// ============================================================
// MEMORIES ROUTES — User template/memory storage
// ============================================================

var express = require('express');
var router = express.Router();
var db = require('../db/database');
var { authMiddleware } = require('../middleware/auth');
var logger = require('../utils/logger');
var cryptoUtil = require('../utils/crypto');

router.use(authMiddleware);
router.use('/memories', require('../utils/policy').requireFeature('memories'));

// Decrypt a row's user-facing fields. Safe against legacy plaintext rows —
// cryptoUtil.decryptString passes through values without the "enc1:" prefix.
function decryptMemory(row) {
  if (!row) return row;
  try { row.name    = cryptoUtil.decryptString(row.name); }    catch (e) {}
  try { row.content = cryptoUtil.decryptString(row.content); } catch (e) {}
  return row;
}

var VALID_CATEGORIES = [
  'physical_exam', 'ros', 'encounter_format', 'family_history', 'assessment_plan', 'custom',
  'template_soap', 'template_hpi', 'template_wellvisit', 'template_sickvisit', 'template_ed'
];

var AI_CONTEXT_CATEGORIES = [
  'physical_exam', 'ros', 'encounter_format', 'family_history', 'assessment_plan',
  'template_soap', 'template_hpi', 'template_wellvisit', 'template_sickvisit', 'template_ed'
];

// ── GET all memories for current user ───────────────────────────────────
router.get('/memories', async function(req, res) {
  try {
    // Legacy correction_* rows from the removed Dragon-style learning feature
    // are filtered out — invisible to UI and to the AI context endpoint, but
    // not dropped from the table.
    var rows = await db.all(
      "SELECT id, category, name, content, created_at, updated_at FROM user_memories WHERE user_id = $1 AND category NOT LIKE 'correction_%' ORDER BY category, id",
      [req.user.id]
    );
    rows.forEach(decryptMemory);
    res.json({ success: true, memories: rows });
  } catch (e) { logger.error('GET /memories', e.message); res.status(500).json({ error: 'Request failed' }); }
});

// ── POST create memory ───────────────────────────────────────────────────
router.post('/memories', async function(req, res) {
  try {
    var { name, category, content } = req.body;
    if (!name || !name.trim()) return res.status(400).json({ error: 'Name required' });
    if (!content || !content.trim()) return res.status(400).json({ error: 'Content required' });
    var cat = VALID_CATEGORIES.includes(category) ? category : 'custom';

    // Limit per user
    var count = await db.get('SELECT COUNT(*) as cnt FROM user_memories WHERE user_id = $1', [req.user.id]);
    if (count && parseInt(count.cnt) >= 200) return res.status(400).json({ error: 'Maximum 200 memories per user' });

    var result = await db.run(
      'INSERT INTO user_memories (user_id, category, name, content) VALUES ($1,$2,$3,$4)',
      [
        req.user.id,
        cat,
        cryptoUtil.encryptString(name.trim().substring(0, 100)),
        cryptoUtil.encryptString(content.trim().substring(0, 5000))
      ]
    );
    res.json({ success: true, id: result.lastInsertRowid });
  } catch (e) { logger.error('POST /memories', e.message); res.status(500).json({ error: 'Request failed' }); }
});

// ── PUT update memory ────────────────────────────────────────────────────
router.put('/memories/:id', async function(req, res) {
  try {
    var { name, category, content } = req.body;
    var cat = VALID_CATEGORIES.includes(category) ? category : 'custom';
    await db.run(
      'UPDATE user_memories SET name=$1, category=$2, content=$3, updated_at=NOW() WHERE id=$4 AND user_id=$5',
      [
        cryptoUtil.encryptString((name || '').trim().substring(0, 100)),
        cat,
        cryptoUtil.encryptString((content || '').trim().substring(0, 5000)),
        req.params.id,
        req.user.id
      ]
    );
    res.json({ success: true });
  } catch (e) { logger.error('PUT /memories/:id', e.message); res.status(500).json({ error: 'Request failed' }); }
});

// ── DELETE memory ────────────────────────────────────────────────────────
router.delete('/memories/:id', async function(req, res) {
  try {
    await db.run('DELETE FROM user_memories WHERE id = $1 AND user_id = $2', [req.params.id, req.user.id]);
    res.json({ success: true });
  } catch (e) { logger.error('DELETE /memories/:id', e.message); res.status(500).json({ error: 'Request failed' }); }
});

// ── GET memories as prompt context (for AI generation) ──────────────────
// Returns user templates concatenated as system-prompt context. Multiple
// templates per category are allowed; we order by id ASC so the newest
// row lands last in the prompt — models weight later context more heavily,
// which gives the most recently saved template implicit predominance.
router.get('/memories/context', async function(req, res) {
  try {
    var rows = await db.all(
      "SELECT category, name, content FROM user_memories WHERE user_id = $1 AND category NOT LIKE 'correction_%' ORDER BY category, id",
      [req.user.id]
    );
    rows.forEach(decryptMemory);
    rows = rows.filter(function(r) { return AI_CONTEXT_CATEGORIES.indexOf(r.category) !== -1; });
    if (rows.length === 0) return res.json({ success: true, context: '' });

    var context = '\n\nPHYSICIAN TEMPLATES AND PREFERENCES:\n';
    rows.forEach(function(r) {
      context += '--- ' + r.category.toUpperCase().replace(/_/g, ' ') + ': ' + r.name + ' ---\n' + r.content + '\n\n';
    });
    res.json({ success: true, context: context.trim() });
  } catch (e) { logger.error('GET /memories/context', e.message); res.status(500).json({ error: 'Request failed' }); }
});

module.exports = router;