import type { Context, Hono } from "hono";
import type { Syncer, SyncTarget } from "../bucket/sync.ts";
import { operatorIssues } from "../issues/store.ts";
import { type Html, html } from "../pages/html.ts";
import { type PageContext, page, plural, relativeTime } from "../pages/layout.ts";
import { backups } from "../server/backup.ts";
import type { Config } from "../server/config.ts";
import { connectKeys, MACHINES_LISTED } from "../server/connect.ts";
import { setting } from "../server/db.ts";
import { formToken } from "../server/login.ts";
import { backupsPage } from "./backups.ts";
import { allRepos } from "./store.ts";

export type AdminContext = PageContext & {
	/** The bucket, kepr.db and mirrors the console reads and writes itself. */
	sync: SyncTarget;
	/** The sync, which may run on its own thread. */
	syncer: Syncer;
	dataDir: string;
	config: Config;
	configPath: string;
};

const SECTIONS = [
	["/admin", "overview"],
	["/admin/repos", "repos"],
	["/admin/issues", "issues"],
	["/admin/downloads", "downloads"],
	["/admin/storage", "storage"],
	["/admin/notifications", "notifications"],
	["/admin/email", "email"],
	["/admin/bucket", "bucket"],
	["/admin?section=backups", "backups"],
	["/admin/site?section=profile", "profile"],
	["/admin/site", "site"],
	["/admin/account", "account"],
] as const;

/** The hidden same-site token (§25) that every admin form posts back. */
export function formField(c: Context): Html {
	return html`<input type="hidden" name="form" value="${formToken(c)}">`;
}

/** A posted form's text fields; the guard has already parsed and checked the body. */
export async function textFields(c: Context): Promise<Record<string, string>> {
	const fields: Record<string, string> = {};
	for (const [name, value] of Object.entries(await c.req.parseBody())) {
		if (typeof value === "string") fields[name] = value;
	}
	return fields;
}

export function notice(error: string): Html | "" {
	return error && html`<p class="issues-error mono" role="alert">${error}</p>`;
}

/** An admin page: the site's own look, with the console's sections and sign-out on top. */
export function adminPage(c: Context, ctx: AdminContext, title: string, body: Html): string {
	const tab = ([href, name]: (typeof SECTIONS)[number]) =>
		html`<a href="${href}"${
			(
				c.req.path === "/admin"
					? (c.req.query("section") === "backups" ? "backups" : "overview") === name
					: c.req.path === "/admin/site"
						? (c.req.query("section") === "profile" ? "profile" : "site") === name
						: c.req.path === href || (href !== "/admin" && c.req.path.startsWith(`${href}/`))
			)
				? html` aria-current="page"`
				: ""
		}>${name}${
			name === "notifications" && unread > 0
				? html` <span class="admin-unread">${String(unread)}</span>`
				: ""
		}</a>`;
	const unread =
		ctx.kepr
			.query<{ n: number }, []>("SELECT COUNT(*) AS n FROM notifications WHERE read = 0")
			.get()?.n ?? 0;
	const handle = setting(ctx.kepr, "handle");
	return page(ctx, {
		title: `${title} · admin`,
		description: "",
		path: c.req.path,
		body: html`<div class="admin-layout">
<aside class="admin-sidebar mono">
<span class="section-label">workspace</span>
<nav aria-label="operator workspace">${SECTIONS.map(tab)}</nav>
<div class="admin-sidebar-foot">
${handle && html`<a href="/@${handle}">view profile ↗</a>`}
<a href="/">view site ↗</a>
<form class="nav-logout" method="post" action="/admin/sign-out">
${formField(c)}<button type="submit">log out</button>
</form></div></aside>
<section class="admin-content">
<header class="admin-heading"><span class="section-label mono">operator</span>
<h1>${title}</h1></header>
${c.req.query("saved") === "1" && html`<p class="admin-notice" role="status">Changes saved.</p>`}
${body}</section></div>`,
	});
}

// ponytail: counted once per process by walking the source, since there is no build step.
let runningLines: number | null = null;
async function sourceLines(): Promise<number> {
	if (runningLines !== null) return runningLines;
	let total = 0;
	const root = `${import.meta.dir}/../..`;
	for await (const path of new Bun.Glob("{src,scripts}/**/*.ts").scan(root)) {
		if (path.endsWith(".test.ts")) continue;
		const text = await Bun.file(`${root}/${path}`).text();
		total += text.split("\n").length - (text.endsWith("\n") ? 1 : 0);
	}
	runningLines = total;
	return total;
}

/** The last machines that redeemed a code, and how to take their access away again. */
function connectedMachines(ctx: AdminContext): Html | "" {
	const rows = ctx.kepr
		.query<{ machine: string; used_at: number }, [number]>(
			`SELECT machine, used_at FROM connect_codes
			 WHERE used_at IS NOT NULL
			 ORDER BY used_at DESC, rowid DESC
			 LIMIT ?`,
		)
		.all(MACHINES_LISTED);
	if (rows.length === 0) return "";
	const led = rows.map((row) => {
		const at = new Date(row.used_at * 1000).toISOString();
		return html`<li>${row.machine} <span class="muted">${at}</span></li>`;
	});
	return html`<h2>Machines connected</h2>
<ul>${led}</ul>
<p class="muted">To revoke access, rotate the bucket key in Scaleway and update it under <a href="/admin/bucket">bucket</a>.</p>`;
}

/**
 * The bucket as the sync last read it, and each repo's format and sync result: the sync checks the
 * format of every repo on every pass, so the console never waits on the bucket itself.
 */
function bucketStatus(ctx: AdminContext): Html {
	const error = setting(ctx.kepr, "bucket_error");
	if (error) {
		return html`<p class="issues-error" role="alert">Bucket unreachable at the last sync: ${error}</p>`;
	}
	const readAt = Number(setting(ctx.kepr, "bucket_read_at") ?? 0);
	if (readAt === 0) return html`<p class="muted">The sync has not read the bucket yet.</p>`;
	// The repos that listing found; Kepr keeps the rows of repos gone from the bucket.
	const seen = JSON.parse(setting(ctx.kepr, "bucket_repos") ?? "[]") as string[];
	const errors = new Map(allRepos(ctx.kepr).map((repo) => [repo.name, repo.last_sync_error]));
	return html`<p>Bucket read by the sync ${relativeTime(readAt)}: ${plural(seen.length, "repo")}.</p>
<ul>${seen.map((name) => {
		const failure = errors.get(name);
		return html`<li><span class="mono">${name}</span> ${
			failure
				? html`<span class="issues-error">${failure}</span>`
				: html`<span class="muted">format ok</span>`
		}</li>`;
	})}</ul>`;
}

/** §24's Status section at `/admin`: the bucket, each repo's format, backups, the running version. */
export function registerStatus(app: Hono, ctx: AdminContext): void {
	app.get("/admin", async (c) => {
		if (c.req.query("section") === "backups") return c.html(await backupsPage(c, ctx));
		const bucket = bucketStatus(ctx);
		const { version } = (await Bun.file(`${import.meta.dir}/../../package.json`).json()) as {
			version: string;
		};
		const lines = (await sourceLines()).toLocaleString("en-US");
		const newest = backups(ctx.dataDir).at(-1);
		const repos = allRepos(ctx.kepr);
		const open = operatorIssues(ctx.kepr, "open").length;
		const attention = repos.filter((repo) => repo.last_sync_error || repo.last_sync_at === null);
		const vital = (label: string, value: number, href: string) =>
			html`<a href="${href}"><strong>${value}</strong><span class="mono">${label}</span></a>`;
		const overview = html`<div class="admin-vitals">
${vital("repositories", repos.length, "/admin/repos")}
${vital("public", repos.filter((repo) => repo.public).length, "/browse")}
${vital("open issues", open, "/admin/issues")}
</div>
<section class="repo-section"><h2 class="section-label mono">needs attention</h2>
${attention.map(
	(repo) => html`<a class="issue-row" href="/admin/repos?repo=${repo.name}">
<span>${repo.name}</span><span class="issues-error">${repo.last_sync_error ?? "Not synced yet"}</span></a>`,
)}
${!newest && html`<p class="issues-error">No backup yet. Check the server log for backup errors.</p>`}
${!setting(ctx.kepr, "handle") && html`<p><a href="/admin/site?section=profile">Set your handle to publish your profile →</a></p>`}
${attention.length === 0 && newest && html`<p class="muted">All repositories are synced. A local backup is available.</p>`}
</section>
<section class="repo-section"><h2 class="section-label mono">repositories</h2>
${repos
	.slice()
	.sort((a, b) => (b.last_sync_at ?? 0) - (a.last_sync_at ?? 0))
	.slice(0, 8)
	.map(
		(repo) => html`
<a class="issue-row" href="/admin/repos?repo=${repo.name}"><span>${repo.name}</span>
<span class="issue-meta mono">${repo.public ? "public" : "private"} · ${repo.last_sync_at === null ? "never synced" : `synced ${relativeTime(repo.last_sync_at)}`}</span></a>`,
	)}
${repos.length === 0 && html`<p class="muted">No repositories yet. Offer one with Koh, then sync it here.</p>`}
</section>`;
		return c.html(
			adminPage(
				c,
				ctx,
				"overview",
				html`${overview}<section class="repo-section markdown">
<p><a href="/admin?section=backups">manage backups →</a></p>
<details><summary class="mono">bucket and runtime</summary>${bucket}
${connectKeys(ctx.config) ? connectedMachines(ctx) : ""}
<p>Running kepr ${version}: ${lines} lines of TypeScript.</p></details></section>`,
			),
		);
	});
}