import { accessSync, constants } from "node:fs";
import { Hono } from "hono";
import { stream } from "hono/streaming";
import { getAllConfig, getDb } from "../db/index";
import { log, error as logError, warn } from "../lib/log";
import { predictExtractedFiles } from "../services/ffmpeg";
import { getItem, refreshItem } from "../services/jellyfin";
import { loadLibrary as loadRadarrLibrary, isUsable as radarrUsable } from "../services/radarr";
import { upsertJellyfinItem } from "../services/rescan";
import {
	getScheduleConfig,
	isInProcessWindow,
	msUntilProcessWindow,
	nextProcessWindowTime,
	sleepBetweenJobs,
	waitForProcessWindow,
} from "../services/scheduler";
import { loadLibrary as loadSonarrLibrary, isUsable as sonarrUsable } from "../services/sonarr";
import { verifyDesiredState } from "../services/verify";
import type { Job, MediaItem, MediaStream } from "../types";

function parseLanguageList(raw: string | null | undefined, fallback: string[]): string[] {
	if (!raw) return fallback;
	try {
		const parsed = JSON.parse(raw);
		return Array.isArray(parsed) ? parsed.filter((v): v is string => typeof v === "string") : fallback;
	} catch {
		return fallback;
	}
}

/**
 * After a job finishes successfully, ask Jellyfin to re-scan the file,
 * fetch the fresh item, and upsert it — including running analyzeItem so the
 * review plan reflects whether the file is now fully conformant. If is_noop
 * is true on the refreshed streams, the plan lands in `done`; otherwise it
 * flips back to `pending` so the user sees what still needs attention.
 */
async function refreshItemFromJellyfin(itemId: number): Promise<void> {
	const db = getDb();
	const row = db.prepare("SELECT jellyfin_id FROM media_items WHERE id = ?").get(itemId) as
		| { jellyfin_id: string }
		| undefined;
	if (!row) return;

	const cfg = getAllConfig();
	const jellyfinCfg = { url: cfg.jellyfin_url, apiKey: cfg.jellyfin_api_key, userId: cfg.jellyfin_user_id };
	if (!jellyfinCfg.url || !jellyfinCfg.apiKey) return;

	try {
		await refreshItem(jellyfinCfg, row.jellyfin_id);
	} catch (err) {
		warn(`Jellyfin refresh for item ${itemId} failed: ${String(err)}`);
	}

	const fresh = await getItem(jellyfinCfg, row.jellyfin_id);
	if (!fresh) {
		warn(`Jellyfin returned no item for ${row.jellyfin_id} after refresh`);
		return;
	}

	const radarrCfg = { url: cfg.radarr_url, apiKey: cfg.radarr_api_key };
	const sonarrCfg = { url: cfg.sonarr_url, apiKey: cfg.sonarr_api_key };
	const radarrEnabled = cfg.radarr_enabled === "1" && radarrUsable(radarrCfg);
	const sonarrEnabled = cfg.sonarr_enabled === "1" && sonarrUsable(sonarrCfg);
	const [radarrLibrary, sonarrLibrary] = await Promise.all([
		radarrEnabled ? loadRadarrLibrary(radarrCfg) : Promise.resolve(null),
		sonarrEnabled ? loadSonarrLibrary(sonarrCfg) : Promise.resolve(null),
	]);

	await upsertJellyfinItem(
		db,
		fresh,
		{
			audioLanguages: parseLanguageList(cfg.audio_languages, []),
			radarr: radarrEnabled ? radarrCfg : null,
			sonarr: sonarrEnabled ? sonarrCfg : null,
			radarrLibrary,
			sonarrLibrary,
		},
		{ executed: true },
	);
}

const app = new Hono();

// ─── Sequential local queue ──────────────────────────────────────────────────

let queueRunning = false;
let runningProc: ReturnType<typeof Bun.spawn> | null = null;
let runningJobId: number | null = null;

function emitQueueStatus(
	status: "running" | "paused" | "sleeping" | "idle",
	extra: { until?: string; seconds?: number } = {},
): void {
	const line = `event: queue_status\ndata: ${JSON.stringify({ status, ...extra })}\n\n`;
	for (const l of jobListeners) l(line);
}

async function runSequential(jobs: Job[]): Promise<void> {
	if (queueRunning) return;
	queueRunning = true;
	try {
		let first = true;
		for (const job of jobs) {
			// Pause outside the processing window
			if (!isInProcessWindow()) {
				emitQueueStatus("paused", {
					until: nextProcessWindowTime(),
					seconds: Math.round(msUntilProcessWindow() / 1000),
				});
				await waitForProcessWindow();
			}

			// Sleep between jobs (but not before the first one)
			if (!first) {
				const cfg = getScheduleConfig();
				if (cfg.job_sleep_seconds > 0) {
					emitQueueStatus("sleeping", { seconds: cfg.job_sleep_seconds });
					await sleepBetweenJobs();
				}
			}
			first = false;

			// Atomic claim: only pick up jobs still pending
			const db = getDb();
			const claimed = db
				.prepare(
					"UPDATE jobs SET status = 'running', started_at = datetime('now'), output = '' WHERE id = ? AND status = 'pending'",
				)
				.run(job.id);
			if (claimed.changes === 0) continue; // cancelled or already running
			emitQueueStatus("running");
			try {
				await runJob(job);
			} catch (err) {
				logError(`Job ${job.id} failed:`, err);
			}
		}
	} finally {
		queueRunning = false;
		emitQueueStatus("idle");
	}
}

// ─── 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 emitJobProgress(jobId: number, seconds: number, total: number): void {
	const line = `event: job_progress\ndata: ${JSON.stringify({ id: jobId, seconds, total })}\n\n`;
	for (const l of jobListeners) l(line);
}

/** Parse "Duration: HH:MM:SS.MS" from ffmpeg startup output. */
function parseFFmpegDuration(line: string): number | null {
	const match = line.match(/Duration:\s*(\d+):(\d+):(\d+)\.(\d+)/);
	if (!match) return null;
	const [, h, m, s] = match.map(Number);
	return h * 3600 + m * 60 + s;
}

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
		FROM jobs j
		LEFT JOIN media_items mi ON mi.id = j.item_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;
		  })
		| undefined;

	if (!row) return null;

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

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

app.get("/", (c) => {
	const db = getDb();
	const filter = (c.req.query("filter") ?? "pending") as "all" | "pending" | "running" | "done" | "error";

	const validFilters = ["all", "pending", "running", "done", "error"];
	const whereClause = validFilters.includes(filter) && filter !== "all" ? `WHERE j.status = ?` : "";
	const params = whereClause ? [filter] : [];

	const jobRows = db
		.prepare(`
		SELECT j.*, mi.name, mi.type, mi.series_name, mi.season_number, mi.episode_number, mi.file_path
		FROM jobs j
		LEFT JOIN media_items mi ON mi.id = j.item_id
		${whereClause}
		ORDER BY j.created_at DESC
		LIMIT 200
	`)
		.all(...params) as (Job & {
		name: string;
		type: string;
		series_name: string | null;
		season_number: number | null;
		episode_number: number | null;
		file_path: string;
	})[];

	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,
	}));

	const countRows = db.prepare("SELECT status, COUNT(*) as cnt FROM jobs GROUP BY status").all() as {
		status: string;
		cnt: number;
	}[];
	const totalCounts: Record<string, number> = { all: 0, pending: 0, running: 0, done: 0, error: 0 };
	for (const row of countRows) {
		totalCounts[row.status] = row.cnt;
		totalCounts.all += row.cnt;
	}

	return c.json({ jobs, filter, totalCounts });
});

// ─── Param helpers ────────────────────────────────────────────────────────────

function parseId(raw: string | undefined): number | null {
	if (!raw) return null;
	const n = Number.parseInt(raw, 10);
	return Number.isFinite(n) && n > 0 ? n : null;
}

// ─── 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[];
	runSequential(pending).catch((err) => logError("Queue failed:", err));
	return c.json({ ok: true, started: pending.length });
});

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

app.post("/job/:id/run", async (c) => {
	const jobId = parseId(c.req.param("id"));
	if (jobId == null) return c.json({ error: "invalid job id" }, 400);
	const db = getDb();
	const job = db.prepare("SELECT * FROM jobs WHERE id = ?").get(jobId) as Job | undefined;
	if (!job) return c.notFound();
	if (job.status !== "pending") {
		const result = loadJobRow(jobId);
		if (!result) return c.notFound();
		return c.json(result);
	}
	runSequential([job]).catch((err) => logError(`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 jobId = parseId(c.req.param("id"));
	if (jobId == null) return c.json({ error: "invalid job id" }, 400);
	const db = getDb();
	db.prepare("DELETE FROM jobs WHERE id = ? AND status = 'pending'").run(jobId);
	return c.json({ ok: true });
});

// ─── Clear queue ──────────────────────────────────────────────────────────────

app.post("/clear", (c) => {
	const db = getDb();
	db
		.prepare(`
		UPDATE review_plans SET status = 'pending', reviewed_at = NULL
		WHERE item_id IN (SELECT item_id FROM jobs WHERE status = 'pending')
		AND status = 'approved'
	`)
		.run();
	const result = db.prepare("DELETE FROM jobs WHERE status = 'pending'").run();
	return c.json({ ok: true, cleared: result.changes });
});

app.post("/clear-completed", (c) => {
	const db = getDb();
	const result = db.prepare("DELETE FROM jobs WHERE status IN ('done', 'error')").run();
	return c.json({ ok: true, cleared: result.changes });
});

// ─── Stop running job ─────────────────────────────────────────────────────────

app.post("/stop", (c) => {
	if (!runningProc || runningJobId == null) {
		return c.json({ ok: false, error: "No job is currently running" }, 409);
	}
	const stoppedId = runningJobId;
	try {
		runningProc.kill("SIGTERM");
	} catch (err) {
		logError(`Failed to kill job ${stoppedId}:`, err);
		return c.json({ ok: false, error: String(err) }, 500);
	}
	// runJob's catch path will mark the job error and clean up runningProc.
	return c.json({ ok: true, stopped: stoppedId });
});

// ─── 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> {
	log(`Job ${job.id} starting (item=${job.item_id})`);
	log(`Job ${job.id} command: ${job.command}`);
	const db = getDb();

	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;
		}

		// Preflight: if the file already matches the plan, skip ffmpeg. Cheap
		// guard against re-running a stream-index-based command against a file
		// that's already been processed — which would either error out or
		// silently corrupt the file.
		try {
			const verify = await verifyDesiredState(db, job.item_id, itemRow.file_path);
			if (verify.matches) {
				const msg = `Preflight check: ${verify.reason}\nSkipping FFmpeg — no work needed.`;
				log(`Job ${job.id} ${msg.replace(/\n/g, " ")}`);
				db.transaction(() => {
					db
						.prepare(
							"UPDATE jobs SET status = 'done', exit_code = 0, output = ?, completed_at = datetime('now') WHERE id = ?",
						)
						.run(msg, job.id);
					db.prepare("UPDATE review_plans SET status = 'done' WHERE item_id = ?").run(job.item_id);
				})();
				emitJobUpdate(job.id, "done", msg);
				return;
			}
			log(`Job ${job.id} preflight: ${verify.reason} — running FFmpeg`);
		} catch (err) {
			warn(`Job ${job.id} preflight check errored: ${String(err)} — proceeding with FFmpeg`);
		}
	}

	emitJobUpdate(job.id, "running");

	const outputLines: string[] = [];
	let pendingFlush = false;
	let lastFlushAt = 0;
	let totalSeconds = 0;
	let lastProgressEmit = 0;
	const updateOutput = db.prepare("UPDATE jobs SET output = ? WHERE id = ?");

	const flush = (final = false) => {
		const text = outputLines.join("\n");
		const now = Date.now();
		if (final || now - lastFlushAt > 500) {
			updateOutput.run(text, job.id);
			lastFlushAt = now;
			pendingFlush = false;
		} else {
			pendingFlush = true;
		}
		emitJobUpdate(job.id, "running", text);
	};

	const consumeProgress = (line: string) => {
		if (totalSeconds === 0) {
			const d = parseFFmpegDuration(line);
			if (d != null) totalSeconds = d;
		}
		const progressed = parseFFmpegProgress(line);
		if (progressed != null && totalSeconds > 0) {
			const now = Date.now();
			if (now - lastProgressEmit > 500) {
				emitJobProgress(job.id, progressed, totalSeconds);
				lastProgressEmit = now;
			}
		}
	};

	try {
		const proc = Bun.spawn(["sh", "-c", job.command], { stdout: "pipe", stderr: "pipe" });
		runningProc = proc;
		runningJobId = job.id;
		const readStream = async (readable: ReadableStream<Uint8Array>, prefix = "") => {
			const reader = readable.getReader();
			const decoder = new TextDecoder();
			let buffer = "";
			try {
				while (true) {
					const { done, value } = await reader.read();
					if (done) break;
					buffer += decoder.decode(value, { stream: true });
					const parts = buffer.split(/\r\n|\n|\r/);
					buffer = parts.pop() ?? "";
					for (const line of parts) {
						if (!line.trim()) continue;
						outputLines.push(prefix + line);
						consumeProgress(line);
					}
					flush();
				}
				if (buffer.trim()) {
					outputLines.push(prefix + buffer);
					consumeProgress(buffer);
				}
			} catch (err) {
				logError(`stream read error (${prefix.trim() || "stdout"}):`, err);
			}
		};
		await Promise.all([readStream(proc.stdout), readStream(proc.stderr, "[stderr] "), proc.exited]);
		const exitCode = await proc.exited;
		if (pendingFlush) updateOutput.run(outputLines.join("\n"), job.id);
		if (exitCode !== 0) throw new Error(`FFmpeg exited with code ${exitCode}`);

		const fullOutput = outputLines.join("\n");

		// Gather sidecar files to record
		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[];
		const files = item && streams.length > 0 ? 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 (?, ?, ?, ?, ?, ?)",
		);
		const markJobDone = db.prepare(
			"UPDATE jobs SET status = 'done', exit_code = 0, output = ?, completed_at = datetime('now') WHERE id = ?",
		);
		const markPlanDone = db.prepare("UPDATE review_plans SET status = 'done' WHERE item_id = ?");
		const markSubsExtracted = db.prepare("UPDATE review_plans SET subs_extracted = 1 WHERE item_id = ?");

		db.transaction(() => {
			markJobDone.run(fullOutput, job.id);
			markPlanDone.run(job.item_id);
			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);
			}
			if (files.length > 0) markSubsExtracted.run(job.item_id);
		})();

		log(`Job ${job.id} completed successfully`);
		emitJobUpdate(job.id, "done", fullOutput);

		// Ask Jellyfin to rescan the file and pull the fresh metadata so our DB
		// reflects what actually ended up on disk. If the refreshed streams still
		// don't satisfy is_noop (e.g. a codec didn't transcode as planned), the
		// plan flips back to 'pending' in the same upsert and the UI shows it.
		try {
			await refreshItemFromJellyfin(job.item_id);
		} catch (refreshErr) {
			warn(`Post-job refresh for item ${job.item_id} failed: ${String(refreshErr)}`);
		}
	} catch (err) {
		logError(`Job ${job.id} failed:`, err);
		const fullOutput = `${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);
	} finally {
		runningProc = null;
		runningJobId = null;
	}
}

// Scheduler endpoints live on /api/settings/schedule now — see server/api/settings.ts.

// ─── FFmpeg progress parsing ───────────────────────────────────────────────────

/** Parse FFmpeg stderr line for progress. Returns seconds processed or null. */
export function parseFFmpegProgress(line: string): number | null {
	const match = line.match(/time=(\d+):(\d+):(\d+)\.(\d+)/);
	if (!match) return null;
	const [, h, m, s] = match.map(Number);
	return h * 3600 + m * 60 + s;
}

export default app;