/**
 * @copyright nhcarrigan
 * @license Naomi's Public License
 * @author Naomi Carrigan
 */
import {
  ActionRowBuilder,
  ButtonBuilder,
  ButtonStyle,
  type Message,
  type OmitPartialGroupDMChannel,
} from "discord.js";
import { makeAiRequest } from "../modules/makeAiRequest.js";
import { sendAiResponse } from "../modules/sendAiResponse.js";
import { calculateCost } from "../utils/calculateCost.js";
import { isNaomiMessage } from "../utils/isNaomi.js";
import { logger } from "../utils/logger.js";
import type { MessageParam } from "@anthropic-ai/sdk/resources/index.js";

/**
 * Handles a direct message from a user.
 * @param message - The message payload from Discord.
 */
export const handleDmMessage
  // eslint-disable-next-line max-lines-per-function, max-statements -- We're off by one bloody line.
  = async(message: OmitPartialGroupDMChannel<Message>): Promise<void> => {
    try {
      if (message.author.bot) {
        return;
      }
      const isNaomi = await isNaomiMessage(message);
      if (!isNaomi) {
        return;
      }
      await message.channel.sendTyping();
      const historyRequest = await message.channel.messages.fetch({
        limit: 20,
      });
      const history = [ ...historyRequest.values() ];
      const clearMessageIndex = history.findIndex((messageInner) => {
        return (
          messageInner.content === "<Clear History>"
          && messageInner.author.id === message.client.user.id
        );
      });
      if (clearMessageIndex !== -1) {
        // Remove the clear message and everything sent before it, which means everything after in the array because the array is backwards
        history.splice(clearMessageIndex, history.length - clearMessageIndex);
      }
      const context: Array<MessageParam> = history.
        reverse().
        map((messageInner) => {
          return {
            content: messageInner.content,
            role:
              messageInner.author.id === message.client.user.id
                ? "assistant"
                : "user",
          };
        });
      const { content, usage } = await makeAiRequest(
        context,
        message.author.displayName,
      );
      const cost = calculateCost(usage);

      await sendAiResponse(
        [ ...content, cost ],
        message.channel.send.bind(message.channel),
        message.channel.sendTyping.bind(message.channel),
      );
      await logger.metric("dm_message", 1, { cost });
    } catch (error) {
      await logger.error(
        "message event",
        error instanceof Error
          ? error
          : new Error(String(error)),
      );
      const button = new ButtonBuilder().
        setLabel("Need help?").
        setStyle(ButtonStyle.Link).
        setURL("https://chat.nhcarrigan.com");
      const row = new ActionRowBuilder<ButtonBuilder>().addComponents(button);
      await message.reply({
        components: [ row ],
        content:
          error instanceof Error
            ? error.message
            : "Something went wrong.",
      });
    }
  };