import { join } from 'path';
import { unlink, writeFile, mkdir, rm } from 'fs/promises';
import { tmpdir } from 'os';
import { query } from '../db/client.js';
import { downloadFromS3, uploadToS3 } from '../s3/client.js';
import { trimSegment, concatSegments, runFFmpeg } from '../ffmpeg/executor.js';
import { parseEDL } from '../edl/parser.js';
import { XMLParser } from 'fast-xml-parser';

const S3_BUCKET = process.env.S3_BUCKET || 'wild-dragon';

const xmlParser = new XMLParser({
  ignoreAttributes: false,
  attributeNamePrefix: '@_',
});

function parseFcpXml(xmlContent) {
  const doc = xmlParser.parse(xmlContent);
  const sequence = doc?.xmeml?.sequence;
  if (!sequence) throw new Error('Invalid FCP XML: no sequence element');

  const name = sequence.name || 'Untitled';
  const rate = sequence?.rate?.timebase ? parseInt(sequence.rate.timebase, 10) : 29.97;
  const width = parseInt(sequence?.media?.video?.format?.samplecharacteristics?.width || 1920, 10);
  const height = parseInt(sequence?.media?.video?.format?.samplecharacteristics?.height || 1080, 10);

  const clips = [];
  const videoTracks = sequence?.media?.video?.track || [];
  const tracks = Array.isArray(videoTracks) ? videoTracks : [videoTracks];

  for (const track of tracks) {
    const trackNum = parseInt(track?.['@_currentExplodedTrackIndex'] || 0, 10);
    const trackItems = track?.clipitem || [];
    const items = Array.isArray(trackItems) ? trackItems : [trackItems];

    for (const item of items) {
      if (!item) continue;
      const fileUrl = item?.file?.name || item?.file?.pathurl || '';
      const fileName = fileUrl.split('/').pop() || fileUrl.split('\\').pop() || 'unknown';
      const srcIn = parseFrame(item?.in?.toString() || '0', rate);
      const srcOut = parseFrame(item?.out?.toString() || '0', rate);
      const recIn = parseFrame(item?.start?.toString() || '0', rate);
      const recOut = parseFrame(item?.end?.toString() || '0', rate);
      const duration = parseFrame(item?.duration?.toString() || '0', rate);

      if (srcOut <= srcIn || recOut <= recIn) continue;

      clips.push({
        trackIndex: trackNum,
        fileName,
        fileUrl,
        sourceInFrames: srcIn,
        sourceOutFrames: srcOut,
        timelineInFrames: recIn,
        timelineOutFrames: recOut,
        duration,
      });
    }
  }

  return { name, frameRate: rate, width, height, clips };
}

function parseFrame(value, fps) {
  // FCP XML stores timecode or frame count
  const trimmed = value.trim();
  // If it's a plain number, return as-is
  if (/^\d+$/.test(trimmed)) return parseInt(trimmed, 10);
  // HH:MM:SS:FF or HH:MM:SS;FF
  const parts = trimmed.split(/[:;]/);
  if (parts.length === 4) {
    const hh = parseInt(parts[0], 10);
    const mm = parseInt(parts[1], 10);
    const ss = parseInt(parts[2], 10);
    const ff = parseInt(parts[3], 10);
    return hh * 3600 * fps + mm * 60 * fps + ss * fps + ff;
  }
  return 0;
}

export const conformWorker = async (job) => {
  const { edl, fcpXml, projectId, sequenceName, frameRate, codec, quality, resolution, audio } = job.data;
  const jobId = job.id;

  const tmpDir = tmpdir();
  const segmentsDir = join(tmpDir, `segments-${jobId}`);
  const segmentListPath = join(tmpDir, `segments-${jobId}.txt`);
  const outputPath = join(tmpDir, `output-${jobId}.mp4`);

  try {
    let edits = [];
    let seqName = sequenceName || 'Conformed';
    let seqFps = parseFloat(frameRate) || 29.97;

    // Parse input — accept EDL, FCP XML, or structured JSON
    if (edl) {
      await job.updateProgress(5);
      console.log(`[conform] Parsing EDL for job ${jobId}`);
      edits = parseEDL(edl).map((e, i) => ({
        editNumber: e.editNumber || i + 1,
        reelName: e.reelName,
        sourceIn: e.sourceIn,
        sourceOut: e.sourceOut,
      }));
    } else if (fcpXml) {
      await job.updateProgress(5);
      console.log(`[conform] Parsing FCP XML for job ${jobId}`);
      const parsed = parseFcpXml(fcpXml);
      seqName = parsed.name || seqName;
      seqFps = parsed.frameRate || seqFps;
      edits = parsed.clips.map((c, i) => ({
        editNumber: i + 1,
        reelName: c.fileName,
        sourceIn: c.sourceInFrames,
        sourceOut: c.sourceOutFrames,
      }));
    } else {
      throw new Error('No input provided — expected edl or fcpXml in job data');
    }

    await mkdir(segmentsDir, { recursive: true });

    let processedEdits = 0;
    const concatList = [];

    for (const edit of edits) {
      await job.updateProgress(Math.min(5 + (processedEdits / edits.length) * 50, 55));
      console.log(`[conform] Processing edit ${edit.editNumber}: ${edit.reelName}`);

      // BUG FIX #9: Scope asset lookup by project_id to prevent cross-project
      // collisions when two projects contain assets with the same filename.
      let assetRes;
      if (projectId) {
        assetRes = await query(
          `SELECT id, original_s3_key FROM assets
           WHERE filename = $1 AND project_id = $2
           LIMIT 1`,
          [edit.reelName, projectId]
        );
        // Fall back to unscoped lookup if no match in the current project
        // (EDL reel names may reference assets not yet assigned to a project)
        if (assetRes.rows.length === 0) {
          assetRes = await query(
            'SELECT id, original_s3_key FROM assets WHERE filename = $1 LIMIT 1',
            [edit.reelName]
          );
        }
      } else {
        assetRes = await query(
          'SELECT id, original_s3_key FROM assets WHERE filename = $1 LIMIT 1',
          [edit.reelName]
        );
      }

      if (assetRes.rows.length === 0) {
        throw new Error(`Asset not found for reel: ${edit.reelName}`);
      }

      const { original_s3_key: sourceKey } = assetRes.rows[0];
      const segmentInputPath = join(segmentsDir, `segment-${edit.editNumber}-src`);
      const segmentOutputPath = join(segmentsDir, `segment-${edit.editNumber}.mov`);

      console.log(`[conform] Downloading segment ${edit.editNumber} from S3 (${sourceKey})`);
      await downloadFromS3(S3_BUCKET, sourceKey, segmentInputPath);

      console.log(`[conform] Trimming ${edit.editNumber}: ${edit.sourceIn} → ${edit.sourceOut}`);
      await trimSegment(segmentInputPath, segmentOutputPath, edit.sourceIn, edit.sourceOut);

      concatList.push(segmentOutputPath);
      await unlink(segmentInputPath).catch(() => {});
      processedEdits++;
    }

    await job.updateProgress(60);
    console.log(`[conform] Writing concat list for ${concatList.length} segments`);
    const concatContent = concatList.map(p => `file '${p}'`).join('\n');
    await writeFile(segmentListPath, concatContent, 'utf-8');

    await job.updateProgress(70);
    console.log(`[conform] Concatenating segments for job ${jobId}`);

    // Use re-encode instead of stream copy for consistent output
    const audioFlag = audio === 'include' ? ['-c:a', 'aac'] : ['-an'];
    await runFFmpeg([
      '-f', 'concat',
      '-safe', '0',
      '-i', segmentListPath,
      '-c:v', codec === 'prores' ? 'prores_ks' : codec === 'h265' ? 'libx265' : 'libx264',
      '-preset', quality === 'high' ? 'slow' : quality === 'broadcast' ? 'veryslow' : 'fast',
      '-crf', quality === 'broadcast' ? '18' : quality === 'high' ? '23' : '28',
      ...audioFlag,
      '-y', outputPath,
    ]);

    await job.updateProgress(85);
    const outputKey = `jobs/${jobId}/conformed.mp4`;
    console.log(`[conform] Uploading output to ${outputKey}`);
    await uploadToS3(S3_BUCKET, outputKey, outputPath);

    // Register the conformed output as a new asset
    const assetRes = await query(
      `INSERT INTO assets (project_id, filename, display_name, media_type, status, original_s3_key, codec, resolution, fps, duration_ms, conform_source_sequence_id)
       VALUES ($1, $2, $3, 'video', 'ready', $4, $5, $6, $7, $8, $9) RETURNING id`,
      [
        projectId || null,
        `conformed-${seqName.replace(/[^a-z0-9]/gi, '_')}.mp4`,
        `Conformed: ${seqName}`,
        outputKey,
        codec === 'prores' ? 'prores' : codec === 'h265' ? 'hevc' : 'h264',
        resolution !== 'match' ? resolution : '1920x1080',
        seqFps,
        null,
        job.data.sequenceId || null,
      ]
    );

    await job.updateProgress(100);
    console.log(`[conform] Job ${jobId} complete → asset ${assetRes.rows[0].id}`);

    return { jobId, outputKey, assetId: assetRes.rows[0].id };

  } catch (error) {
    console.error(`[conform] Error in job ${jobId}:`, error);
    // BUG FIX #1: Mark the output asset (if any) as 'error' so the UI doesn't
    // show a perpetually-spinning 'processing' state when the conform fails.
    // We don't have an assetId until the INSERT succeeds, so target by job key.
    await query(
      `UPDATE assets
       SET status = 'error', updated_at = NOW()
       WHERE original_s3_key = $1`,
      [`jobs/${jobId}/conformed.mp4`]
    ).catch(e => console.error('[conform] Failed to mark asset error:', e.message));
    throw error;
  } finally {
    await Promise.all([
      unlink(segmentListPath).catch(() => {}),
      unlink(outputPath).catch(() => {}),
      rm(segmentsDir, { recursive: true, force: true }).catch(() => {}),
    ]);
  }
};