/**
 * TypeScript types for the leave management module.
 */

// ── Leave Types ──────────────────────────────────────────────

export interface LeaveType {
  id: string;
  organisation_id: string;
  name: string;
  default_days_per_year: number;
  is_paid: boolean;
  created_at: string;
}

// ── Leave Requests ───────────────────────────────────────────

export type LeaveRequestStatus = "pending" | "approved" | "rejected" | "cancelled";

export interface LeaveRequest {
  id: string;
  employee_id: string;
  organisation_id: string;
  leave_type_id: string;
  start_date: string;
  end_date: string;
  days_count: number;
  reason: string | null;
  status: LeaveRequestStatus;
  approved_by: string | null;
  rejected_reason: string | null;
  created_at: string;
  updated_at: string;
}

export interface LeaveRequestWithDetails extends LeaveRequest {
  employee: {
    id: string;
    first_name: string;
    last_name: string;
    email: string;
    job_title: string | null;
  };
  leave_type: LeaveType;
  approver: {
    first_name: string;
    last_name: string;
  } | null;
}

// ── Leave Balances ───────────────────────────────────────────

export interface LeaveBalance {
  leave_type_id: string;
  leave_type_name: string;
  total_days_per_year: number;
  used_days: number;
  approved_days: number;
  remaining_days: number;
  is_paid: boolean;
}

// ── Form Inputs ──────────────────────────────────────────────

export interface CreateLeaveRequestInput {
  employee_id: string;
  leave_type_id: string;
  start_date: string;
  end_date: string;
  days_count: number;
  reason?: string;
}

export interface ApproveLeaveRequestInput {
  leaveRequestId: string;
  action: "approve" | "reject";
  rejectedReason?: string;
}

// ── Helpers ──────────────────────────────────────────────────

export const STATUS_LABELS: Record<LeaveRequestStatus, string> = {
  pending: "Pending",
  approved: "Approved",
  rejected: "Rejected",
  cancelled: "Cancelled",
};

export const STATUS_COLORS: Record<LeaveRequestStatus, string> = {
  pending: "bg-amber-100 text-amber-700 border-amber-200",
  approved: "bg-emerald-100 text-emerald-700 border-emerald-200",
  rejected: "bg-red-100 text-red-700 border-red-200",
  cancelled: "bg-gray-100 text-gray-600 border-gray-200",
};

export const DEFAULT_LEAVE_TYPES = [
  { name: "Annual Leave", default_days_per_year: 20, is_paid: true },
  { name: "Sick Leave", default_days_per_year: 10, is_paid: true },
  { name: "Personal Leave", default_days_per_year: 5, is_paid: true },
  { name: "Bereavement Leave", default_days_per_year: 3, is_paid: true },
  { name: "Unpaid Leave", default_days_per_year: 0, is_paid: false },
];

/**
 * Calculate working days between two dates (excludes weekends).
 */
export function calculateWorkingDays(startDate: string, endDate: string): number {
  const start = new Date(startDate + "T00:00:00");
  const end = new Date(endDate + "T00:00:00");

  if (end < start) return 0;

  let days = 0;
  const current = new Date(start);

  while (current <= end) {
    const dayOfWeek = current.getDay();
    if (dayOfWeek !== 0 && dayOfWeek !== 6) {
      days++;
    }
    current.setDate(current.getDate() + 1);
  }

  return days;
}

export function formatDate(dateStr: string): string {
  return new Date(dateStr + "T00:00:00").toLocaleDateString("en-AU", {
    day: "numeric",
    month: "short",
    year: "numeric",
  });
}

export function formatDateShort(dateStr: string): string {
  return new Date(dateStr + "T00:00:00").toLocaleDateString("en-AU", {
    day: "numeric",
    month: "short",
  });
}