const express = require('express');
const pool = require('../db');
const { requirePermission } = require('../middleware/auth');
const { logCuratorAction } = require('../audit-log');
const {
  COLUMN_ROLES,
  PRESETS,
  parseBuffer,
  suggestPreset,
  autoMapColumns,
  buildPreview,
  commitProposals,
  hashBuffer,
  hashImportPayload,
  findPriorImport,
} = require('../influence-import-service');

const router = express.Router();

const MAX_UPLOAD_BYTES = 10 * 1024 * 1024;

function parseId(value) {
  const n = Number(value);
  return Number.isFinite(n) && n > 0 ? Math.floor(n) : null;
}

router.get('/presets', requirePermission('influences'), (_req, res) => {
  res.json({
    roles: COLUMN_ROLES,
    presets: Object.values(PRESETS).map((p) => ({
      id: p.id,
      label: p.label,
      mapping: p.mapping,
    })),
  });
});

router.get('/', requirePermission('influences'), async (req, res) => {
  try {
    const artistId = parseId(req.query.artistId);
    const paintingId = parseId(req.query.paintingId);
    const q = typeof req.query.q === 'string' ? req.query.q.trim() : '';
    const limit = Math.min(500, Math.max(1, Number(req.query.limit) || 100));
    const offset = Math.max(0, Number(req.query.offset) || 0);

    const params = [];
    const where = [];
    if (artistId) {
      params.push(artistId);
      where.push(`a.id = $${params.length}`);
    }
    if (paintingId) {
      params.push(paintingId);
      where.push(`pis.painting_id = $${params.length}`);
    }
    if (q) {
      params.push(`%${q}%`);
      const i = params.length;
      where.push(`(
        p.title ILIKE $${i} OR a.name ILIKE $${i}
        OR sa.name ILIKE $${i} OR sp.title ILIKE $${i} OR m.name ILIKE $${i}
        OR pis.notes ILIKE $${i} OR pis.source ILIKE $${i}
      )`);
    }

    const whereSql = where.length ? `WHERE ${where.join(' AND ')}` : '';
    params.push(limit);
    const limitIdx = params.length;
    params.push(offset);
    const offsetIdx = params.length;

    const { rows } = await pool.query(
      `SELECT pis.id, pis.painting_id, pis.source_type,
              pis.source_painting_id, pis.source_artist_id, pis.source_movement_id,
              pis.notes, pis.source, pis.source_url, pis.aspects, pis.quote,
              pis.confidence, pis.discovered_via, pis.updated_at,
              p.title AS painting_title, p.year AS painting_year,
              a.id AS artist_id, a.name AS artist_name,
              sp.title AS source_painting_title,
              sa.name AS source_artist_name,
              m.name AS source_movement_name
       FROM painting_influence_sources pis
       JOIN paintings p ON p.id = pis.painting_id
       JOIN artists a ON a.id = p.artist_id
       LEFT JOIN paintings sp ON sp.id = pis.source_painting_id
       LEFT JOIN artists sa ON sa.id = pis.source_artist_id
       LEFT JOIN art_movements m ON m.id = pis.source_movement_id
       ${whereSql}
       ORDER BY pis.id DESC
       LIMIT $${limitIdx} OFFSET $${offsetIdx}`,
      params,
    );

    const countParams = params.slice(0, -2);
    const { rows: countRows } = await pool.query(
      `SELECT COUNT(*)::int AS n
       FROM painting_influence_sources pis
       JOIN paintings p ON p.id = pis.painting_id
       JOIN artists a ON a.id = p.artist_id
       LEFT JOIN paintings sp ON sp.id = pis.source_painting_id
       LEFT JOIN artists sa ON sa.id = pis.source_artist_id
       LEFT JOIN art_movements m ON m.id = pis.source_movement_id
       ${whereSql}`,
      countParams,
    );

    const items = rows.map((r) => ({
      id: r.id,
      paintingId: r.painting_id,
      paintingTitle: r.painting_title,
      paintingYear: r.painting_year,
      artistId: r.artist_id,
      artistName: r.artist_name,
      sourceType: r.source_type,
      sourcePaintingId: r.source_painting_id,
      sourceArtistId: r.source_artist_id,
      sourceMovementId: r.source_movement_id,
      sourceLabel:
        r.source_type === 'painting'
          ? r.source_painting_title
          : r.source_type === 'artist'
            ? r.source_artist_name
            : r.source_movement_name,
      notes: r.notes,
      source: r.source,
      sourceUrl: r.source_url,
      aspects: r.aspects,
      quote: r.quote,
      confidence: r.confidence,
      discoveredVia: r.discovered_via,
      updatedAt: r.updated_at,
    }));

    res.json({ items, total: countRows[0]?.n || 0, limit, offset });
  } catch (err) {
    console.error('Influences list error:', err.message);
    res.status(500).json({ error: 'Failed to list influences' });
  }
});

router.get('/graph', requirePermission('influences'), async (req, res) => {
  try {
    const artistId = parseId(req.query.artistId);
    const paintingId = parseId(req.query.paintingId);
    if (!artistId && !paintingId) {
      return res.status(400).json({ error: 'artistId or paintingId required' });
    }

    let paintingIds = [];
    let focusArtistId = artistId;
    let focusLabel = '';

    if (paintingId) {
      const { rows } = await pool.query(
        `SELECT p.id, p.title, p.artist_id, a.name AS artist_name
         FROM paintings p JOIN artists a ON a.id = p.artist_id WHERE p.id = $1`,
        [paintingId],
      );
      if (!rows[0]) return res.status(404).json({ error: 'Painting not found' });
      paintingIds = [paintingId];
      focusArtistId = rows[0].artist_id;
      focusLabel = `${rows[0].artist_name} — ${rows[0].title}`;
    } else {
      const { rows: artistRows } = await pool.query('SELECT id, name FROM artists WHERE id = $1', [artistId]);
      if (!artistRows[0]) return res.status(404).json({ error: 'Artist not found' });
      focusLabel = artistRows[0].name;
      const { rows: paints } = await pool.query('SELECT id FROM paintings WHERE artist_id = $1', [artistId]);
      paintingIds = paints.map((p) => p.id);
    }

    if (!paintingIds.length) {
      return res.json({ focus: { artistId: focusArtistId, label: focusLabel }, nodes: [], edges: [] });
    }

    const { rows: outgoing } = await pool.query(
      `SELECT pis.id, pis.painting_id, pis.source_type,
              pis.source_painting_id, pis.source_artist_id, pis.source_movement_id,
              p.title AS painting_title, a.name AS artist_name,
              sp.title AS source_painting_title, spa.name AS source_painting_artist,
              sa.name AS source_artist_name, m.name AS source_movement_name
       FROM painting_influence_sources pis
       JOIN paintings p ON p.id = pis.painting_id
       JOIN artists a ON a.id = p.artist_id
       LEFT JOIN paintings sp ON sp.id = pis.source_painting_id
       LEFT JOIN artists spa ON spa.id = sp.artist_id
       LEFT JOIN artists sa ON sa.id = pis.source_artist_id
       LEFT JOIN art_movements m ON m.id = pis.source_movement_id
       WHERE pis.painting_id = ANY($1::int[])`,
      [paintingIds],
    );

    const { rows: incoming } = await pool.query(
      `SELECT pis.id, pis.painting_id, pis.source_type,
              pis.source_painting_id, pis.source_artist_id, pis.source_movement_id,
              p.title AS painting_title, a.name AS artist_name, a.id AS subject_artist_id
       FROM painting_influence_sources pis
       JOIN paintings p ON p.id = pis.painting_id
       JOIN artists a ON a.id = p.artist_id
       WHERE (
         (pis.source_type = 'artist' AND pis.source_artist_id = $1)
         OR (pis.source_type = 'painting' AND pis.source_painting_id = ANY($2::int[]))
       )`,
      [focusArtistId, paintingIds],
    );

    const nodes = new Map();
    const addNode = (id, type, label, meta = {}) => {
      if (!nodes.has(id)) nodes.set(id, { id, type, label, ...meta });
    };

    addNode(`artist:${focusArtistId}`, 'artist', focusLabel, { artistId: focusArtistId, focus: true });

    const edges = [];

    for (const r of outgoing) {
      let targetId;
      let targetLabel;
      let targetType = r.source_type;
      if (r.source_type === 'artist') {
        targetId = `artist:${r.source_artist_id}`;
        targetLabel = r.source_artist_name;
        addNode(targetId, 'artist', targetLabel, { artistId: r.source_artist_id });
      } else if (r.source_type === 'movement') {
        targetId = `movement:${r.source_movement_id}`;
        targetLabel = r.source_movement_name;
        addNode(targetId, 'movement', targetLabel, { movementId: r.source_movement_id });
      } else {
        targetId = `painting:${r.source_painting_id}`;
        targetLabel = `${r.source_painting_artist} — ${r.source_painting_title}`;
        addNode(targetId, 'painting', targetLabel, { paintingId: r.source_painting_id });
      }
      edges.push({
        id: r.id,
        from: `artist:${focusArtistId}`,
        to: targetId,
        direction: 'influenced_by',
        label: r.painting_title,
      });
    }

    for (const r of incoming) {
      const fromId = `artist:${r.subject_artist_id}`;
      addNode(fromId, 'artist', r.artist_name, { artistId: r.subject_artist_id });
      edges.push({
        id: r.id,
        from: fromId,
        to: `artist:${focusArtistId}`,
        direction: 'influenced',
        label: r.painting_title,
      });
    }

    res.json({
      focus: { artistId: focusArtistId, paintingId: paintingId || null, label: focusLabel },
      nodes: [...nodes.values()],
      edges,
    });
  } catch (err) {
    console.error('Influences graph error:', err.message);
    res.status(500).json({ error: 'Failed to load influence graph' });
  }
});

router.post('/', requirePermission('influences'), async (req, res) => {
  try {
    const {
      paintingId,
      sourceType,
      sourcePaintingId,
      sourceArtistId,
      sourceMovementId,
      notes,
      source,
      sourceUrl,
      aspects,
      quote,
      confidence,
    } = req.body || {};

    const pid = parseId(paintingId);
    if (!pid) return res.status(400).json({ error: 'paintingId required' });
    if (!['painting', 'artist', 'movement'].includes(sourceType)) {
      return res.status(400).json({ error: 'sourceType must be painting, artist, or movement' });
    }

    const sourceIds = {
      source_painting_id: sourceType === 'painting' ? parseId(sourcePaintingId) : null,
      source_artist_id: sourceType === 'artist' ? parseId(sourceArtistId) : null,
      source_movement_id: sourceType === 'movement' ? parseId(sourceMovementId) : null,
    };
    if (sourceType === 'painting' && !sourceIds.source_painting_id) {
      return res.status(400).json({ error: 'sourcePaintingId required' });
    }
    if (sourceType === 'artist' && !sourceIds.source_artist_id) {
      return res.status(400).json({ error: 'sourceArtistId required' });
    }
    if (sourceType === 'movement' && !sourceIds.source_movement_id) {
      return res.status(400).json({ error: 'sourceMovementId required' });
    }

    const edge = {
      notes: notes || null,
      source: source || null,
      source_url: sourceUrl || null,
      aspects: aspects || null,
      quote: quote || null,
      confidence: confidence || 'curated',
      discovered_via: 'curator-ui',
    };

    if (sourceType === 'painting') {
      await pool.query(
        `INSERT INTO painting_influences
           (painting_id, influenced_by_painting_id, notes, source, aspects, quote, source_url)
         VALUES ($1,$2,$3,$4,$5,$6,$7)
         ON CONFLICT (painting_id, influenced_by_painting_id) DO NOTHING`,
        [pid, sourceIds.source_painting_id, edge.notes, edge.source, edge.aspects, edge.quote, edge.source_url],
      );
    }

    const result = await pool.query(
      `INSERT INTO painting_influence_sources (
         painting_id, source_type, source_painting_id, source_artist_id, source_movement_id,
         notes, source, aspects, quote, source_url, discovered_via, confidence
       ) VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12)
       ON CONFLICT DO NOTHING
       RETURNING id`,
      [
        pid,
        sourceType,
        sourceIds.source_painting_id,
        sourceIds.source_artist_id,
        sourceIds.source_movement_id,
        edge.notes,
        edge.source,
        edge.aspects,
        edge.quote,
        edge.source_url,
        edge.discovered_via,
        edge.confidence,
      ],
    );

    if (!result.rows[0]) {
      return res.status(409).json({ error: 'Influence edge already exists' });
    }

    await logCuratorAction({
      userId: req.curatorUser.id,
      action: 'influence.create',
      resourceType: 'influence_source',
      resourceId: result.rows[0].id,
      details: { paintingId: pid, sourceType, ...sourceIds },
      req,
    });

    res.status(201).json({ id: result.rows[0].id });
  } catch (err) {
    console.error('Influence create error:', err.message);
    res.status(500).json({ error: 'Failed to create influence' });
  }
});

router.patch('/:id', requirePermission('influences'), async (req, res) => {
  try {
    const id = parseId(req.params.id);
    if (!id) return res.status(400).json({ error: 'Invalid id' });

    const {
      notes,
      source,
      sourceUrl,
      aspects,
      quote,
      confidence,
      sourceType,
      sourcePaintingId,
      sourceArtistId,
      sourceMovementId,
    } = req.body || {};

    const { rows: existing } = await pool.query(
      'SELECT * FROM painting_influence_sources WHERE id = $1',
      [id],
    );
    if (!existing[0]) return res.status(404).json({ error: 'Not found' });

    const nextType = sourceType || existing[0].source_type;
    const nextPainting =
      sourceType === 'painting'
        ? parseId(sourcePaintingId)
        : sourceType
          ? null
          : existing[0].source_painting_id;
    const nextArtist =
      sourceType === 'artist'
        ? parseId(sourceArtistId)
        : sourceType
          ? null
          : existing[0].source_artist_id;
    const nextMovement =
      sourceType === 'movement'
        ? parseId(sourceMovementId)
        : sourceType
          ? null
          : existing[0].source_movement_id;

    const result = await pool.query(
      `UPDATE painting_influence_sources SET
         source_type = $2,
         source_painting_id = $3,
         source_artist_id = $4,
         source_movement_id = $5,
         notes = COALESCE($6, notes),
         source = COALESCE($7, source),
         source_url = COALESCE($8, source_url),
         aspects = COALESCE($9, aspects),
         quote = COALESCE($10, quote),
         confidence = COALESCE($11, confidence)
       WHERE id = $1
       RETURNING id`,
      [
        id,
        nextType,
        nextPainting,
        nextArtist,
        nextMovement,
        notes !== undefined ? notes : null,
        source !== undefined ? source : null,
        sourceUrl !== undefined ? sourceUrl : null,
        aspects !== undefined ? aspects : null,
        quote !== undefined ? quote : null,
        confidence !== undefined ? confidence : null,
      ],
    );

    await logCuratorAction({
      userId: req.curatorUser.id,
      action: 'influence.update',
      resourceType: 'influence_source',
      resourceId: id,
      details: { sourceType: nextType },
      req,
    });

    res.json({ id: result.rows[0].id });
  } catch (err) {
    console.error('Influence update error:', err.message);
    res.status(500).json({ error: 'Failed to update influence' });
  }
});

router.delete('/:id', requirePermission('influences'), async (req, res) => {
  try {
    const id = parseId(req.params.id);
    if (!id) return res.status(400).json({ error: 'Invalid id' });

    const { rows } = await pool.query(
      'SELECT * FROM painting_influence_sources WHERE id = $1',
      [id],
    );
    if (!rows[0]) return res.status(404).json({ error: 'Not found' });
    const row = rows[0];

    if (row.source_type === 'painting' && row.source_painting_id) {
      await pool.query(
        `DELETE FROM painting_influences
         WHERE painting_id = $1 AND influenced_by_painting_id = $2`,
        [row.painting_id, row.source_painting_id],
      );
    }

    await pool.query('DELETE FROM painting_influence_sources WHERE id = $1', [id]);

    await logCuratorAction({
      userId: req.curatorUser.id,
      action: 'influence.delete',
      resourceType: 'influence_source',
      resourceId: id,
      details: {
        paintingId: row.painting_id,
        sourceType: row.source_type,
      },
      req,
    });

    res.json({ ok: true });
  } catch (err) {
    console.error('Influence delete error:', err.message);
    res.status(500).json({ error: 'Failed to delete influence' });
  }
});

router.post('/import/parse', requirePermission('influences'), async (req, res) => {
  try {
    const { filename, sheet, contentBase64, content } = req.body || {};
    let buffer;
    if (typeof contentBase64 === 'string' && contentBase64.length) {
      buffer = Buffer.from(contentBase64, 'base64');
    } else if (typeof content === 'string' && content.length) {
      buffer = Buffer.from(content, 'utf8');
    } else {
      return res.status(400).json({ error: 'contentBase64 or content required' });
    }
    if (!buffer.length) return res.status(400).json({ error: 'Empty file' });
    if (buffer.length > MAX_UPLOAD_BYTES) {
      return res.status(413).json({ error: 'File too large (max 10 MB)' });
    }

    const name = typeof filename === 'string' && filename ? filename : 'upload.csv';
    const sheetName = typeof sheet === 'string' ? sheet : undefined;

    const parsed = parseBuffer(buffer, name, { sheet: sheetName });
    const contentHash = hashBuffer(buffer);
    const presetId = suggestPreset(parsed.columns);
    const preset = PRESETS[presetId] || PRESETS.custom;
    const mapping = Object.keys(preset.mapping).length
      ? {
        ...autoMapColumns(parsed.columns),
        ...Object.fromEntries(
          Object.entries(preset.mapping).filter(([col]) => parsed.columns.includes(col)),
        ),
      }
      : autoMapColumns(parsed.columns);

    const includeAll = parsed.rowCount <= 2000;
    const rowsForHash = includeAll ? parsed.rows : parsed.rows;
    const payloadHash = hashImportPayload(rowsForHash || [], mapping);
    const priorImport = await findPriorImport({ contentHash, payloadHash });

    res.json({
      filename: name,
      format: parsed.format,
      sheets: parsed.sheets,
      sheet: parsed.sheet,
      columns: parsed.columns,
      rowCount: parsed.rowCount,
      sampleRows: parsed.sampleRows,
      rows: includeAll ? parsed.rows : undefined,
      suggestedPreset: presetId,
      suggestedMapping: mapping,
      roles: COLUMN_ROLES,
      presets: Object.values(PRESETS).map((p) => ({ id: p.id, label: p.label, mapping: p.mapping })),
      contentHash,
      payloadHash,
      alreadyImported: Boolean(priorImport),
      priorImport,
    });
  } catch (err) {
    console.error('Influence import parse error:', err.message);
    res.status(400).json({ error: err.message || 'Failed to parse file' });
  }
});

router.post('/import/preview', requirePermission('influences'), async (req, res) => {
  try {
    const { rows, mapping, sourceLabel, contentHash, payloadHash } = req.body || {};
    if (!Array.isArray(rows) || !rows.length) {
      return res.status(400).json({ error: 'rows array required' });
    }
    if (!mapping || typeof mapping !== 'object') {
      return res.status(400).json({ error: 'mapping object required' });
    }
    if (rows.length > 2000) {
      return res.status(400).json({ error: 'Too many rows (max 2000 per preview)' });
    }

    const computedPayloadHash = payloadHash || hashImportPayload(rows, mapping);
    const priorImport = await findPriorImport({
      contentHash: contentHash || null,
      payloadHash: computedPayloadHash,
    });

    const preview = await buildPreview(rows, mapping, { sourceLabel });
    res.json({
      ...preview,
      contentHash: contentHash || null,
      payloadHash: computedPayloadHash,
      alreadyImported: Boolean(priorImport),
      priorImport,
    });
  } catch (err) {
    console.error('Influence import preview error:', err.message);
    res.status(500).json({ error: 'Failed to build preview' });
  }
});

router.post('/import/commit', requirePermission('influences'), async (req, res) => {
  try {
    const { proposals, fileName, contentHash, payloadHash, force } = req.body || {};
    if (!Array.isArray(proposals)) {
      return res.status(400).json({ error: 'proposals array required' });
    }

    if (!force && (contentHash || payloadHash)) {
      const priorImport = await findPriorImport({
        contentHash: contentHash || null,
        payloadHash: payloadHash || null,
      });
      if (priorImport) {
        return res.status(409).json({
          error: 'This file or identical data was already imported',
          code: 'ALREADY_IMPORTED',
          priorImport,
        });
      }
    }

    const result = await commitProposals(proposals, {
      userId: req.curatorUser.id,
      req,
      fileName,
    });

    await logCuratorAction({
      userId: req.curatorUser.id,
      action: 'influence.import',
      resourceType: 'influence_source',
      resourceId: 0,
      details: {
        fileName: fileName || null,
        inserted: result.inserted,
        skipped: result.skipped,
        attempted: result.attempted,
        contentHash: contentHash || null,
        payloadHash: payloadHash || null,
        forced: Boolean(force),
      },
      req,
    });

    res.json({
      ...result,
      contentHash: contentHash || null,
      payloadHash: payloadHash || null,
    });
  } catch (err) {
    console.error('Influence import commit error:', err.message);
    res.status(500).json({ error: 'Failed to commit import' });
  }
});

module.exports = router;