import { Database } from "bun:sqlite";
import { mkdirSync } from "node:fs";
import { join } from "node:path";
import { DEFAULT_CONFIG, SCHEMA } from "./schema";

const dataDir = process.env.DATA_DIR ?? "./data";
mkdirSync(dataDir, { recursive: true });

const isDev = process.env.NODE_ENV === "development";
const dbPath = join(dataDir, isDev ? "netfelix-dev.db" : "netfelix.db");

// ─── Env-var → config key mapping ─────────────────────────────────────────────

const ENV_MAP: Record<string, string> = {
	jellyfin_url: "JELLYFIN_URL",
	jellyfin_api_key: "JELLYFIN_API_KEY",
	jellyfin_user_id: "JELLYFIN_USER_ID",
	radarr_url: "RADARR_URL",
	radarr_api_key: "RADARR_API_KEY",
	radarr_enabled: "RADARR_ENABLED",
	sonarr_url: "SONARR_URL",
	sonarr_api_key: "SONARR_API_KEY",
	sonarr_enabled: "SONARR_ENABLED",
	audio_languages: "AUDIO_LANGUAGES",
	mqtt_enabled: "MQTT_ENABLED",
	mqtt_url: "MQTT_URL",
	mqtt_topic: "MQTT_TOPIC",
	mqtt_username: "MQTT_USERNAME",
	mqtt_password: "MQTT_PASSWORD",
};

/** Read a config key from environment variables (returns null if not set). */
function envValue(key: string): string | null {
	const envKey = ENV_MAP[key];
	if (!envKey) return null;
	const val = process.env[envKey];
	if (!val) return null;
	if (key.endsWith("_enabled")) return val === "1" || val.toLowerCase() === "true" ? "1" : "0";
	if (key === "audio_languages") return JSON.stringify(val.split(",").map((s) => s.trim()));
	if (key.endsWith("_url")) return val.replace(/\/$/, "");
	return val;
}

/** True when minimum required Jellyfin env vars are present — skips the setup wizard. */
function isEnvConfigured(): boolean {
	return !!(process.env.JELLYFIN_URL && process.env.JELLYFIN_API_KEY);
}

// ─── Database ──────────────────────────────────────────────────────────────────

let _db: Database | null = null;

export function getDb(): Database {
	if (_db) return _db;
	_db = new Database(dbPath, { create: true });
	_db.exec(SCHEMA);
	migrate(_db);
	seedDefaults(_db);
	return _db;
}

/**
 * Idempotent ALTER TABLE migrations for columns added after the initial
 * CREATE TABLE ships. Each block swallows "duplicate column" errors so the
 * same code path is safe on fresh and existing databases. Do not remove old
 * migrations — databases in the wild may be several versions behind.
 */
function migrate(db: Database): void {
	const alter = (sql: string) => {
		try {
			db.exec(sql);
		} catch (_err) {
			// column already present — ignore
		}
	};
	alter("ALTER TABLE review_plans ADD COLUMN webhook_verified INTEGER NOT NULL DEFAULT 0");
	// 2026-04-14: renamed webhook_verified → verified once we realized the
	// signal would come from our own ffprobe, not from a Jellyfin webhook.
	// RENAME COLUMN preserves values; both alters are no-ops on fresh DBs.
	alter("ALTER TABLE review_plans RENAME COLUMN webhook_verified TO verified");
	alter("ALTER TABLE review_plans DROP COLUMN verified");
	alter("ALTER TABLE media_items ADD COLUMN ingest_source TEXT NOT NULL DEFAULT 'scan'");
}

function seedDefaults(db: Database): void {
	const insert = db.prepare("INSERT OR IGNORE INTO config (key, value) VALUES (?, ?)");
	for (const [key, value] of Object.entries(DEFAULT_CONFIG)) {
		insert.run(key, value);
	}
}

/** Re-seed config defaults after a truncating reset. Caller owns the delete. */
export function reseedDefaults(): void {
	seedDefaults(getDb());
}

export function getConfig(key: string): string | null {
	// Env vars take precedence over DB
	const fromEnv = envValue(key);
	if (fromEnv !== null) return fromEnv;
	// Auto-complete setup when all required Jellyfin env vars are present
	if (key === "setup_complete" && isEnvConfigured()) return "1";
	const row = getDb().prepare("SELECT value FROM config WHERE key = ?").get(key) as { value: string } | undefined;
	return row?.value ?? null;
}

export function setConfig(key: string, value: string): void {
	getDb().prepare("INSERT OR REPLACE INTO config (key, value) VALUES (?, ?)").run(key, value);
}

/** Returns the set of config keys currently overridden by environment variables. */
export function getEnvLockedKeys(): Set<string> {
	const locked = new Set<string>();
	for (const key of Object.keys(ENV_MAP)) {
		if (envValue(key) !== null) locked.add(key);
	}
	return locked;
}

export function getAllConfig(): Record<string, string> {
	const rows = getDb().prepare("SELECT key, value FROM config").all() as { key: string; value: string }[];
	const result = Object.fromEntries(rows.map((r) => [r.key, r.value ?? ""]));
	// Apply env overrides on top of DB values
	for (const key of Object.keys(ENV_MAP)) {
		const fromEnv = envValue(key);
		if (fromEnv !== null) result[key] = fromEnv;
	}
	// Auto-complete setup when all required Jellyfin env vars are present
	if (isEnvConfigured()) result.setup_complete = "1";
	return result;
}