const API_BASE = process.env.NEXT_PUBLIC_API_URL || "http://localhost:8000";

async function fetchWithAuth(
  url: string,
  options: RequestInit = {},
  token?: string
) {
  const headers: Record<string, string> = {
    "Content-Type": "application/json",
    ...((options.headers as Record<string, string>) || {}),
  };
  if (token) {
    headers["Authorization"] = `Bearer ${token}`;
  }
  const res = await fetch(`${API_BASE}${url}`, { ...options, headers });

  if (res.status === 401) {
    if (typeof window !== "undefined") {
      window.location.href = "/login";
    }
    throw new Error("登录已过期，请重新登录");
  }

  if (!res.ok) {
    let errorDetail = `请求失败 (HTTP ${res.status})`;
    try {
      const error = await res.json();
      errorDetail = error.detail || error.message || errorDetail;
    } catch {
      // 解析失败，使用默认错误信息
    }
    throw new Error(errorDetail);
  }

  if (res.status === 204) {
    return null;
  }

  return res.json();
}

export const api = {
  auth: {
    register: (data: { name: string; email: string; password: string }) =>
      fetchWithAuth("/api/v1/auth/register", {
        method: "POST",
        body: JSON.stringify(data),
      }),
    login: (data: { email: string; password: string }) =>
      fetchWithAuth("/api/v1/auth/login", {
        method: "POST",
        body: JSON.stringify(data),
      }),
    getMe: (token: string) => fetchWithAuth("/api/v1/auth/me", {}, token),
    forgotPassword: (email: string) =>
      fetchWithAuth("/api/v1/auth/forgot-password", {
        method: "POST",
        body: JSON.stringify({ email }),
      }),
    resetPassword: (token: string, newPassword: string) =>
      fetchWithAuth("/api/v1/auth/reset-password", {
        method: "POST",
        body: JSON.stringify({ token, new_password: newPassword }),
      }),
    verifyEmail: (email: string, code: string) =>
      fetchWithAuth("/api/v1/auth/verify-email", {
        method: "POST",
        body: JSON.stringify({ email, code }),
      }),
    resendVerification: (email: string) =>
      fetchWithAuth("/api/v1/auth/resend-verification", {
        method: "POST",
        body: JSON.stringify({ email }),
      }),
    changePassword: (token: string, oldPassword: string, newPassword: string) =>
      fetchWithAuth("/api/v1/auth/change-password", {
        method: "PUT",
        body: JSON.stringify({ old_password: oldPassword, new_password: newPassword }),
      }, token),
    updateProfile: (token: string, data: { name?: string; avatar_url?: string }) =>
      fetchWithAuth("/api/v1/auth/profile", {
        method: "PUT",
        body: JSON.stringify(data),
      }, token),
  },
  queries: {
    list: (token: string) => fetchWithAuth("/api/v1/queries/", {}, token),
    create: (token: string, data: unknown) =>
      fetchWithAuth("/api/v1/queries/", { method: "POST", body: JSON.stringify(data) }, token),
    update: (token: string, id: string, data: unknown) =>
      fetchWithAuth(`/api/v1/queries/${id}`, { method: "PUT", body: JSON.stringify(data) }, token),
    delete: (token: string, id: string) =>
      fetchWithAuth(`/api/v1/queries/${id}`, { method: "DELETE" }, token),
    runNow: (token: string, id: string) =>
      fetchWithAuth(`/api/v1/queries/${id}/run-now`, { method: "POST" }, token),
  },
  citations: {
    list: (token: string, params?: string) =>
      fetchWithAuth(`/api/v1/citations/${params ? `?${params}` : ""}`, {}, token),
    getStats: (token: string) => fetchWithAuth("/api/v1/citations/stats/", {}, token),
  },
  subscriptions: {
    getPlans: async () => {
      const res = await fetch(`${API_BASE}/api/v1/subscriptions/plans`);
      if (!res.ok) throw new Error("获取套餐失败");
      return res.json();
    },
    getCurrent: async (token: string) =>
      fetchWithAuth("/api/v1/subscriptions/current", {}, token),
    subscribe: async (token: string, plan: string) =>
      fetchWithAuth("/api/v1/subscriptions/subscribe", {
        method: "POST",
        body: JSON.stringify({ plan }),
      }, token),
    cancel: async (token: string) =>
      fetchWithAuth("/api/v1/subscriptions/cancel", { method: "POST" }, token),
    getHistory: async (token: string) =>
      fetchWithAuth("/api/v1/subscriptions/history", {}, token),
  },
  admin: {
    getStats: async (token: string) =>
      fetchWithAuth("/api/v1/admin/stats", {}, token),
    getUsers: async (token: string, params?: { skip?: number; limit?: number; search?: string }) => {
      const query = params
        ? "?" + new URLSearchParams(Object.entries(params).filter(([, v]) => v !== undefined) as [string, string][]).toString()
        : "";
      return fetchWithAuth(`/api/v1/admin/users${query}`, {}, token);
    },
    getUserDetail: async (token: string, userId: string) =>
      fetchWithAuth(`/api/v1/admin/users/${userId}`, {}, token),
    toggleUserActive: async (token: string, userId: string) =>
      fetchWithAuth(`/api/v1/admin/users/${userId}/toggle-active`, { method: "POST" }, token),
    updateUserPlan: async (token: string, userId: string, plan: string) =>
      fetchWithAuth(`/api/v1/admin/users/${userId}/update-plan`, {
        method: "PUT",
        body: JSON.stringify({ plan }),
      }, token),
  },
  reports: {
    exportCSV: (token: string, queryId?: string) => {
      const query = queryId ? `?query_id=${queryId}` : "";
      return fetchWithAuth(`/api/v1/reports/export/csv${query}`, {}, token);
    },
    exportPDF: async (token: string, queryId?: string) => {
      const query = queryId ? `?query_id=${queryId}` : "";
      const res = await fetch(`${API_BASE}/api/v1/reports/export/pdf${query}`, {
        headers: { Authorization: `Bearer ${token}` },
      });
      if (!res.ok) throw new Error("导出失败");
      return res.blob();
    },
  },
};