import { env as cloudflareEnv } from "cloudflare:workers";
import type { HonoRequest } from "hono";
import { DateTime, Duration, type DurationLike } from "luxon";

import { AnilistUpdateType } from "~/libs/anilist/updateType.ts";
import type { WatchStatus } from "~/types/title/watchStatus";

import type { QueueName } from "./queueName";

export type QueueBody = {
  ANILIST_UPDATES: {
    [AnilistUpdateType.UpdateWatchStatus]: {
      titleId: number;
      watchStatus: WatchStatus | null;
      aniListToken: string;
    };
    updateType: AnilistUpdateType;
  };
  NEW_EPISODE: { aniListId: number; episodeNumber: number };
};

type ScheduleConfig =
  | { delay: DurationLike; epochTime?: never }
  | { epochTime: number; delay?: never };

interface QueueTaskOptionalArgs {
  scheduleConfig?: ScheduleConfig;
  /** when req is not provided, that means the task is being created locally */
  req?: HonoRequest;
  env?: Cloudflare.Env;
}

export const MAX_DELAY_SECONDS = Duration.fromObject({ hours: 9 }).as(
  "seconds",
);

export async function queueTask(
  queueName: QueueName,
  body: QueueBody[QueueName],
  { scheduleConfig, req, env = cloudflareEnv }: QueueTaskOptionalArgs = {},
) {
  const { scheduleTime, headers } = buildTask(
    queueName,
    scheduleConfig,
    body,
    req?.header(),
  );

  // If delay exceeds 9 hours, store in KV for later processing
  if (scheduleTime > MAX_DELAY_SECONDS) {
    if (!env || !env.DELAYED_TASKS) {
      throw new Error("DELAYED_TASKS KV namespace not available");
    }

    const { generateTaskKey, serializeDelayedTask } =
      await import("./delayedTask");
    const taskId = crypto.randomUUID();
    const scheduledEpochTime = Math.floor(Date.now() / 1000) + scheduleTime;

    const metadata = {
      queueName,
      body,
      headers,
      scheduledEpochTime,
      taskId,
      createdAt: Math.floor(Date.now() / 1000),
      retryCount: 0,
    };

    const key = generateTaskKey(scheduledEpochTime, taskId);
    await env.DELAYED_TASKS.put(key, serializeDelayedTask(metadata));

    console.log(
      `Task stored in KV for delayed execution. Scheduled for: ${new Date(scheduledEpochTime * 1000).toISOString()}, Key: ${key}`,
    );
    return;
  }

  // Otherwise, queue directly
  const contentType =
    headers["Content-Type"] === "application/json" ? "json" : "text";
  if (!env) {
    const Cloudflare = await import("cloudflare").then(
      ({ Cloudflare }) => Cloudflare,
    );
    const client = new Cloudflare({ apiToken: env.CLOUDFLARE_TOKEN });
    let queueId: string | null = null;
    const queues = await client.queues.list({
      account_id: env.CLOUDFLARE_ACCOUNT_ID,
    });
    for await (const queue of queues) {
      if (queueId == queue.queue_name) {
        queueId = queue.queue_id!;
      }
    }
    if (!queueId) {
      throw new Error(`Queue ${queueName} not found`);
    }

    await client.queues.messages.push(queueId, {
      body: { body, headers },
      content_type: contentType,
      delay_seconds: scheduleTime,
      account_id: env.CLOUDFLARE_ACCOUNT_ID,
    });
  } else {
    await env[queueName].send(
      { body, headers },
      {
        contentType,
        delaySeconds: scheduleTime,
      },
    );
  }
}
function buildTask(
  queueName: QueueName,
  scheduleConfig: ScheduleConfig | undefined,
  body: QueueBody[QueueName],
  headers: Record<string, string> | undefined,
) {
  let scheduleTime: number = 0;
  if (scheduleConfig) {
    const { delay, epochTime } = scheduleConfig;
    if (epochTime) {
      console.log("epochTime", epochTime);
      scheduleTime = DateTime.fromSeconds(epochTime)
        .diffNow("second")
        .as("second");
    } else if (delay) {
      console.log("delay", delay);
      scheduleTime = Duration.fromDurationLike(delay).as("second");
    }
  }
  const authorizationHeader = headers?.["X-Anilist-Token"] ? { Authorization: `Bearer ${headers["X-Anilist-Token"]}` } : {};

  switch (queueName) {
    case "ANILIST_UPDATES":
    case "NEW_EPISODE":
      return {
        body,
        scheduleTime,
        headers: {
          ...authorizationHeader,
          "Content-Type": "application/json",
        },
      };
    default:
      throw new Error(`Unknown queue name: ${queueName}`);
  }
}