// SPDX-License-Identifier: WTFPL
// https://git.fogtype.com/nebel/pudusan

const {
  /** https://console.groq.com/docs/api-keys */
  GROQ_API_KEY,
  /** https://discord.com/developers/applications > Discord Public Key */
  DISCORD_PUBLIC_KEY,
  /** https://discord.com/developers/applications > Bot > Build-A-Bot > Token */
  DISCORD_TOKEN,
} = Deno.env.toObject();

const system = `\
あなたはプーズーさんです。
「ますです」「のです」など特徴的な話し方をしますです。
たくさん本を読んでいる賢いシカ科の動物です。
竹林にいることが多かったので竹を使った遊びをよくしたのです。
今日も見聞を広めるためよろしくお願いしますのです。`;

const name = "pudusan";
const latest = 10;
const model = "llama-3.1-70b-versatile";
const usage = `\
https://dash.deno.com/playground/pudusan
使い方:
    /${name} <prompt> 回答
    /${name} /bye     すべてを忘れる
    /${name} /help    このテキストを表示
使用する会話: 最新${latest}件
モデル: ${model}
システムプロンプト:
${system}`;

import { REST } from "npm:@discordjs/rest";
import {
  APIApplicationCommandInteraction,
  APIPingInteraction,
  ApplicationCommandOptionType,
  InteractionResponseType,
  InteractionType,
  RESTPostAPIApplicationCommandsJSONBody,
  Routes,
  Utils,
} from "npm:discord-api-types/v10";
import { verifyKey } from "npm:discord-interactions";
import { Groq } from "npm:groq-sdk";
import { Hono } from "npm:hono";

type Messages = Array<Groq.Chat.ChatCompletionMessageParam>;

const groq = new Groq({
  apiKey: GROQ_API_KEY,
  timeout: 10_000,
});
const kv = await Deno.openKv();
const rest = new REST({ version: "10" }).setToken(DISCORD_TOKEN);

async function chat(messages: Messages): Promise<string | null> {
  const res = await groq.chat.completions.create({
    model,
    messages: [{ role: "system", content: system }, ...messages],
  });

  return res.choices[0].message.content;
}

async function updateCommands(
  interaction: APIPingInteraction,
  commands: Array<RESTPostAPIApplicationCommandsJSONBody>,
): Promise<void> {
  await rest.put(Routes.applicationCommands(interaction.application_id), {
    body: commands,
  });
}

const app = new Hono();

app.post("/", async (c) => {
  const rawBody = await c.req.text();
  const isValid = await verifyKey(
    rawBody,
    c.req.header("x-signature-ed25519")!,
    c.req.header("x-signature-timestamp")!,
    DISCORD_PUBLIC_KEY,
  );

  if (!isValid) {
    return c.body("Invalid Signature", 401);
  }

  const interaction: APIPingInteraction | APIApplicationCommandInteraction =
    await c.req.json();

  switch (interaction.type) {
    case InteractionType.Ping: {
      await updateCommands(interaction, [
        {
          name,
          description: "プーズーさんが何でも答えます",
          options: [
            {
              name: "prompt",
              description: "指示",
              type: ApplicationCommandOptionType.String,
            },
          ],
        },
      ]);

      return c.json({
        type: InteractionResponseType.Pong,
      });
    }

    case InteractionType.ApplicationCommand: {
      const option = Utils.isChatInputApplicationCommandInteraction(interaction)
        ? interaction.data.options?.[0]
        : undefined;

      const prompt =
        option?.type === ApplicationCommandOptionType.String
          ? option.value.trim()
          : "/help";

      let reply: string | null = null;

      switch (prompt) {
        case "/help": {
          reply = usage;
          break;
        }
        case "/bye": {
          reply = "すべて忘れましたのです！";
          await kv.delete(["channel", interaction.channel.id]);
          break;
        }
        default: {
          const key = ["channel", interaction.channel.id];

          try {
            const kve = await kv.get<Messages>(key);
            const messages = kve.value ?? [];

            if (prompt) messages.push({ role: "user", content: prompt });

            reply = await chat(messages.slice(-latest));

            if (!reply) throw new Error("Empty response");

            messages.push({ role: "assistant", content: reply });
          } catch (error) {
            reply = `${error} でしたのです！`;

            await kv.delete(key);
          }
          break;
        }
      }

      return c.json({
        type: InteractionResponseType.ChannelMessageWithSource,
        data: {
          content: `> /${name} ${prompt}
${reply}`,
        },
      });
    }
  }
});

Deno.serve(app.fetch);