import express from 'express'
import { mkdir, readFile, writeFile } from 'node:fs/promises'
import path from 'node:path'
import { fileURLToPath } from 'node:url'
import { Resend } from 'resend'

const __filename = fileURLToPath(import.meta.url)
const __dirname = path.dirname(__filename)
const DATA_DIR = path.join(__dirname, 'data')
const DATA_FILE = path.join(DATA_DIR, 'admin-content.json')
const DIST_DIR = path.join(__dirname, 'dist')
const INDEX_FILE = path.join(DIST_DIR, 'index.html')

const app = express()
app.use(express.json({ limit: '10mb' }))

app.get('/api/admin-content', async (_req, res) => {
  try {
    const raw = await readFile(DATA_FILE, 'utf8')
    const parsed = JSON.parse(raw)
    res.json(parsed)
  } catch {
    res.status(404).json({ message: 'No saved admin content file yet.' })
  }
})

app.put('/api/admin-content', async (req, res) => {
  try {
    const { siteContent } = req.body ?? {}

    if (!siteContent || typeof siteContent !== 'object' || Array.isArray(siteContent)) {
      res.status(400).json({ message: 'Invalid payload: siteContent must be an object.' })
      return
    }

    await mkdir(DATA_DIR, { recursive: true })
    await writeFile(
      DATA_FILE,
      JSON.stringify({ siteContent, updatedAt: new Date().toISOString() }, null, 2),
      'utf8',
    )

    res.json({ ok: true })
  } catch {
    res.status(500).json({ message: 'Failed to persist admin content.' })
  }
})

// Rate-limit contact submissions: max 5 per IP per 10 minutes
const contactHits = new Map()
function contactRateLimit(req, res, next) {
  const ip = req.ip ?? 'unknown'
  const now = Date.now()
  const windowMs = 10 * 60 * 1000
  const entry = contactHits.get(ip) ?? { count: 0, start: now }
  if (now - entry.start > windowMs) {
    entry.count = 0
    entry.start = now
  }
  entry.count += 1
  contactHits.set(ip, entry)
  if (entry.count > 5) {
    res.status(429).json({ message: 'Too many messages. Please wait a few minutes.' })
    return
  }
  next()
}

app.post('/api/contact', contactRateLimit, async (req, res) => {
  try {
    const { name, email, message, _honey } = req.body ?? {}

    // Honeypot — silently discard if filled by a bot
    if (_honey) {
      res.json({ ok: true })
      return
    }

    if (!name || typeof name !== 'string' || name.trim().length < 1 || name.trim().length > 200) {
      res.status(400).json({ message: 'Name is required.' })
      return
    }
    if (!email || typeof email !== 'string' || !/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email.trim())) {
      res.status(400).json({ message: 'A valid email address is required.' })
      return
    }
    if (!message || typeof message !== 'string' || message.trim().length < 5 || message.trim().length > 3000) {
      res.status(400).json({ message: 'Message must be between 5 and 3000 characters.' })
      return
    }

    if (!process.env.RESEND_API_KEY) {
      console.error('[contact] RESEND_API_KEY env var not set')
      res.status(503).json({ message: 'The contact form is not yet configured on the server.' })
      return
    }

    const resend = new Resend(process.env.RESEND_API_KEY)
    const { error } = await resend.emails.send({
      from: process.env.RESEND_FROM ?? 'Verse by Verse <onboarding@resend.dev>',
      to: [process.env.RESEND_TO ?? 'vbvwithnate@outlook.com'],
      reply_to: `${name.trim()} <${email.trim()}>`,
      subject: `New message from Verse by Verse website — ${name.trim()}`,
      text: `Name: ${name.trim()}\nEmail: ${email.trim()}\n\nMessage:\n${message.trim()}`,
    })
    if (error) throw error

    res.json({ ok: true })
  } catch (err) {
    console.error('[contact] send error:', err)
    res.status(500).json({ message: 'Failed to send your message. Please try again or email us directly.' })
  }
})

app.use(express.static(DIST_DIR))

app.use(async (_req, res) => {
  try {
    const html = await readFile(INDEX_FILE, 'utf8')
    res.type('html').send(html)
  } catch {
    res.status(503).send('Frontend build not found. Run "npm run build" first.')
  }
})

const PORT = Number(process.env.PORT ?? 4173)
app.listen(PORT, () => {
  console.log(`Portfolio app listening on http://localhost:${PORT}`)
})