"use node"

import tls from "tls"
import { action } from "./_generated/server"
import { v } from "convex/values"

function b64(input: string) {
  return Buffer.from(input, "utf8").toString("base64")
}

async function sendSmtpMail(cfg: { host: string; port: number; username: string; password: string; from: string }, to: string, subject: string, html: string) {
  return new Promise<void>((resolve, reject) => {
    const socket = tls.connect(cfg.port, cfg.host, { rejectUnauthorized: false }, () => {
      let buffer = ""
      const send = (line: string) => socket.write(line + "\r\n")
      const wait = (expected: string | RegExp) =>
        new Promise<void>((res) => {
          const onData = (data: Buffer) => {
            buffer += data.toString()
            const lines = buffer.split(/\r?\n/)
            const last = lines.filter(Boolean).slice(-1)[0] ?? ""
            if (typeof expected === "string" ? last.startsWith(expected) : expected.test(last)) {
              socket.removeListener("data", onData)
              res()
            }
          }
          socket.on("data", onData)
          socket.on("error", reject)
        })

      ;(async () => {
        await wait(/^220 /)
        send(`EHLO ${cfg.host}`)
        await wait(/^250-/)
        await wait(/^250 /)
        send("AUTH LOGIN")
        await wait(/^334 /)
        send(b64(cfg.username))
        await wait(/^334 /)
        send(b64(cfg.password))
        await wait(/^235 /)
        send(`MAIL FROM:<${cfg.from.match(/<(.+)>/)?.[1] ?? cfg.from}>`)
        await wait(/^250 /)
        send(`RCPT TO:<${to}>`)
        await wait(/^250 /)
        send("DATA")
        await wait(/^354 /)
        const headers = [
          `From: ${cfg.from}`,
          `To: ${to}`,
          `Subject: ${subject}`,
          "MIME-Version: 1.0",
          "Content-Type: text/html; charset=UTF-8",
        ].join("\r\n")
        send(headers + "\r\n\r\n" + html + "\r\n.")
        await wait(/^250 /)
        send("QUIT")
        socket.end()
        resolve()
      })().catch(reject)
    })
    socket.on("error", reject)
  })
}

function buildBaseUrl() {
  return process.env.NEXT_PUBLIC_APP_URL || process.env.APP_BASE_URL || "http://localhost:3000"
}

function emailTemplate({ title, message, ctaLabel, ctaUrl }: { title: string; message: string; ctaLabel: string; ctaUrl: string }) {
  return `
  <table width="100%" cellpadding="0" cellspacing="0" role="presentation" style="background:#f8fafc;padding:24px 0;font-family:Arial,Helvetica,sans-serif;color:#0f172a;">
    <tr>
      <td align="center">
        <table width="600" cellpadding="0" cellspacing="0" role="presentation" style="background:white;border:1px solid #e2e8f0;border-radius:12px;padding:24px;">
          <tr>
            <td style="text-align:left;">
              <div style="display:flex;align-items:center;gap:12px;">
                <img src="${buildBaseUrl()}/logo-raven.png" alt="Raven" style="width:36px;height:36px;border-radius:8px;"/>
                <span style="font-weight:700;font-size:18px;">Raven</span>
              </div>
              <h1 style="font-size:20px;line-height:1.3;margin:16px 0 8px 0;">${title}</h1>
              <p style="font-size:14px;line-height:1.6;margin:0 0 16px 0;color:#334155;">${message}</p>
              <a href="${ctaUrl}" style="display:inline-block;background:#111827;color:#fff;text-decoration:none;border-radius:10px;padding:10px 16px;font-weight:600;">${ctaLabel}</a>
              <p style="font-size:12px;color:#64748b;margin-top:20px;">Se o botão não funcionar, copie e cole esta URL no navegador:<br/><a href="${ctaUrl}" style="color:#0ea5e9;text-decoration:none;">${ctaUrl}</a></p>
            </td>
          </tr>
        </table>
        <p style="font-size:12px;color:#94a3b8;margin-top:12px;">&copy; ${new Date().getFullYear()} Raven — Rever Tecnologia</p>
      </td>
    </tr>
  </table>`
}

export const sendPublicCommentEmail = action({
  args: {
    to: v.string(),
    ticketId: v.string(),
    reference: v.number(),
    subject: v.string(),
  },
  handler: async (_ctx, { to, ticketId, reference, subject }) => {
    const smtp = {
      host: process.env.SMTP_ADDRESS!,
      port: Number(process.env.SMTP_PORT ?? 465),
      username: process.env.SMTP_USERNAME!,
      password: process.env.SMTP_PASSWORD!,
      from: process.env.MAILER_SENDER_EMAIL || "Raven <no-reply@example.com>",
    }
    if (!smtp.host || !smtp.username || !smtp.password) {
      console.warn("SMTP not configured; skipping ticket comment email")
      return { skipped: true }
    }
    const baseUrl = buildBaseUrl()
    const url = `${baseUrl}/portal/tickets/${ticketId}`
    const mailSubject = `Atualização no chamado #${reference}: ${subject}`
    const html = emailTemplate({
      title: `Nova atualização no seu chamado #${reference}`,
      message: `Um novo comentário foi adicionado ao chamado “${subject}”. Clique abaixo para visualizar e responder pelo portal.`,
      ctaLabel: "Abrir e responder",
      ctaUrl: url,
    })
    await sendSmtpMail(smtp, to, mailSubject, html)
    return { ok: true }
  },
})

export const sendResolvedEmail = action({
  args: {
    to: v.string(),
    ticketId: v.string(),
    reference: v.number(),
    subject: v.string(),
  },
  handler: async (_ctx, { to, ticketId, reference, subject }) => {
    const smtp = {
      host: process.env.SMTP_ADDRESS!,
      port: Number(process.env.SMTP_PORT ?? 465),
      username: process.env.SMTP_USERNAME!,
      password: process.env.SMTP_PASSWORD!,
      from: process.env.MAILER_SENDER_EMAIL || "Raven <no-reply@example.com>",
    }
    if (!smtp.host || !smtp.username || !smtp.password) {
      console.warn("SMTP not configured; skipping ticket resolution email")
      return { skipped: true }
    }
    const baseUrl = buildBaseUrl()
    const url = `${baseUrl}/portal/tickets/${ticketId}`
    const mailSubject = `Seu chamado #${reference} foi encerrado`
    const html = emailTemplate({
      title: `Chamado #${reference} encerrado`,
      message: `O chamado “${subject}” foi marcado como concluído. Caso necessário, você pode responder pelo portal para reabrir dentro do prazo.`,
      ctaLabel: "Ver detalhes",
      ctaUrl: url,
    })
    await sendSmtpMail(smtp, to, mailSubject, html)
    return { ok: true }
  },
})