const BASE_URL = import.meta.env.VITE_API_URL || '/app/api';

async function request<T>(path: string, options: RequestInit = {}): Promise<T> {
  const token = localStorage.getItem('auth_token');
  const headers: Record<string, string> = {
    'Content-Type': 'application/json',
    ...(token ? { Authorization: `Bearer ${token}` } : {}),
    ...(options.headers as Record<string, string> || {}),
  };

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

  if (res.status === 401) {
    localStorage.removeItem('auth_token');
    window.location.href = '/login';
    throw new Error('Unauthorized');
  }

  if (!res.ok) {
    const err = await res.json().catch(() => ({ detail: res.statusText }));
    throw new Error(err.detail || `HTTP ${res.status}`);
  }

  return res.json();
}

// Backend responses use a unified envelope `{code, data, message}`.
// `request<T>()` returns the raw envelope; `data<T>()` unwraps `.data`.
async function data<T>(path: string, options: RequestInit = {}): Promise<T> {
  const env = await request<{ code: number; data: T; message: string }>(path, options);
  return env.data;
}

// ─── Auth ───────────────────────────────────────────────────────────────────────

export const authApi = {
  login: (data: { username: string; password: string }) =>
    request<{ access_token: string; token_type: string }>('/auth/login', {
      method: 'POST',
      body: JSON.stringify(data),
    }),

  register: (data: { username: string; email: string; password: string; code: string }) =>
    request<{ access_token: string }>('/auth/register', {
      method: 'POST',
      body: JSON.stringify(data),
    }),

  me: () => request<{ id: string; username: string; email: string; avatar_url: string }>('/auth/me'),

  logout: () => request('/auth/logout', { method: 'POST' }),

  sendCode: (data: { email: string }) =>
    request('/auth/send-code', { method: 'POST', body: JSON.stringify(data) }),
};

// ─── Chat ────────────────────────────────────────────────────────────────────────

export interface Conversation {
  id: string;
  title: string;
  model: string;
  created_at: string;
  updated_at: string;
  message_count: number;
}

export interface ChatMessage {
  id: string;
  conversation_id: string;
  role: 'user' | 'assistant';
  content: string;
  model: string;
  created_at: string;
}

export const chatApi = {
  listConversations: () => request<Conversation[]>('/chat/conversations'),

  createConversation: (data: { title?: string; model?: string }) =>
    request<Conversation>('/chat/conversations', {
      method: 'POST',
      body: JSON.stringify(data),
    }),

  deleteConversation: (id: string) =>
    request(`/chat/conversations/${id}`, { method: 'DELETE' }),

  getMessages: (convId: string) =>
    request<ChatMessage[]>(`/chat/conversations/${convId}/messages`),

  sendMessage: (convId: string, data: { content: string; model?: string }) =>
    request<ChatMessage>(`/chat/conversations/${convId}/messages`, {
      method: 'POST',
      body: JSON.stringify(data),
    }),

  streamMessage: async function* (convId: string, data: { content: string; model?: string }) {
    const token = localStorage.getItem('auth_token');
    const res = await fetch(`${BASE_URL}/chat/conversations/${convId}/messages/stream`, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        ...(token ? { Authorization: `Bearer ${token}` } : {}),
      },
      body: JSON.stringify(data),
    });

    const reader = res.body?.getReader();
    const decoder = new TextDecoder();

    if (!reader) return;

    while (true) {
      const { done, value } = await reader.read();
      if (done) break;
      const chunk = decoder.decode(value);
      const lines = chunk.split('\n').filter(l => l.startsWith('data: '));
      for (const line of lines) {
        try {
          const data = JSON.parse(line.slice(6));
          if (data.content) yield data.content;
        } catch {}
      }
    }
  },

  getModels: () => request<{ id: string; name: string; provider: string }[]>('/chat/models'),
};

// ─── Knowledge ───────────────────────────────────────────────────────────────────

export interface KnowledgeBase {
  id: string;
  name: string;
  description: string;
  document_count: number;
  status: 'active' | 'building' | 'error';
  created_at: string;
  updated_at: string;
}

export const knowledgeApi = {
  listBases: () => request<KnowledgeBase[]>('/knowledge/bases'),

  createBase: (data: { name: string; description?: string }) =>
    request<KnowledgeBase>('/knowledge/bases', {
      method: 'POST',
      body: JSON.stringify(data),
    }),

  deleteBase: (id: string) =>
    request(`/knowledge/bases/${id}`, { method: 'DELETE' }),

  search: (baseId: string, query: string) =>
    request<{ results: { content: string; score: number; source: string }[] }>(
      `/knowledge/bases/${baseId}/search?q=${encodeURIComponent(query)}`
    ),

  getDocuments: (baseId: string) =>
    request<{ id: string; name: string; status: string; size: number }[]>(
      `/knowledge/bases/${baseId}/documents`
    ),
};

// ─── Market / Apps ──────────────────────────────────────────────────────────────

export interface MarketApp {
  id: string;
  name: string;
  description: string;
  icon: string;
  category: string;
  status: 'enabled' | 'disabled';
  type: 'standalone' | 'embedded';
  downloads: number;
  rating: number;
}

export const marketApi = {
  listApps: () => request<MarketApp[]>('/market/apps'),

  getMyApps: () => request<MarketApp[]>('/market/my-apps'),

  installApp: (appId: string) =>
    request(`/market/apps/${appId}/install`, { method: 'POST' }),

  uninstallApp: (appId: string) =>
    request(`/market/apps/${appId}/uninstall`, { method: 'DELETE' }),

  getAds: () => request<{ id: string; title: string; image_url: string; url: string }[]>('/market/ads'),
};

// ─── IM Bot ──────────────────────────────────────────────────────────────────────

export interface ImBotStatus {
  status: 'connected' | 'disconnected' | 'expired';
  ilink_bot_id: string;
  connected_at: string;
  last_active: string;
  message_count: number;
}

export const imBotApi = {
  getStatus: () => request<ImBotStatus>('/im-bot/status'),

  getQRCode: () => request<{ qr_url: string; expire_at: string }>('/im-bot/qrcode'),

  checkQRStatus: (ticket: string) =>
    request<{ status: string }>('/im-bot/qrcode/status', {
      method: 'POST',
      body: JSON.stringify({ ticket }),
    }),

  disconnect: () => request('/im-bot/disconnect', { method: 'POST' }),

  getHistory: () => request<{ id: string; role: string; content: string; created_at: string }[]>('/im-bot/history'),
};

// ─── Profile ─────────────────────────────────────────────────────────────────────

export interface UserProfile {
  id: string;
  username: string;
  email: string;
  avatar_url: string;
  balance: number;
  membership: string;
}

export const profileApi = {
  get: () => request<UserProfile>('/profile/'),
  update: (data: Partial<UserProfile>) =>
    request<UserProfile>('/profile/', { method: 'PUT', body: JSON.stringify(data) }),

  getBalance: () => request<{ balance: number; total_used: number }>('/profile/balance'),
};

// ─── Token 驾驶舱 ────────────────────────────────────────────────────────────────

export interface TokenOverview {
  total_used: number;
  balance: number;
  today_apps: number;
  server_time: string;
}

export interface ModelRanking {
  model_id: string;
  model_name: string;
  total_tokens: number;
  usage_count: number;
}

export interface TopApp {
  conversation_id: string;
  total_tokens: number;
}

export interface TokenRankings {
  model_rankings: ModelRanking[];
  top_apps: TopApp[];
}

export interface TokenLogItem {
  id: string;
  model_id: string;
  model_name: string;
  prompt_tokens: number;
  completion_tokens: number;
  total_tokens: number;
  conversation_id: string;
  created_at: string | null;
}

export interface TokenLogPage {
  total: number;
  page: number;
  page_size: number;
  items: TokenLogItem[];
}

export interface TokenBalance {
  balance: number;
  updated_at: string | null;
}

export const tokenApi = {
  getOverview: () => data<TokenOverview>('/token/overview'),

  getRankings: () => data<TokenRankings>('/token/rankings'),

  getLogs: (params: {
    start_date?: string;
    end_date?: string;
    model_id?: string;
    app_type?: string;
    page?: number;
    page_size?: number;
  } = {}) => {
    const qs = new URLSearchParams();
    if (params.start_date) qs.set('start_date', params.start_date);
    if (params.end_date) qs.set('end_date', params.end_date);
    if (params.model_id) qs.set('model_id', params.model_id);
    if (params.app_type) qs.set('app_type', params.app_type);
    if (params.page) qs.set('page', String(params.page));
    if (params.page_size) qs.set('page_size', String(params.page_size));
    const q = qs.toString();
    return data<TokenLogPage>(`/token/logs${q ? `?${q}` : ''}`);
  },

  getBalance: () => data<TokenBalance>('/token/balance'),
};