const express = require('express');
const { requireAuth, requireAdmin } = require('../auth');
const liveProjection = require('../services/liveProjectionService');
const iptvOrgCatalog = require('../services/iptvOrgCatalogService');
const { getDb } = require('../db/sqlite');
const { sources } = require('../db');

const router = express.Router();

function serializeState(state) {
    const emptyProjectionWithLiveInput = state.total_count > 0 && state.projected_count === 0;
    return {
        status: state.status,
        stale: state.status !== 'success' || emptyProjectionWithLiveInput,
        startedAt: state.started_at,
        completedAt: state.completed_at,
        inputHash: state.input_hash,
        projectedCount: state.projected_count,
        phase: state.phase,
        processed: state.processed_count,
        total: state.total_count,
        layaProcessed: state.laya_processed_count,
        layaTotal: state.laya_total_count,
        error: state.error
    };
}

router.get('/channels', requireAuth, async (req, res) => {
    const sourceId = req.query.sourceId === undefined ? null : Number(req.query.sourceId);
    if (sourceId !== null && (!Number.isInteger(sourceId) || sourceId <= 0)) {
        return res.status(400).json({ error: 'sourceId must be a positive integer' });
    }
    if (req.query.includeHidden !== undefined && !['true', 'false'].includes(req.query.includeHidden)) {
        return res.status(400).json({ error: 'includeHidden must be true or false' });
    }
    const includeHidden = req.query.includeHidden === 'true';
    const q = String(req.query.q || '').slice(0, 200);
    const languages = String(req.query.languages || '').split(',').map(value => value.trim().toLowerCase()).filter(Boolean);
    if (languages.some(code => !/^(?:[a-z]{2,3}|und)$/.test(code))) {
        return res.status(400).json({ error: 'languages must be comma-separated language codes' });
    }

    try {
        let state = liveProjection.projectionState();
        if (state.status !== 'success' && state.status !== 'building') {
            state = await liveProjection.startRebuild(null, { mode: 'algo' }).promise;
        }
        const epgSources = await sources.getByType('epg');
        const { channels, availableLanguages } = liveProjection.getChannelPage({
            sourceId, includeHidden, userId: req.user.id, epgSources, q, languages
        });
        return res.json({ projection: serializeState(state), filters: { availableLanguages }, channels });
    } catch (error) {
        console.error('[LiveProjection] Failed to serve projected channels:', error.message);
        const state = liveProjection.projectionState();
        return res.status(503).json({
            projection: serializeState(state),
            channels: [],
            error: 'Live channel projection is unavailable'
        });
    }
});

router.get('/projection/status', requireAuth, (req, res) => {
    try {
        return res.json(serializeState(liveProjection.projectionState()));
    } catch (error) {
        return res.status(500).json({ error: 'Unable to read Live projection status' });
    }
});

router.post('/projection/rebuild', requireAuth, requireAdmin, (req, res) => {
    try {
        const started = liveProjection.startRebuild();
        started.promise.catch(error => {
            console.error('[LiveProjection] Manual rebuild failed:', error.message);
        });
        return res.status(202).json({
            alreadyRunning: started.alreadyRunning,
            projection: serializeState(started.state)
        });
    } catch (error) {
        console.error('[LiveProjection] Unable to start manual rebuild:', error.message);
        return res.status(500).json({ error: 'Unable to start Live projection rebuild' });
    }
});

router.post('/projection/standards/refresh', requireAuth, requireAdmin, async (req, res) => {
    try {
        const result = await iptvOrgCatalog.refresh(getDb());
        await liveProjection.queueRebuild();
        return res.json(result);
    } catch (error) {
        console.error('[LiveProjection] iptv-org refresh failed:', error.message);
        return res.status(502).json({ error: 'Unable to refresh the iptv-org catalog' });
    }
});

module.exports = router;
module.exports.serializeState = serializeState;