export type InstructorStudentIssue = {
  type: 'MISSING_SUBMISSION' | 'COMPLETED_WITHOUT_SUBMISSION' | 'LOW_AVERAGE_SCORE';
  title: string;
  detail: string;
  week?: number;
};

export type InstructorStudent = {
  id: string;
  name: string;
  email: string;
  group: string;
  week: string;
  progress: number;
  commits: number;
  issues: number;
  issueItems: InstructorStudentIssue[];
  lastActive: string;
  online: boolean;
  courseTitle?: string;
};

export type InstructorStudentsSummary = {
  totalStudents: number;
  onlineStudents: number;
  averageProgress: number;
  unresolvedIssues: number;
};

export type InstructorStudentsResponse = {
  organization: {
    id?: string;
    name: string;
  } | null;
  summary: InstructorStudentsSummary;
  students: InstructorStudent[];
};

export type CreateInstructorStudentInput = {
  courseId?: string | null;
  email: string;
  name: string;
  groupId?: string | null;
};

const LMS_API_BASE_URL = (import.meta.env.VITE_API_BASE_URL ?? 'https://workspace.autonomystudio.net/lms-api/api').replace(/\/+$/, '');

export async function listInstructorStudents(accessToken: string, courseId?: string | null): Promise<InstructorStudentsResponse> {
  const query = courseId ? `?courseId=${encodeURIComponent(courseId)}` : '';
  const response = await fetch(`${LMS_API_BASE_URL}/instructor/students${query}`, {
    headers: {
      Authorization: `Bearer ${accessToken}`,
    },
  });

  if (!response.ok) {
    throw new Error(`수강생 현황을 불러오지 못했습니다. (${response.status})`);
  }

  return response.json() as Promise<InstructorStudentsResponse>;
}

export async function createInstructorStudent(
  accessToken: string,
  input: CreateInstructorStudentInput,
): Promise<InstructorStudentsResponse> {
  const response = await fetch(`${LMS_API_BASE_URL}/instructor/students`, {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${accessToken}`,
      'content-type': 'application/json',
    },
    body: JSON.stringify(input),
  });

  if (!response.ok) {
    const payload = await response.json().catch((): null => null);
    const message =
      payload && typeof payload === 'object' && 'message' in payload
        ? String(payload.message)
        : `수강생을 등록하지 못했습니다. (${response.status})`;
    throw new Error(message);
  }

  return response.json() as Promise<InstructorStudentsResponse>;
}

export async function removeInstructorStudent(
  accessToken: string,
  studentId: string,
): Promise<InstructorStudentsResponse> {
  const response = await fetch(`${LMS_API_BASE_URL}/instructor/students/${studentId}`, {
    method: 'DELETE',
    headers: {
      Authorization: `Bearer ${accessToken}`,
    },
  });

  if (!response.ok) {
    const payload = await response.json().catch((): null => null);
    const message =
      payload && typeof payload === 'object' && 'message' in payload
        ? String(payload.message)
        : `수강생을 제외하지 못했습니다. (${response.status})`;
    throw new Error(message);
  }

  return response.json() as Promise<InstructorStudentsResponse>;
}