<?php

namespace App\Http\Controllers;

use App\Models\Department;
use App\Models\StudentAcademicHistory;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\Rule;
use Illuminate\View\View;
use RealRashid\SweetAlert\Facades\Alert;

class DepartmentController extends Controller
{
    public function index(Request $request): View
    {
        $search = trim((string) $request->get('search'));

        $departments = Department::withCount(['classes', 'students'])
            ->when($search !== '', function ($query) use ($search) {
                $query->where('code', 'like', "%{$search}%")
                    ->orWhere('name', 'like', "%{$search}%")
                    ->orWhere('description', 'like', "%{$search}%");
            })
            ->latest()
            ->paginate(10)
            ->withQueryString();

        return view('departments.index', compact('departments', 'search'));
    }

    public function create(): View
    {
        return view('departments.create');
    }

    public function store(Request $request): RedirectResponse
    {
        $data = $request->validate([
            'code' => ['required', 'string', 'max:20', 'unique:departments,code'],
            'name' => ['required', 'string', 'max:100'],
            'description' => ['nullable', 'string'],
            'is_active' => ['nullable', 'boolean'],
        ]);

        $data['is_active'] = $request->boolean('is_active');
        $data['code'] = strtoupper($data['code']);

        Department::create($data);

        return redirect()->route('departments.index')->with('success', 'Program keahlian berhasil ditambahkan.');
    }

    public function show(Department $department): RedirectResponse
    {
        return redirect()->route('departments.edit', $department);
    }

    public function edit(Department $department): View
    {
        return view('departments.edit', [
            'department' => $department,
        ]);
    }

    public function update(Request $request, Department $department): RedirectResponse
    {
        $data = $request->validate([
            'code' => ['required', 'string', 'max:20', Rule::unique('departments', 'code')->ignore($department->id)],
            'name' => ['required', 'string', 'max:100'],
            'description' => ['nullable', 'string'],
            'is_active' => ['nullable', 'boolean'],
        ]);

        $data['is_active'] = $request->boolean('is_active');
        $data['code'] = strtoupper($data['code']);

        $department->update($data);

        return redirect()->route('departments.index')->with('success', 'Program keahlian berhasil diperbarui.');
    }

    public function destroy(Department $department): RedirectResponse
    {
        $department->loadCount('students');
        $classesWithStudentsCount = $department->classes()->withCount('students')->get()->where('students_count', '>', 0)->count();
        $emptyClassesCount = $department->classes()->withCount('students')->get()->where('students_count', 0)->count();

        if ($department->students_count > 0 || $classesWithStudentsCount > 0) {
            Alert::error('Tidak bisa dihapus', 'Program keahlian ini masih digunakan oleh data siswa aktif atau kelas yang masih berisi siswa.');

            return redirect()->route('departments.index')->withErrors([
                'delete' => 'Program keahlian tidak bisa dihapus karena masih digunakan oleh data siswa aktif atau kelas yang masih berisi siswa.',
            ]);
        }

        DB::transaction(function () use ($department) {
            $classIds = $department->classes()->pluck('id');

            StudentAcademicHistory::query()
                ->whereIn('class_id', $classIds)
                ->delete();

            $department->classes()->delete();
            $department->delete();
        });

        $message = $emptyClassesCount > 0
            ? "Program keahlian berhasil dihapus beserta {$emptyClassesCount} kelas kosong terkait."
            : 'Program keahlian berhasil dihapus.';

        Alert::success('Berhasil', $message);

        return redirect()->route('departments.index')->with('success', $message);
    }
}