<?php

namespace App\Http\Controllers;

use App\Models\LeaveRequest;
use App\Models\StaffMember;
use Illuminate\Http\Request;
use Carbon\Carbon;

class LeaveRequestController extends Controller
{


    public function index(Request $request)
    {
        $query = LeaveRequest::with('staff');

        
        if ($request->filled('search')) {
            $search = $request->search;
            $query->whereHas('staff', function($q) use ($search) {
                $q->where('name', 'like', "%{$search}%");
            });
        }

        if ($request->filled('status')) {
            $query->where('status', $request->status);
        } 
        else {

            $query->orderByRaw("FIELD(status, 'PENDING', 'APPROVED', 'REJECTED')");
        }

        $leaveRequests = $query->orderBy('created_at', 'desc')->paginate(15);
        $leaveRequests->appends($request->query());

        $pendingCount = LeaveRequest::where('status', 'PENDING')->count();
        $approvedThisMonth = LeaveRequest::where('status', 'APPROVED')
            ->whereMonth('start_date', Carbon::now()->month)
            ->whereYear('start_date', Carbon::now()->year)
            ->count();

        $data = [
            'leaveRequests'     => $leaveRequests,
            'pendingCount'      => $pendingCount,
            'approvedThisMonth' => $approvedThisMonth,
        ];

        return view('leave.index', $data);
    }
    public function myLeave()
    {

        $staff = StaffMember::where('email', auth()->user()->email)->firstOrFail();
        $leaveRequests = LeaveRequest::where('staff_member_id', $staff->id)
                                     ->orderBy('created_at', 'desc')
                                     ->paginate(10);

        $data = [
            'staff' => $staff,
            'leaveRequests' => $leaveRequests,
        ];

        return view('leave.my_leave', $data);
    }

    public function store(Request $request)
    {
        $validated = $request->validate([
            'staff_member_id' => 'required|exists:staff_members,id',
            'leave_type'      => 'required|string',
            'start_date'      => 'required|date',
            'end_date'        => 'required|date|after_or_equal:start_date',
            'reason'          => 'required|string',
        ]);

        $start = Carbon::parse($validated['start_date']);
        $end = Carbon::parse($validated['end_date']);

        $totalDays = $start->diffInDaysFiltered(function (Carbon $date) {
            return !$date->isWeekend();
        }, $end) + 1; // +1 to include both the start and end day


        if ($validated['leave_type'] === 'Annual') {
            $staff = StaffMember::find($validated['staff_member_id']);
            if ($staff->annual_leave_balance < $totalDays) {
                return response()->json([
                    'success' => false, 
                    'message' => "Insufficient balance. Requested: $totalDays days. Available: {$staff->annual_leave_balance} days."
                ], 422);
            }
        }

        $validated['total_days'] = $totalDays;
        $validated['status'] = 'PENDING';

        LeaveRequest::create($validated);

        return response()->json(['success' => true, 'message' => 'Leave request submitted successfully!']);
    }


    public function updateStatusOld(Request $request, $id)
    {
        $leaveRequest = LeaveRequest::findOrFail($id);

        $validated = $request->validate([
            'status'        => 'required|in:APPROVED,REJECTED',
            'admin_remarks' => 'nullable|string',
        ]);

        if ($validated['status'] === 'APPROVED' && $leaveRequest->status !== 'APPROVED') {
            if ($leaveRequest->leave_type === 'Annual') {
                $staff = $leaveRequest->staff;
                $staff->annual_leave_balance -= $leaveRequest->total_days;
                $staff->save();
            }
        }

        if ($validated['status'] === 'REJECTED' && $leaveRequest->status === 'APPROVED') {
            if ($leaveRequest->leave_type === 'Annual') {
                $staff = $leaveRequest->staff;
                $staff->annual_leave_balance += $leaveRequest->total_days;
                $staff->save();
            }
        }

        $leaveRequest->update([
            'status'        => $validated['status'],
            'admin_remarks' => $validated['admin_remarks'],
            'approved_by'   => auth()->id(),
        ]);

        return response()->json(['success' => true, 'message' => 'Leave status updated successfully!']);
    }
    public function updateStatus(Request $request, $id)
    {
        $leaveRequest = LeaveRequest::findOrFail($id);

        $incomingStatus = strtoupper($request->status);
        $request->merge(['status' => $incomingStatus]);

        $validated = $request->validate([
            'status'        => 'required|in:APPROVED,REJECTED',
            'admin_remarks' => 'nullable|string',
        ]);

        $currentStatus = strtoupper($leaveRequest->status);
        $newStatus = $validated['status'];

        $staff = $leaveRequest->staff; 

        if ($staff && strtolower($leaveRequest->leave_type) === 'annual') { // only annual leave affects leave balance
            
            if ($newStatus === 'APPROVED' && $currentStatus !== 'APPROVED') {
                $staff->annual_leave_balance -= $leaveRequest->total_days;
                $staff->save();
            }

            if ($newStatus === 'REJECTED' && $currentStatus === 'APPROVED') {
                $staff->annual_leave_balance += $leaveRequest->total_days;
                $staff->save();
            }
        }

        $leaveRequest->update([
            'status'        => $newStatus,
            'admin_remarks' => $validated['admin_remarks'] ?? null,
            'approved_by'   => auth()->id(),
        ]);

        return response()->json(['success' => true, 'message' => 'Leave status updated successfully!']);
    }
}