import Database from 'better-sqlite3'
import { join } from 'path'
import bcrypt from 'bcrypt'

let db: Database.Database | null = null

export interface Sermon {
  id?: number
  slug: string
  title: string
  date: string
  dates?: string
  bible_references: string
  personal_appliance: string
  pastors_challenge: string
  worship_songs?: string
  created_at?: string
}

export interface User {
  id?: number
  username: string
  password: string
  email?: string
  first_name?: string
  last_name?: string
  is_admin: number
}

export interface PasswordResetCode {
  id?: number
  email: string
  code: string
  expires_at: string
  created_at?: string
}

export interface SermonNote {
  id?: number
  user_id: number
  sermon_id: number
  notes: string
  created_at?: string
  updated_at?: string
}

export interface Session {
  id?: number
  token: string
  username: string
  expires_at: string
  created_at?: string
}

export interface RateLimit {
  id?: number
  identifier: string
  endpoint: string
  attempts: number
  reset_at: string
}

export function getDatabase() {
  if (!db) {
    const dbPath = join(process.cwd(), 'data', 'sermons.db')
    db = new Database(dbPath)
    
    // Create tables if they don't exist
  db.exec(`
    CREATE TABLE IF NOT EXISTS sermons (
      id INTEGER PRIMARY KEY AUTOINCREMENT,
      slug TEXT UNIQUE NOT NULL,
      title TEXT NOT NULL,
      date TEXT NOT NULL,
      dates TEXT,
      bible_references TEXT NOT NULL,
      personal_appliance TEXT NOT NULL,
      pastors_challenge TEXT NOT NULL,
      worship_songs TEXT,
      archived INTEGER DEFAULT 0,
      created_at DATETIME DEFAULT CURRENT_TIMESTAMP
    )
  `)
    
    db.exec(`
      CREATE TABLE IF NOT EXISTS users (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        username TEXT UNIQUE NOT NULL,
        password TEXT NOT NULL,
        email TEXT,
        first_name TEXT,
        last_name TEXT,
        is_admin INTEGER DEFAULT 0
      )
    `)
    
    db.exec(`
      CREATE TABLE IF NOT EXISTS password_reset_codes (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        email TEXT NOT NULL,
        code TEXT NOT NULL,
        expires_at DATETIME NOT NULL,
        created_at DATETIME DEFAULT CURRENT_TIMESTAMP
      )
    `)
    
    db.exec(`
      CREATE TABLE IF NOT EXISTS sermon_notes (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        user_id INTEGER NOT NULL,
        sermon_id INTEGER NOT NULL,
        notes TEXT NOT NULL,
        created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
        updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
        FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
        FOREIGN KEY (sermon_id) REFERENCES sermons(id) ON DELETE CASCADE,
        UNIQUE(user_id, sermon_id)
      )
    `)
    
    db.exec(`
      CREATE TABLE IF NOT EXISTS sessions (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        token TEXT UNIQUE NOT NULL,
        username TEXT NOT NULL,
        expires_at DATETIME NOT NULL,
        created_at DATETIME DEFAULT CURRENT_TIMESTAMP
      )
    `)
    
    db.exec(`
      CREATE TABLE IF NOT EXISTS rate_limits (
        id INTEGER PRIMARY KEY AUTOINCREMENT,
        identifier TEXT NOT NULL,
        endpoint TEXT NOT NULL,
        attempts INTEGER DEFAULT 1,
        reset_at DATETIME NOT NULL,
        UNIQUE(identifier, endpoint)
      )
    `)
    
    // Insert default admin user from environment variables with hashed password
    const config = useRuntimeConfig()
    const adminUsername = config.adminUsername
    const adminPassword = config.adminPassword
    
    const userExists = db.prepare('SELECT COUNT(*) as count FROM users WHERE username = ?').get(adminUsername) as { count: number }
    if (userExists.count === 0) {
      // Hash the password before storing
      const saltRounds = 10
      const hashedPassword = bcrypt.hashSync(adminPassword, saltRounds)
      db.prepare('INSERT INTO users (username, password, is_admin) VALUES (?, ?, 1)').run(adminUsername, hashedPassword)
    }
  }
  
  return db
}

export function getAllSermons(limit?: number, includeArchived: boolean = false) {
  const db = getDatabase()
  const whereClause = includeArchived ? '' : 'WHERE archived = 0'
  
  if (limit) {
    return db.prepare(`SELECT * FROM sermons ${whereClause} ORDER BY date DESC LIMIT ?`).all(limit) as Sermon[]
  }
  return db.prepare(`SELECT * FROM sermons ${whereClause} ORDER BY date DESC`).all() as Sermon[]
}

export function getArchivedSermons() {
  const db = getDatabase()
  return db.prepare('SELECT * FROM sermons WHERE archived = 1 ORDER BY date DESC').all() as Sermon[]
}

export function archiveSermon(id: number) {
  const db = getDatabase()
  return db.prepare('UPDATE sermons SET archived = 1 WHERE id = ?').run(id)
}

export function getSermonBySlug(slug: string) {
  const db = getDatabase()
  return db.prepare('SELECT * FROM sermons WHERE slug = ?').get(slug) as Sermon | undefined
}

export function createSermon(sermon: Sermon) {
  const db = getDatabase()
  const stmt = db.prepare(`
    INSERT INTO sermons (slug, title, date, dates, bible_references, personal_appliance, pastors_challenge, worship_songs)
    VALUES (?, ?, ?, ?, ?, ?, ?, ?)
  `)
  return stmt.run(
    sermon.slug,
    sermon.title,
    sermon.date,
    sermon.dates || null,
    sermon.bible_references,
    sermon.personal_appliance,
    sermon.pastors_challenge,
    sermon.worship_songs || null
  )
}

export function getUserByUsername(username: string) {
  const db = getDatabase()
  return db.prepare('SELECT * FROM users WHERE username = ?').get(username) as User | undefined
}

export function createUser(username: string, password: string, email?: string, firstName?: string, lastName?: string) {
  const db = getDatabase()
  const saltRounds = 10
  const hashedPassword = bcrypt.hashSync(password, saltRounds)
  return db.prepare('INSERT INTO users (username, password, email, first_name, last_name, is_admin) VALUES (?, ?, ?, ?, ?, 0)')
    .run(username, hashedPassword, email || null, firstName || null, lastName || null)
}

export function getUserByEmail(email: string) {
  const db = getDatabase()
  return db.prepare('SELECT * FROM users WHERE email = ?').get(email) as User | undefined
}

export function createPasswordResetCode(email: string, code: string, expiresAt: string) {
  const db = getDatabase()
  // Delete any existing codes for this email
  db.prepare('DELETE FROM password_reset_codes WHERE email = ?').run(email)
  return db.prepare('INSERT INTO password_reset_codes (email, code, expires_at) VALUES (?, ?, ?)')
    .run(email, code, expiresAt)
}

export function getPasswordResetCode(email: string, code: string) {
  const db = getDatabase()
  return db.prepare("SELECT * FROM password_reset_codes WHERE email = ? AND code = ? AND expires_at > datetime('now')")
    .get(email, code) as PasswordResetCode | undefined
}

export function deletePasswordResetCode(email: string) {
  const db = getDatabase()
  return db.prepare('DELETE FROM password_reset_codes WHERE email = ?').run(email)
}

export function resetPasswordByEmail(email: string, newPassword: string) {
  const db = getDatabase()
  const saltRounds = 10
  const hashedPassword = bcrypt.hashSync(newPassword, saltRounds)
  const result = db.prepare('UPDATE users SET password = ? WHERE LOWER(email) = LOWER(?)').run(hashedPassword, email)
  return result
}

export function getAllUsers() {
  const db = getDatabase()
  return db.prepare('SELECT id, username, email, first_name, last_name, is_admin FROM users ORDER BY username').all() as Omit<User, 'password'>[]
}

export function deleteUser(id: number) {
  const db = getDatabase()
  return db.prepare('DELETE FROM users WHERE id = ?').run(id)
}

export function updateUserRole(id: number, isAdmin: number) {
  const db = getDatabase()
  return db.prepare('UPDATE users SET is_admin = ? WHERE id = ?').run(isAdmin, id)
}

export function resetUserPassword(id: number, newPassword: string) {
  const db = getDatabase()
  const saltRounds = 10
  const hashedPassword = bcrypt.hashSync(newPassword, saltRounds)
  return db.prepare('UPDATE users SET password = ? WHERE id = ?').run(hashedPassword, id)
}

export function getSermonNote(userId: number, sermonId: number) {
  const db = getDatabase()
  return db.prepare('SELECT * FROM sermon_notes WHERE user_id = ? AND sermon_id = ?').get(userId, sermonId) as SermonNote | undefined
}

export function saveSermonNote(userId: number, sermonId: number, notes: string) {
  const db = getDatabase()
  const existing = getSermonNote(userId, sermonId)
  
  if (existing) {
    return db.prepare('UPDATE sermon_notes SET notes = ?, updated_at = CURRENT_TIMESTAMP WHERE user_id = ? AND sermon_id = ?').run(notes, userId, sermonId)
  } else {
    return db.prepare('INSERT INTO sermon_notes (user_id, sermon_id, notes) VALUES (?, ?, ?)').run(userId, sermonId, notes)
  }
}

export function deleteSermonNote(userId: number, sermonId: number) {
  const db = getDatabase()
  return db.prepare('DELETE FROM sermon_notes WHERE user_id = ? AND sermon_id = ?').run(userId, sermonId)
}

// Session management functions
export function createSession(token: string, username: string, expiresAt: string) {
  const db = getDatabase()
  return db.prepare('INSERT INTO sessions (token, username, expires_at) VALUES (?, ?, ?)')
    .run(token, username, expiresAt)
}

export function getSessionByToken(token: string) {
  const db = getDatabase()
  return db.prepare("SELECT * FROM sessions WHERE token = ? AND expires_at > datetime('now')")
    .get(token) as Session | undefined
}

export function deleteSession(token: string) {
  const db = getDatabase()
  return db.prepare('DELETE FROM sessions WHERE token = ?').run(token)
}

export function deleteExpiredSessions() {
  const db = getDatabase()
  return db.prepare("DELETE FROM sessions WHERE expires_at <= datetime('now')").run()
}

// Rate limiting functions
export function checkRateLimit(identifier: string, endpoint: string, maxAttempts: number, windowMinutes: number): boolean {
  const db = getDatabase()
  
  // Clean up expired rate limit records
  db.prepare("DELETE FROM rate_limits WHERE reset_at <= datetime('now')").run()
  
  const existing = db.prepare('SELECT * FROM rate_limits WHERE identifier = ? AND endpoint = ?')
    .get(identifier, endpoint) as RateLimit | undefined
  
  if (!existing) {
    // First attempt - create new record
    const resetAt = new Date(Date.now() + windowMinutes * 60 * 1000).toISOString()
    db.prepare('INSERT INTO rate_limits (identifier, endpoint, attempts, reset_at) VALUES (?, ?, 1, ?)')
      .run(identifier, endpoint, resetAt)
    return true
  }
  
  if (existing.attempts >= maxAttempts) {
    // Rate limit exceeded
    return false
  }
  
  // Increment attempts
  db.prepare('UPDATE rate_limits SET attempts = attempts + 1 WHERE identifier = ? AND endpoint = ?')
    .run(identifier, endpoint)
  return true
}

export function resetRateLimit(identifier: string, endpoint: string) {
  const db = getDatabase()
  return db.prepare('DELETE FROM rate_limits WHERE identifier = ? AND endpoint = ?')
    .run(identifier, endpoint)
}