import type {
  TokenResponse,
  UserResponse,
  ConfigResponse,
  ChannelResponse,
  CreateChannelRequest,
  UpdateChannelRequest,
  ScheduleResponse,
  ScheduledSlotResponse,
  CurrentBroadcastResponse,
  CollectionResponse,
  SeriesResponse,
  LibraryItemResponse,
  MediaFilter,
  TranscodeSettings,
  TranscodeStats,
  ActivityEvent,
  ProviderConfig,
  ProviderTestResult,
  ConfigSnapshot,
  ScheduleHistoryEntry,
} from "@/lib/types";

const API_BASE =
  process.env.NEXT_PUBLIC_API_URL ?? "http://localhost:4000/api/v1";

export class ApiRequestError extends Error {
  constructor(
    public readonly status: number,
    message: string,
  ) {
    super(message);
    this.name = "ApiRequestError";
  }
}

async function request<T>(
  path: string,
  options: RequestInit & { token?: string } = {},
): Promise<T> {
  const { token, ...init } = options;
  const headers = new Headers(init.headers);

  if (token) {
    headers.set("Authorization", `Bearer ${token}`);
  }
  if (init.body && !headers.has("Content-Type")) {
    headers.set("Content-Type", "application/json");
  }

  const res = await fetch(`${API_BASE}${path}`, { ...init, headers });

  if (!res.ok) {
    let message = res.statusText;
    try {
      const body = await res.json();
      message = body.message ?? body.error ?? message;
    } catch {
      // ignore parse error, use statusText
    }
    throw new ApiRequestError(res.status, message);
  }

  if (res.status === 204) return null as T;
  return res.json() as Promise<T>;
}

export const api = {
  config: {
    get: () => request<ConfigResponse>("/config"),
  },

  auth: {
    register: (email: string, password: string) =>
      request<TokenResponse>("/auth/register", {
        method: "POST",
        body: JSON.stringify({ email, password }),
      }),

    login: (email: string, password: string) =>
      request<TokenResponse>("/auth/login", {
        method: "POST",
        body: JSON.stringify({ email, password }),
      }),

    logout: (token: string) =>
      request<void>("/auth/logout", { method: "POST", token }),

    me: (token: string) => request<UserResponse>("/auth/me", { token }),
  },

  channels: {
    list: (token: string) =>
      request<ChannelResponse[]>("/channels", { token }),

    get: (id: string, token: string) =>
      request<ChannelResponse>(`/channels/${id}`, { token }),

    create: (data: CreateChannelRequest, token: string) =>
      request<ChannelResponse>("/channels", {
        method: "POST",
        body: JSON.stringify(data),
        token,
      }),

    update: (id: string, data: UpdateChannelRequest, token: string) =>
      request<ChannelResponse>(`/channels/${id}`, {
        method: "PUT",
        body: JSON.stringify(data),
        token,
      }),

    delete: (id: string, token: string) =>
      request<void>(`/channels/${id}`, { method: "DELETE", token }),

    listConfigHistory: (channelId: string, token: string) =>
      request<ConfigSnapshot[]>(`/channels/${channelId}/config/history`, { token }),

    patchConfigSnapshot: (channelId: string, snapId: string, label: string | null, token: string) =>
      request<ConfigSnapshot>(`/channels/${channelId}/config/history/${snapId}`, {
        method: "PATCH",
        body: JSON.stringify({ label }),
        token,
      }),

    restoreConfigSnapshot: (channelId: string, snapId: string, token: string) =>
      request<ChannelResponse>(`/channels/${channelId}/config/history/${snapId}/restore`, {
        method: "POST",
        token,
      }),

    listScheduleHistory: (channelId: string, token: string) =>
      request<ScheduleHistoryEntry[]>(`/channels/${channelId}/schedule/history`, { token }),

    getScheduleGeneration: (channelId: string, genId: string, token: string) =>
      request<ScheduleResponse>(`/channels/${channelId}/schedule/history/${genId}`, { token }),

    rollbackSchedule: (channelId: string, genId: string, token: string) =>
      request<ScheduleResponse>(`/channels/${channelId}/schedule/history/${genId}/rollback`, {
        method: "POST",
        token,
      }),
  },

  library: {
    collections: (token: string, provider?: string) => {
      const params = new URLSearchParams();
      if (provider) params.set("provider", provider);
      const qs = params.toString();
      return request<CollectionResponse[]>(`/library/collections${qs ? `?${qs}` : ""}`, { token });
    },

    series: (token: string, collectionId?: string, provider?: string) => {
      const params = new URLSearchParams();
      if (collectionId) params.set("collection", collectionId);
      if (provider) params.set("provider", provider);
      const qs = params.toString();
      return request<SeriesResponse[]>(`/library/series${qs ? `?${qs}` : ""}`, { token });
    },

    genres: (token: string, contentType?: string, provider?: string) => {
      const params = new URLSearchParams();
      if (contentType) params.set("type", contentType);
      if (provider) params.set("provider", provider);
      const qs = params.toString();
      return request<string[]>(`/library/genres${qs ? `?${qs}` : ""}`, { token });
    },

    items: (
      token: string,
      filter: Pick<MediaFilter, "content_type" | "series_names" | "collections" | "search_term" | "genres">,
      limit = 50,
      strategy?: string,
      provider?: string,
    ) => {
      const params = new URLSearchParams();
      if (filter.search_term) params.set("q", filter.search_term);
      if (filter.content_type) params.set("type", filter.content_type);
      filter.series_names?.forEach((name) => params.append("series[]", name));
      if (filter.collections?.[0]) params.set("collection", filter.collections[0]);
      params.set("limit", String(limit));
      if (strategy) params.set("strategy", strategy);
      if (provider) params.set("provider", provider);
      return request<LibraryItemResponse[]>(`/library/items?${params}`, { token });
    },
  },

  files: {
    rescan: (token: string) =>
      request<{ items_found: number }>("/files/rescan", { method: "POST", token }),
  },

  transcode: {
    getSettings: (token: string) =>
      request<TranscodeSettings>("/files/transcode-settings", { token }),

    updateSettings: (data: TranscodeSettings, token: string) =>
      request<TranscodeSettings>("/files/transcode-settings", {
        method: "PUT",
        body: JSON.stringify(data),
        token,
      }),

    getStats: (token: string) =>
      request<TranscodeStats>("/files/transcode-stats", { token }),

    clearCache: (token: string) =>
      request<void>("/files/transcode-cache", { method: "DELETE", token }),
  },

  admin: {
    activity: (token: string) =>
      request<ActivityEvent[]>("/admin/activity", { token }),

    providers: {
      getProviders: (token: string) =>
        request<ProviderConfig[]>("/admin/providers", { token }),

      updateProvider: (
        token: string,
        type: string,
        payload: { config_json: Record<string, string>; enabled: boolean },
      ) =>
        request<ProviderConfig>(`/admin/providers/${type}`, {
          method: "PUT",
          body: JSON.stringify(payload),
          token,
        }),

      deleteProvider: (token: string, type: string) =>
        request<void>(`/admin/providers/${type}`, { method: "DELETE", token }),

      testProvider: (
        token: string,
        type: string,
        payload: { config_json: Record<string, string>; enabled: boolean },
      ) =>
        request<ProviderTestResult>(`/admin/providers/${type}/test`, {
          method: "POST",
          body: JSON.stringify(payload),
          token,
        }),
    },
  },

  schedule: {
    generate: (channelId: string, token: string) =>
      request<ScheduleResponse>(`/channels/${channelId}/schedule`, {
        method: "POST",
        token,
      }),

    getActive: (channelId: string, token: string) =>
      request<ScheduleResponse>(`/channels/${channelId}/schedule`, { token }),

    getCurrentBroadcast: (channelId: string, token: string, channelPassword?: string) => {
      const headers: Record<string, string> = {};
      if (channelPassword) headers["X-Channel-Password"] = channelPassword;
      return request<CurrentBroadcastResponse | null>(`/channels/${channelId}/now`, {
        token,
        headers,
      });
    },

    getEpg: (
      channelId: string,
      token: string,
      from?: string,
      until?: string,
      channelPassword?: string,
    ) => {
      const params = new URLSearchParams();
      if (from) params.set("from", from);
      if (until) params.set("until", until);
      const qs = params.toString();
      const headers: Record<string, string> = {};
      if (channelPassword) headers["X-Channel-Password"] = channelPassword;
      return request<ScheduledSlotResponse[]>(
        `/channels/${channelId}/epg${qs ? `?${qs}` : ""}`,
        { token, headers },
      );
    },
  },
};