import pool, { run } from '../db/index.js';
import { DEFAULT_LAYOUT_PRESETS } from '../db/defaultLayouts.js';

const MAX_NAME_LENGTH = 100;
const PRESET_COLUMNS = 'id, seed_key, name, description, config, sort_order, created_at, updated_at';

let seeded = null;

/**
 * Synchronise les dispositions intégrées avec leur définition en code (insertion ou mise à jour).
 * Une disposition intégrée supprimée reste masquée (active = 0).
 */
function ensureDefaultLayouts() {
  if (!seeded) {
    seeded = (async () => {
      const { rows } = await pool.query(
        'SELECT seed_key, name, description, config, sort_order FROM layout_presets WHERE seed_key IS NOT NULL'
      );
      const existing = new Map(rows.map((r) => [r.seed_key, r]));
      for (const [index, preset] of DEFAULT_LAYOUT_PRESETS.entries()) {
        const config = JSON.stringify(preset.config);
        const row = existing.get(preset.seedKey);
        if (row) {
          const unchanged = row.name === preset.name && row.description === preset.description
            && row.config === config && Number(row.sort_order) === index;
          if (!unchanged) {
            await run(
              `UPDATE layout_presets
               SET name = $1, description = $2, config = $3, sort_order = $4, updated_at = datetime('now')
               WHERE seed_key = $5`,
              [preset.name, preset.description, config, index, preset.seedKey]
            );
          }
          continue;
        }
        await run(
          `INSERT INTO layout_presets (seed_key, name, description, config, sort_order)
           VALUES ($1, $2, $3, $4, $5)`,
          [preset.seedKey, preset.name, preset.description, config, index]
        );
      }
    })().catch((err) => {
      seeded = null;
      throw err;
    });
  }
  return seeded;
}

function parsePreset(row) {
  if (!row) return null;
  let config = null;
  try {
    config = JSON.parse(row.config);
  } catch { /* config illisible → null */ }
  return { ...row, builtin: row.seed_key != null, config };
}

export async function getLayoutPresets(req, res) {
  try {
    await ensureDefaultLayouts();
    const { rows } = await pool.query(
      `SELECT ${PRESET_COLUMNS}
       FROM layout_presets
       WHERE active = 1
       ORDER BY sort_order ASC, id ASC`
    );
    res.json(rows.map(parsePreset));
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
}

export async function createLayoutPreset(req, res) {
  try {
    const name = String(req.body?.name || '').trim();
    const description = String(req.body?.description || '').trim() || null;
    const config = req.body?.config;

    if (!name) return res.status(400).json({ error: 'Le nom est requis.' });
    if (name.length > MAX_NAME_LENGTH) {
      return res.status(400).json({ error: `Le nom ne peut pas dépasser ${MAX_NAME_LENGTH} caractères.` });
    }
    if (!config || typeof config !== 'object' || Array.isArray(config) || !Array.isArray(config.modules) || config.modules.length === 0) {
      return res.status(400).json({ error: 'Disposition invalide (au moins une colonne requise).' });
    }

    await ensureDefaultLayouts();
    await run(
      `INSERT INTO layout_presets (name, description, config, sort_order)
       VALUES ($1, $2, $3, 1000)`,
      [name, description, JSON.stringify(config)]
    );
    const { rows } = await pool.query(
      `SELECT ${PRESET_COLUMNS}
       FROM layout_presets
       ORDER BY id DESC
       LIMIT 1`
    );
    res.status(201).json(parsePreset(rows[0]));
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
}

export async function deleteLayoutPreset(req, res) {
  try {
    const id = Number(req.params.id);
    if (!Number.isInteger(id) || id < 1) {
      return res.status(400).json({ error: 'Identifiant invalide.' });
    }

    const { rows } = await pool.query('SELECT id, seed_key FROM layout_presets WHERE id = $1 LIMIT 1', [id]);
    if (rows.length === 0) return res.status(404).json({ error: 'Disposition introuvable.' });

    if (rows[0].seed_key != null) {
      await run(`UPDATE layout_presets SET active = 0, updated_at = datetime('now') WHERE id = $1`, [id]);
    } else {
      await run('DELETE FROM layout_presets WHERE id = $1', [id]);
    }
    res.status(204).end();
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
}