import type { HonoRequest } from "hono";
import isEqual from "lodash.isequal";
import { DateTime, type DurationLike } from "luxon";

import type { Env } from "~/types/env";
import type { WatchStatus } from "~/types/title/watchStatus";

import { FailedToQueueTaskError } from "../errors/FailedToQueueTask";
import { getAdminSdkCredentials } from "../gcloud/getAdminSdkCredentials";
import { getGoogleAuthToken } from "../gcloud/getGoogleAuthToken";
import { getCurrentDomain } from "../getCurrentDomain";
import { buildAnilistRetryTaskId, buildNewEpisodeTaskId } from "./id";
import type { QueueName } from "./queueName";

type QueueBody = {
  "anilist-updates": {
    deviceId: string;
    watchStatus: WatchStatus | null;
    titleId: number;
    isRetrying: true;
  };
  "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;
}

export async function queueTask(
  env: Env,
  queueName: QueueName,
  body: QueueBody[QueueName],
  { scheduleConfig, req }: QueueTaskOptionalArgs = {},
) {
  const domain = req
    ? getCurrentDomain(req)
    : "https://aniplay-v2.rururu.workers.dev";
  if (!domain) {
    console.log("Skipping queue task due to local domain", queueName, body);
    return;
  }

  const adminSdkCredentials = getAdminSdkCredentials(env);
  const { projectId } = adminSdkCredentials;

  const task = buildTask(
    projectId,
    queueName,
    scheduleConfig,
    domain,
    body,
    req?.header(),
  );
  const { res } = await queueCloudTask(task);

  if (!res.ok) {
    if (res.status === 409) {
      if (
        await checkIfTaskExists(
          env,
          queueName,
          task.name.split("/").at(-1)!,
          body,
        )
      ) {
        return;
      } else {
        const hashedTaskName = await import("node:crypto").then(
          ({ createHash }) =>
            createHash("sha256")
              .update(task.name.split("/").at(-1)!)
              .digest("hex"),
        );
        console.log(hashedTaskName);
        console.log(
          {
            ...task,
            name: hashedTaskName,
          },
          {
            ...task,
            name:
              task.name.split("/").slice(0, -1).join("/") +
              "/" +
              hashedTaskName,
          },
        );
        const { res } = await queueCloudTask({
          ...task,
          name:
            task.name.split("/").slice(0, -1).join("/") + "/" + hashedTaskName,
        });
        if (!res.ok) {
          throw new FailedToQueueTaskError(res.status, await res.text());
        }
      }
    }

    throw new FailedToQueueTaskError(res.status, await res.text());
  }

  async function queueCloudTask(task: object) {
    const res = await fetch(
      `https://content-cloudtasks.googleapis.com/v2/projects/${projectId}/locations/northamerica-northeast1/queues/${queueName}/tasks?alt=json`,
      {
        headers: {
          Authorization: `Bearer ${await getGoogleAuthToken(adminSdkCredentials)}`,
          "Content-Type": "application/json",
        },
        body: JSON.stringify({ task }),
        method: "POST",
      },
    );
    return { res };
  }
}

async function checkIfTaskExists(
  env: Env,
  queueName: QueueName,
  taskId: string,
  expectedBody: QueueBody[QueueName],
) {
  const adminSdkCredentials = getAdminSdkCredentials(env);

  const body = await fetch(
    `https://content-cloudtasks.googleapis.com/v2/projects/${adminSdkCredentials.projectId}/locations/northamerica-northeast1/queues/${queueName}/tasks/${taskId}?responseView=FULL`,
    {
      headers: {
        Authorization: `Bearer ${await getGoogleAuthToken(adminSdkCredentials)}`,
      },
    },
  )
    .then((res) => res.json())
    .then(({ httpRequest: { body } }) => body);

  return isEqual(
    JSON.parse(Buffer.from(body as string, "base64").toString()),
    expectedBody,
  );
}

function buildTask(
  projectId: string,
  queueName: QueueName,
  scheduleConfig: ScheduleConfig | undefined,
  domain: string,
  body: QueueBody[QueueName],
  headers: Record<string, string> | undefined,
) {
  let scheduleTime: string | undefined;
  if (scheduleConfig) {
    const { delay, epochTime } = scheduleConfig;
    if (epochTime) {
      scheduleTime = DateTime.fromSeconds(epochTime).toUTC().toISO();
    } else if (delay) {
      scheduleTime = DateTime.now().plus(delay).toUTC().toISO();
    }
  }
  let taskId: string;

  switch (queueName) {
    case "new-episode":
      const { aniListId } = body as QueueBody["new-episode"];
      taskId = buildNewEpisodeTaskId(aniListId);

      return {
        name: `projects/${projectId}/locations/northamerica-northeast1/queues/${queueName}/tasks/${taskId}`,
        scheduleTime,
        httpRequest: {
          url: `${domain}/internal/new-episode`,
          httpMethod: "POST",
          body: Buffer.from(JSON.stringify(body)).toString("base64"),
          headers: {
            "Content-Type": "application/json",
            "X-Anilist-Token": headers?.["X-Anilist-Token"],
          },
        },
      };
    case "anilist-updates":
      const { deviceId, titleId } = body as QueueBody[typeof queueName];
      taskId = buildAnilistRetryTaskId(deviceId, titleId);

      return {
        name: `projects/${projectId}/locations/northamerica-northeast1/queues/${queueName}/tasks/${taskId}`,
        scheduleTime,
        httpRequest: {
          url: `${domain}/watch-status`,
          httpMethod: "POST",
          body: JSON.stringify(body),
          headers: {
            "Content-Type": "application/json",
            "X-Anilist-Token": headers?.["X-Anilist-Token"],
          },
        },
      };
    default:
      throw new Error(`Unknown queue name: ${queueName}`);
  }
}