@extends('layouts.app')

@section('content')
<div class="max-w-6xl mx-auto space-y-8">
    <div class="flex items-center gap-4 mb-4">
        <a href="{{ route('staff.dashboard') }}" class="btn-icon-slate">
            <span class="material-icons-round">arrow_back</span>
        </a>
        <div class="flex-1">
            <h2 class="text-3xl font-black text-slate-800 tracking-tight">Select Your <span class="text-brand-primary">Subjects</span></h2>
            <p class="text-slate-500 mt-1 flex items-center gap-2">
                <span class="w-1.5 h-1.5 rounded-full bg-brand-primary"></span>
                Choose subjects from any category you wish to teach
            </p>
        </div>
        <div class="text-right">
            <div class="text-sm font-bold text-slate-600">Selected: <span id="selected-count" class="text-brand-primary">{{ $selectedCount }}</span> / {{ $maxSubjectsPerFaculty }}</div>
            <div class="text-xs text-slate-400 mt-1">Maximum {{ $maxSubjectsPerFaculty }} subjects allowed</div>
        </div>
    </div>

    @if(session('success'))
    <div class="bg-green-50 border border-green-200 text-green-700 px-6 py-4 rounded-2xl flex items-center gap-3">
        <span class="material-icons-round">check_circle</span>
        <span>{{ session('success') }}</span>
    </div>
    @endif

    @if($errors->any())
    <div class="bg-red-50 border border-red-200 text-red-700 px-6 py-4 rounded-2xl">
        <div class="flex items-center gap-3 mb-2">
            <span class="material-icons-round">error</span>
            <span class="font-bold">Error</span>
        </div>
        <ul class="list-disc list-inside text-sm">
            @foreach($errors->all() as $error)
                <li>{{ $error }}</li>
            @endforeach
        </ul>
    </div>
    @endif

    <form action="{{ route('staff.subjects.store') }}" method="POST" id="subject-form">
        @csrf
        <div class="table-container bg-white/50 backdrop-blur-md">
            <div class="p-8 space-y-8">
                @if($subjectCategories->isEmpty())
                    <div class="text-center py-12">
                        <div class="w-16 h-16 bg-slate-50 rounded-full flex items-center justify-center mx-auto mb-4">
                            <span class="material-icons-round text-slate-300 text-3xl">library_books</span>
                        </div>
                        <h3 class="text-lg font-semibold text-slate-700">No Subject Categories Found</h3>
                        <p class="text-slate-500 text-sm mt-1">There are no subject categories available yet.</p>
                    </div>
                @else
                    @foreach($subjectCategories as $category)
                        @if($category->subjects->isNotEmpty())
                        <div class="space-y-4">
                            <div class="flex items-center gap-3 pb-3 border-b border-slate-200">
                                <span class="material-icons-round text-brand-primary">category</span>
                                <h3 class="text-xl font-black text-slate-800">{{ $category->name }}</h3>
                                <span class="text-xs text-slate-400 font-bold uppercase tracking-wider">({{ $category->subjects->count() }} subjects)</span>
                            </div>

                            <div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
                                @foreach($category->subjects as $subject)
                                    @php
                                        $facultyCount = $subject->staff()->count();
                                        $maxFacultyPerSubject = \App\Models\Setting::get('max_faculty_per_subject', 5);
                                        $isFull = $facultyCount >= $maxFacultyPerSubject && !in_array($subject->id, $selected_subjects);
                                    @endphp
                                    <label class="cursor-pointer group relative {{ $isFull ? 'opacity-50 cursor-not-allowed' : '' }}">
                                        <input type="checkbox" 
                                               name="subjects[]" 
                                               value="{{ $subject->id }}" 
                                               class="peer sr-only subject-checkbox" 
                                               {{ in_array($subject->id, $selected_subjects) ? 'checked' : '' }}
                                               {{ $isFull ? 'disabled' : '' }}
                                               data-subject-name="{{ $subject->name }}">
                                        
                                        <div class="p-4 rounded-xl border border-slate-200 bg-slate-50 hover:bg-white transition-all peer-checked:bg-brand-primary/5 peer-checked:border-brand-primary peer-checked:shadow-md {{ $isFull ? 'bg-slate-100' : '' }}">
                                            <div class="flex items-start justify-between mb-2">
                                                <div class="flex-1">
                                                    <h4 class="font-bold text-slate-700 peer-checked:text-brand-primary text-sm">{{ $subject->name }}</h4>
                                                    <p class="text-xs text-slate-500 mt-1">{{ $subject->code }}</p>
                                                </div>
                                                <div class="w-5 h-5 rounded-full border-2 border-slate-300 flex items-center justify-center peer-checked:border-brand-primary peer-checked:bg-brand-primary transition-colors flex-shrink-0 ml-2">
                                                    <span class="material-icons-round text-white text-xs opacity-0 peer-checked:opacity-100">check</span>
                                                </div>
                                            </div>
                                            <div class="flex items-center justify-between gap-2 mt-3">
                                                <span class="px-2 py-0.5 rounded text-[10px] uppercase font-bold bg-slate-200 text-slate-600 peer-checked:bg-brand-primary/20 peer-checked:text-brand-primary">
                                                    {{ $subject->credits ?? 3 }} Credits
                                                </span>
                                                <span class="text-[10px] text-slate-400 font-bold">
                                                    {{ $facultyCount }}/{{ $maxFacultyPerSubject }} Faculty
                                                </span>
                                            </div>
                                            @if($isFull)
                                            <div class="mt-2 text-[10px] text-red-600 font-bold uppercase">
                                                <span class="material-icons-round text-xs align-middle">block</span> Faculty Limit Reached
                                            </div>
                                            @endif
                                        </div>
                                    </label>
                                @endforeach
                            </div>
                        </div>
                        @endif
                    @endforeach
                @endif

                <div class="pt-6 border-t border-slate-100 flex justify-between items-center">
                    <div class="text-sm text-slate-600">
                        <span class="font-bold">Note:</span> You can select up to <span class="text-brand-primary font-bold">{{ $maxSubjectsPerFaculty }}</span> subjects from any category.
                    </div>
                    <button type="submit" class="btn-primary flex items-center gap-2" id="submit-btn">
                        <span class="material-icons-round text-sm">save</span>
                        <span class="font-black text-sm uppercase tracking-wider">Save Selections</span>
                    </button>
                </div>
            </div>
        </div>
    </form>
</div>

<!-- Alert Modal -->
<div id="alert-modal" class="fixed inset-0 bg-black/50 backdrop-blur-sm z-50 hidden flex items-center justify-center">
    <div class="bg-white rounded-2xl shadow-2xl max-w-md w-full mx-4 overflow-hidden">
        <div class="p-6 bg-gradient-to-br from-red-50 to-orange-50 border-b border-red-100">
            <div class="flex items-center gap-3">
                <div class="w-12 h-12 bg-red-500 rounded-full flex items-center justify-center">
                    <span class="material-icons-round text-white">warning</span>
                </div>
                <div>
                    <h3 class="text-xl font-black text-slate-800">Selection Limit Reached</h3>
                    <p class="text-sm text-slate-600 mt-1">Maximum subjects exceeded</p>
                </div>
            </div>
        </div>
        <div class="p-6">
            <p class="text-slate-700 mb-6" id="alert-message"></p>
            <button onclick="closeAlertModal()" class="w-full btn-primary">
                <span class="material-icons-round text-sm">check</span>
                <span class="font-black text-sm uppercase tracking-wider">Understood</span>
            </button>
        </div>
    </div>
</div>

<script>
const maxSubjects = {{ $maxSubjectsPerFaculty }};
let selectedCount = {{ $selectedCount }};

// Update selected count
function updateSelectedCount() {
    const checkboxes = document.querySelectorAll('.subject-checkbox:checked:not([disabled])');
    selectedCount = checkboxes.length;
    document.getElementById('selected-count').textContent = selectedCount;
}

// Show alert modal
function showAlertModal(message) {
    document.getElementById('alert-message').textContent = message;
    document.getElementById('alert-modal').classList.remove('hidden');
}

// Close alert modal
function closeAlertModal() {
    document.getElementById('alert-modal').classList.add('hidden');
}

// Handle checkbox changes
document.addEventListener('DOMContentLoaded', function() {
    const checkboxes = document.querySelectorAll('.subject-checkbox');
    
    checkboxes.forEach(checkbox => {
        checkbox.addEventListener('change', function() {
            if (this.checked) {
                const currentChecked = document.querySelectorAll('.subject-checkbox:checked:not([disabled])').length;
                if (currentChecked > maxSubjects) {
                    this.checked = false;
                    showAlertModal(`You cannot select more than ${maxSubjects} subjects. Please deselect a subject before selecting a new one.`);
                    return;
                }
            }
            updateSelectedCount();
        });
    });

    // Form submission validation
    document.getElementById('subject-form').addEventListener('submit', function(e) {
        const checkedCount = document.querySelectorAll('.subject-checkbox:checked:not([disabled])').length;
        if (checkedCount > maxSubjects) {
            e.preventDefault();
            showAlertModal(`You have selected ${checkedCount} subjects, but the maximum allowed is ${maxSubjects}. Please deselect some subjects.`);
        }
    });

    // Close modal on outside click
    document.getElementById('alert-modal').addEventListener('click', function(e) {
        if (e.target === this) {
            closeAlertModal();
        }
    });
});
</script>
@endsection