feat: first take at M4

crates/bds-core/src/engine/preview.rs

@@ -0,0 +1,126 @@
+use crate::engine::{EngineError, EngineResult};
+use crate::engine::generation::PublishedPostSource;
+use crate::model::ProjectMetadata;
+use crate::render::{build_canonical_post_path, render_starter_list_page, render_starter_single_post_page};
+
+pub fn render_preview_path(
+    path: &str,
+    metadata: &ProjectMetadata,
+    posts: &[PublishedPostSource],
+) -> EngineResult<Option<String>> {
+    let normalized = if path.is_empty() { "/" } else { path };
+    let main_language = metadata.main_language.as_deref().unwrap_or("en");
+
+    if normalized == "/" {
+        let list_posts = posts
+            .iter()
+            .map(|source| (source.post.clone(), source.body_markdown.clone()))
+            .collect::<Vec<_>>();
+        return render_starter_list_page(&list_posts, metadata, main_language)
+            .map(|page| Some(page.html))
+            .map_err(|error| EngineError::Parse(error.to_string()));
+    }
+
+    let (language, route_path) = split_language_prefix(normalized, metadata);
+    if let Some(source) = posts.iter().find(|source| {
+        build_canonical_post_path(&source.post, &language, main_language) == route_path
+    }) {
+        return render_starter_single_post_page(&source.post, &source.body_markdown, metadata, &language)
+            .map(|page| Some(page.html))
+            .map_err(|error| EngineError::Parse(error.to_string()));
+    }
+
+    Ok(None)
+}
+
+fn split_language_prefix(path: &str, metadata: &ProjectMetadata) -> (String, String) {
+    let trimmed = path.trim_start_matches('/');
+    let mut segments = trimmed.split('/');
+    let first = segments.next().unwrap_or_default();
+    if metadata.blog_languages.iter().any(|language| language == first) {
+        let remainder = segments.collect::<Vec<_>>().join("/");
+        return (first.to_string(), format!("/{first}/{}", remainder.trim_start_matches('/')));
+    }
+
+    (
+        metadata.main_language.as_deref().unwrap_or("en").to_string(),
+        path.to_string(),
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::model::{Post, PostStatus};
+
+    fn make_metadata() -> ProjectMetadata {
+        ProjectMetadata {
+            name: "Blog".into(),
+            description: None,
+            public_url: Some("https://example.com".into()),
+            main_language: Some("en".into()),
+            default_author: None,
+            max_posts_per_page: 50,
+            blogmark_category: None,
+            pico_theme: None,
+            semantic_similarity_enabled: false,
+            blog_languages: vec!["en".into(), "de".into()],
+        }
+    }
+
+    fn make_post() -> PublishedPostSource {
+        PublishedPostSource {
+            post: Post {
+                id: "post-1".into(),
+                project_id: "project-1".into(),
+                title: "Hello".into(),
+                slug: "hello".into(),
+                excerpt: None,
+                content: Some("Body".into()),
+                status: PostStatus::Published,
+                author: None,
+                language: Some("en".into()),
+                do_not_translate: false,
+                template_slug: None,
+                file_path: String::new(),
+                checksum: None,
+                tags: vec![],
+                categories: vec![],
+                published_title: None,
+                published_content: None,
+                published_tags: None,
+                published_categories: None,
+                published_excerpt: None,
+                created_at: 1_710_000_000_000,
+                updated_at: 1_710_000_000_000,
+                published_at: Some(1_710_000_000_000),
+            },
+            body_markdown: "Hello **world**".into(),
+        }
+    }
+
+    #[test]
+    fn root_preview_renders_index_page() {
+        let html = render_preview_path("/", &make_metadata(), &[make_post()])
+            .unwrap()
+            .unwrap();
+        assert!(html.contains("post-list"));
+    }
+
+    #[test]
+    fn preview_renders_single_post_for_canonical_path() {
+        let html = render_preview_path("/2024/03/09/hello", &make_metadata(), &[make_post()])
+            .unwrap()
+            .unwrap();
+        assert!(html.contains("<h1>Hello</h1>"));
+        assert!(html.contains("<strong>world</strong>"));
+    }
+
+    #[test]
+    fn preview_renders_language_prefixed_single_post() {
+        let html = render_preview_path("/de/2024/03/09/hello", &make_metadata(), &[make_post()])
+            .unwrap()
+            .unwrap();
+        assert!(html.contains("lang=\"de\""));
+    }
+}