import { Hono } from 'hono';
import { stream } from 'hono/streaming';
import { getDb } from '../db/index';
import { execStream } from '../services/ssh';
import type { Job, Node, MediaItem, MediaStream } from '../types';
import { predictExtractedFiles } from '../services/ffmpeg';
import { accessSync, constants } from 'node:fs';

const app = new Hono();

// ─── SSE state ────────────────────────────────────────────────────────────────

const jobListeners = new Set<(data: string) => void>();

function emitJobUpdate(jobId: number, status: string, output?: string): void {
	const line = `event: job_update\ndata: ${JSON.stringify({ id: jobId, status, output })}\n\n`;
	for (const l of jobListeners) l(line);
}

function loadJobRow(jobId: number) {
	const db = getDb();
	const row = db.prepare(`
		SELECT j.*, mi.id as mi_id, mi.name, mi.type, mi.series_name, mi.season_number,
		       mi.episode_number, mi.file_path,
		       n.id as n_id, n.name as node_name, n.host, n.port, n.username,
		       n.private_key, n.ffmpeg_path, n.work_dir, n.status as node_status
		FROM jobs j
		LEFT JOIN media_items mi ON mi.id = j.item_id
		LEFT JOIN nodes n ON n.id = j.node_id
		WHERE j.id = ?
	`).get(jobId) as (Job & {
		mi_id: number | null; name: string | null; type: string | null;
		series_name: string | null; season_number: number | null; episode_number: number | null;
		file_path: string | null; n_id: number | null; node_name: string | null;
		host: string | null; port: number | null; username: string | null;
		private_key: string | null; ffmpeg_path: string | null; work_dir: string | null; node_status: string | null;
	}) | undefined;

	if (!row) return null;

	const nodes = db.prepare('SELECT * FROM nodes ORDER BY name').all() as Node[];
	const item = row.name ? { id: row.item_id, name: row.name, type: row.type, series_name: row.series_name, season_number: row.season_number, episode_number: row.episode_number, file_path: row.file_path } as unknown as MediaItem : null;
	const node = row.node_name ? { id: row.node_id!, name: row.node_name, host: row.host!, port: row.port!, username: row.username!, private_key: row.private_key!, ffmpeg_path: row.ffmpeg_path!, work_dir: row.work_dir!, status: row.node_status! } as unknown as Node : null;

	return { job: row as unknown as Job, item, node, nodes };
}

// ─── List ─────────────────────────────────────────────────────────────────────

app.get('/', (c) => {
	const db = getDb();
	const jobRows = db.prepare(`
		SELECT j.*, mi.name, mi.type, mi.series_name, mi.season_number, mi.episode_number, mi.file_path,
		       n.name as node_name, n.host, n.port, n.username, n.private_key, n.ffmpeg_path, n.work_dir, n.status as node_status
		FROM jobs j
		LEFT JOIN media_items mi ON mi.id = j.item_id
		LEFT JOIN nodes n ON n.id = j.node_id
		ORDER BY j.created_at DESC LIMIT 200
	`).all() as (Job & { name: string; type: string; series_name: string | null; season_number: number | null; episode_number: number | null; file_path: string; node_name: string | null; host: string | null; port: number | null; username: string | null; private_key: string | null; ffmpeg_path: string | null; work_dir: string | null; node_status: string | null; })[];

	const jobs = jobRows.map((r) => ({
		job: r as unknown as Job,
		item: r.name ? { id: r.item_id, name: r.name, type: r.type, series_name: r.series_name, season_number: r.season_number, episode_number: r.episode_number, file_path: r.file_path } as unknown as MediaItem : null,
		node: r.node_name ? { id: r.node_id!, name: r.node_name, host: r.host!, port: r.port!, username: r.username!, private_key: r.private_key!, ffmpeg_path: r.ffmpeg_path!, work_dir: r.work_dir!, status: r.node_status! } as unknown as Node : null,
	}));

	const nodes = db.prepare('SELECT * FROM nodes ORDER BY name').all() as Node[];
	return c.json({ jobs, nodes });
});

// ─── Start all pending ────────────────────────────────────────────────────────

app.post('/start', (c) => {
	const db = getDb();
	const pending = db.prepare("SELECT * FROM jobs WHERE status = 'pending' ORDER BY created_at").all() as Job[];
	for (const job of pending) runJob(job).catch((err) => console.error(`Job ${job.id} failed:`, err));
	return c.json({ ok: true, started: pending.length });
});

// ─── Assign node ──────────────────────────────────────────────────────────────

app.post('/job/:id/assign', async (c) => {
	const db = getDb();
	const jobId = Number(c.req.param('id'));
	const body = await c.req.json<{ node_id: number | null }>();
	db.prepare('UPDATE jobs SET node_id = ? WHERE id = ?').run(body.node_id, jobId);
	const result = loadJobRow(jobId);
	if (!result) return c.notFound();
	return c.json(result);
});

// ─── Run single ───────────────────────────────────────────────────────────────

app.post('/job/:id/run', async (c) => {
	const db = getDb();
	const jobId = Number(c.req.param('id'));
	const job = db.prepare('SELECT * FROM jobs WHERE id = ?').get(jobId) as Job | undefined;
	if (!job || job.status !== 'pending') {
		const result = loadJobRow(jobId);
		if (!result) return c.notFound();
		return c.json(result);
	}
	runJob(job).catch((err) => console.error(`Job ${job.id} failed:`, err));
	const result = loadJobRow(jobId);
	if (!result) return c.notFound();
	return c.json(result);
});

// ─── Cancel ───────────────────────────────────────────────────────────────────

app.post('/job/:id/cancel', (c) => {
	const db = getDb();
	const jobId = Number(c.req.param('id'));
	db.prepare("DELETE FROM jobs WHERE id = ? AND status = 'pending'").run(jobId);
	return c.json({ ok: true });
});

// ─── SSE ──────────────────────────────────────────────────────────────────────

app.get('/events', (c) => {
	return stream(c, async (s) => {
		c.header('Content-Type', 'text/event-stream');
		c.header('Cache-Control', 'no-cache');

		const queue: string[] = [];
		let resolve: (() => void) | null = null;
		const listener = (data: string) => { queue.push(data); resolve?.(); };

		jobListeners.add(listener);
		s.onAbort(() => { jobListeners.delete(listener); });

		try {
			while (!s.closed) {
				if (queue.length > 0) {
					await s.write(queue.shift()!);
				} else {
					await new Promise<void>((res) => { resolve = res; setTimeout(res, 15_000); });
					resolve = null;
					if (queue.length === 0) await s.write(': keepalive\n\n');
				}
			}
		} finally {
			jobListeners.delete(listener);
		}
	});
});

// ─── Job execution ────────────────────────────────────────────────────────────

async function runJob(job: Job): Promise<void> {
	const db = getDb();

	if (!job.node_id) {
		const itemRow = db.prepare('SELECT file_path FROM media_items WHERE id = ?').get(job.item_id) as { file_path: string } | undefined;
		if (itemRow?.file_path) {
			try { accessSync(itemRow.file_path, constants.R_OK | constants.W_OK); } catch (fsErr) {
				const msg = `File not accessible: ${itemRow.file_path}\n${(fsErr as Error).message}`;
				db.prepare("UPDATE jobs SET status = 'error', output = ?, exit_code = 1, completed_at = datetime('now') WHERE id = ?").run(msg, job.id);
				emitJobUpdate(job.id, 'error', msg);
				db.prepare("UPDATE review_plans SET status = 'error' WHERE item_id = ?").run(job.item_id);
				return;
			}
		}
	}

	db.prepare("UPDATE jobs SET status = 'running', started_at = datetime('now'), output = '' WHERE id = ?").run(job.id);
	emitJobUpdate(job.id, 'running');

	let outputLines: string[] = [];
	const flush = (final = false) => {
		const text = outputLines.join('\n');
		if (final || outputLines.length % 10 === 0) db.prepare('UPDATE jobs SET output = ? WHERE id = ?').run(text, job.id);
		emitJobUpdate(job.id, 'running', text);
	};

	try {
		if (job.node_id) {
			const node = db.prepare('SELECT * FROM nodes WHERE id = ?').get(job.node_id) as Node | undefined;
			if (!node) throw new Error(`Node ${job.node_id} not found`);
			for await (const line of execStream(node, job.command)) { outputLines.push(line); flush(); }
		} else {
			const proc = Bun.spawn(['sh', '-c', job.command], { stdout: 'pipe', stderr: 'pipe' });
			const readStream = async (readable: ReadableStream<Uint8Array>, prefix = '') => {
				const reader = readable.getReader();
				const decoder = new TextDecoder();
				try {
					while (true) {
						const { done, value } = await reader.read();
						if (done) break;
						const text = decoder.decode(value);
						const lines = text.split('\n').filter((l) => l.trim());
						for (const line of lines) outputLines.push(prefix + line);
						flush();
					}
				} catch { /* ignore */ }
			};
			await Promise.all([readStream(proc.stdout), readStream(proc.stderr, '[stderr] '), proc.exited]);
			const exitCode = await proc.exited;
			if (exitCode !== 0) throw new Error(`FFmpeg exited with code ${exitCode}`);
		}

		const fullOutput = outputLines.join('\n');
		db.prepare("UPDATE jobs SET status = 'done', exit_code = 0, output = ?, completed_at = datetime('now') WHERE id = ?").run(fullOutput, job.id);
		emitJobUpdate(job.id, 'done', fullOutput);
		db.prepare("UPDATE review_plans SET status = 'done' WHERE item_id = ?").run(job.item_id);

		// Populate subtitle_files table with extracted sidecar files
		try {
			const item = db.prepare('SELECT * FROM media_items WHERE id = ?').get(job.item_id) as MediaItem | undefined;
			const streams = db.prepare('SELECT * FROM media_streams WHERE item_id = ?').all(job.item_id) as MediaStream[];
			if (item && streams.length > 0) {
				const files = predictExtractedFiles(item, streams);
				const insertFile = db.prepare('INSERT OR IGNORE INTO subtitle_files (item_id, file_path, language, codec, is_forced, is_hearing_impaired) VALUES (?, ?, ?, ?, ?, ?)');
				for (const f of files) {
					insertFile.run(job.item_id, f.file_path, f.language, f.codec, f.is_forced ? 1 : 0, f.is_hearing_impaired ? 1 : 0);
				}
				db.prepare('UPDATE review_plans SET subs_extracted = 1 WHERE item_id = ?').run(job.item_id);
			}
		} catch (subErr) { console.error('Failed to record extracted subtitle files:', subErr); }
	} catch (err) {
		const fullOutput = outputLines.join('\n') + '\n' + String(err);
		db.prepare("UPDATE jobs SET status = 'error', exit_code = 1, output = ?, completed_at = datetime('now') WHERE id = ?").run(fullOutput, job.id);
		emitJobUpdate(job.id, 'error', fullOutput);
		db.prepare("UPDATE review_plans SET status = 'error' WHERE item_id = ?").run(job.item_id);
	}
}

export default app;