initial commit

crates/cli/src/config.rs

@@ -0,0 +1,348 @@
+use std::{
+    collections::BTreeMap,
+    env, fs,
+    io::Write,
+    path::PathBuf,
+    process::{self, Command},
+    time::{SystemTime, UNIX_EPOCH},
+};
+
+#[cfg(unix)]
+use std::os::unix::fs::{OpenOptionsExt, PermissionsExt};
+
+use gotcha_gitea::{Client, Url};
+use serde::{Deserialize, Serialize};
+
+type Result<T> = std::result::Result<T, String>;
+
+#[derive(Clone, Default, Deserialize, Serialize)]
+pub struct Server {
+    pub url: String,
+    pub token: String,
+}
+
+#[derive(Default, Deserialize, Serialize)]
+pub struct Config {
+    #[serde(skip)]
+    path: PathBuf,
+    #[serde(default)]
+    pub servers: BTreeMap<String, Server>,
+}
+
+pub struct Selection {
+    pub name: Option<String>,
+    pub url: String,
+    pub token: Option<String>,
+    pub repository: Option<RepositoryScope>,
+}
+
+#[derive(Clone)]
+pub struct RepositoryScope {
+    pub owner: String,
+    pub repository: String,
+}
+
+impl RepositoryScope {
+    pub fn parse(value: &str) -> Result<Self> {
+        let (owner, repository) = value
+            .split_once('/')
+            .ok_or("repository must be OWNER/REPOSITORY")?;
+        if owner.is_empty() || repository.is_empty() || repository.contains('/') {
+            return Err("repository must be OWNER/REPOSITORY".into());
+        }
+        Ok(Self {
+            owner: owner.into(),
+            repository: repository.into(),
+        })
+    }
+}
+
+impl Config {
+    pub fn load() -> Result<Self> {
+        let home = env::var_os("HOME").ok_or("HOME is not set")?;
+        Self::load_from(PathBuf::from(home).join(".config/gotcha/config"))
+    }
+
+    fn load_from(path: PathBuf) -> Result<Self> {
+        if !path.exists() {
+            return Ok(Self {
+                path,
+                ..Self::default()
+            });
+        }
+
+        let text = fs::read_to_string(&path)
+            .map_err(|error| format!("cannot read {}: {error}", path.display()))?;
+        let mut config: Self = serde_yaml::from_str(&text)
+            .map_err(|error| format!("invalid {}: {error}", path.display()))?;
+        config.path = path;
+        for (name, server) in &config.servers {
+            validate_name(name)?;
+            Client::new(&server.url, Some(&server.token))
+                .map_err(|error| format!("invalid server {name}: {error}"))?;
+        }
+        Ok(config)
+    }
+
+    pub fn login(&mut self, name: &str, token: &str) -> Result<()> {
+        let url = server_url(name)?;
+        Client::new(&url, Some(token)).map_err(|error| error.to_string())?;
+        self.servers.insert(
+            name.into(),
+            Server {
+                url,
+                token: token.into(),
+            },
+        );
+        self.save()
+    }
+
+    pub fn logout(&mut self, name: &str) -> Result<()> {
+        if self.servers.remove(name).is_none() {
+            return Err(format!("server profile {name:?} does not exist"));
+        }
+        self.save()
+    }
+
+    pub fn select(&self, name: Option<&str>, url: Option<&str>) -> Result<Selection> {
+        if name.is_some() && url.is_some() {
+            return Err("use either --server or --url, not both".into());
+        }
+        let remotes = git_remotes().unwrap_or_default();
+
+        if let Some(name) = name {
+            let server = self
+                .servers
+                .get(name)
+                .ok_or_else(|| format!("server profile {name:?} does not exist"))?;
+            return Ok(selection(Some(name), server, &remotes));
+        }
+
+        if let Some(url) = url {
+            let matches: Vec<_> = self
+                .servers
+                .iter()
+                .filter(|(_, server)| same_instance(&server.url, url))
+                .collect();
+            return match matches.as_slice() {
+                [] => Ok(selection(
+                    None,
+                    &Server {
+                        url: url.into(),
+                        token: String::new(),
+                    },
+                    &remotes,
+                )),
+                [(name, server)] => Ok(selection(Some(name.as_str()), server, &remotes)),
+                _ => Err("multiple profiles use that URL; select one with --server".into()),
+            };
+        }
+
+        let mut matches = BTreeMap::new();
+        for (name, server) in &self.servers {
+            if let Some(scope) = remotes
+                .iter()
+                .find_map(|remote| repository_scope(&server.url, remote))
+            {
+                matches.insert(name, (server, scope));
+            }
+        }
+
+        match matches.into_iter().collect::<Vec<_>>().as_slice() {
+            [] if self.servers.is_empty() => {
+                Err("no servers configured; run `gotcha auth login SERVER`".into())
+            }
+            [] => Err("no configured server matches this Git repository; use --server NAME".into()),
+            [(name, (server, scope))] => Ok(Selection {
+                name: Some((*name).clone()),
+                url: server.url.clone(),
+                token: Some(server.token.clone()),
+                repository: Some(scope.clone()),
+            }),
+            _ => Err("multiple server profiles match this Git repository; use --server".into()),
+        }
+    }
+
+    fn save(&self) -> Result<()> {
+        let parent = self
+            .path
+            .parent()
+            .ok_or_else(|| format!("invalid config path: {}", self.path.display()))?;
+        fs::create_dir_all(parent)
+            .map_err(|error| format!("cannot create {}: {error}", parent.display()))?;
+
+        let nonce = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .map_err(|error| error.to_string())?
+            .as_nanos();
+        let temporary = parent.join(format!(".config.{}.{nonce}.tmp", process::id()));
+        let text = serde_yaml::to_string(self).map_err(|error| error.to_string())?;
+        let result = (|| -> std::io::Result<()> {
+            let mut options = fs::OpenOptions::new();
+            options.write(true).create_new(true);
+            #[cfg(unix)]
+            options.mode(0o600);
+            let mut file = options.open(&temporary)?;
+            file.write_all(text.as_bytes())?;
+            file.sync_all()?;
+            fs::rename(&temporary, &self.path)?;
+            #[cfg(unix)]
+            fs::set_permissions(&self.path, fs::Permissions::from_mode(0o600))?;
+            Ok(())
+        })();
+        if result.is_err() {
+            let _ = fs::remove_file(&temporary);
+        }
+        result.map_err(|error| format!("cannot write {}: {error}", self.path.display()))
+    }
+}
+
+fn selection(name: Option<&str>, server: &Server, remotes: &[String]) -> Selection {
+    Selection {
+        name: name.map(str::to_owned),
+        url: server.url.clone(),
+        token: (!server.token.is_empty()).then(|| server.token.clone()),
+        repository: remotes
+            .iter()
+            .find_map(|remote| repository_scope(&server.url, remote)),
+    }
+}
+
+fn validate_name(name: &str) -> Result<()> {
+    server_url(name)?;
+    Ok(())
+}
+
+pub fn server_url(name: &str) -> Result<String> {
+    if name.is_empty()
+        || name.contains('/')
+        || name.contains('@')
+        || name.chars().any(char::is_whitespace)
+    {
+        return Err("server name must be a hostname, optionally followed by a port".into());
+    }
+    let url = format!("https://{name}");
+    let parsed = Url::parse(&url).map_err(|_| "invalid server name")?;
+    if parsed.host_str().is_none() || parsed.path() != "/" {
+        return Err("server name must be a hostname, optionally followed by a port".into());
+    }
+    if parsed.query().is_some() || parsed.fragment().is_some() {
+        return Err("server name must be a hostname, optionally followed by a port".into());
+    }
+    Ok(url)
+}
+
+fn same_instance(left: &str, right: &str) -> bool {
+    let api_url = |url| {
+        Client::new(url, None)
+            .ok()
+            .map(|client| client.api_url().clone())
+    };
+    api_url(left) == api_url(right)
+}
+
+fn git_remotes() -> Result<Vec<String>> {
+    let output = Command::new("git")
+        .args(["config", "--get-regexp", r"^remote\..*\.url$"])
+        .output()
+        .map_err(|error| format!("cannot inspect Git remotes: {error}"))?;
+    if !output.status.success() {
+        return Ok(Vec::new());
+    }
+
+    Ok(String::from_utf8_lossy(&output.stdout)
+        .lines()
+        .filter_map(|line| line.split_once(char::is_whitespace))
+        .map(|(_, url)| url.trim().to_owned())
+        .collect())
+}
+
+fn repository_scope(server_url: &str, remote: &str) -> Option<RepositoryScope> {
+    let server = Url::parse(server_url).ok()?;
+    let server_host = server.host_str()?;
+    let (remote_host, mut remote_path, is_http) = if let Ok(url) = Url::parse(remote) {
+        (
+            url.host_str()?.to_owned(),
+            url.path().trim_matches('/').to_owned(),
+            matches!(url.scheme(), "http" | "https"),
+        )
+    } else {
+        let remote = remote.rsplit_once('@').map_or(remote, |(_, rest)| rest);
+        let (host, path) = remote.split_once(':')?;
+        (host.into(), path.trim_matches('/').into(), false)
+    };
+    if !server_host.eq_ignore_ascii_case(&remote_host) {
+        return None;
+    }
+
+    let prefix = server.path().trim_matches('/');
+    if is_http && !prefix.is_empty() {
+        remote_path = remote_path
+            .strip_prefix(prefix)?
+            .strip_prefix('/')?
+            .to_owned();
+    }
+    let parts: Vec<_> = remote_path
+        .split('/')
+        .filter(|part| !part.is_empty())
+        .collect();
+    let [.., owner, repository] = parts.as_slice() else {
+        return None;
+    };
+    let repository = repository.strip_suffix(".git").unwrap_or(repository);
+    (!owner.is_empty() && !repository.is_empty()).then(|| RepositoryScope {
+        owner: (*owner).into(),
+        repository: repository.into(),
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn config_round_trip_and_remote_scope() {
+        let directory = env::temp_dir().join(format!(
+            "gotcha-config-test-{}-{}",
+            process::id(),
+            SystemTime::now()
+                .duration_since(UNIX_EPOCH)
+                .unwrap()
+                .as_nanos()
+        ));
+        let path = directory.join("config");
+        let mut config = Config {
+            path: path.clone(),
+            ..Config::default()
+        };
+        assert_eq!(
+            config.select(None, None).err().unwrap(),
+            "no servers configured; run `gotcha auth login SERVER`"
+        );
+        config.login("code.example", "secret").unwrap();
+
+        let loaded = Config::load_from(path).unwrap();
+        assert_eq!(loaded.servers["code.example"].token, "secret");
+        assert!(
+            fs::read_to_string(&loaded.path)
+                .unwrap()
+                .contains("token: secret")
+        );
+        let scope = repository_scope(
+            "https://code.example/gitea",
+            "https://code.example/gitea/alice/project.git",
+        )
+        .unwrap();
+        assert_eq!(
+            (scope.owner.as_str(), scope.repository.as_str()),
+            ("alice", "project")
+        );
+        #[cfg(unix)]
+        assert_eq!(
+            fs::metadata(&loaded.path).unwrap().permissions().mode() & 0o777,
+            0o600
+        );
+
+        fs::remove_dir_all(directory).unwrap();
+    }
+}