<?php

namespace App\Http\Controllers\Api\Admin;

use App\Http\Controllers\Controller;
use App\Models\User;
use App\Models\RiwayatRekomendasi;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Schema;
use Exception;

class DashboardAdminController extends Controller
{
    public function index(Request $request)
    {
        try {
            $tableName = (new RiwayatRekomendasi())->getTable();

            $totalSiswa = User::whereIn('role', ['siswa', 'student'])->count();

            if ($totalSiswa === 0) {
                $totalSiswa = RiwayatRekomendasi::distinct('user_id')->count('user_id');
            }

            $totalRekomendasi = RiwayatRekomendasi::count();

            $kolomAkurasi = null;

            if (Schema::hasColumn($tableName, 'akurasi_prediksi')) {
                $kolomAkurasi = 'akurasi_prediksi';
            } elseif (Schema::hasColumn($tableName, 'probabilitas')) {
                $kolomAkurasi = 'probabilitas';
            } elseif (Schema::hasColumn($tableName, 'akurasi')) {
                $kolomAkurasi = 'akurasi';
            }

            $rataAkurasi = null;

            if ($kolomAkurasi) {
                $avg = RiwayatRekomendasi::whereNotNull($kolomAkurasi)->avg($kolomAkurasi);
                $rataAkurasi = $avg !== null ? round((float) $avg, 2) : null;
            }

            $akurasiStatus = $rataAkurasi !== null
                ? 'Berdasarkan rata-rata tingkat keyakinan dari seluruh hasil rekomendasi.'
                : 'Belum ada nilai keyakinan prediksi yang tersimpan. Lakukan prediksi baru terlebih dahulu.';

            $selectDistribusi = 'hasil_rekomendasi_jurusan as jurusan, COUNT(*) as total';

            if ($kolomAkurasi) {
                $selectDistribusi .= ', ROUND(AVG(' . $kolomAkurasi . '), 2) as rata_akurasi';
            }

            $distribusiJurusan = RiwayatRekomendasi::selectRaw($selectDistribusi)
                ->whereNotNull('hasil_rekomendasi_jurusan')
                ->groupBy('hasil_rekomendasi_jurusan')
                ->orderBy('total', 'desc')
                ->limit(10)
                ->get()
                ->map(function ($item) use ($kolomAkurasi) {
                    return [
                        'jurusan' => $item->jurusan,
                        'total' => (int) $item->total,
                        'rata_akurasi' => $kolomAkurasi && $item->rata_akurasi !== null
                            ? round((float) $item->rata_akurasi, 2)
                            : null,
                    ];
                });

            return response()->json([
                'success' => true,
                'data' => [
                    'total_siswa' => $totalSiswa,
                    'rekomendasi_diproses' => $totalRekomendasi,
                    'rata_rata_akurasi' => $rataAkurasi,
                    'akurasi_status' => $akurasiStatus,
                    'distribusi_jurusan' => $distribusiJurusan,
                ]
            ], 200);

        } catch (Exception $e) {
            return response()->json([
                'success' => false,
                'message' => 'Error: ' . $e->getMessage()
            ], 500);
        }
    }
}