// npm install discord.js@14
// Demo state is in memory. Replace attempts/locks with durable application state.
import { randomUUID } from 'node:crypto';
import {
  ActionRowBuilder, ButtonBuilder, ButtonStyle, Client, Events,
  GatewayIntentBits, MessageFlags, SlashCommandBuilder
} from 'discord.js';
import { createVerification, getVerification } from './sendwich-client.mjs';

const { DISCORD_TOKEN, DISCORD_GUILD_ID, DISCORD_ROLE_ID, SENDWICH_API_KEY } = process.env;
if (!DISCORD_TOKEN || !DISCORD_GUILD_ID || !DISCORD_ROLE_ID || !SENDWICH_API_KEY?.startsWith('veri_live_')) {
  throw new Error('Set the four server environment variables from the documentation.');
}
const client = new Client({ intents: [GatewayIntentBits.Guilds] });
const attempts = new Map();
const locks = new Set();

client.once(Events.ClientReady, async ready => {
  try {
    // Creates/updates this command only; does not replace unrelated commands.
    await ready.application.commands.create(
      new SlashCommandBuilder().setName('인증').setDescription('휴대폰 번호 인증을 시작해요.').toJSON(),
      DISCORD_GUILD_ID
    );
    console.log('sendwich verification command ready.');
  } catch { console.error('Could not register the command. Check Discord permissions.'); }
});

function instructions(attempt) {
  const session = attempt.session;
  return {
    content: `본인 휴대폰에서 아래 문자를 보내 주세요.\n받는 번호: ${session.destination}\n인증 문자: ${session.sms_text}\n만료: <t:${Math.floor(Date.parse(session.expires_at) / 1000)}:R>\n코드를 다른 사람에게 공유하지 마세요. 문자 요금이 발생할 수 있어요.`,
    components: [new ActionRowBuilder().addComponents(
      new ButtonBuilder().setCustomId('sw:check:' + attempt.reference)
        .setLabel('인증 확인').setStyle(ButtonStyle.Primary)
    )],
    allowedMentions: { parse: [] }
  };
}

async function handle(interaction) {
  const start = interaction.isChatInputCommand() && interaction.commandName === '인증';
  const check = interaction.isButton() && interaction.customId.startsWith('sw:check:');
  if ((!start && !check) || interaction.guildId !== DISCORD_GUILD_ID) return;
  // Acknowledge promptly; the SMS may arrive much later.
  if (start) await interaction.deferReply({ flags: MessageFlags.Ephemeral });
  else await interaction.deferUpdate();
  const owner = interaction.guildId + ':' + interaction.user.id;
  if (locks.has(owner)) {
    await interaction.followUp({ content: '확인 중이에요. 잠시 기다려 주세요.', flags: MessageFlags.Ephemeral });
    return;
  }
  locks.add(owner);
  try {
    let attempt = attempts.get(owner);
    if (start) {
      if (!attempt || Date.now() > attempt.keepUntil) {
        attempt = { reference: randomUUID(), state: randomUUID(), keepUntil: Date.now() + 20 * 60000, lastCheck: 0 };
        attempts.set(owner, attempt);
      }
      if (!attempt.session) {
        // A retry after a timeout retains this request and its idempotency key.
        attempt.session = await createVerification({ mode: 'discover', client_reference: attempt.reference, state: attempt.state }, attempt.reference);
      }
      if (Date.parse(attempt.session.expires_at) <= Date.now()) {
        attempts.delete(owner);
        await interaction.editReply({ content: '이전 인증이 만료됐어요. /인증으로 다시 시작해 주세요.', components: [] });
      } else await interaction.editReply(instructions(attempt));
      return;
    }
    if (!attempt?.session || interaction.customId !== 'sw:check:' + attempt.reference) {
      await interaction.editReply({ content: '이 시도를 찾을 수 없어요. /인증으로 다시 시작해 주세요.', components: [] });
      return;
    }
    if (Date.now() - attempt.lastCheck < 5000) return;
    attempt.lastCheck = Date.now();
    const result = await getVerification(attempt.session.id);
    if (result.id !== attempt.session.id || result.environment !== 'live' || result.mode !== 'discover' ||
        result.client_reference !== attempt.reference || result.state !== attempt.state) throw new Error('Unexpected result.');
    if (result.status === 'pending') {
      await interaction.editReply({ ...instructions(attempt), content: instructions(attempt).content + '\n아직 확인되지 않았어요. 전송 후 잠시 뒤 확인해 주세요.' });
      return;
    }
    if (result.status === 'verified' && result.phone) {
      const member = await interaction.guild.members.fetch(interaction.user.id);
      // Adding this one role is idempotent. Do not post the full phone in chat.
      await member.roles.add(DISCORD_ROLE_ID, 'sendwich phone verification');
      await interaction.editReply({ content: '인증됐어요. 역할을 부여했어요.', components: [] });
    } else if (['expired', 'cancelled'].includes(result.status)) {
      await interaction.editReply({ content: '인증이 만료되거나 취소됐어요. /인증으로 다시 시작해 주세요.', components: [] });
    } else throw new Error('Unexpected result.');
    attempts.delete(owner);
  } catch (error) {
    const message = error.code === 'monthly_call_limit'
      ? '서비스의 월 호출 한도에 도달했어요. 운영자에게 문의해 주세요.'
      : '처리하지 못했어요. 잠시 뒤 다시 확인해 주세요. 시작 중이었다면 /인증으로 재시도해 주세요.';
    await interaction.followUp({ content: message, flags: MessageFlags.Ephemeral });
  } finally { locks.delete(owner); }
}

client.on(Events.InteractionCreate, interaction => {
  void handle(interaction).catch(() => console.error('Discord response unavailable.'));
});
setInterval(() => {
  for (const [owner, attempt] of attempts) if (attempt.keepUntil < Date.now() && !locks.has(owner)) attempts.delete(owner);
}, 60000).unref();
await client.login(DISCORD_TOKEN);