import { apiRequestData } from "./http";

export type LeaveSession = "am" | "pm";
export type LeaveRequestStatus = "draft" | "reviewing" | "approved" | "rejected" | "cancelled";

export type LeaveType = {
  id: string;
  code: string;
  name: string;
  description: string | null;
  enabled: boolean;
  requiresAttachment: boolean;
  attachmentMimeTypes: string[];
  sortOrder: number;
  policy: {
    id: string;
    annualQuotaDays: number;
    enabled: boolean;
    description: string | null;
  } | null;
  createdAt: string | null;
  updatedAt: string | null;
};

export type LeaveBalanceItem = {
  leaveType: LeaveType;
  policy: {
    id: string;
    annualQuotaDays: number;
    enabled: boolean;
    description: string | null;
  };
  granted: number;
  adjusted: number;
  reserved: number;
  used: number;
  available: number;
  periodStart: string | null;
  periodEnd: string | null;
};

export type LeaveRequestItem = {
  id: string;
  ownerId: string;
  departmentId: string;
  status: LeaveRequestStatus;
  startDate: string;
  endDate: string;
  startSession: LeaveSession;
  endSession: LeaveSession;
  requestedDays: number;
  reason: string | null;
  attachment: {
    originalName: string | null;
    mimeType: string | null;
  } | null;
  leaveType: {
    id: string;
    code: string;
    name: string;
    requiresAttachment: boolean;
    attachmentMimeTypes: string[];
  } | null;
  owner: {
    id: string;
    employeeNo: string;
    name: string;
  } | null;
  createdAt: string | null;
  updatedAt: string | null;
};

export type LeaveRequestListResponse = {
  page: number;
  pageSize: number;
  total: number;
  scope: "own" | "all";
  items: LeaveRequestItem[];
};

export type LeaveBalanceResponse = {
  employeeId: string;
  items: LeaveBalanceItem[];
};

export type LeaveWorkingDaysPreview = {
  requestedDays: number;
  naturalRequestedDays: number;
  holidayDayCount: number;
  weekendDayCount: number;
  adjustedWorkdayCount: number;
  calendarApplied: boolean;
};

export type LeaveListQuery = {
  status?: LeaveRequestStatus;
  scope?: "own" | "all";
  page?: number;
  pageSize?: number;
  dateFrom?: string;
  dateTo?: string;
  departmentId?: string;
};

function toQueryString(query: Record<string, string | number | undefined>) {
  const params = new URLSearchParams();
  for (const [key, value] of Object.entries(query)) {
    if (value == null || value === "") {
      continue;
    }
    params.set(key, String(value));
  }
  const encoded = params.toString();
  return encoded ? `?${encoded}` : "";
}

export async function fetchLeaveTypes(params?: { enabled?: boolean }) {
  return apiRequestData<{ items: LeaveType[] }>(
    `/api/leave-types${toQueryString({ enabled: params?.enabled == null ? undefined : String(params.enabled) })}`,
  );
}

export async function createLeaveType(payload: {
  code: string;
  name: string;
  description?: string | null;
  enabled?: boolean;
  requiresAttachment?: boolean;
  attachmentMimeTypes?: string[];
  sortOrder?: number;
  annualQuotaDays: number;
  policyDescription?: string | null;
}) {
  return apiRequestData<LeaveType>("/api/leave-types", {
    method: "POST",
    body: JSON.stringify(payload),
  });
}

export async function patchLeaveType(
  leaveTypeId: string,
  payload: Partial<{
    code: string;
    name: string;
    description: string | null;
    enabled: boolean;
    requiresAttachment: boolean;
    attachmentMimeTypes: string[];
    sortOrder: number;
    annualQuotaDays: number;
    policyDescription: string | null;
  }>,
) {
  return apiRequestData<LeaveType>(`/api/leave-types/${leaveTypeId}`, {
    method: "PATCH",
    body: JSON.stringify(payload),
  });
}

export async function fetchLeaveBalances(employeeId?: string) {
  return apiRequestData<LeaveBalanceResponse>(
    `/api/leave-balances${toQueryString({ employeeId })}`,
  );
}

export async function fetchLeaveRequests(query: LeaveListQuery = {}) {
  return apiRequestData<LeaveRequestListResponse>(
    `/api/leave-requests${toQueryString(query as Record<string, string | number | undefined>)}`,
  );
}

export async function fetchLeaveRequestDetail(leaveRequestId: string) {
  return apiRequestData<LeaveRequestItem>(`/api/leave-requests/${leaveRequestId}`);
}

export async function fetchLeaveWorkingDaysPreview(query: {
  startDate: string;
  endDate: string;
  startSession: LeaveSession;
  endSession: LeaveSession;
}) {
  return apiRequestData<LeaveWorkingDaysPreview>(
    `/api/leave-requests/working-days${toQueryString(query)}`,
  );
}

export async function createLeaveRequest(payload: {
  leaveTypeId: string;
  startDate: string;
  endDate: string;
  startSession: LeaveSession;
  endSession: LeaveSession;
  reason?: string;
  file?: File | null;
}) {
  const formData = new FormData();
  formData.append("leaveTypeId", payload.leaveTypeId);
  formData.append("startDate", payload.startDate);
  formData.append("endDate", payload.endDate);
  formData.append("startSession", payload.startSession);
  formData.append("endSession", payload.endSession);
  if (payload.reason?.trim()) {
    formData.append("reason", payload.reason.trim());
  }
  if (payload.file) {
    formData.append("file", payload.file);
  }

  return apiRequestData<LeaveRequestItem>("/api/leave-requests", {
    method: "POST",
    body: formData,
  });
}

export async function submitLeaveRequest(leaveRequestId: string) {
  return apiRequestData<Record<string, unknown>>(`/api/leave-requests/${leaveRequestId}/submit`, {
    method: "POST",
  body: JSON.stringify({}),
  });
}

export async function patchLeaveRequest(
  leaveRequestId: string,
  payload: {
    leaveTypeId: string;
    startDate: string;
    endDate: string;
    startSession: LeaveSession;
    endSession: LeaveSession;
    reason?: string;
    file?: File | null;
  },
) {
  const formData = new FormData();
  formData.append("leaveTypeId", payload.leaveTypeId);
  formData.append("startDate", payload.startDate);
  formData.append("endDate", payload.endDate);
  formData.append("startSession", payload.startSession);
  formData.append("endSession", payload.endSession);
  if (payload.reason?.trim()) {
    formData.append("reason", payload.reason.trim());
  }
  if (payload.file) {
    formData.append("file", payload.file);
  }

  return apiRequestData<LeaveRequestItem>(`/api/leave-requests/${leaveRequestId}`, {
    method: "PATCH",
    body: formData,
  });
}

export async function withdrawLeaveRequest(leaveRequestId: string, comment?: string) {
  return apiRequestData<Record<string, unknown>>(`/api/leave-requests/${leaveRequestId}/withdraw`, {
    method: "POST",
    body: JSON.stringify({ comment }),
  });
}