import {
  AttachmentBuilder,
  Client,
  Events,
  GatewayIntentBits,
  MessageFlags,
  SlashCommandBuilder,
  type BaseMessageOptions,
} from 'discord.js';
import { VoiceConnectionStatus, entersState } from '@discordjs/voice';
import { Recording } from './recorder.js';
import { FALLBACK_MODEL, MODEL, generateNotes } from './gemini.js';

for (const key of ['DISCORD_TOKEN', 'GEMINI_API_KEY', 'GEMINI_MODEL']) {
  if (!process.env[key]) throw new Error(`Falta la variable de entorno ${key}`);
}

const MAX_MINUTES = 30;
const sessions = new Map<string, Recording>();

const commands = [
  new SlashCommandBuilder().setName('start').setDescription('Empieza a grabar tu canal de voz para tomar notas'),
  new SlashCommandBuilder().setName('stop').setDescription('Termina la grabación y genera las notas'),
];

const client = new Client({ intents: [GatewayIntentBits.Guilds, GatewayIntentBits.GuildVoiceStates] });

function fileName(date: Date) {
  const p = (n: number) => String(n).padStart(2, '0');
  return `notas-${date.getFullYear()}-${p(date.getMonth() + 1)}-${p(date.getDate())}-${p(date.getHours())}${p(date.getMinutes())}.md`;
}

async function finish(guildId: string): Promise<BaseMessageOptions> {
  const rec = sessions.get(guildId);
  if (!rec) return { content: 'No hay ninguna grabación en curso.' };
  sessions.delete(guildId);
  try {
    const tracks = await rec.stop();
    if (tracks.length === 0) return { content: 'No se grabó nada de audio. 🤷' };
    const notes = await generateNotes(tracks, rec.startedAt);
    const minutes = Math.round((Date.now() - rec.startedAt.getTime()) / 60000);
    return {
      content: `📝 Notas listas (${minutes} min, ${tracks.map((t) => t.name).join(', ')})`,
      files: [new AttachmentBuilder(Buffer.from(notes, 'utf8'), { name: fileName(rec.startedAt) })],
    };
  } catch (err) {
    console.error(err);
    return { content: `❌ Error generando las notas: ${(err as Error).message}` };
  } finally {
    await rec.cleanup();
  }
}

// Para cortes automáticos (límite de tiempo, canal vacío, desconexión)
async function autoFinish(guildId: string, reason: string) {
  const rec = sessions.get(guildId);
  if (!rec) return;
  await rec.textChannel.send(`⏹️ ${reason}. Generando notas…`).catch(() => {});
  const msg = await finish(guildId);
  await rec.textChannel.send(msg).catch(console.error);
}

client.once(Events.ClientReady, async (c) => {
  await c.application.commands.set(commands.map((cmd) => cmd.toJSON()));
  console.log(`ready as ${c.user.tag} | modelo: ${MODEL} | respaldo: ${FALLBACK_MODEL ?? '(ninguno)'}`);
});

client.on(Events.InteractionCreate, async (interaction) => {
  if (!interaction.isChatInputCommand()) return;
  console.log(`/${interaction.commandName} de ${interaction.user.tag} en guild ${interaction.guildId}`);
  if (!interaction.inCachedGuild()) {
    console.warn('guild no cacheada: ¿el bot está invitado con el scope "bot"?');
    return interaction.reply({ content: 'El bot no está bien agregado a este servidor.', flags: MessageFlags.Ephemeral });
  }
  const { guildId } = interaction;

  if (interaction.commandName === 'start') {
    const voice = interaction.member.voice.channel;
    if (!voice) {
      return interaction.reply({ content: 'Entrá a un canal de voz primero.', flags: MessageFlags.Ephemeral });
    }
    if (sessions.has(guildId)) {
      return interaction.reply({ content: 'Ya estoy grabando en este servidor.', flags: MessageFlags.Ephemeral });
    }
    if (!interaction.channel?.isSendable()) {
      return interaction.reply({ content: 'No puedo escribir en este canal.', flags: MessageFlags.Ephemeral });
    }
    await interaction.deferReply();
    try {
      const rec = await Recording.start(voice, interaction.channel);
      sessions.set(guildId, rec);
      rec.timer = setTimeout(() => autoFinish(guildId, `Límite de ${MAX_MINUTES} min alcanzado`), MAX_MINUTES * 60_000);
      rec.connection.on(VoiceConnectionStatus.Disconnected, async () => {
        try {
          await Promise.race([
            entersState(rec.connection, VoiceConnectionStatus.Signalling, 5_000),
            entersState(rec.connection, VoiceConnectionStatus.Connecting, 5_000),
          ]);
        } catch {
          autoFinish(guildId, 'Me desconectaron del canal');
        }
      });
      await interaction.editReply(`🔴 Grabando en ${voice}. Usá \`/stop\` para terminar y recibir las notas.`);
    } catch (err) {
      console.error(err);
      await interaction.editReply('❌ No pude conectarme al canal de voz.');
    }
  }

  if (interaction.commandName === 'stop') {
    if (!sessions.has(guildId)) {
      return interaction.reply({ content: 'No hay ninguna grabación en curso.', flags: MessageFlags.Ephemeral });
    }
    await interaction.deferReply();
    await interaction.editReply(await finish(guildId));
  }
});

// Si todos (menos bots) salen del canal, corta solo
client.on(Events.VoiceStateUpdate, (oldState) => {
  const rec = sessions.get(oldState.guild.id);
  if (!rec || oldState.channelId !== rec.voiceChannel.id) return;
  if (rec.voiceChannel.members.every((m) => m.user.bot)) {
    autoFinish(oldState.guild.id, 'Todos salieron del canal');
  }
});

process.on('unhandledRejection', (err) => console.error('unhandledRejection:', err));
client.on(Events.Error, (err) => console.error('client error:', err));

console.log('iniciando bot…');
client.login(process.env.DISCORD_TOKEN);