import { CommandContext } from "grammy";
import { StatelessQuestion } from "grammy_stateless_question";
import { maxBy } from "std/collections/max_by.ts";
import { debug } from "std/log/mod.ts";
import { getConfig } from "../app/config.ts";
import { generationQueue } from "../app/generationQueue.ts";
import { formatUserChat } from "../utils/formatUserChat.ts";
import { ErisContext } from "./mod.ts";
import { parsePngInfo, PngInfo } from "./parsePngInfo.ts";

type QuestionState = { fileId?: string; params?: Partial<PngInfo> };

export const img2imgQuestion = new StatelessQuestion<ErisContext>(
  "img2img",
  async (ctx, stateString) => {
    const state: QuestionState = JSON.parse(stateString);
    await img2img(ctx, ctx.message.text, false, state);
  },
);

export async function img2imgCommand(ctx: CommandContext<ErisContext>) {
  await img2img(ctx, ctx.match, true);
}

async function img2img(
  ctx: ErisContext,
  match: string | undefined,
  includeRepliedTo: boolean,
  state: QuestionState = {},
): Promise<void> {
  if (!ctx.message?.from?.id) {
    return;
  }

  const config = await getConfig();

  if (config.pausedReason != null) {
    await ctx.reply(`I'm paused: ${config.pausedReason || "No reason given"}`, {
      reply_to_message_id: ctx.message?.message_id,
    });
    return;
  }

  const jobs = await generationQueue.getAllJobs();
  if (jobs.length >= config.maxJobs) {
    await ctx.reply(`The queue is full. Try again later. (Max queue size: ${config.maxJobs})`, {
      reply_to_message_id: ctx.message?.message_id,
    });
    return;
  }

  const userJobs = jobs.filter((job) => job.state.from.id === ctx.message?.from?.id);
  if (userJobs.length >= config.maxUserJobs) {
    await ctx.reply(`You already have ${userJobs.length} jobs in queue. Try again later.`, {
      reply_to_message_id: ctx.message?.message_id,
    });
    return;
  }

  const repliedToMsg = ctx.message.reply_to_message;

  if (includeRepliedTo && repliedToMsg?.photo) {
    const photos = repliedToMsg.photo;
    const biggestPhoto = maxBy(photos, (p) => p.width * p.height);
    if (!biggestPhoto) throw new Error("Message was a photo but had no photos?");
    state.fileId = biggestPhoto.file_id;
    if (!state.params) state.params = {};
    state.params.width = biggestPhoto.width;
    state.params.height = biggestPhoto.height;
  }

  if (ctx.message.photo) {
    const photos = ctx.message.photo;
    const biggestPhoto = maxBy(photos, (p) => p.width * p.height);
    if (!biggestPhoto) throw new Error("Message was a photo but had no photos?");
    state.fileId = biggestPhoto.file_id;
    if (!state.params) state.params = {};
    state.params.width = biggestPhoto.width;
    state.params.height = biggestPhoto.height;
  }

  const repliedToText = repliedToMsg?.text || repliedToMsg?.caption;
  if (includeRepliedTo && repliedToText) {
    // TODO: remove bot command from replied to text
    state.params = parsePngInfo(repliedToText, state.params);
  }

  if (match) {
    state.params = parsePngInfo(match, state.params);
  }

  if (!state.fileId) {
    await ctx.reply(
      "Please show me a picture to repaint." +
        img2imgQuestion.messageSuffixMarkdown(JSON.stringify(state satisfies QuestionState)),
      {
        reply_markup: { force_reply: true, selective: true },
        parse_mode: "Markdown",
        reply_to_message_id: ctx.message?.message_id,
      },
    );
    return;
  }

  if (!state.params?.prompt) {
    await ctx.reply(
      "Please describe the picture you want to repaint." +
        img2imgQuestion.messageSuffixMarkdown(JSON.stringify(state satisfies QuestionState)),
      {
        reply_markup: { force_reply: true, selective: true },
        parse_mode: "Markdown",
        reply_to_message_id: ctx.message?.message_id,
      },
    );
    return;
  }

  const replyMessage = await ctx.reply("Accepted. You are now in queue.", {
    reply_to_message_id: ctx.message?.message_id,
  });

  await generationQueue.pushJob({
    task: { type: "img2img", fileId: state.fileId, params: state.params },
    from: ctx.message.from,
    chat: ctx.message.chat,
    requestMessage: ctx.message,
    replyMessage: replyMessage,
  }, { retryCount: 3, repeatDelayMs: 10_000 });

  debug(`Generation (img2img) enqueued for ${formatUserChat(ctx.message)}`);
}