@extends('layouts.app')
@section('title', 'Cohorts')
@section('content')

<div class="mb-4">
    <h4 class="page-title">Cohorts</h4>
    <p class="page-subtitle">Move students between semesters and manage the intake list.</p>
</div>

@if($errors->any())
<div class="alert alert-danger"><ul class="mb-0 small">@foreach($errors->all() as $e)<li>{{ $e }}</li>@endforeach</ul></div>
@endif

{{-- ── Where everyone is ──────────────────────────────────────────────── --}}
<h6 class="proc-section-title"><i class="bi bi-diagram-3 text-primary"></i> Current distribution</h6>

<div class="card mb-4">
    <div class="card-body">
        @php $max = max(1, $distribution->max() ?: 1); @endphp
        @foreach($semesters as $sem)
        @php $n = $distribution->get($sem->id, 0); @endphp
        <div class="d-flex align-items-center gap-2 mb-2">
            <span class="small text-muted text-truncate" style="min-width:11rem">{{ $sem->name }}</span>
            <div class="progress progress-xs flex-grow-1">
                <div class="progress-bar bg-primary" style="width:{{ round($n / $max * 100) }}%"></div>
            </div>
            <span class="small fw-bold" style="min-width:2.5rem;text-align:right">{{ $n }}</span>
        </div>
        @endforeach

        @if($unassigned > 0)
        <div class="d-flex align-items-center gap-2 mt-3 pt-3 border-top">
            <span class="small fw-semibold text-warning-emphasis" style="min-width:11rem">
                <i class="bi bi-exclamation-triangle me-1"></i>No semester set
            </span>
            <div class="flex-grow-1"></div>
            <span class="badge bg-warning-subtle text-warning-emphasis">{{ $unassigned }}</span>
        </div>
        <div class="form-text mt-1">
            These students are excluded from every progress figure until a semester is set.
            Use “Set to a specific semester” below, or edit them individually.
        </div>
        @endif
    </div>
</div>

<div class="row g-4">
    {{-- ── Advance ────────────────────────────────────────────────────── --}}
    <div class="col-lg-7">
        <h6 class="proc-section-title"><i class="bi bi-arrow-right-circle text-primary"></i> Advance to next semester</h6>

        <div class="card mb-4">
            <div class="card-body">
                <p class="text-muted small">
                    Moves each student forward by <strong>one</strong> semester, in syllabus order.
                    Students already in the final semester are left alone.
                </p>

                <form method="GET" class="row g-2 align-items-end mb-3">
                    <input type="hidden" name="preview" value="1">
                    <div class="col-sm">
                        <label class="form-label" for="intakeSelect">Intake</label>
                        <select name="intake" id="intakeSelect" class="form-select" onchange="this.form.submit()">
                            <option value="">— All intakes —</option>
                            @foreach($intakes as $intake)
                            <option value="{{ $intake->name }}" @selected($selectedIntake === $intake->name)>
                                {{ $intake->name }}
                            </option>
                            @endforeach
                        </select>
                    </div>
                    <div class="col-sm-auto">
                        <button class="btn btn-outline-secondary w-100"><i class="bi bi-eye me-1"></i>Preview</button>
                    </div>
                </form>

                @if($preview)
                <div class="border rounded p-3 mb-3" style="background:var(--surface-2)">
                    <div class="preview-label mb-2">What will happen</div>

                    @forelse($preview['moves'] as $move)
                    <div class="d-flex align-items-center gap-2 small mb-2">
                        <span class="badge bg-secondary-subtle text-secondary-emphasis">{{ $move['count'] }}</span>
                        <span class="text-truncate">{{ $move['from']->name }}</span>
                        <i class="bi bi-arrow-right text-muted"></i>
                        <span class="fw-semibold text-truncate">{{ $move['to']->name }}</span>
                    </div>
                    @empty
                    <div class="small text-muted">No student in this selection can move forward.</div>
                    @endforelse

                    @foreach($preview['final'] as $stuck)
                    <div class="d-flex align-items-center gap-2 small text-muted mb-2">
                        <span class="badge bg-light text-muted border">{{ $stuck['count'] }}</span>
                        <span>{{ $stuck['semester']->name }}</span>
                        <span class="fst-italic">— final semester, will not move</span>
                    </div>
                    @endforeach

                    @if($preview['none'] > 0)
                    <div class="small text-warning-emphasis mt-2">
                        <i class="bi bi-exclamation-triangle me-1"></i>
                        {{ $preview['none'] }} student(s) have no semester set and will be skipped.
                    </div>
                    @endif
                </div>

                @if($preview['movable']->isNotEmpty())
                <form method="POST" action="{{ route('admin.cohorts.advance') }}">
                    @csrf
                    <input type="hidden" name="intake" value="{{ $selectedIntake }}">
                    <button class="btn btn-primary"
                            onclick="return confirm('Advance {{ $preview['movable']->sum() }} student(s) by one semester? This cannot be undone automatically.')">
                        <i class="bi bi-arrow-right-circle me-1"></i>
                        Advance {{ $preview['movable']->sum() }} student(s)
                    </button>
                </form>
                @endif
                @else
                <div class="text-muted small">Choose an intake and press Preview to see exactly who would move.</div>
                @endif
            </div>
        </div>

        {{-- ── Absolute set ───────────────────────────────────────────── --}}
        <h6 class="proc-section-title"><i class="bi bi-pin-map text-muted"></i> Set to a specific semester</h6>
        <div class="card">
            <div class="card-body">
                <p class="text-muted small">
                    Places a group directly in one semester. Use this for a freshly imported
                    cohort or to correct a mistake.
                </p>
                <form method="POST" action="{{ route('admin.cohorts.set-semester') }}" class="row g-2 align-items-end">
                    @csrf
                    <div class="col-sm-5">
                        <label class="form-label">Intake</label>
                        <select name="intake" class="form-select">
                            <option value="">— All students —</option>
                            @foreach($intakes as $intake)
                            <option value="{{ $intake->name }}">{{ $intake->name }}</option>
                            @endforeach
                        </select>
                    </div>
                    <div class="col-sm-5">
                        <label class="form-label">Semester <span class="text-danger">*</span></label>
                        <select name="semester_id" class="form-select" required>
                            <option value="">— Select —</option>
                            @foreach($semesters as $sem)
                            <option value="{{ $sem->id }}">{{ $sem->name }}</option>
                            @endforeach
                        </select>
                    </div>
                    <div class="col-sm-2">
                        <button class="btn btn-warning w-100"
                                onclick="return confirm('Overwrite the current semester for every matching student?')">
                            Apply
                        </button>
                    </div>
                </form>
            </div>
        </div>
    </div>

    {{-- ── Intakes ────────────────────────────────────────────────────── --}}
    <div class="col-lg-5">
        <h6 class="proc-section-title"><i class="bi bi-calendar3 text-muted"></i> Intakes</h6>

        <div class="card mb-3">
            <div class="card-body">
                <p class="text-muted small">
                    Students pick their intake from this list, so cohorts stay groupable.
                    Renaming one updates every student who has it.
                </p>
                @can('intakes.manage')
                <form method="POST" action="{{ route('admin.cohorts.intakes.store') }}" class="d-flex gap-2">
                    @csrf
                    <input type="text" name="name" class="form-control form-control-sm"
                           placeholder="e.g. March 2026" maxlength="100" required>
                    <button class="btn btn-sm btn-primary flex-shrink-0"><i class="bi bi-plus-lg"></i></button>
                </form>
                @endcan
            </div>
        </div>

        <div class="card">
            <div class="card-body p-0">
                <ul class="list-group list-group-flush">
                    @forelse($intakes as $intake)
                    @php $count = \App\Models\StudentProfile::where('intake', $intake->name)->count(); @endphp
                    <li class="list-group-item">
                        @can('intakes.manage')
                        <form method="POST" action="{{ route('admin.cohorts.intakes.update', $intake) }}"
                              class="d-flex align-items-center gap-2">
                            @csrf @method('PUT')
                            <input type="text" name="name" value="{{ $intake->name }}"
                                   class="form-control form-control-sm" maxlength="100">
                            <div class="form-check form-switch m-0 flex-shrink-0" title="Offered to new students">
                                <input type="hidden" name="is_active" value="0">
                                <input type="checkbox" class="form-check-input" name="is_active" value="1"
                                       @checked($intake->is_active)>
                            </div>
                            <span class="badge bg-secondary-subtle text-secondary-emphasis flex-shrink-0">{{ $count }}</span>
                            <button class="btn btn-sm btn-outline-secondary flex-shrink-0" title="Save">
                                <i class="bi bi-check-lg"></i>
                            </button>
                        </form>
                        @if($count === 0)
                        <form method="POST" action="{{ route('admin.cohorts.intakes.destroy', $intake) }}"
                              class="mt-1" onsubmit="return confirm('Delete intake “{{ $intake->name }}”?')">
                            @csrf @method('DELETE')
                            <button class="btn btn-sm btn-link text-danger p-0" style="font-size:.75rem">Delete</button>
                        </form>
                        @endif
                        @else
                        <div class="d-flex justify-content-between align-items-center">
                            <span class="small">{{ $intake->name }}</span>
                            <span class="badge bg-secondary-subtle text-secondary-emphasis">{{ $count }}</span>
                        </div>
                        @endcan
                    </li>
                    @empty
                    <li class="list-group-item text-center text-muted py-4 small">
                        No intakes defined yet.
                    </li>
                    @endforelse
                </ul>
            </div>
        </div>
    </div>
</div>
@endsection