import type {
  SessionAnswerResponse,
  SessionQuestionsResponse,
  SessionRequest,
  SessionResponse,
  SubmitAnswer,
} from "../types/session";
import type { PracticeSheet } from "../types/sheet";

const API_URL = "https://ed-dev-api.omukk.dev";

export interface LoginRequest {
  email: string;
  password: string;
}

export interface User {
  email: string;
  name: string;
  role: "STUDENT" | "TEACHER" | "ADMIN";
  avatar_url: string;
  id: string;
  status: "ACTIVE" | "INACTIVE";
  joined_at: string;
  last_active: string;
}

export interface LoginResponse {
  token: string;
  token_type: string;
  user: User;
}

export interface ApiError {
  detail?: string;
  message?: string;
}

class ApiClient {
  private baseURL: string;

  constructor(baseURL: string) {
    this.baseURL = baseURL;
  }

  private async request<T>(
    endpoint: string,
    options: RequestInit = {},
  ): Promise<T> {
    const url = `${this.baseURL}${endpoint}`;

    const config: RequestInit = {
      ...options,
      headers: {
        "Content-Type": "application/json",
        ...options.headers,
      },
    };

    try {
      const response = await fetch(url, config);

      if (!response.ok) {
        const error: ApiError = await response.json().catch(() => ({
          message: "An error occurred",
        }));
        throw new Error(error.detail || error.message || "Request failed");
      }

      return await response.json();
    } catch (error) {
      if (error instanceof Error) {
        throw error;
      }
      throw new Error("Network error occurred");
    }
  }

  // Auth endpoints
  async login(credentials: LoginRequest): Promise<LoginResponse> {
    return this.request<LoginResponse>("/auth/login/", {
      method: "POST",
      body: JSON.stringify(credentials),
    });
  }

  // Authenticated request helper
  async authenticatedRequest<T>(
    endpoint: string,
    token: string,
    options: RequestInit = {},
  ): Promise<T> {
    return this.request<T>(endpoint, {
      ...options,
      headers: {
        ...options.headers,
        Authorization: `Bearer ${token}`,
      },
    });
  }

  // Example: Get user profile (authenticated endpoint)
  async getUserProfile(token: string): Promise<User> {
    return this.authenticatedRequest<User>("/auth/me/", token);
  }

  async getPracticeSheets(
    token: string,
    page: number,
    limit: number,
  ): Promise<any> {
    const queryParams = new URLSearchParams({
      page: page.toString(),
      limit: limit.toString(),
    }).toString();
    return this.authenticatedRequest<any>(
      `/practice-sheets/?${queryParams}`,
      token,
    );
  }

  async getPracticeSheetById(
    token: string,
    sheetId: string,
  ): Promise<PracticeSheet> {
    return this.authenticatedRequest<PracticeSheet>(
      `/practice-sheets/${sheetId}`,
      token,
    );
  }

  async startSession(
    token: string,
    sessionData: SessionRequest,
  ): Promise<SessionResponse> {
    return this.authenticatedRequest<SessionResponse>(`/sessions/`, token, {
      method: "POST",
      body: JSON.stringify(sessionData),
    });
  }

  async fetchSessionQuestions(
    token: string,
    sessionId: string,
  ): Promise<SessionQuestionsResponse> {
    return this.authenticatedRequest<SessionQuestionsResponse>(
      `/sessions/${sessionId}/questions/`,
      token,
    );
  }

  async submitAnswer(
    token: string,
    sessionId: string,
    answerSubmissionData: SubmitAnswer,
  ): Promise<SessionAnswerResponse> {
    return this.authenticatedRequest<SessionAnswerResponse>(
      `/sessions/${sessionId}/answer/`,
      token,
      {
        method: "POST",
        body: JSON.stringify(answerSubmissionData),
      },
    );
  }

  async fetchNextModule(token: string, sessionId: string): Promise<any> {
    return this.authenticatedRequest<any>(
      `/sessions/${sessionId}/next-module/`,
      token,
      {
        method: "POST",
      },
    );
  }

  async fetchSessionStateById(
    token: string,
    sessionId: string,
  ): Promise<SessionResponse> {
    return this.authenticatedRequest<SessionResponse>(
      `/sessions/${sessionId}`,
      token,
    );
  }
}
export const api = new ApiClient(API_URL);