel_lift(_ buf: RustBuffer) throws -> IssueEditorLabel {
+    return try FfiConverterTypeIssueEditorLabel.lift(buf)
+}
+
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+public func FfiConverterTypeIssueEditorLabel_lower(_ value: IssueEditorLabel) -> RustBuffer {
+    return FfiConverterTypeIssueEditorLabel.lower(value)
+}
+
+
+public struct IssueEditorMilestone: Equatable, Hashable {
+    public var id: Int64
+    public var title: String
+    public var selected: Bool
+
+    // Default memberwise initializers are never public by default, so we
+    // declare one manually.
+    public init(id: Int64, title: String, selected: Bool) {
+        self.id = id
+        self.title = title
+        self.selected = selected
+    }
+
+
+
+
+}
+
+#if compiler(>=6)
+extension IssueEditorMilestone: Sendable {}
+#endif
+
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+public struct FfiConverterTypeIssueEditorMilestone: FfiConverterRustBuffer {
+    public static func read(from buf: inout (data: Data, offset: Data.Index)) throws -> IssueEditorMilestone {
+        return
+            try IssueEditorMilestone(
+                id: FfiConverterInt64.read(from: &buf),
+                title: FfiConverterString.read(from: &buf),
+                selected: FfiConverterBool.read(from: &buf)
+        )
+    }
+
+    public static func write(_ value: IssueEditorMilestone, into buf: inout [UInt8]) {
+        FfiConverterInt64.write(value.id, into: &buf)
+        FfiConverterString.write(value.title, into: &buf)
+        FfiConverterBool.write(value.selected, into: &buf)
+    }
+}
+
+
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+public func FfiConverterTypeIssueEditorMilestone_lift(_ buf: RustBuffer) throws -> IssueEditorMilestone {
+    return try FfiConverterTypeIssueEditorMilestone.lift(buf)
+}
+
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+public func FfiConverterTypeIssueEditorMilestone_lower(_ value: IssueEditorMilestone) -> RustBuffer {
+    return FfiConverterTypeIssueEditorMilestone.lower(value)
+}
+
+
+public struct IssueEditorPage: Equatable, Hashable {
+    public var title: String
+    public var body: String
+    public var dueDate: Int64?
+    public var labels: [IssueEditorLabel]
+    public var milestones: [IssueEditorMilestone]
+
+    // Default memberwise initializers are never public by default, so we
+    // declare one manually.
+    public init(title: String, body: String, dueDate: Int64?, labels: [IssueEditorLabel], milestones: [IssueEditorMilestone]) {
+        self.title = title
+        self.body = body
+        self.dueDate = dueDate
+        self.labels = labels
+        self.milestones = milestones
+    }
+
+
+
+
+}
+
+#if compiler(>=6)
+extension IssueEditorPage: Sendable {}
+#endif
+
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+public struct FfiConverterTypeIssueEditorPage: FfiConverterRustBuffer {
+    public static func read(from buf: inout (data: Data, offset: Data.Index)) throws -> IssueEditorPage {
+        return
+            try IssueEditorPage(
+                title: FfiConverterString.read(from: &buf),
+                body: FfiConverterString.read(from: &buf),
+                dueDate: FfiConverterOptionInt64.read(from: &buf),
+                labels: FfiConverterSequenceTypeIssueEditorLabel.read(from: &buf),
+                milestones: FfiConverterSequenceTypeIssueEditorMilestone.read(from: &buf)
+        )
+    }
+
+    public static func write(_ value: IssueEditorPage, into buf: inout [UInt8]) {
+        FfiConverterString.write(value.title, into: &buf)
+        FfiConverterString.write(value.body, into: &buf)
+        FfiConverterOptionInt64.write(value.dueDate, into: &buf)
+        FfiConverterSequenceTypeIssueEditorLabel.write(value.labels, into: &buf)
+        FfiConverterSequenceTypeIssueEditorMilestone.write(value.milestones, into: &buf)
+    }
+}
+
+
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+public func FfiConverterTypeIssueEditorPage_lift(_ buf: RustBuffer) throws -> IssueEditorPage {
+    return try FfiConverterTypeIssueEditorPage.lift(buf)
+}
+
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+public func FfiConverterTypeIssueEditorPage_lower(_ value: IssueEditorPage) -> RustBuffer {
+    return FfiConverterTypeIssueEditorPage.lower(value)
+}
+
+
 public struct IssueFilterOptions: Equatable, Hashable {
     public var milestones: [String]
     public var labels: [String]
@@ -2744,6 +2962,30 @@ fileprivate struct FfiConverterOptionUInt32: FfiConverterRustBuffer {
     }
 }
 
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+fileprivate struct FfiConverterOptionInt64: FfiConverterRustBuffer {
+    typealias SwiftType = Int64?
+
+    public static func write(_ value: SwiftType, into buf: inout [UInt8]) {
+        guard let value = value else {
+            writeInt(&buf, Int8(0))
+            return
+        }
+        writeInt(&buf, Int8(1))
+        FfiConverterInt64.write(value, into: &buf)
+    }
+
+    public static func read(from buf: inout (data: Data, offset: Data.Index)) throws -> SwiftType {
+        switch try readInt(&buf) as Int8 {
+        case 0: return nil
+        case 1: return try FfiConverterInt64.read(from: &buf)
+        default: throw UniffiInternalError.unexpectedOptionalTag
+        }
+    }
+}
+
 #if swift(>=5.8)
 @_documentation(visibility: private)
 #endif
@@ -2793,6 +3035,31 @@ fileprivate struct FfiConverterSequenceUInt32: FfiConverterRustBuffer {
     }
 }
 
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+fileprivate struct FfiConverterSequenceInt64: FfiConverterRustBuffer {
+    typealias SwiftType = [Int64]
+
+    public static func write(_ value: [Int64], into buf: inout [UInt8]) {
+        let len = Int32(value.count)
+        writeInt(&buf, len)
+        for item in value {
+            FfiConverterInt64.write(item, into: &buf)
+        }
+    }
+
+    public static func read(from buf: inout (data: Data, offset: Data.Index)) throws -> [Int64] {
+        let len: Int32 = try readInt(&buf)
+        var seq = [Int64]()
+        seq.reserveCapacity(Int(len))
+        for _ in 0 ..< len {
+            seq.append(try FfiConverterInt64.read(from: &buf))
+        }
+        return seq
+    }
+}
+
 #if swift(>=5.8)
 @_documentation(visibility: private)
 #endif
@@ -2968,6 +3235,56 @@ fileprivate struct FfiConverterSequenceTypeHeatCell: FfiConverterRustBuffer {
     }
 }
 
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+fileprivate struct FfiConverterSequenceTypeIssueEditorLabel: FfiConverterRustBuffer {
+    typealias SwiftType = [IssueEditorLabel]
+
+    public static func write(_ value: [IssueEditorLabel], into buf: inout [UInt8]) {
+        let len = Int32(value.count)
+        writeInt(&buf, len)
+        for item in value {
+            FfiConverterTypeIssueEditorLabel.write(item, into: &buf)
+        }
+    }
+
+    public static func read(from buf: inout (data: Data, offset: Data.Index)) throws -> [IssueEditorLabel] {
+        let len: Int32 = try readInt(&buf)
+        var seq = [IssueEditorLabel]()
+        seq.reserveCapacity(Int(len))
+        for _ in 0 ..< len {
+            seq.append(try FfiConverterTypeIssueEditorLabel.read(from: &buf))
+        }
+        return seq
+    }
+}
+
+#if swift(>=5.8)
+@_documentation(visibility: private)
+#endif
+fileprivate struct FfiConverterSequenceTypeIssueEditorMilestone: FfiConverterRustBuffer {
+    typealias SwiftType = [IssueEditorMilestone]
+
+    public static func write(_ value: [IssueEditorMilestone], into buf: inout [UInt8]) {
+        let len = Int32(value.count)
+        writeInt(&buf, len)
+        for item in value {
+            FfiConverterTypeIssueEditorMilestone.write(item, into: &buf)
+        }
+    }
+
+    public static func read(from buf: inout (data: Data, offset: Data.Index)) throws -> [IssueEditorMilestone] {
+        let len: Int32 = try readInt(&buf)
+        var seq = [IssueEditorMilestone]()
+        seq.reserveCapacity(Int(len))
+        for _ in 0 ..< len {
+            seq.append(try FfiConverterTypeIssueEditorMilestone.read(from: &buf))
+        }
+        return seq
+    }
+}
+
 #if swift(>=5.8)
 @_documentation(visibility: private)
 #endif
@@ -3230,6 +3547,9 @@ private let initializationResult: InitializationResult = {
     if (uniffi_gotcha_core_checksum_method_gotchacore_issue() != 56735) {
         return InitializationResult.apiChecksumMismatch
     }
+    if (uniffi_gotcha_core_checksum_method_gotchacore_issue_editor() != 10078) {
+        return InitializationResult.apiChecksumMismatch
+    }
     if (uniffi_gotcha_core_checksum_method_gotchacore_issue_filters() != 24054) {
         return InitializationResult.apiChecksumMismatch
     }
@@ -3269,6 +3589,9 @@ private let initializationResult: InitializationResult = {
     if (uniffi_gotcha_core_checksum_method_gotchacore_repository_file() != 44948) {
         return InitializationResult.apiChecksumMismatch
     }
+    if (uniffi_gotcha_core_checksum_method_gotchacore_save_issue() != 55053) {
+        return InitializationResult.apiChecksumMismatch
+    }
     if (uniffi_gotcha_core_checksum_method_gotchacore_select_server() != 22721) {
         return InitializationResult.apiChecksumMismatch
     }

ios/Generated/gotcha_coreFFI.h

@@ -299,6 +299,11 @@ uint64_t uniffi_gotcha_core_fn_method_gotchacore_home(uint64_t ptr
 uint64_t uniffi_gotcha_core_fn_method_gotchacore_issue(uint64_t ptr, RustBuffer owner, RustBuffer repository, int64_t number
 );
 #endif
+#ifndef UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_FN_METHOD_GOTCHACORE_ISSUE_EDITOR
+#define UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_FN_METHOD_GOTCHACORE_ISSUE_EDITOR
+uint64_t uniffi_gotcha_core_fn_method_gotchacore_issue_editor(uint64_t ptr, RustBuffer owner, RustBuffer repository, RustBuffer number
+);
+#endif
 #ifndef UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_FN_METHOD_GOTCHACORE_ISSUE_FILTERS
 #define UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_FN_METHOD_GOTCHACORE_ISSUE_FILTERS
 uint64_t uniffi_gotcha_core_fn_method_gotchacore_issue_filters(uint64_t ptr, RustBuffer owner, RustBuffer repository
@@ -364,6 +369,11 @@ uint64_t uniffi_gotcha_core_fn_method_gotchacore_repository_contents(uint64_t pt
 uint64_t uniffi_gotcha_core_fn_method_gotchacore_repository_file(uint64_t ptr, RustBuffer owner, RustBuffer repository, RustBuffer path
 );
 #endif
+#ifndef UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_FN_METHOD_GOTCHACORE_SAVE_ISSUE
+#define UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_FN_METHOD_GOTCHACORE_SAVE_ISSUE
+uint64_t uniffi_gotcha_core_fn_method_gotchacore_save_issue(uint64_t ptr, RustBuffer owner, RustBuffer repository, RustBuffer number, RustBuffer title, RustBuffer body, RustBuffer label_ids, RustBuffer milestone_id, RustBuffer due_date
+);
+#endif
 #ifndef UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_FN_METHOD_GOTCHACORE_SELECT_SERVER
 #define UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_FN_METHOD_GOTCHACORE_SELECT_SERVER
 void uniffi_gotcha_core_fn_method_gotchacore_select_server(uint64_t ptr, uint32_t index, RustCallStatus *_Nonnull out_status
@@ -720,6 +730,12 @@ uint16_t uniffi_gotcha_core_checksum_method_gotchacore_home(void
 #define UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_CHECKSUM_METHOD_GOTCHACORE_ISSUE
 uint16_t uniffi_gotcha_core_checksum_method_gotchacore_issue(void
 
+);
+#endif
+#ifndef UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_CHECKSUM_METHOD_GOTCHACORE_ISSUE_EDITOR
+#define UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_CHECKSUM_METHOD_GOTCHACORE_ISSUE_EDITOR
+uint16_t uniffi_gotcha_core_checksum_method_gotchacore_issue_editor(void
+
 );
 #endif
 #ifndef UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_CHECKSUM_METHOD_GOTCHACORE_ISSUE_FILTERS
@@ -798,6 +814,12 @@ uint16_t uniffi_gotcha_core_checksum_method_gotchacore_repository_contents(void
 #define UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_CHECKSUM_METHOD_GOTCHACORE_REPOSITORY_FILE
 uint16_t uniffi_gotcha_core_checksum_method_gotchacore_repository_file(void
 
+);
+#endif
+#ifndef UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_CHECKSUM_METHOD_GOTCHACORE_SAVE_ISSUE
+#define UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_CHECKSUM_METHOD_GOTCHACORE_SAVE_ISSUE
+uint16_t uniffi_gotcha_core_checksum_method_gotchacore_save_issue(void
+
 );
 #endif
 #ifndef UNIFFI_FFIDEF_UNIFFI_GOTCHA_CORE_CHECKSUM_METHOD_GOTCHACORE_SELECT_SERVER

ios/Gotcha.xcodeproj/project.pbxproj

@@ -13,6 +13,7 @@
 		7DD332583B169B3CA1CA46E0 /* Highlighter in Frameworks */ = {isa = PBXBuildFile; productRef = EC5F999F50905E3801E8A71A /* Highlighter */; };
 		950C584D58E80106DF350A22 /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 9C0921C76676A14A024BA417 /* AppDelegate.swift */; };
 		96C4AFC206A1DBAE3D3E00CE /* SettingsViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8F145F13B8ED83A5AB0009A4 /* SettingsViewController.swift */; };
+		D2B9B033E92BF8E7C0BDCDB0 /* IssueEditorViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 722405F999984C7CBE838711 /* IssueEditorViewController.swift */; };
 		D59D3ED36ABCC1D8690A9088 /* gotcha_core.swift in Sources */ = {isa = PBXBuildFile; fileRef = FE12480725C13293FAFDDA52 /* gotcha_core.swift */; };
 		D78A121E9ADA0B72E2CF94DC /* MarkdownUI in Frameworks */ = {isa = PBXBuildFile; productRef = 8AD463F3AC817A44306C2297 /* MarkdownUI */; };
 		E7AC0B140F5CFC5EF226D174 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = DDAABE6B13ADC6D08D9438AF /* Assets.xcassets */; };
@@ -23,6 +24,7 @@
 /* Begin PBXFileReference section */
 		13EFB48F40AEB3016D3CF643 /* DetailScreens.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DetailScreens.swift; sourceTree = "<group>"; };
 		5FB3250A93766966A60A685E /* Gotcha.app */ = {isa = PBXFileReference; includeInIndex = 0; lastKnownFileType = wrapper.application; path = Gotcha.app; sourceTree = BUILT_PRODUCTS_DIR; };
+		722405F999984C7CBE838711 /* IssueEditorViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = IssueEditorViewController.swift; sourceTree = "<group>"; };
 		8F145F13B8ED83A5AB0009A4 /* SettingsViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SettingsViewController.swift; sourceTree = "<group>"; };
 		9C0921C76676A14A024BA417 /* AppDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AppDelegate.swift; sourceTree = "<group>"; };
 		AC828923A1E11A58AE348A74 /* ListScreens.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ListScreens.swift; sourceTree = "<group>"; };
@@ -53,6 +55,7 @@
 				9C0921C76676A14A024BA417 /* AppDelegate.swift */,
 				CE5E10787062D1175125BB4C /* ContentScreens.swift */,
 				13EFB48F40AEB3016D3CF643 /* DetailScreens.swift */,
+				722405F999984C7CBE838711 /* IssueEditorViewController.swift */,
 				AC828923A1E11A58AE348A74 /* ListScreens.swift */,
 				8F145F13B8ED83A5AB0009A4 /* SettingsViewController.swift */,
 				F75B3E4FFB9C9992517C4D69 /* Support.swift */,
@@ -192,6 +195,7 @@
 				950C584D58E80106DF350A22 /* AppDelegate.swift in Sources */,
 				1AED04075E363FBC0FF55773 /* ContentScreens.swift in Sources */,
 				25BDBDED14B3B886E19F511C /* DetailScreens.swift in Sources */,
+				D2B9B033E92BF8E7C0BDCDB0 /* IssueEditorViewController.swift in Sources */,
 				374320EB00185A0C8E40D985 /* ListScreens.swift in Sources */,
 				96C4AFC206A1DBAE3D3E00CE /* SettingsViewController.swift in Sources */,
 				F55A89489B2758D694F3B27D /* Support.swift in Sources */,

ios/Sources/ContentScreens.swift

@@ -8,6 +8,9 @@ final class IssuesViewController: RefreshingTableViewController {
     private var rows: [IssueRow] = []
     private var filterOptions: IssueFilterOptions?
     private var filterTask: Task<Void, Never>?
+    private lazy var filterButton = UIBarButtonItem(
+        image: context.symbol("line.3.horizontal.decrease.circle")
+    )
 
     init(context: AppContext, owner: String, repository: String) {
         self.context = context
@@ -25,6 +28,13 @@ final class IssuesViewController: RefreshingTableViewController {
     override func viewDidLoad() {
         super.viewDidLoad()
         tableView.register(IssueCell.self, forCellReuseIdentifier: "issue")
+        let addButton = UIBarButtonItem(
+            barButtonSystemItem: .add,
+            target: self,
+            action: #selector(createIssue)
+        )
+        addButton.accessibilityLabel = "New issue"
+        navigationItem.rightBarButtonItems = [addButton, filterButton]
         updateFilterMenu()
         loadContent(refreshing: false)
     }
@@ -122,14 +132,8 @@ final class IssuesViewController: RefreshingTableViewController {
         } else {
             children.append(UIAction(title: "Loading filters…", attributes: .disabled) { _ in })
         }
-        let item = navigationItem.rightBarButtonItem ?? UIBarButtonItem(
+        filterButton.menu = UIMenu(children: children)
-            image: context.symbol("line.3.horizontal.decrease.circle")
+        filterButton.accessibilityLabel = "Filter issues"
-        )
-        item.menu = UIMenu(children: children)
-        item.accessibilityLabel = "Filter issues"
-        if navigationItem.rightBarButtonItem == nil {
-            navigationItem.rightBarButtonItem = item
-        }
         updateFilterTint()
     }
 
@@ -211,12 +215,35 @@ final class IssuesViewController: RefreshingTableViewController {
     }
 
     private func updateFilterTint() {
-        navigationItem.rightBarButtonItem?.tintColor = filtersActive ? .tintColor : .secondaryLabel
+        filterButton.tintColor = filtersActive ? .tintColor : .secondaryLabel
-        navigationItem.rightBarButtonItem?.accessibilityValue = filtersActive
+        filterButton.accessibilityValue = filtersActive
             ? "Filters active"
             : "Default filters"
     }
 
+    @objc private func createIssue() {
+        let editor = IssueEditorViewController(
+            context: context,
+            owner: owner,
+            repository: repository
+        ) { [weak self] number in
+            guard let self else { return }
+            self.dismiss(animated: true) {
+                self.loadContent(refreshing: false)
+                self.navigationController?.pushViewController(
+                    IssueViewController(
+                        context: self.context,
+                        owner: self.owner,
+                        repository: self.repository,
+                        number: number
+                    ),
+                    animated: true
+                )
+            }
+        }
+        present(UINavigationController(rootViewController: editor), animated: true)
+    }
+
     private func updateEmptyState() {
         guard rows.isEmpty else {
             tableView.backgroundView = nil

ios/Sources/DetailScreens.swift

@@ -87,9 +87,28 @@ final class IssueViewController: MarkdownPageViewController {
 
     override func viewDidLoad() {
         super.viewDidLoad()
+        navigationItem.rightBarButtonItem = UIBarButtonItem(
+            title: "Edit",
+            style: .plain,
+            target: self,
+            action: #selector(editIssue)
+        )
         loadContent(refreshing: false)
     }
 
+    @objc private func editIssue() {
+        let editor = IssueEditorViewController(
+            context: context,
+            owner: owner,
+            repository: repository,
+            number: number
+        ) { [weak self] _ in
+            guard let self else { return }
+            self.dismiss(animated: true) { self.loadContent(refreshing: false) }
+        }
+        present(UINavigationController(rootViewController: editor), animated: true)
+    }
+
     override func loadContent(refreshing: Bool) {
         beginLoading(refreshing: refreshing)
         loadingTask?.cancel()
@@ -538,7 +557,7 @@ final class RepositoryFileViewController: UIViewController, QLPreviewControllerD
     }
 }
 
-private struct RepositoryMarkdownPreview: View {
+struct RepositoryMarkdownPreview: View {
     let source: String
 
     var body: some View {

ios/Sources/IssueEditorViewController.swift

@@ -0,0 +1,353 @@
+import Highlighter
+import SwiftUI
+import UIKit
+
+@MainActor
+final class IssueEditorViewController: UIViewController, UITextFieldDelegate, UITextViewDelegate {
+    private let context: AppContext
+    private let owner: String
+    private let repository: String
+    private let number: Int64?
+    private let saved: (Int64) -> Void
+    private let scrollView = UIScrollView()
+    private let stack = UIStackView()
+    private let titleField = UITextField()
+    private let modeControl = UISegmentedControl(items: ["Write", "Preview"])
+    private let bodyView = UITextView()
+    private let previewView = UIView()
+    private let labelsButton = UIButton(type: .system)
+    private let milestoneButton = UIButton(type: .system)
+    private let dueSwitch = UISwitch()
+    private let duePicker = UIDatePicker()
+    private let spinner = UIActivityIndicatorView(style: .medium)
+    private var page: IssueEditorPage?
+    private var selectedLabels = Set<Int64>()
+    private var selectedMilestone: Int64?
+    private var task: Task<Void, Never>?
+    private var previewController: UIViewController?
+    private var editorFont: UIFont {
+        UIFontMetrics(forTextStyle: .body).scaledFont(
+            for: .monospacedSystemFont(ofSize: 15, weight: .regular)
+        )
+    }
+
+    init(
+        context: AppContext,
+        owner: String,
+        repository: String,
+        number: Int64? = nil,
+        saved: @escaping (Int64) -> Void
+    ) {
+        self.context = context
+        self.owner = owner
+        self.repository = repository
+        self.number = number
+        self.saved = saved
+        super.init(nibName: nil, bundle: nil)
+        title = number == nil ? "New Issue" : "Edit Issue"
+    }
+
+    @available(*, unavailable)
+    required init?(coder: NSCoder) { fatalError("init(coder:) is not supported") }
+
+    deinit { task?.cancel() }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        view.backgroundColor = .systemGroupedBackground
+        navigationItem.leftBarButtonItem = UIBarButtonItem(
+            barButtonSystemItem: .cancel,
+            target: self,
+            action: #selector(cancel)
+        )
+        navigationItem.rightBarButtonItem = UIBarButtonItem(
+            title: "Save",
+            style: .done,
+            target: self,
+            action: #selector(save)
+        )
+        navigationItem.rightBarButtonItem = UIBarButtonItem(customView: spinner)
+        spinner.startAnimating()
+        configureForm()
+        task = Task { await load() }
+    }
+
+    private func configureForm() {
+        scrollView.translatesAutoresizingMaskIntoConstraints = false
+        scrollView.keyboardDismissMode = .interactive
+        view.addSubview(scrollView)
+        stack.axis = .vertical
+        stack.spacing = 12
+        stack.translatesAutoresizingMaskIntoConstraints = false
+        stack.isHidden = true
+        scrollView.addSubview(stack)
+
+        titleField.placeholder = "Title"
+        titleField.delegate = self
+        titleField.font = .preferredFont(forTextStyle: .headline)
+        titleField.adjustsFontForContentSizeCategory = true
+        titleField.borderStyle = .roundedRect
+        titleField.autocapitalizationType = .sentences
+        titleField.returnKeyType = .next
+        titleField.accessibilityLabel = "Issue title"
+        titleField.addTarget(self, action: #selector(titleChanged), for: .editingChanged)
+
+        [labelsButton, milestoneButton].forEach { button in
+            var configuration = UIButton.Configuration.tinted()
+            configuration.imagePlacement = .leading
+            configuration.imagePadding = 8
+            button.configuration = configuration
+            button.showsMenuAsPrimaryAction = true
+            button.contentHorizontalAlignment = .leading
+        }
+        labelsButton.configuration?.image = context.symbol("tag")
+        milestoneButton.configuration?.image = context.symbol("flag")
+
+        let dueLabel = UILabel()
+        dueLabel.text = "Due Date"
+        dueLabel.font = .preferredFont(forTextStyle: .body)
+        dueLabel.adjustsFontForContentSizeCategory = true
+        let dueRow = UIStackView(arrangedSubviews: [dueLabel, dueSwitch])
+        dueRow.alignment = .center
+        dueSwitch.accessibilityLabel = "Set due date"
+        dueSwitch.addTarget(self, action: #selector(dueChanged), for: .valueChanged)
+        duePicker.datePickerMode = .date
+        duePicker.preferredDatePickerStyle = .inline
+        duePicker.isHidden = true
+
+        modeControl.selectedSegmentIndex = 0
+        modeControl.addTarget(self, action: #selector(modeChanged), for: .valueChanged)
+        bodyView.delegate = self
+        bodyView.font = editorFont
+        bodyView.adjustsFontForContentSizeCategory = true
+        bodyView.backgroundColor = .secondarySystemGroupedBackground
+        bodyView.layer.cornerRadius = 10
+        bodyView.textContainerInset = UIEdgeInsets(top: 12, left: 8, bottom: 12, right: 8)
+        bodyView.autocapitalizationType = .sentences
+        bodyView.accessibilityLabel = "Issue description in Markdown"
+        previewView.backgroundColor = .secondarySystemGroupedBackground
+        previewView.layer.cornerRadius = 10
+        previewView.accessibilityLabel = "Issue description preview"
+        previewView.isHidden = true
+
+        stack.addArrangedSubview(titleField)
+        stack.addArrangedSubview(labelsButton)
+        stack.addArrangedSubview(milestoneButton)
+        stack.addArrangedSubview(dueRow)
+        stack.addArrangedSubview(duePicker)
+        stack.addArrangedSubview(modeControl)
+        stack.addArrangedSubview(bodyView)
+        stack.addArrangedSubview(previewView)
+        NSLayoutConstraint.activate([
+            scrollView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
+            scrollView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
+            scrollView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
+            scrollView.bottomAnchor.constraint(equalTo: view.keyboardLayoutGuide.topAnchor),
+            stack.leadingAnchor.constraint(equalTo: scrollView.contentLayoutGuide.leadingAnchor, constant: 16),
+            stack.trailingAnchor.constraint(equalTo: scrollView.contentLayoutGuide.trailingAnchor, constant: -16),
+            stack.topAnchor.constraint(equalTo: scrollView.contentLayoutGuide.topAnchor, constant: 16),
+            stack.bottomAnchor.constraint(equalTo: scrollView.contentLayoutGuide.bottomAnchor, constant: -16),
+            stack.widthAnchor.constraint(equalTo: scrollView.frameLayoutGuide.widthAnchor, constant: -32),
+            bodyView.heightAnchor.constraint(greaterThanOrEqualToConstant: 280),
+            previewView.heightAnchor.constraint(greaterThanOrEqualToConstant: 280),
+        ])
+    }
+
+    private func load() async {
+        do {
+            let page = try await context.core.issueEditor(
+                owner: owner,
+                repository: repository,
+                number: number
+            )
+            guard !Task.isCancelled else { return }
+            self.page = page
+            titleField.text = page.title
+            bodyView.text = page.body
+            selectedLabels = Set(page.labels.filter(\.selected).map(\.id))
+            selectedMilestone = page.milestones.first(where: \.selected)?.id
+            if let timestamp = page.dueDate {
+                dueSwitch.isOn = true
+                duePicker.date = localDate(forUTCTimestamp: timestamp)
+                duePicker.isHidden = false
+            }
+            updateLabelsMenu()
+            updateMilestoneMenu()
+            highlightBody()
+            stack.isHidden = false
+            navigationItem.rightBarButtonItem?.isEnabled = !page.title.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
+        } catch {
+            if !Task.isCancelled { show(error: error) }
+        }
+        restoreSaveButton()
+    }
+
+    private func updateLabelsMenu() {
+        guard let page else { return }
+        labelsButton.configuration?.title = selectedLabels.isEmpty
+            ? "Labels"
+            : "Labels (\(selectedLabels.count))"
+        labelsButton.accessibilityValue = selectedLabels.isEmpty
+            ? "None"
+            : page.labels.filter { selectedLabels.contains($0.id) }.map(\.name).joined(separator: ", ")
+        let actions = page.labels.map { label in
+            UIAction(
+                title: label.name,
+                attributes: .keepsMenuPresented,
+                state: selectedLabels.contains(label.id) ? .on : .off
+            ) { [weak self] action in
+                guard let self else { return }
+                if self.selectedLabels.remove(label.id) == nil { self.selectedLabels.insert(label.id) }
+                action.state = self.selectedLabels.contains(label.id) ? .on : .off
+                self.updateLabelsMenu()
+            }
+        }
+        labelsButton.menu = UIMenu(children: actions.isEmpty
+            ? [UIAction(title: "No labels", attributes: .disabled) { _ in }]
+            : actions)
+    }
+
+    private func updateMilestoneMenu() {
+        guard let page else { return }
+        milestoneButton.configuration?.title = page.milestones
+            .first(where: { $0.id == selectedMilestone })?.title ?? "Milestone"
+        milestoneButton.accessibilityValue = page.milestones
+            .first(where: { $0.id == selectedMilestone })?.title ?? "None"
+        let none = UIAction(title: "No Milestone", state: selectedMilestone == nil ? .on : .off) {
+            [weak self] _ in
+            self?.selectedMilestone = nil
+            self?.updateMilestoneMenu()
+        }
+        milestoneButton.menu = UIMenu(options: .singleSelection, children: [none] + page.milestones.map { milestone in
+            UIAction(
+                title: milestone.title,
+                state: milestone.id == selectedMilestone ? .on : .off
+            ) { [weak self] _ in
+                self?.selectedMilestone = milestone.id
+                self?.updateMilestoneMenu()
+            }
+        })
+    }
+
+    func textViewDidChange(_ textView: UITextView) {
+        highlightBody()
+    }
+
+    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
+        bodyView.becomeFirstResponder()
+        return true
+    }
+
+    private func highlightBody() {
+        let source = bodyView.text ?? ""
+        let selection = bodyView.selectedRange
+        let highlighter = Highlighter()
+        highlighter?.setTheme(traitCollection.userInterfaceStyle == .dark ? "atom-one-dark" : "atom-one-light")
+        highlighter?.theme.setCodeFont(editorFont)
+        bodyView.attributedText = highlighter?.highlight(source, as: "markdown")
+            ?? NSAttributedString(string: source, attributes: [
+                .font: editorFont,
+                .foregroundColor: UIColor.label,
+            ])
+        bodyView.selectedRange = selection
+        bodyView.typingAttributes = [
+            .font: editorFont,
+            .foregroundColor: UIColor.label,
+        ]
+    }
+
+    @objc private func modeChanged() {
+        let preview = modeControl.selectedSegmentIndex == 1
+        if preview {
+            previewController?.willMove(toParent: nil)
+            previewController?.view.removeFromSuperview()
+            previewController?.removeFromParent()
+            let controller = UIHostingController(
+                rootView: RepositoryMarkdownPreview(source: bodyView.text ?? "")
+            )
+            addChild(controller)
+            controller.view.translatesAutoresizingMaskIntoConstraints = false
+            controller.view.layer.cornerRadius = 10
+            controller.view.clipsToBounds = true
+            previewView.addSubview(controller.view)
+            NSLayoutConstraint.activate([
+                controller.view.leadingAnchor.constraint(equalTo: previewView.leadingAnchor),
+                controller.view.trailingAnchor.constraint(equalTo: previewView.trailingAnchor),
+                controller.view.topAnchor.constraint(equalTo: previewView.topAnchor),
+                controller.view.bottomAnchor.constraint(equalTo: previewView.bottomAnchor),
+            ])
+            controller.didMove(toParent: self)
+            previewController = controller
+        }
+        bodyView.isHidden = preview
+        previewView.isHidden = !preview
+        view.endEditing(true)
+    }
+
+    @objc private func dueChanged() {
+        duePicker.isHidden = !dueSwitch.isOn
+        if dueSwitch.isOn, page?.dueDate == nil { duePicker.date = Date() }
+    }
+
+    @objc private func titleChanged() {
+        navigationItem.rightBarButtonItem?.isEnabled = !(titleField.text ?? "")
+            .trimmingCharacters(in: .whitespacesAndNewlines).isEmpty
+    }
+
+    @objc private func save() {
+        view.endEditing(true)
+        navigationItem.leftBarButtonItem?.isEnabled = false
+        navigationItem.rightBarButtonItem = UIBarButtonItem(customView: spinner)
+        spinner.startAnimating()
+        task?.cancel()
+        task = Task {
+            do {
+                let number = try await context.core.saveIssue(
+                    owner: owner,
+                    repository: repository,
+                    number: number,
+                    title: titleField.text ?? "",
+                    body: bodyView.text ?? "",
+                    labelIds: Array(selectedLabels),
+                    milestoneId: selectedMilestone,
+                    dueDate: dueSwitch.isOn ? utcTimestamp(forLocalDate: duePicker.date) : nil
+                )
+                guard !Task.isCancelled else { return }
+                saved(number)
+            } catch {
+                if !Task.isCancelled {
+                    show(error: error)
+                    restoreSaveButton()
+                }
+            }
+        }
+    }
+
+    private func restoreSaveButton() {
+        spinner.stopAnimating()
+        navigationItem.leftBarButtonItem?.isEnabled = true
+        navigationItem.rightBarButtonItem = UIBarButtonItem(
+            title: "Save",
+            style: .done,
+            target: self,
+            action: #selector(save)
+        )
+        titleChanged()
+    }
+
+    @objc private func cancel() { dismiss(animated: true) }
+
+    private func localDate(forUTCTimestamp timestamp: Int64) -> Date {
+        var utc = Calendar(identifier: .gregorian)
+        utc.timeZone = TimeZone(secondsFromGMT: 0)!
+        let components = utc.dateComponents([.year, .month, .day], from: Date(timeIntervalSince1970: TimeInterval(timestamp)))
+        return Calendar.current.date(from: components) ?? Date()
+    }
+
+    private func utcTimestamp(forLocalDate date: Date) -> Int64 {
+        let components = Calendar.current.dateComponents([.year, .month, .day], from: date)
+        var utc = Calendar(identifier: .gregorian)
+        utc.timeZone = TimeZone(secondsFromGMT: 0)!
+        return Int64((utc.date(from: components) ?? date).timeIntervalSince1970)
+    }
+}