import type { TypedDocumentNode } from "@graphql-typed-document-node/core";
import { DurableObject } from "cloudflare:workers";
import { print } from "graphql";
import { z } from "zod";

import {
  BrowsePopularQuery,
  GetNextEpisodeAiringAtQuery,
  GetPopularTitlesQuery,
  GetTitleQuery,
  GetTrendingTitlesQuery,
  GetUpcomingTitlesQuery,
  GetUserProfileQuery,
  GetUserQuery,
  MarkEpisodeAsWatchedMutation,
  MarkTitleAsWatchedMutation,
  NextSeasonPopularQuery,
  SearchQuery,
} from "~/libs/anilist/queries";
import { sleep } from "~/libs/sleep.ts";

const nextAiringEpisodeSchema = z.nullable(
  z.object({
    episode: z.number().int(),
    airingAt: z.number().int(),
    timeUntilAiring: z.number().int(),
  }),
);

export class AnilistDurableObject extends DurableObject {
  state: DurableObjectState;

  constructor(state: DurableObjectState, env: Env) {
    super(state, env);
    this.state = state;
  }
  async fetch(request: Request) {
    return new Response("Not found", { status: 404 });
  }

  async getTitle(id: number, token?: string) {
    return this.handleCachedRequest(
      `title:${id}`,
      async () => {
        const anilistResponse = await this.fetchFromAnilist(
          GetTitleQuery,
          { id },
          token,
        );
        return anilistResponse?.Media ?? null;
      },
      (media) => {
        if (!media) return undefined;
        // Cast to any to access fragment fields without unmasking
        const nextAiringEpisode = nextAiringEpisodeSchema.parse(
          (media as any)?.nextAiringEpisode,
        );
        const airingAt = (nextAiringEpisode?.airingAt ?? 0) * 1000;
        if (airingAt) {
          return airingAt - Date.now();
        }
        return undefined;
      },
    );
  }

  async getNextEpisodeAiringAt(id: number) {
    return this.handleCachedRequest(
      `next_airing:${id}`,
      async () => {
        const data = await this.fetchFromAnilist(GetNextEpisodeAiringAtQuery, {
          id,
        });
        return data?.Media;
      },
      60 * 60 * 1000,
    );
  }

  async search(query: string, page: number, limit: number) {
    return this.handleCachedRequest(
      `search:${JSON.stringify({ query, page, limit })}`,
      async () => {
        const data = await this.fetchFromAnilist(SearchQuery, {
          query,
          page,
          limit,
        });
        return data?.Page;
      },
      60 * 60 * 1000,
    );
  }

  async browsePopular(
    season: any,
    seasonYear: number,
    nextSeason: any,
    nextYear: number,
    limit: number,
  ) {
    return this.handleCachedRequest(
      `popular:${JSON.stringify({ season, seasonYear, nextSeason, nextYear, limit })}`,
      async () => {
        console.log(nextSeason, nextYear, print(BrowsePopularQuery));
        return this.fetchFromAnilist(BrowsePopularQuery, {
          season,
          seasonYear,
          nextSeason,
          nextYear,
          limit,
        });
      },
      24 * 60 * 60 * 1000,
    );
  }

  async nextSeasonPopular(nextSeason: any, nextYear: number, limit: number) {
    return this.handleCachedRequest(
      `next_season:${JSON.stringify({ nextSeason, nextYear, limit })}`,
      async () => {
        return this.fetchFromAnilist(NextSeasonPopularQuery, {
          nextSeason,
          nextYear,
          limit,
        });
      },
      24 * 60 * 60 * 1000,
    );
  }

  async getPopularTitles(
    page: number,
    limit: number,
    season: any,
    seasonYear: number,
  ) {
    return this.handleCachedRequest(
      `popular:${JSON.stringify({ page, limit, season, seasonYear })}`,
      async () => {
        const data = await this.fetchFromAnilist(GetPopularTitlesQuery, {
          page,
          limit,
          season,
          seasonYear,
        });
        return data?.Page;
      },
      24 * 60 * 60 * 1000,
    );
  }

  async getTrendingTitles(page: number, limit: number) {
    return this.handleCachedRequest(
      `trending:${JSON.stringify({ page, limit })}`,
      async () => {
        const data = await this.fetchFromAnilist(GetTrendingTitlesQuery, {
          page,
          limit,
        });
        return data?.Page;
      },
      24 * 60 * 60 * 1000,
    );
  }

  async getUpcomingTitles(
    page: number,
    airingAtLowerBound: number,
    airingAtUpperBound: number,
  ) {
    return this.handleCachedRequest(
      `upcoming:${JSON.stringify({ page, airingAtLowerBound, airingAtUpperBound })}`,
      async () => {
        const data = await this.fetchFromAnilist(GetUpcomingTitlesQuery, {
          page,
          airingAtLowerBound,
          airingAtUpperBound,
        });
        return data?.Page;
      },
      24 * 60 * 60 * 1000,
    );
  }

  async getUser(token: string) {
    return this.handleCachedRequest(
      `user:${token}`,
      async () => {
        const data = await this.fetchFromAnilist(GetUserQuery, {}, token);
        return data?.Viewer;
      },
      60 * 60 * 24 * 30 * 1000,
    );
  }

  async getUserProfile(token: string) {
    return this.handleCachedRequest(
      `user_profile:${token}`,
      async () => {
        const data = await this.fetchFromAnilist(
          GetUserProfileQuery,
          { token },
          token,
        );
        return data?.Viewer;
      },
      60 * 60 * 24 * 30 * 1000,
    );
  }

  async markEpisodeAsWatched(
    titleId: number,
    episodeNumber: number,
    token: string,
  ) {
    const data = await this.fetchFromAnilist(
      MarkEpisodeAsWatchedMutation,
      { titleId, episodeNumber },
      token,
    );
    return data?.SaveMediaListEntry;
  }

  async markTitleAsWatched(titleId: number, token: string) {
    const data = await this.fetchFromAnilist(
      MarkTitleAsWatchedMutation,
      { titleId },
      token,
    );
    return data?.SaveMediaListEntry;
  }

  // Helper to handle caching logic
  async handleCachedRequest<T>(
    key: string,
    fetcher: () => Promise<T>,
    ttl?: number | ((data: T) => number | undefined),
  ) {
    const cache = await this.state.storage.get(key);
    console.debug(`Retrieving request ${key} from cache:`, cache != null);
    if (cache) {
      return cache as T;
    }

    const result = await fetcher();
    await this.state.storage.put(key, result);

    const calculatedTtl = typeof ttl === "function" ? ttl(result) : ttl;

    if (calculatedTtl && calculatedTtl > 0) {
      const alarmTime = Date.now() + calculatedTtl;
      await this.state.storage.setAlarm(alarmTime);
      await this.state.storage.put(`alarm:${key}`, alarmTime);
    }

    return result;
  }

  async alarm() {
    const now = Date.now();
    const alarms = await this.state.storage.list({ prefix: "alarm:" });
    for (const [key, ttl] of Object.entries(alarms)) {
      if (now >= ttl) {
        // The key in alarms is `alarm:${storageKey}`
        // We want to delete the storageKey
        const storageKey = key.replace("alarm:", "");
        await this.state.storage.delete(storageKey);
        await this.state.storage.delete(key);
      }
    }
  }

  async fetchFromAnilist<Result = any, Variables = any>(
    query: TypedDocumentNode<Result, Variables>,
    variables: Variables,
    token?: string | undefined,
  ): Promise<Result> {
    const headers: any = {
      "Content-Type": "application/json",
    };

    if (token) {
      headers["Authorization"] = `Bearer ${token}`;
    }

    // Use the query passed in, or fallback if needed (though we expect it to be passed)
    // We print the query to string
    const queryString = print(query);

    const response = await fetch(`${this.env.PROXY_URL}/proxy`, {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
      },
      body: JSON.stringify({
        url: "https://graphql.anilist.co/",
        method: "POST",
        headers, // Pass the original headers here
        data: {
          query: queryString,
          variables,
        },
      }),
    });

    // 1. Handle Rate Limiting (429)
    if (response.status === 429) {
      const retryAfter = await response
        .json()
        .then(({ headers }) => new Headers(headers).get("Retry-After"));
      console.log("429, retrying in", retryAfter);

      await sleep(Number(retryAfter || 1) * 1000); // specific fallback or ensure logic
      return this.fetchFromAnilist(query, variables, token);
    }

    // 2. Handle HTTP Errors (like 404 or 500)
    if (!response.ok) {
      // If it is specifically a 404 Not Found HTTP status
      if (response.status === 404) {
        return undefined;
      }

      if (response.headers.get("Content-Type") === "application/json") {
        console.error(JSON.stringify(await response.json(), null, 2));
      } else {
        console.error(await response.text());
      }
      // Throw for other HTTP errors to be caught by caller
      throw new Error(`HTTP Error: ${response.status} ${response.statusText}`);
    }

    // 3. Parse JSON
    const result = (await response.json().then((json: any) => json.data)) as {
      data?: any;
      errors?: any[];
    };

    // 4. Handle GraphQL Specific Errors (Anilist might return 200 OK but include errors)
    if (result.errors && result.errors.length > 0) {
      const errorMessage = JSON.stringify(result.errors);

      if (errorMessage.includes("Not Found")) {
        return undefined;
      }

      throw new Error(`GraphQL Error: ${errorMessage}`);
    }

    return result.data ?? undefined;
  }
}