docgen-render 0.1.0

use docgen_core::headings::Heading;
use docgen_core::model::{Backlink, TreeNode};
use minijinja::{context, Environment};
use serde::Serialize;

/// The built-in page template, embedded at compile time.
pub const DEFAULT_PAGE_TEMPLATE: &str = include_str!("../templates/page.html");

/// The vendored search client script, emitted to `dist/search.js`.
///
/// Deprecated: assets now flow through the `docgen-assets` crate. Kept for one
/// phase so dependents migrate without breakage. The bytes are byte-identical to
/// `docgen-assets`' embedded copy.
#[deprecated(note = "use docgen-assets::core_assets() / emit()")]
pub const SEARCH_JS: &str = include_str!("../assets/search.js");

// The canonical, fully-themed stylesheet now lives in the `docgen-assets` crate
// (`assets/docgen/docgen.css`, embedded via include_dir and emitted as
// `dist/docgen.css`). The previous stale 37-line copy under
// `crates/docgen-render/assets/docgen.css` was deleted to avoid divergence; use
// `docgen-assets::core_assets()` / `emit()` for the shipped theme.

/// The built-in per-doc history-timeline template, embedded at compile time.
pub const DEFAULT_HISTORY_TEMPLATE: &str = include_str!("../templates/history.html");

/// The built-in `/graph/` doc-link-graph template, embedded at compile time.
pub const DEFAULT_GRAPH_TEMPLATE: &str = include_str!("../templates/graph.html");

/// The built-in `/diff/` workspace shell template, embedded at compile time.
/// The page is a mount point (`#docgen-diff-root`) hydrated by `islands/diff.js`
/// from the build-time `timeline.json` + `revisions/<id>.json` payloads.
pub const DEFAULT_DIFF_TEMPLATE: &str = include_str!("../templates/diff.html");

/// The dev editor's live-preview document template, embedded at compile time.
/// Content-only (no app chrome): the rendered article wrapped in the SAME asset
/// and island stack a published page uses, so a doc previewed in the editor
/// renders identically to its built page (mermaid, components, tooltips, math).
pub const DEFAULT_PREVIEW_TEMPLATE: &str = include_str!("../templates/preview.html");

/// One diff line, render-friendly. `kind`/line numbers are pre-stringified by
/// the caller so `docgen-render` stays free of the `docgen-diff` domain types.
#[derive(Serialize)]
pub struct LineView {
    pub kind: String,
    pub text: String,
    pub old_line: Option<u32>,
    pub new_line: Option<u32>,
}

/// A contiguous diff hunk (run of lines).
#[derive(Serialize)]
pub struct HunkView {
    pub lines: Vec<LineView>,
}

/// One changed file within a timeline point.
#[derive(Serialize)]
pub struct FileView {
    pub path: String,
    pub status: String,
    pub hunks: Vec<HunkView>,
}

/// One commit in the timeline (render-friendly projection of a `DocDiffTimelinePoint`).
#[derive(Serialize)]
pub struct TimelinePointView {
    pub short_hash: String,
    pub subject: String,
    pub author: Option<String>,
    pub date: Option<String>,
    pub added_lines: u32,
    pub removed_lines: u32,
    pub files: Vec<FileView>,
}

/// A labelled bucket of timeline points (e.g. "Today").
#[derive(Serialize)]
pub struct TimelineBucketView {
    pub label: String,
    pub points: Vec<TimelinePointView>,
}

/// Everything the history page render needs.
#[derive(Serialize)]
pub struct HistoryContext<'a> {
    pub title: &'a str,
    pub slug: &'a str,
    pub tree: &'a [TreeNode],
    pub buckets: &'a [TimelineBucketView],
    /// Deployed base path (e.g. `/docs`); `""` → no `<base>` tag (default).
    pub base: &'a str,
    /// Site title; `""` → no `"page — site"` suffix (default).
    pub site_title: &'a str,
    /// Whether the search UI ships (gates the trigger + `search.js`).
    pub search_enabled: bool,
}

/// Everything the `/graph/` page render needs. `graph_json` is the serialized
/// `GraphData` embedded verbatim into a `<script type="application/json">` tag.
#[derive(Serialize)]
pub struct GraphContext<'a> {
    pub tree: &'a [TreeNode],
    pub graph_json: &'a str,
    pub node_count: usize,
    pub edge_count: usize,
    /// Deployed base path (e.g. `/docs`); `""` → no `<base>` tag (default).
    pub base: &'a str,
    /// Site title; `""` → no `"page — site"` suffix (default).
    pub site_title: &'a str,
    /// Whether the search UI ships (gates the trigger + `search.js`).
    pub search_enabled: bool,
    /// Whether the `/diff/` workspace page exists (drives the topbar diff icon).
    pub has_diff: bool,
}

/// Everything the `/diff/` workspace shell render needs. The diff data itself
/// is not templated — it ships as `timeline.json` + `revisions/<id>.json` and
/// is hydrated client-side by `islands/diff.js` into `#docgen-diff-root`.
#[derive(Serialize)]
pub struct DiffContext<'a> {
    pub tree: &'a [TreeNode],
    /// Deployed base path (e.g. `/docs`); `""` → no `<base>` tag (default).
    pub base: &'a str,
    /// Site title; `""` → no `"page — site"` suffix (default).
    pub site_title: &'a str,
    /// Whether the search UI ships (gates the trigger + `search.js`).
    pub search_enabled: bool,
}

/// Everything the editor's live-preview document render needs. The body is the
/// already-rendered inner HTML (run through the same per-doc pipeline as a build);
/// the flags gate the same conditional asset links a published page uses.
#[derive(Serialize)]
pub struct PreviewContext<'a> {
    pub title: &'a str,
    pub body_html: &'a str,
    /// Deployed base path (e.g. `/docs`); `""` for the dev server root (default).
    pub base: &'a str,
    /// Whether this doc contains a mermaid diagram (gates the mermaid island).
    pub has_mermaid: bool,
    /// Whether this doc contains math (gates the KaTeX stylesheet link).
    pub has_math: bool,
    /// Whether any component shipped a `style.css` (links `/components.css`).
    pub has_components_css: bool,
    /// Whether this doc used a component with an `island.js` (links `/components.js`).
    pub has_component_island: bool,
}

/// One section card on the home dashboard: a top-level folder ("section"), the
/// number of docs in it, and a link to its first page. Mirrors the original
/// home's `sectionCards`.
#[derive(Serialize)]
pub struct HomeSection<'a> {
    pub label: &'a str,
    /// Slug of the section's first doc (template prefixes `base`). Folders have no
    /// index doc, so this points at a real page.
    pub slug: &'a str,
    pub count: usize,
}

/// One row in the home dashboard's "Recent" list.
#[derive(Serialize)]
pub struct HomeRecent<'a> {
    pub title: &'a str,
    pub slug: &'a str,
    /// The doc's top-level section label (or `""` for a root-level doc).
    pub section: &'a str,
}

/// The home dashboard payload. `PageContext.home` is `Some` only for the index
/// doc; every other page passes `None` (and the template skips the dashboard).
#[derive(Serialize)]
pub struct HomeData<'a> {
    /// Hero subtitle (the index doc's frontmatter `description`). `""` → omitted.
    pub description: &'a str,
    /// Total published doc count — the "pages" stat tile.
    pub pages: usize,
    /// Total resolved wikilink count — the "links" stat tile.
    pub links: usize,
    /// Section cards (top-level folders). Empty → the Sections column is omitted.
    pub sections: &'a [HomeSection<'a>],
    /// The most-recent docs (build order, home excluded), capped for the panel.
    pub recent: &'a [HomeRecent<'a>],
}

/// Everything a single page render needs.
#[derive(Serialize)]
pub struct PageContext<'a> {
    pub title: &'a str,
    /// Optional frontmatter `description:`, rendered as the page header "lede"
    /// under the title on doc pages. `""` → no lede paragraph.
    pub description: &'a str,
    pub slug: &'a str,
    pub body_html: &'a str,
    pub tree: &'a [TreeNode],
    /// Inbound references, rendered as cards in the right rail's "Referenced by"
    /// section (this supersedes the old in-content backlinks block).
    pub backlinks: &'a [Backlink],
    /// The `h2`/`h3` outline of this page, for the right-rail "On this page" TOC.
    pub headings: &'a [Heading],
    /// Short commit hash for the rail's "Additional info" → Commit row. `""` →
    /// the Commit row is omitted (no git repo / detached build).
    pub commit: &'a str,
    /// Build timestamp (`YYYY-MM-DD HH:MM`) for the "Built" row. `""` → omitted.
    pub built: &'a str,
    /// Whether this doc has an emitted `/<slug>/history/` page (drives the nav link).
    pub has_history: bool,
    /// Whether this page contains a mermaid diagram (gates the mermaid island script).
    pub has_mermaid: bool,
    /// Whether this page contains math (gates the KaTeX stylesheet `<head>` link).
    pub has_math: bool,
    /// Deployed base path (e.g. `/docs`); `""` → no `<base>` tag (default).
    pub base: &'a str,
    /// Site title; `""` → no `"page — site"` suffix (default).
    pub site_title: &'a str,
    /// Whether the search UI ships (gates the trigger + `search.js`).
    pub search_enabled: bool,
    /// Whether the `/diff/` workspace page exists (drives the topbar diff icon).
    pub has_diff: bool,
    /// Whether any component shipped a `style.css` (links `/components.css`). The
    /// component stylesheet is small + cacheable, so it links on every page when
    /// present rather than per-page.
    pub has_components_css: bool,
    /// Whether this page used ≥1 component with an `island.js` (links
    /// `/components.js`, gated per-page like the mermaid island).
    pub has_component_island: bool,
    /// Whether this page is the site home. Drives the home-only graph embed
    /// (the original surfaces the doc graph on the home page, not the sidebar).
    pub is_home: bool,
    /// Force-layout graph JSON for the home embed (raw — `render_page` applies
    /// the `</` → `<\/` escaping for the inline `<script>`). `""` → no graph
    /// block (not home, or the graph feature is off).
    pub graph_json: &'a str,
    /// Node/edge counts for the home graph caption (ignored when `graph_json` is empty).
    pub graph_node_count: usize,
    pub graph_edge_count: usize,
    /// Home dashboard payload (hero/stats/sections/recent). `Some` only for the
    /// index doc; `None` everywhere else.
    pub home: Option<HomeData<'a>>,
}

/// Owns a configured minijinja environment with the `page` template registered.
pub struct Renderer {
    env: Environment<'static>,
}

impl Renderer {
    /// Build a renderer from a page-template source string.
    pub fn new(page_template: &str) -> Result<Self, minijinja::Error> {
        let mut env = Environment::new();
        // Register under a `.html` name so minijinja's default auto-escape callback
        // enables HTML escaping for `{{ title }}`, `{{ node.name }}`, `{{ node.title }}`.
        // `{{ body | safe }}` remains raw, as intended for already-rendered markdown.
        env.add_template_owned("page.html", page_template.to_string())?;
        env.add_template_owned("history.html", DEFAULT_HISTORY_TEMPLATE.to_string())?;
        env.add_template_owned("graph.html", DEFAULT_GRAPH_TEMPLATE.to_string())?;
        env.add_template_owned("diff.html", DEFAULT_DIFF_TEMPLATE.to_string())?;
        env.add_template_owned("preview.html", DEFAULT_PREVIEW_TEMPLATE.to_string())?;
        Ok(Self { env })
    }

    /// Render one page to a full HTML document.
    pub fn render_page(&self, ctx: &PageContext) -> Result<String, minijinja::Error> {
        let tmpl = self.env.get_template("page.html")?;
        // Escape `</` so a literal `</script>` inside a doc title can't break out
        // of the inline `<script type="application/json">` graph payload (same
        // guard as `render_graph`). Empty → still empty, so the block is skipped.
        let safe_graph_json = ctx.graph_json.replace("</", "<\\/");
        tmpl.render(context! {
            title => ctx.title,
            description => ctx.description,
            body => ctx.body_html,
            slug => ctx.slug,
            tree => ctx.tree,
            backlinks => ctx.backlinks,
            headings => ctx.headings,
            commit => ctx.commit,
            built => ctx.built,
            has_history => ctx.has_history,
            has_mermaid => ctx.has_mermaid,
            has_math => ctx.has_math,
            base => ctx.base,
            site_title => ctx.site_title,
            search_enabled => ctx.search_enabled,
            has_components_css => ctx.has_components_css,
            has_component_island => ctx.has_component_island,
            is_home => ctx.is_home,
            has_diff => ctx.has_diff,
            graph_json => safe_graph_json,
            graph_node_count => ctx.graph_node_count,
            graph_edge_count => ctx.graph_edge_count,
            home => ctx.home,
        })
    }

    /// Render the `/graph/` doc-link-graph page to a full HTML document.
    ///
    /// `graph_json` is injected raw (the island's `JSON.parse` needs valid JSON,
    /// not HTML-escaped text). To stop a literal `</script>` inside a doc title
    /// from breaking out of the embedding `<script type="application/json">` tag,
    /// `</` is rewritten to `<\/` first — still valid JSON, inert as markup.
    pub fn render_graph(&self, ctx: &GraphContext) -> Result<String, minijinja::Error> {
        let tmpl = self.env.get_template("graph.html")?;
        let safe_json = ctx.graph_json.replace("</", "<\\/");
        tmpl.render(context! {
            tree => ctx.tree,
            slug => "",
            graph_json => safe_json,
            node_count => ctx.node_count,
            edge_count => ctx.edge_count,
            base => ctx.base,
            site_title => ctx.site_title,
            search_enabled => ctx.search_enabled,
            has_diff => ctx.has_diff,
        })
    }

    /// Render one doc's history timeline to a full HTML document.
    pub fn render_history(&self, ctx: &HistoryContext) -> Result<String, minijinja::Error> {
        let tmpl = self.env.get_template("history.html")?;
        tmpl.render(context! {
            title => ctx.title,
            slug => ctx.slug,
            tree => ctx.tree,
            buckets => ctx.buckets,
            base => ctx.base,
            site_title => ctx.site_title,
            search_enabled => ctx.search_enabled,
        })
    }

    /// Render the editor's live-preview document (content-only, real asset stack).
    pub fn render_preview(&self, ctx: &PreviewContext) -> Result<String, minijinja::Error> {
        let tmpl = self.env.get_template("preview.html")?;
        tmpl.render(context! {
            title => ctx.title,
            body => ctx.body_html,
            base => ctx.base,
            has_mermaid => ctx.has_mermaid,
            has_math => ctx.has_math,
            has_components_css => ctx.has_components_css,
            has_component_island => ctx.has_component_island,
        })
    }

    /// Render the `/diff/` workspace shell to a full HTML document.
    pub fn render_diff(&self, ctx: &DiffContext) -> Result<String, minijinja::Error> {
        let tmpl = self.env.get_template("diff.html")?;
        tmpl.render(context! {
            tree => ctx.tree,
            slug => "",
            base => ctx.base,
            site_title => ctx.site_title,
            search_enabled => ctx.search_enabled,
        })
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use docgen_core::model::TreeNode;

    fn renderer() -> Renderer {
        Renderer::new(DEFAULT_PAGE_TEMPLATE).unwrap()
    }

    #[test]
    fn renders_title_and_body() {
        let html = renderer()
            .render_page(&PageContext {
                title: "My Page",
                slug: "my-page",
                body_html: "<p>hello</p>",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        assert!(html.contains("<title>My Page</title>"));
        assert!(html.contains("<p>hello</p>"));
    }

    #[test]
    fn page_has_accessibility_landmarks() {
        let html = renderer()
            .render_page(&PageContext {
                title: "P",
                slug: "p",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        // Skip link targets a labelled, focusable <main>.
        assert!(html.contains(r##"class="docgen-skip-link" href="#docgen-main""##));
        assert!(html.contains(r#"id="docgen-main""#));
        assert!(html.contains(r#"tabindex="-1""#));
        // Hamburger links to the drawer it controls; Escape closes it.
        assert!(html.contains(r#"aria-controls="docgen-sidebar""#));
        assert!(html.contains("@keydown.escape.window=\"navOpen=false\""));
        // Theme toggle exposes pressed state to AT.
        assert!(html.contains(":aria-pressed=\"theme==='light'\""));
        assert!(html.contains(":aria-pressed=\"theme==='dark'\""));
    }

    #[test]
    fn component_asset_links_are_gated() {
        let off = renderer()
            .render_page(&PageContext {
                title: "P",
                slug: "p",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        assert!(!off.contains("/components.css"));
        assert!(!off.contains("/components.js"));

        let on = renderer()
            .render_page(&PageContext {
                title: "P",
                slug: "p",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: true,
                has_component_island: true,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        assert!(on.contains(r#"<link rel="stylesheet" href="/components.css" />"#));
        assert!(on.contains(r#"<script src="/components.js"></script>"#));
    }

    #[test]
    fn page_title_gets_site_suffix_when_configured() {
        let html = renderer()
            .render_page(&PageContext {
                title: "Intro",
                site_title: "My Docs",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
                base: "",
                slug: "x",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
            })
            .unwrap();
        assert!(html.contains("<title>Intro — My Docs</title>"));
    }

    #[test]
    fn no_site_title_leaves_plain_title_and_no_base() {
        let html = renderer()
            .render_page(&PageContext {
                title: "Intro",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
                base: "",
                slug: "x",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
            })
            .unwrap();
        assert!(html.contains("<title>Intro</title>"));
        assert!(!html.contains("<base"));
    }

    #[test]
    fn search_disabled_hides_search_ui() {
        let on = renderer()
            .render_page(&PageContext {
                title: "X",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
                base: "",
                slug: "x",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
            })
            .unwrap();
        assert!(on.contains("data-docgen-search"));

        let off = renderer()
            .render_page(&PageContext {
                title: "X",
                site_title: "",
                search_enabled: false,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
                base: "",
                slug: "x",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
            })
            .unwrap();
        assert!(!off.contains("data-docgen-search"));
        assert!(!off.contains("/search.js"));
    }

    #[test]
    fn base_prefixes_every_asset_and_nav_link_and_emits_no_base_tag() {
        // A sub-path deployment must rewrite every root-absolute URL to live under
        // `base`; <base> alone cannot do this (it only affects relative URLs).
        let tree = vec![TreeNode::Doc {
            name: "guide".into(),
            slug: "guide".into(),
            title: "Guide".into(),
        }];
        let html = renderer()
            .render_page(&PageContext {
                title: "X",
                site_title: "",
                search_enabled: true,
                has_components_css: true,
                has_component_island: false,
                is_home: false,
                has_diff: true,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
                base: "/docs",
                slug: "x",
                body_html: "",
                tree: &tree,
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
            })
            .unwrap();
        // No <base> tag — links are prefixed directly so they actually resolve.
        assert!(!html.contains("<base"));
        // Assets under base.
        assert!(html.contains(r#"href="/docs/docgen.css""#));
        assert!(html.contains(r#"href="/docs/components.css""#));
        assert!(html.contains(r#"src="/docs/bootstrap.js""#));
        assert!(html.contains(r#"src="/docs/search.js""#));
        // Nav + diff links under base. (The sidebar graph link was removed;
        // the graph now lives on the home page, covered by its own test.)
        assert!(html.contains(r#"href="/docs/guide""#));
        assert!(html.contains(r#"href="/docs/diff""#));
        // Nothing left at the bare root.
        assert!(!html.contains(r#"href="/docgen.css""#));
        assert!(!html.contains(r#"src="/bootstrap.js""#));
    }

    #[test]
    fn renders_sidebar_links() {
        let tree = vec![TreeNode::Doc {
            name: "intro".into(),
            slug: "guide/intro".into(),
            title: "Intro".into(),
        }];
        let html = renderer()
            .render_page(&PageContext {
                title: "X",
                slug: "x",
                body_html: "",
                tree: &tree,
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        assert!(html.contains(r#"href="/guide/intro""#));
        assert!(html.contains(">Intro</a>"));
    }

    #[test]
    fn escapes_title_and_sidebar_text_but_not_body() {
        let tree = vec![TreeNode::Doc {
            name: "intro".into(),
            slug: "guide/intro".into(),
            title: "A & B <x>".into(),
        }];
        let html = renderer()
            .render_page(&PageContext {
                title: "Tom & Jerry <script>",
                slug: "tj",
                body_html: "<p>raw & ok</p>",
                tree: &tree,
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        // Title is HTML-escaped.
        assert!(html.contains("<title>Tom &amp; Jerry &lt;script&gt;</title>"));
        assert!(!html.contains("<title>Tom & Jerry <script>"));
        // Sidebar link text is escaped.
        assert!(html.contains("A &amp; B &lt;x&gt;"));
        // Body marked `| safe` is emitted raw.
        assert!(html.contains("<p>raw & ok</p>"));
    }

    #[test]
    fn renders_backlinks_section() {
        use docgen_core::model::Backlink;
        let backlinks = vec![Backlink {
            slug: "a".into(),
            title: "Page A".into(),
            description: Some("All about A".into()),
        }];
        let html = renderer()
            .render_page(&PageContext {
                title: "X",
                slug: "x",
                body_html: "",
                tree: &[],
                backlinks: &backlinks,
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        // Backlinks now live in the right rail's "Referenced by" section as cards.
        assert!(html.contains("Referenced by"));
        assert!(html.contains(r#"class="docgen-rail__backlink" href="/a""#));
        assert!(html.contains("<span>Page A</span>"));
        assert!(html.contains("<small>All about A</small>"));
        // The old in-content backlinks block is gone.
        assert!(!html.contains("docgen-backlinks"));
    }

    #[test]
    fn omits_backlinks_section_when_empty() {
        let html = renderer()
            .render_page(&PageContext {
                title: "X",
                slug: "x",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        // No backlinks → the "Referenced by" rail section is omitted entirely.
        assert!(!html.contains("Referenced by"));
        assert!(!html.contains("docgen-rail__backlink"));
    }

    #[test]
    fn renders_diff_link_only_when_has_diff() {
        let with = renderer()
            .render_page(&PageContext {
                title: "X",
                slug: "guide/intro",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: true,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        assert!(with.contains(r#"href="/diff""#));

        let without = renderer()
            .render_page(&PageContext {
                title: "X",
                slug: "guide/intro",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        assert!(!without.contains(r#"href="/diff""#));
    }

    #[test]
    fn page_loads_bootstrap_and_alpine_and_gates_mermaid_island() {
        let html = renderer()
            .render_page(&PageContext {
                title: "X",
                slug: "x",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        assert!(html.contains(r#"src="/bootstrap.js""#));
        assert!(html.contains(r#"src="/vendor/alpine/alpine.min.js""#));
        assert!(!html.contains("islands/mermaid.js")); // gated off

        let withm = renderer()
            .render_page(&PageContext {
                title: "X",
                slug: "x",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: true,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        assert!(withm.contains(r#"src="/islands/mermaid.js""#));
    }

    #[test]
    fn page_links_katex_css_only_when_has_math() {
        let no_math = renderer()
            .render_page(&PageContext {
                title: "X",
                slug: "x",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        assert!(!no_math.contains("katex.min.css"));

        let with_math = renderer()
            .render_page(&PageContext {
                title: "X",
                slug: "x",
                body_html: "",
                tree: &[],
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: true,
                base: "",
                site_title: "",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap();
        assert!(with_math.contains(r#"href="/vendor/katex/katex.min.css""#));
    }

    #[test]
    #[allow(deprecated)] // SEARCH_JS kept one phase as a byte-identical re-export
    fn ships_self_contained_search_assets() {
        assert!(SEARCH_JS.contains("search-index.json"));
        assert!(SEARCH_JS.contains("metaKey"));
        assert!(!SEARCH_JS.contains("import ")); // no module imports / npm
    }

    // ---- editor live-preview document ----

    #[test]
    fn preview_is_content_only_with_real_asset_stack() {
        let r = renderer();
        let html = r
            .render_preview(&PreviewContext {
                title: "Intro",
                body_html: r#"<h1>Intro</h1><p>See <a class="docgen-wikilink" href="/guide">g</a></p>"#,
                base: "",
                has_mermaid: false,
                has_math: false,
                has_components_css: false,
                has_component_island: false,
            })
            .unwrap();
        // The article content is emitted raw inside the published prose wrapper.
        assert!(html.contains(r#"<article class="docgen-doc-content">"#));
        assert!(html.contains(r#"href="/guide""#));
        // Same content + island stack a built page uses — so islands hydrate.
        assert!(html.contains(r#"href="/docgen.css""#));
        assert!(html.contains(r#"href="/code.css""#));
        assert!(html.contains(r#"src="/bootstrap.js""#));
        assert!(html.contains(r#"src="/islands/wikilink.js""#));
        assert!(html.contains(r#"src="/vendor/alpine/alpine.min.js""#));
        // No app chrome: this is a preview pane, not a full page.
        assert!(!html.contains("docgen-topbar"));
        assert!(!html.contains("docgen-sidebar"));
        assert!(!html.contains("docgen-rail"));
        // Conditional assets gated off.
        assert!(!html.contains("islands/mermaid.js"));
        assert!(!html.contains("components.css"));
        assert!(!html.contains("katex.min.css"));
    }

    #[test]
    fn preview_gates_mermaid_math_and_component_assets() {
        let r = renderer();
        let html = r
            .render_preview(&PreviewContext {
                title: "D",
                body_html: r#"<div class="docgen-mermaid"></div>"#,
                base: "",
                has_mermaid: true,
                has_math: true,
                has_components_css: true,
                has_component_island: true,
            })
            .unwrap();
        assert!(html.contains(r#"src="/islands/mermaid.js""#));
        assert!(html.contains(r#"href="/vendor/katex/katex.min.css""#));
        assert!(html.contains(r#"href="/components.css""#));
        assert!(html.contains(r#"src="/components.js""#));
    }

    #[test]
    fn preview_prefixes_base() {
        let r = renderer();
        let html = r
            .render_preview(&PreviewContext {
                title: "X",
                body_html: "<p>x</p>",
                base: "/docs",
                has_mermaid: true,
                has_math: false,
                has_components_css: false,
                has_component_island: false,
            })
            .unwrap();
        assert!(html.contains(r#"href="/docs/docgen.css""#));
        assert!(html.contains(r#"src="/docs/bootstrap.js""#));
        assert!(html.contains(r#"src="/docs/islands/mermaid.js""#));
        assert!(!html.contains(r#"href="/docgen.css""#));
    }

    fn sample_buckets() -> Vec<TimelineBucketView> {
        vec![TimelineBucketView {
            label: "Today".into(),
            points: vec![TimelinePointView {
                short_hash: "abc1234".into(),
                subject: "edit a".into(),
                author: Some("docgen test".into()),
                date: Some("2026-05-15".into()),
                added_lines: 1,
                removed_lines: 1,
                files: vec![FileView {
                    path: "docs/a.md".into(),
                    status: "modified".into(),
                    hunks: vec![HunkView {
                        lines: vec![
                            LineView {
                                kind: "context".into(),
                                text: "# A".into(),
                                old_line: Some(1),
                                new_line: Some(1),
                            },
                            LineView {
                                kind: "removed".into(),
                                text: "first".into(),
                                old_line: Some(2),
                                new_line: None,
                            },
                            LineView {
                                kind: "added".into(),
                                text: "second".into(),
                                old_line: None,
                                new_line: Some(2),
                            },
                        ],
                    }],
                }],
            }],
        }]
    }

    // ---- P4 B-4: /graph/ page ----

    #[test]
    fn renders_graph_page_with_embedded_json_and_island() {
        let r = Renderer::new(DEFAULT_PAGE_TEMPLATE).unwrap();
        let json = r#"{"nodes":[{"slug":"a","title":"A","x":1.0,"y":2.0,"degree":0}],"edges":[]}"#;
        let html = r
            .render_graph(&GraphContext {
                tree: &[],
                graph_json: json,
                node_count: 1,
                has_diff: false,
                edge_count: 0,
                base: "",
                site_title: "",
                search_enabled: true,
            })
            .unwrap();
        assert!(html.contains("<title>Graph</title>"));
        assert!(html.contains(r#"id="docgen-graph-data""#));
        assert!(html.contains(r#"type="application/json""#));
        assert!(html.contains(json)); // JSON embedded verbatim, NOT escaped
        assert!(html.contains(r#"x-data="docgenGraph""#));
        assert!(html.contains(r#"src="/islands/graph.js""#));
        assert!(html.contains(r#"src="/bootstrap.js""#));
        assert!(html.contains(r#"src="/vendor/alpine/alpine.min.js""#));
        assert!(html.contains("1 nodes")); // meta caption
    }

    #[test]
    fn graph_page_renders_sidebar_tree() {
        let r = Renderer::new(DEFAULT_PAGE_TEMPLATE).unwrap();
        let tree = vec![docgen_core::model::TreeNode::Doc {
            name: "intro".into(),
            slug: "guide/intro".into(),
            title: "Intro".into(),
        }];
        let html = r
            .render_graph(&GraphContext {
                tree: &tree,
                graph_json: r#"{"nodes":[],"edges":[]}"#,
                node_count: 0,
                has_diff: false,
                edge_count: 0,
                base: "",
                site_title: "",
                search_enabled: true,
            })
            .unwrap();
        assert!(html.contains(r#"href="/guide/intro""#));
    }

    #[test]
    fn embedded_json_neutralizes_script_close() {
        let r = Renderer::new(DEFAULT_PAGE_TEMPLATE).unwrap();
        let json = r#"{"nodes":[{"slug":"x","title":"a</script>b","x":0.0,"y":0.0,"degree":0}],"edges":[]}"#;
        let html = r
            .render_graph(&GraphContext {
                tree: &[],
                graph_json: json,
                node_count: 1,
                has_diff: false,
                edge_count: 0,
                base: "",
                site_title: "",
                search_enabled: true,
            })
            .unwrap();
        assert!(!html.contains("a</script>b")); // raw close-tag must not survive
        assert!(html.contains(r#"a<\/script>b"#)); // escaped form present
    }

    #[test]
    fn graph_page_renders_graph_canvas_without_sidebar_link() {
        let r = Renderer::new(DEFAULT_PAGE_TEMPLATE).unwrap();
        let html = r
            .render_graph(&GraphContext {
                tree: &[],
                graph_json: r#"{"nodes":[],"edges":[]}"#,
                node_count: 0,
                has_diff: false,
                edge_count: 0,
                base: "",
                site_title: "",
                search_enabled: true,
            })
            .unwrap();
        // The standalone /graph page still renders its graph canvas + island.
        assert!(html.contains(r#"x-data="docgenGraph""#));
        assert!(html.contains("docgen-graph__svg"));
        // The sidebar graph link was removed (the graph lives on the home page).
        assert!(!html.contains("docgen-sidebar__graph"));
    }

    #[test]
    fn home_page_embeds_graph_and_non_home_does_not() {
        let r = renderer();
        let ctx = |is_home: bool, graph_json: &'static str| PageContext {
            title: "X",
            slug: if is_home { "index" } else { "x" },
            body_html: "",
            tree: &[],
            backlinks: &[],
            headings: &[],
            commit: "",
            built: "",
            has_history: false,
            has_mermaid: false,
            has_math: false,
            base: "",
            site_title: "",
            search_enabled: true,
            has_diff: false,
            has_components_css: false,
            has_component_island: false,
            is_home,
            graph_json,
            graph_node_count: 2,
            graph_edge_count: 1,
            description: "",
            home: None,
        };
        // Home page with graph data: embeds the graph block + data + island script.
        let home = r
            .render_page(&ctx(true, r#"{"nodes":[],"edges":[]}"#))
            .unwrap();
        assert!(home.contains("docgen-home-graph"));
        assert!(home.contains(r#"id="docgen-graph-data""#));
        assert!(home.contains(r#"x-data="docgenGraph""#));
        assert!(home.contains("islands/graph.js"));
        // The sidebar graph link is gone.
        assert!(!home.contains("docgen-sidebar__graph"));
        // A non-home page (even if a graph_json were passed) embeds nothing.
        let other = r.render_page(&ctx(false, "")).unwrap();
        assert!(!other.contains("docgen-home-graph"));
        assert!(!other.contains("islands/graph.js"));
    }

    #[test]
    fn renders_history_timeline_with_buckets_and_diff_lines() {
        let buckets = sample_buckets();
        let html = renderer()
            .render_history(&HistoryContext {
                title: "A",
                slug: "a",
                tree: &[],
                buckets: &buckets,
                base: "",
                site_title: "",
                search_enabled: true,
            })
            .unwrap();
        assert!(html.contains("<title>History: A</title>"));
        assert!(html.contains("Today"));
        assert!(html.contains("edit a"));
        assert!(html.contains("abc1234"));
        assert!(html.contains("docgen-diff-line--removed"));
        assert!(html.contains("docgen-diff-line--added"));
        assert!(html.contains("first"));
        assert!(html.contains(r#"href="/a""#));
    }

    #[test]
    fn history_escapes_diff_text() {
        let buckets = vec![TimelineBucketView {
            label: "Today".into(),
            points: vec![TimelinePointView {
                short_hash: "abc1234".into(),
                subject: "edit".into(),
                author: None,
                date: None,
                added_lines: 1,
                removed_lines: 0,
                files: vec![FileView {
                    path: "docs/a.md".into(),
                    status: "modified".into(),
                    hunks: vec![HunkView {
                        lines: vec![LineView {
                            kind: "added".into(),
                            text: "<script>alert(1)</script>".into(),
                            old_line: None,
                            new_line: Some(1),
                        }],
                    }],
                }],
            }],
        }];
        let html = renderer()
            .render_history(&HistoryContext {
                title: "A",
                slug: "a",
                tree: &[],
                buckets: &buckets,
                base: "",
                site_title: "",
                search_enabled: true,
            })
            .unwrap();
        assert!(html.contains("&lt;script&gt;alert(1)&lt;&#x2f;script&gt;"));
        assert!(!html.contains("<script>alert(1)</script>"));
    }

    // ---- P7 Cluster A: app shell, themes, theme-toggle, sidebar tree ----

    fn page(slug: &str, tree: &[TreeNode]) -> String {
        renderer()
            .render_page(&PageContext {
                title: "X",
                slug,
                body_html: "<p>hi</p>",
                tree,
                backlinks: &[],
                headings: &[],
                commit: "",
                built: "",
                has_history: false,
                has_mermaid: false,
                has_math: false,
                base: "",
                site_title: "Docs",
                search_enabled: true,
                has_components_css: false,
                has_component_island: false,
                is_home: false,
                has_diff: false,
                graph_json: "",
                graph_node_count: 0,
                graph_edge_count: 0,
                description: "",
                home: None,
            })
            .unwrap()
    }

    #[test]
    fn page_has_app_shell() {
        let html = page("x", &[]);
        for cls in [
            "docgen-app",
            "docgen-topbar",
            "docgen-layout",
            "docgen-sidebar",
            "docgen-content",
            "docgen-doc-content",
        ] {
            assert!(html.contains(cls), "app shell missing {cls}");
        }
    }

    #[test]
    fn page_has_no_flash_script_in_head() {
        let html = page("x", &[]);
        let script_at = html
            .find("localStorage.getItem('doc-theme')")
            .expect("no-flash script present");
        let css_at = html.find("/docgen.css").expect("docgen.css link present");
        assert!(
            script_at < css_at,
            "no-flash script must precede docgen.css link"
        );
        assert!(html.contains("prefers-color-scheme"));
        // Dark is the bare default: pre-paint falls back to dark, not light.
        assert!(html.contains("'light':'dark'"));
    }

    #[test]
    fn page_has_theme_toggle_island() {
        let html = page("x", &[]);
        assert!(html.contains(r#"x-data="docgenThemeToggle""#));
        assert!(html.contains("/islands/theme-toggle.js"));
        // Dark is the bare default: <html> carries NO data-theme attr server-side;
        // the pre-paint script sets it (dark when nothing stored / no light pref).
        assert!(!html.contains(r#"<html lang="en" data-theme="#));
    }

    #[test]
    fn sidebar_marks_active_doc() {
        let tree = vec![TreeNode::Doc {
            name: "a".into(),
            slug: "a".into(),
            title: "A".into(),
        }];
        let active = page("a", &tree);
        assert!(active.contains(r#"docgen-tree__item is-active"#));
        assert!(active.contains(r#"aria-current="page""#));

        let inactive = page("b", &tree);
        assert!(!inactive.contains(r#"docgen-tree__item is-active"#));
        assert!(!inactive.contains(r#"aria-current="page""#));
    }

    #[test]
    fn sidebar_renders_nested_dir_as_details() {
        let tree = vec![TreeNode::Dir {
            name: "guide".into(),
            slug: None,
            children: vec![TreeNode::Doc {
                name: "intro".into(),
                slug: "guide/intro".into(),
                title: "Intro".into(),
            }],
        }];
        let html = page("x", &tree);
        assert!(html.contains("<details"));
        assert!(html.contains("<summary"));
        assert!(html.contains("docgen-tree"));
        // Each folder carries a stable path key so its collapse state persists.
        assert!(html.contains(r#"data-tree-path="/guide""#));
    }

    #[test]
    fn graph_and_history_share_shell() {
        let r = Renderer::new(DEFAULT_PAGE_TEMPLATE).unwrap();
        let graph = r
            .render_graph(&GraphContext {
                tree: &[],
                graph_json: r#"{"nodes":[],"edges":[]}"#,
                node_count: 0,
                has_diff: false,
                edge_count: 0,
                base: "",
                site_title: "",
                search_enabled: true,
            })
            .unwrap();
        let hist = r
            .render_history(&HistoryContext {
                title: "A",
                slug: "a",
                tree: &[],
                buckets: &[],
                base: "",
                site_title: "",
                search_enabled: true,
            })
            .unwrap();
        for html in [&graph, &hist] {
            assert!(html.contains("docgen-topbar"));
            assert!(html.contains("data-theme"));
            assert!(html.contains("/islands/theme-toggle.js"));
            assert!(html.contains("localStorage.getItem('doc-theme')"));
        }
    }
}