import type { Database } from "bun:sqlite";
import { readFileSync } from "node:fs";
import { join } from "node:path";
import type { Hono } from "hono";
import { describeFile } from "../describe/describe.ts";
import { setting } from "../server/db.ts";
import { type Html, html } from "./html.ts";
import { cacheFor, notFound, type PageContext, page } from "./layout.ts";
import { renderParagraph, renderSiteMarkdown } from "./markdown.ts";

const SITE_DIR = join(import.meta.dir, "../../docs/site");

/**
 * §21.10: `/docs` is a Markdown file in Kepr's repo, rendered once at startup. `/support` is the
 * operator's, edited in the console (June, 2026-09-29): the shipped file is only its first words,
 * and the page can be switched off, which takes it out of the nav too.
 */
export function registerDocsPages(app: Hono, ctx: PageContext): void {
	const docs = readFileSync(join(SITE_DIR, "docs.md"), "utf8");
	const docsBody = sitePage(docs, true);
	app.get("/docs", (c) => {
		cacheFor(c, false);
		return c.html(page(ctx, { title: "docs", path: "/docs", ...docsBody }));
	});
	app.get("/support", (c) => {
		if (setting(ctx.kepr, "support_off")) return notFound(c, ctx);
		cacheFor(c, false);
		const body = sitePage(supportText(ctx.kepr));
		return c.html(page(ctx, { title: "support", path: "/support", ...body }));
	});
}

/** The support page's Markdown: the operator's, or the shipped words until they write their own. */
export function supportText(db: Database): string {
	return setting(db, "support_page") ?? readFileSync(join(SITE_DIR, "support.md"), "utf8");
}

/** A site page; with `contents`, a sidebar links each of its sections. */
function sitePage(source: string, contents = false): { description: string; body: Html } {
	const intro = describeFile("page.md", source);
	const doc = renderSiteMarkdown(source);
	const article = html`<article class="site-doc markdown">${doc.html}</article>`;
	const links = doc.sections.map(({ id, title }) => html`<a href="#${id}">${title}</a>`);
	return {
		description: intro ? renderParagraph(intro, { repo: "", dir: "", at: null }).text : "",
		body: contents
			? html`<div class="site-doc-layout">
<nav class="site-doc-nav mono" aria-label="sections">${links}</nav>
${article}
</div>`
			: article,
	};
}