const crypto = require('crypto');

function defaultDependencies() {
    return { Bonjour: require('bonjour-service'), castClient: require('chromecast-client') };
}

function firstAddress(service) {
    return (service.addresses || []).find(address => /^\d{1,3}(?:\.\d{1,3}){3}$/.test(address)) ||
        service.addresses?.[0] || service.referer?.address || service.host || null;
}

function normalizeDevice(service) {
    const txt = service.txt || {};
    const model = String(txt.md || txt.model || '').trim();
    const descriptor = `${model} ${service.name || ''}`.toLowerCase();
    const host = firstAddress(service);
    return {
        id: String(txt.id || service.fqdn || service.name || `${host}:${service.port || 8009}`),
        name: String(txt.fn || service.name || model || 'Google Cast device'),
        type: /android tv|google tv|chromecast built-in|bravia|shield/.test(descriptor) ? 'android_tv_cast' : 'google_cast',
        ready: Boolean(host),
        host,
        port: Number(service.port || 8009),
        model: model || null
    };
}

function unwrap(result, castClient) {
    if (result && typeof result.unwrapAndThrow === 'function') return result.unwrapAndThrow();
    if (castClient.Result?.unwrapAndThrow) return castClient.Result.unwrapAndThrow(result);
    if (result && result.isOk === false) throw result.value;
    if (result && result.isOk === true) return result.value;
    return result;
}

function createGoogleCastAdapter(options = {}) {
    let dependencies;
    try { dependencies = options.dependencies || defaultDependencies(); }
    catch (error) {
        return {
            async discover() { return []; },
            async startSession() {
                throw Object.assign(new Error(`Google Cast support is unavailable: ${error.message}`), { code: 'CAST_ADAPTER_UNAVAILABLE' });
            }
        };
    }

    const { Bonjour, castClient } = dependencies;
    const discoveryTimeoutMs = Number(options.discoveryTimeoutMs || 1500);
    const connectTimeoutMs = Number(options.connectTimeoutMs || 8000);
    const sessions = new Map();

    async function discover() {
        const bonjour = new Bonjour(undefined, () => {});
        const found = new Map();
        let browser;
        let timer;
        try {
            await new Promise(resolve => {
                timer = setTimeout(resolve, discoveryTimeoutMs);
                browser = bonjour.find({ type: 'googlecast', protocol: 'tcp' }, service => {
                    const device = normalizeDevice(service);
                    if (device.host) found.set(device.id, device);
                });
                browser?.on?.('error', resolve);
            });
            return [...found.values()].sort((left, right) => left.name.localeCompare(right.name));
        } catch (error) {
            throw Object.assign(new Error(`Google Cast discovery failed: ${error.message}`), { code: 'CAST_DISCOVERY_FAILED' });
        } finally {
            clearTimeout(timer);
            try { browser?.stop?.(); } catch { /* best effort */ }
            try { bonjour.destroy(); } catch { /* best effort */ }
        }
    }

    async function startSession({ device, mediaUrl, media = {} }) {
        if (!device?.host) throw Object.assign(new Error('Google Cast device has no reachable host'), { code: 'CAST_DEVICE_UNREACHABLE' });
        let client;
        let controller;
        try {
            client = await castClient.connect({ host: device.host, port: device.port || 8009, timeout: connectTimeoutMs });
            controller = unwrap(await castClient.DefaultMediaApp.launchAndJoin({ client }), castClient);
            const status = unwrap(await controller.load({
                media: {
                    contentId: mediaUrl,
                    contentType: media.contentType || 'application/vnd.apple.mpegurl',
                    streamType: media.streamType || 'LIVE',
                    metadata: media.metadata || { metadataType: 0, title: media.title || 'Nodecast TV' }
                },
                autoplay: media.autoplay !== false,
                currentTime: Number(media.currentTime || 0)
            }), castClient);
            const sessionId = crypto.randomUUID();
            sessions.set(sessionId, { client, controller, device });
            return { sessionId, state: String(status?.playerState || 'PLAYING').toLowerCase(), currentTime: Number(status?.currentTime || 0) };
        } catch (error) {
            try { controller?.dispose?.(); } catch { /* best effort */ }
            try { client?.close?.(); } catch { /* best effort */ }
            throw Object.assign(new Error(`Unable to start Google Cast playback: ${error.message}`), { code: 'CAST_START_FAILED' });
        }
    }

    async function command({ session, action, ...payload }) {
        const active = sessions.get(session.sessionId || session.id);
        if (!active) throw Object.assign(new Error('Google Cast connection is no longer active'), { code: 'CAST_SESSION_DISCONNECTED' });
        if (action === 'volume') throw Object.assign(new Error('Volume control is unavailable for this Cast adapter'), { code: 'CAST_CONTROL_UNAVAILABLE' });
        const method = active.controller[action];
        if (typeof method !== 'function') throw Object.assign(new Error(`Unsupported Cast command: ${action}`), { code: 'CAST_CONTROL_UNAVAILABLE' });
        const argument = action === 'seek'
            ? (payload.currentTime !== undefined ? { currentTime: Number(payload.currentTime) } : { relativeTime: Number(payload.relativeTime || 0) })
            : undefined;
        const status = unwrap(await (argument ? method(argument) : method()), castClient);
        return { state: String(status?.playerState || action).toLowerCase(), currentTime: Number(status?.currentTime || 0) };
    }

    async function stopSession(session) {
        const id = session.sessionId || session.id;
        const active = sessions.get(id);
        if (!active) return;
        try { unwrap(await active.controller.stop(), castClient); } finally {
            try { active.controller.dispose?.(); } catch { /* best effort */ }
            try { active.client.close?.(); } catch { /* best effort */ }
            sessions.delete(id);
        }
    }

    return { command, discover, startSession, stopSession };
}

module.exports = { createGoogleCastAdapter, normalizeDevice };