// ============================================================================
// Mock API Handlers
// ============================================================================

import {
  mockCurrentUser,
  mockTokens,
  mockTargetChannels,
  mockExternalChannels,
  mockCreatives,
  mockPlacements,
  mockSubscriptions,
  mockViewsHistory,
  mockAnalyticsOverview,
  mockCostsReportByDay,
  mockCostsReportByWeek,
  mockCostsReportByMonth,
  mockAnalyticsChannelsData,
  mockAnalyticsCreativesData,
} from "./index";

import type {
  ListResponse,
  SuccessResponse,
  ApiError,
  TargetChannel,
  ExternalChannel,
  Creative,
  Placement,
  PlacementCreateRequest,
  PlacementUpdateRequest,
  CreativeCreateRequest,
  ExternalChannelCreateRequest,
  ViewsFetchResponse,
  ViewsHistoryResponse,
  AuthCompleteRequest,
  AuthCompleteResponse,
  AuthRefreshRequest,
  AuthRefreshResponse,
  AuthInitResponse,
  ExternalChannelUpdateRequest,
  CreativeUpdateRequest,
  ExternalChannelsListResponse,
} from "@/lib/types/api";

// Simulate network delay
const delay = (ms: number = 300) =>
  new Promise((resolve) => setTimeout(resolve, ms));

// Helper to generate mock error
const mockError = (code: string, message: string): ApiError => ({
  error: { code, message },
});

// Helper to generate IDs
let idCounter = 1000;
const generateId = () => `mock_${idCounter++}`;

// ============================================================================
// Mock API Handlers
// ============================================================================

export const mockApiHandlers = {
  // --------------------------------------------------------------------------
  // Auth
  // --------------------------------------------------------------------------
  async authInit(): Promise<AuthInitResponse> {
    await delay();
    return {
      bot_username: "tgex_bot",
      start_param: "login",
    };
  },

  async authComplete(
    data: AuthCompleteRequest | { token: string | null }
  ): Promise<{ access_token: string }> {
    await delay();
    if (!data.token) {
      throw mockError("VALIDATION_ERROR", "Token is required");
    }

    // Save mock user to localStorage for later retrieval
    if (typeof window !== "undefined") {
      localStorage.setItem("tgex_user", JSON.stringify(mockCurrentUser));
    }

    return {
      access_token: mockTokens.access_token,
    };
  },

  async authRefresh(data: AuthRefreshRequest): Promise<AuthRefreshResponse> {
    await delay();
    if (!data.refresh_token) {
      throw mockError("VALIDATION_ERROR", "Refresh token is required");
    }
    return {
      access_token: `${mockTokens.access_token}_refreshed`,
    };
  },

  async authMe() {
    await delay();
    return mockCurrentUser;
  },

  // --------------------------------------------------------------------------
  // Target Channels
  // --------------------------------------------------------------------------
  async getTargetChannels() {
    await delay();
    return {
      target_channels: mockTargetChannels,
    };
  },

  async deleteTargetChannel(id: string): Promise<SuccessResponse> {
    await delay();
    const channel = mockTargetChannels.find((c) => c.id === id);
    if (!channel) {
      throw mockError("NOT_FOUND", "Target channel not found");
    }
    return { success: true };
  },

  // --------------------------------------------------------------------------
  // External Channels
  // --------------------------------------------------------------------------
  async getExternalChannels(
    targetChannelId: string
  ): Promise<ExternalChannelsListResponse> {
    await delay();
    // Возвращаем все каналы для указанного target channel
    // В реальном API это будет фильтрация по связям через промежуточную таблицу
    return {
      external_channels: mockExternalChannels,
    };
  },

  async getExternalChannel(id: string): Promise<ExternalChannel> {
    await delay();
    const channel = mockExternalChannels.find((c) => c.id === id);
    if (!channel) {
      throw mockError("NOT_FOUND", "External channel not found");
    }
    return channel;
  },

  async createExternalChannel(
    data: ExternalChannelCreateRequest
  ): Promise<ExternalChannel> {
    await delay(500);
    const newChannel: ExternalChannel = {
      id: generateId(),
      telegram_id: data.telegram_id,
      title: data.title,
      username: data.username || null,
      subscribers_count: data.subscribers_count || null,
      description: data.description || null,
    };
    mockExternalChannels.push(newChannel);
    return newChannel;
  },

  async updateExternalChannel(
    id: string,
    data: ExternalChannelUpdateRequest
  ): Promise<ExternalChannel> {
    await delay();
    const channel = mockExternalChannels.find((c) => c.id === id);
    if (!channel) {
      throw mockError("NOT_FOUND", "External channel not found");
    }
    return {
      ...channel,
      ...data,
    };
  },

  async deleteExternalChannel(id: string): Promise<SuccessResponse> {
    await delay();
    const index = mockExternalChannels.findIndex((c) => c.id === id);
    if (index === -1) {
      throw mockError("NOT_FOUND", "External channel not found");
    }
    mockExternalChannels.splice(index, 1);
    return { success: true };
  },

  async updateExternalChannelLinks(
    id: string,
    data: {
      add_target_channel_ids?: string[];
      remove_target_channel_ids?: string[];
    }
  ): Promise<ExternalChannel> {
    await delay();
    const channel = mockExternalChannels.find((c) => c.id === id);
    if (!channel) {
      throw mockError("NOT_FOUND", "External channel not found");
    }
    // В упрощенной версии просто возвращаем канал
    return channel;
  },

  // --------------------------------------------------------------------------
  // Creatives
  // --------------------------------------------------------------------------
  async getCreatives(params?: {
    target_channel_id?: string;
    include_archived?: boolean;
  }) {
    await delay();
    let filtered = [...mockCreatives];

    if (params?.target_channel_id) {
      filtered = filtered.filter(
        (c) => c.target_channel_id === params.target_channel_id
      );
    }

    if (!params?.include_archived) {
      filtered = filtered.filter((c) => c.status !== "archived");
    }

    return {
      creatives: filtered,
    };
  },

  async getCreative(id: string): Promise<Creative> {
    await delay();
    const creative = mockCreatives.find((c) => c.id === id);
    if (!creative) {
      throw mockError("NOT_FOUND", "Creative not found");
    }
    return creative;
  },

  async createCreative(data: CreativeCreateRequest): Promise<Creative> {
    await delay(500);

    const targetChannel = mockTargetChannels.find(
      (c) => c.id === data.target_channel_id
    );
    if (!targetChannel) {
      throw mockError("NOT_FOUND", "Target channel not found");
    }

    const newCreative: Creative = {
      id: generateId(),
      name: data.name,
      text: data.text,
      target_channel_id: data.target_channel_id,
      target_channel_title: targetChannel.title,
      created_at: new Date().toISOString(),
      status: "active",
      placements_count: 0,
    };
    mockCreatives.push(newCreative);
    return newCreative;
  },

  async updateCreative(
    id: string,
    data: CreativeUpdateRequest
  ): Promise<Creative> {
    await delay();
    const creative = mockCreatives.find((c) => c.id === id);
    if (!creative) {
      throw mockError("NOT_FOUND", "Creative not found");
    }

    if (data.text && !data.text.includes("{link}")) {
      throw mockError(
        "VALIDATION_ERROR",
        "Creative text must contain {link} placeholder"
      );
    }

    return {
      ...creative,
      ...data,
    };
  },

  async deleteCreative(id: string): Promise<SuccessResponse> {
    await delay();
    const creative = mockCreatives.find((c) => c.id === id);
    if (!creative) {
      throw mockError("NOT_FOUND", "Creative not found");
    }

    if (creative.placements_count > 0) {
      throw mockError(
        "CREATIVE_IN_USE",
        "Cannot delete creative with active placements"
      );
    }

    const index = mockCreatives.findIndex((c) => c.id === id);
    mockCreatives.splice(index, 1);
    return { success: true };
  },

  // --------------------------------------------------------------------------
  // Placements (Purchases)
  // --------------------------------------------------------------------------
  async getPlacements(params?: {
    target_channel_id?: string;
    external_channel_id?: string;
    creative_id?: string;
    include_archived?: boolean;
  }) {
    await delay();
    let filtered = [...mockPlacements];

    if (params?.target_channel_id) {
      filtered = filtered.filter(
        (p) => p.target_channel_id === params.target_channel_id
      );
    }

    if (params?.external_channel_id) {
      filtered = filtered.filter(
        (p) => p.external_channel_id === params.external_channel_id
      );
    }

    if (params?.creative_id) {
      filtered = filtered.filter((p) => p.creative_id === params.creative_id);
    }

    if (!params?.include_archived) {
      filtered = filtered.filter((p) => p.status !== "archived");
    }

    return {
      placements: filtered,
    };
  },

  async getPlacement(id: string): Promise<Placement> {
    await delay();
    const placement = mockPlacements.find((p) => p.id === id);
    if (!placement) {
      throw mockError("NOT_FOUND", "Placement not found");
    }
    return placement;
  },

  async createPlacement(data: PlacementCreateRequest): Promise<Placement> {
    await delay(800);

    const targetChannel = mockTargetChannels.find(
      (c) => c.id === data.target_channel_id
    );
    const externalChannel = mockExternalChannels.find(
      (c) => c.id === data.external_channel_id
    );
    const creative = mockCreatives.find((c) => c.id === data.creative_id);

    if (!targetChannel || !externalChannel || !creative) {
      throw mockError("NOT_FOUND", "One of the required entities not found");
    }

    // Generate mock invite link
    const inviteLink = `https://t.me/+${Math.random()
      .toString(36)
      .substring(2, 15)}`;

    const newPlacement: Placement = {
      id: generateId(),
      target_channel_id: data.target_channel_id,
      target_channel_title: targetChannel.title,
      external_channel_id: data.external_channel_id,
      external_channel_title: externalChannel.title,
      creative_id: data.creative_id,
      creative_name: creative.name,
      placement_date: data.placement_date,
      cost: data.cost || null,
      comment: data.comment || null,
      ad_post_url: data.ad_post_url || null,
      invite_link_type: data.invite_link_type || "public",
      invite_link: inviteLink,
      status: "active",
      subscriptions_count: 0,
      views_count: null,
      views_availability: "unknown",
      last_views_fetch_at: null,
      created_at: new Date().toISOString(),
    };

    mockPlacements.push(newPlacement);
    return newPlacement;
  },

  async updatePlacement(
    id: string,
    data: PlacementUpdateRequest
  ): Promise<Placement> {
    await delay();
    const placement = mockPlacements.find((p) => p.id === id);
    if (!placement) {
      throw mockError("NOT_FOUND", "Placement not found");
    }

    return {
      ...placement,
      ...data,
    };
  },

  async deletePlacement(id: string): Promise<SuccessResponse> {
    await delay();
    const index = mockPlacements.findIndex((p) => p.id === id);
    if (index === -1) {
      throw mockError("NOT_FOUND", "Placement not found");
    }
    mockPlacements.splice(index, 1);
    return { success: true };
  },

  async fetchPlacementViews(id: string): Promise<ViewsFetchResponse> {
    await delay(1000);
    const placement = mockPlacements.find((p) => p.id === id);
    if (!placement) {
      throw mockError("NOT_FOUND", "Placement not found");
    }

    // Mock: add some random views
    const newViews =
      (placement.views_count || 0) + Math.floor(Math.random() * 500);

    return {
      placement_id: id,
      views_count: newViews,
      views_availability: "available",
      fetched_at: new Date().toISOString(),
      error_message: null,
    };
  },

  async getPlacementViewsHistory(
    id: string,
    params?: { from_date?: string; to_date?: string }
  ): Promise<ViewsHistoryResponse> {
    await delay();
    const placement = mockPlacements.find((p) => p.id === id);
    if (!placement) {
      throw mockError("NOT_FOUND", "Placement not found");
    }

    const filteredHistory = mockViewsHistory.filter(
      (v) => v.purchase_id === id
    );
    return {
      histories: filteredHistory,
    };
  },

  async setPlacementViewsManually(
    id: string,
    views_count: number
  ): Promise<Placement> {
    await delay();
    const placement = mockPlacements.find((p) => p.id === id);
    if (!placement) {
      throw mockError("NOT_FOUND", "Placement not found");
    }

    return {
      ...placement,
      views_count,
      views_availability: "manual",
      last_views_fetch_at: new Date().toISOString(),
    };
  },

  // --------------------------------------------------------------------------
  // Analytics
  // --------------------------------------------------------------------------
  async getAnalyticsOverview(params?: {
    target_channel_id?: string;
    date_from?: string;
    date_to?: string;
  }) {
    await delay();
    return mockAnalyticsOverview;
  },

  async getAnalyticsCosts(params?: {
    period?: "day" | "week" | "month";
    target_channel_id?: string;
  }) {
    await delay();
    const period = params?.period || "week";

    if (period === "day") {
      return mockCostsReportByDay;
    } else if (period === "month") {
      return mockCostsReportByMonth;
    }
    return mockCostsReportByWeek;
  },

  async getAnalyticsChannels(params?: {
    target_channel_id?: string;
    date_from?: string;
    date_to?: string;
    type?: "external" | "target";
  }) {
    await delay();
    return {
      data: mockAnalyticsChannelsData,
    };
  },

  async getAnalyticsCreatives(params?: {
    target_channel_id?: string;
    date_from?: string;
    date_to?: string;
  }) {
    await delay();
    return {
      data: mockAnalyticsCreativesData,
    };
  },
};