const Database = require('better-sqlite3')
const fs = require('fs')
const path = require('path')
const { ensureDecrypted } = require('./weekly_crypto')

let db = null

const getDB = () => {
  if (!db) throw new Error('Database not initialized')
  return db
}

const tryOpen = (dbPath) => {
  try {
    const d = new Database(dbPath)
    try {
      const row = d.prepare(`PRAGMA integrity_check`).get()
      const ok = row && (row.integrity_check === 'ok' || row['integrity_check'] === 'ok' || Object.values(row)[0] === 'ok')
      if (!ok) throw new Error('integrity_check_failed')
    } catch (e) {
      throw e
    }
    return d
  } catch (e) {
    return null
  }
}

const initDB = (dbPath, sealPath) => {
  if (db) return db
  
  // Robust Open
  db = tryOpen(dbPath)
  if (!db) {
    // Attempt recovery
    if (fs.existsSync(dbPath)) {
      const badName = `${dbPath}.bad-${Date.now()}`
      try { fs.renameSync(dbPath, badName) } catch {}
      console.warn(`Database corrupt, renamed to ${badName}`)
    }
    
    // Try decrypt from seal
    if (sealPath) ensureDecrypted(dbPath, sealPath)
    
    db = tryOpen(dbPath)
    if (!db) {
      // If still fails, create fresh (previous was renamed or didn't exist)
      db = new Database(dbPath)
    }
  }

  // Pragma
  db.pragma('journal_mode = WAL');
  db.pragma('synchronous = NORMAL');
  db.pragma('busy_timeout = 4000');
  
  // Users
  db.exec(`CREATE TABLE IF NOT EXISTS users (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    username TEXT UNIQUE,
    pass_salt TEXT,
    pass_hash TEXT,
    created_at TEXT DEFAULT (datetime('now')),
    updated_at TEXT DEFAULT (datetime('now'))
  )`)

  // Reports
  db.exec(`CREATE TABLE IF NOT EXISTS reports (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    week_id TEXT UNIQUE,
    title_enc TEXT, title_iv TEXT, title_tag TEXT,
    summary_enc TEXT, summary_iv TEXT, summary_tag TEXT,
    content_enc TEXT, content_iv TEXT, content_tag TEXT,
    created_at TEXT DEFAULT (datetime('now')),
    updated_at TEXT DEFAULT (datetime('now'))
  )`)

  // Events
  db.exec(`CREATE TABLE IF NOT EXISTS events (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    report_id INTEGER,
    parent_event_id INTEGER,
    title_enc TEXT, title_iv TEXT, title_tag TEXT,
    content_enc TEXT, content_iv TEXT, content_tag TEXT,
    status_code TEXT,
    status_enc TEXT, status_iv TEXT, status_tag TEXT,
    deadline TEXT,
    push_required INTEGER DEFAULT 0,
    created_at TEXT DEFAULT (datetime('now')),
    updated_at TEXT DEFAULT (datetime('now')),
    completed_at TEXT,
    FOREIGN KEY(report_id) REFERENCES reports(id)
  )`)

  // Event Reviews
  db.exec(`CREATE TABLE IF NOT EXISTS event_reviews (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    event_id INTEGER,
    review_enc TEXT, review_iv TEXT, review_tag TEXT,
    rating INTEGER,
    created_at TEXT DEFAULT (datetime('now')),
    FOREIGN KEY(event_id) REFERENCES events(id)
  )`)

  // Attachments
  db.exec(`CREATE TABLE IF NOT EXISTS attachments (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    event_id INTEGER,
    filename_enc TEXT, filename_iv TEXT, filename_tag TEXT,
    mime_enc TEXT, mime_iv TEXT, mime_tag TEXT,
    size INTEGER,
    chunks INTEGER DEFAULT 1,
    store_enc TEXT, store_iv TEXT, store_tag TEXT,
    created_at TEXT DEFAULT (datetime('now')),
    FOREIGN KEY(event_id) REFERENCES events(id)
  )`)

  // Versions
  db.exec(`CREATE TABLE IF NOT EXISTS versions (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    subject_type TEXT,
    subject_id INTEGER,
    snapshot_enc TEXT, snapshot_iv TEXT, snapshot_tag TEXT,
    created_at TEXT DEFAULT (datetime('now'))
  )`)

  // Logs
  db.exec(`CREATE TABLE IF NOT EXISTS logs (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    action TEXT,
    details TEXT,
    source TEXT,
    created_at TEXT DEFAULT (datetime('now'))
  )`)

  // Email Sends
  db.exec(`CREATE TABLE IF NOT EXISTS email_sends (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    day TEXT,
    report_id INTEGER,
    event_id INTEGER,
    category TEXT,
    created_at TEXT DEFAULT (datetime('now')),
    UNIQUE(day, report_id, event_id, category)
  )`)
  
  // Event External (Ensure table exists for integrations)
  db.exec(`CREATE TABLE IF NOT EXISTS event_external (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    source TEXT NOT NULL,
    ext_id TEXT NOT NULL,
    event_id INTEGER NOT NULL,
    created_at TEXT DEFAULT (datetime('now')),
    UNIQUE(source, ext_id),
    FOREIGN KEY(event_id) REFERENCES events(id)
  );`)

  // Event Relations
  db.exec(`CREATE TABLE IF NOT EXISTS event_relations (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    event_id INTEGER NOT NULL,
    target_event_id INTEGER NOT NULL,
    relation_type TEXT,
    created_at TEXT DEFAULT (datetime('now')),
    FOREIGN KEY(event_id) REFERENCES events(id),
    FOREIGN KEY(target_event_id) REFERENCES events(id)
  );`)

  db.exec(`CREATE INDEX IF NOT EXISTS idx_reports_week_id ON reports(week_id)`)
  db.exec(`CREATE INDEX IF NOT EXISTS idx_events_report_id ON events(report_id)`)
  db.exec(`CREATE INDEX IF NOT EXISTS idx_events_parent_event_id ON events(parent_event_id)`)
  db.exec(`CREATE INDEX IF NOT EXISTS idx_event_reviews_event_id ON event_reviews(event_id)`)
  db.exec(`CREATE INDEX IF NOT EXISTS idx_attachments_event_id ON attachments(event_id)`)
  db.exec(`CREATE INDEX IF NOT EXISTS idx_versions_subject ON versions(subject_type, subject_id)`)
  db.exec(`CREATE INDEX IF NOT EXISTS idx_event_external_event_id ON event_external(event_id)`)
  db.exec(`CREATE INDEX IF NOT EXISTS idx_event_relations_event_id ON event_relations(event_id)`)
  db.exec(`CREATE INDEX IF NOT EXISTS idx_event_relations_target_event_id ON event_relations(target_event_id)`)

  return db
}

module.exports = {
  initDB,
  getDB
}