/**
 * Application Configuration
 * Centralized configuration management
 */

import { readFileSync, existsSync } from 'fs'
import { dirname, join } from 'path'
import { fileURLToPath } from 'url'
import { log } from '../middleware/logger.mjs'

const _configDir = dirname(fileURLToPath(import.meta.url))
const _repoRoot = join(_configDir, '..', '..')

/** Default dev API port from repo root `mailflow.dev.port.json` (avoids clashes with other apps on 3000). */
function readDevPortFromFile() {
  try {
    const f = join(_repoRoot, 'mailflow.dev.port.json')
    if (!existsSync(f)) return 3030
    const j = JSON.parse(readFileSync(f, 'utf8'))
    const p = parseInt(String(j.port), 10)
    return Number.isFinite(p) && p > 0 ? p : 3030
  } catch {
    return 3030
  }
}

const nodeEnv = process.env.NODE_ENV || 'development'
const listenPort = process.env.PORT
  ? parseInt(process.env.PORT, 10)
  : nodeEnv === 'production'
    ? 3000
    : readDevPortFromFile()
const defaultLocalBase = `http://localhost:${listenPort}`

/**
 * Environment configuration
 */
export const config = {
  // Server
  port: listenPort,
  nodeEnv,
  isDev: nodeEnv !== 'production',
  isProd: nodeEnv === 'production',

  // URLs
  baseUrl: process.env.BASE_URL || defaultLocalBase,
  frontendUrl: process.env.FRONTEND_URL || 'http://localhost:5173',

  // Appwrite
  appwrite: {
    endpoint: process.env.APPWRITE_ENDPOINT,
    projectId: process.env.APPWRITE_PROJECT_ID,
    apiKey: process.env.APPWRITE_API_KEY,
    databaseId: process.env.APPWRITE_DATABASE_ID,
  },

  // Stripe
  stripe: {
    secretKey: process.env.STRIPE_SECRET_KEY,
    webhookSecret: process.env.STRIPE_WEBHOOK_SECRET,
    prices: {
      basic: process.env.STRIPE_PRICE_BASIC || 'price_basic_monthly',
      pro: process.env.STRIPE_PRICE_PRO || 'price_pro_monthly',
      business: process.env.STRIPE_PRICE_BUSINESS || 'price_business_monthly',
    },
  },

  // Google OAuth
  google: {
    clientId: process.env.GOOGLE_CLIENT_ID,
    clientSecret: process.env.GOOGLE_CLIENT_SECRET,
    redirectUri: process.env.GOOGLE_REDIRECT_URI || `${defaultLocalBase}/api/oauth/gmail/callback`,
  },

  // Microsoft OAuth
  microsoft: {
    clientId: process.env.MICROSOFT_CLIENT_ID,
    clientSecret: process.env.MICROSOFT_CLIENT_SECRET,
    redirectUri: process.env.MICROSOFT_REDIRECT_URI || `${defaultLocalBase}/api/oauth/outlook/callback`,
  },

  // Mistral AI
  mistral: {
    apiKey: process.env.MISTRAL_API_KEY,
  },

  // Rate Limiting
  rateLimit: {
    windowMs: parseInt(process.env.RATE_LIMIT_WINDOW_MS || '60000', 10),
    max: parseInt(process.env.RATE_LIMIT_MAX || '100', 10),
  },

  // CORS (Dev: localhost + 127.0.0.1 für Vite, Browser ruft API oft direkt auf 127.0.0.1:PORT)
  cors: {
    origin:
      process.env.NODE_ENV === 'production'
        ? process.env.CORS_ORIGIN || process.env.FRONTEND_URL || 'http://localhost:5173'
        : [
            process.env.CORS_ORIGIN,
            process.env.FRONTEND_URL,
            'http://localhost:5173',
            'http://127.0.0.1:5173',
          ]
            .filter(Boolean)
            .filter((o, i, a) => a.indexOf(o) === i),
    credentials: true,
  },

  // Free Tier Limits
  freeTier: {
    emailsPerMonth: parseInt(process.env.FREE_TIER_EMAILS_PER_MONTH || '500', 10),
    emailAccounts: 1,
    autoSchedule: false, // manual only
  },

  /** Highest product tier (admin comped plan, PLANS key in stripe.mjs). Optional env: TOP_SUBSCRIPTION_PLAN */
  topSubscriptionPlan: (process.env.TOP_SUBSCRIPTION_PLAN || 'business').trim().toLowerCase(),

  // Admin: comma-separated list of emails with admin rights (e.g. support).
  // support@webklar.com is always included; env adds more.
  adminEmails: (() => {
    const fromEnv = (process.env.ADMIN_EMAILS || '')
      .split(',')
      .map((e) => e.trim().toLowerCase())
      .filter(Boolean)
    return [...new Set(['support@webklar.com', ...fromEnv])]
  })(),

  // Gitea Webhook (Deployment) — trim: trailing newlines in .env break HMAC/Bearer match
  gitea: (() => {
    const secret = (process.env.GITEA_WEBHOOK_SECRET || '').trim()
    const auth = (process.env.GITEA_WEBHOOK_AUTH_TOKEN || '').trim()
    return {
      webhookSecret: secret,
      webhookAuthToken: auth || secret,
    }
  })(),

  /** HMAC secret for Gmail/Outlook OAuth state (recommended in production) */
  oauthStateSecret: process.env.OAUTH_STATE_SECRET || '',
}

/**
 * Required environment variables
 */
const requiredVars = [
  'APPWRITE_ENDPOINT',
  'APPWRITE_PROJECT_ID',
  'APPWRITE_API_KEY',
  'APPWRITE_DATABASE_ID',
  'STRIPE_SECRET_KEY',
  'STRIPE_WEBHOOK_SECRET',
]

/**
 * Optional but recommended variables
 */
const recommendedVars = [
  'MISTRAL_API_KEY',
  'GOOGLE_CLIENT_ID',
  'MICROSOFT_CLIENT_ID',
]

/**
 * Validate configuration
 */
export function validateConfig() {
  const missing = []
  const warnings = []

  // Check required variables
  for (const varName of requiredVars) {
    if (!process.env[varName]) {
      missing.push(varName)
    }
  }

  if (missing.length > 0) {
    log.error(`Fehlende Umgebungsvariablen: ${missing.join(', ')}`)
    process.exit(1)
  }

  // Check recommended variables
  for (const varName of recommendedVars) {
    if (!process.env[varName]) {
      warnings.push(varName)
    }
  }

  if (warnings.length > 0) {
    log.warn(`Optionale Variablen fehlen: ${warnings.join(', ')}`)
  }

  log.success('Konfiguration validiert')
  return true
}

/**
 * Feature flags based on available config
 */
export const features = {
  gmail: () => Boolean(config.google.clientId && config.google.clientSecret),
  outlook: () => Boolean(config.microsoft.clientId && config.microsoft.clientSecret),
  ai: () => Boolean(config.mistral.apiKey),
}

/**
 * Check if an email has admin rights (support, etc.)
 */
export function isAdmin(email) {
  if (!email || typeof email !== 'string') return false
  return config.adminEmails.includes(email.trim().toLowerCase())
}

export default config