<?php

namespace App\Http\Controllers;

use App\Models\Disease;
use App\Models\Symptom;
use Illuminate\Http\Request;

class GuestDiagnosisController extends Controller
{
    /**
     * Tampilkan data gejala untuk modal di landing page (JSON)
     */
    public function symptoms()
    {
        $symptoms = Symptom::orderBy('code')->get(['code', 'name']);
        return response()->json($symptoms);
    }

    /**
     * Proses diagnosis guest — hitung CF, kembalikan hasil ringkas (JSON)
     * Tidak disimpan ke DB, tidak butuh auth
     */
    public function process(Request $request)
    {
        $validated = $request->validate([
            'symptoms'   => 'required|array|min:4',
            'symptoms.*' => 'numeric|min:0|max:0.8',
        ]);

        $gejalaInput = [];
        foreach ($validated['symptoms'] as $kode => $cfUser) {
            if ($cfUser !== '' && $cfUser !== null) {
                $gejalaInput[$kode] = min((float) $cfUser, 0.8);
            }
        }

        if (count($gejalaInput) < 4) {
            return response()->json(['error' => 'Pilih minimal 4 gejala.'], 422);
        }

        $hasil  = $this->hitungCF($gejalaInput);
        $utama  = $hasil[0] ?? null;

        // Kembalikan hasil RINGKAS saja (tanpa penanganan lengkap)
        return response()->json([
            'disease_name' => $utama ? $utama['nama']       : 'Tidak Terdeteksi',
            'confidence'   => $utama ? $utama['persentase'] : 0,
            'level'        => $utama ? $this->level($utama['persentase']) : 'Tidak Terdeteksi',
            'top_results'  => array_slice(array_map(fn($h) => [
                'nama'       => $h['nama'],
                'persentase' => $h['persentase'],
                'level'      => $this->level($h['persentase']),
            ], $hasil), 0, 3),
        ]);
    }

    /* ── Helpers ──────────────────────────────────────────────────────── */

    private function hitungCF(array $gejalaInput): array
    {
        $hasil    = [];
        $diseases = Disease::with('symptoms')->get();

        foreach ($diseases as $disease) {
            $cfCombine = 0;
            $first     = true;
            $cocok     = false;

            foreach ($disease->symptoms as $symptom) {
                $kode    = $symptom->code;
                $cfPakar = (float) $symptom->pivot->cf_value;

                if (isset($gejalaInput[$kode])) {
                    $cocok = true;
                    $cf    = $gejalaInput[$kode] * $cfPakar;

                    if ($first) {
                        $cfCombine = $cf;
                        $first     = false;
                    } else {
                        $cfCombine = $cfCombine + ($cf * (1 - $cfCombine));
                    }
                }
            }

            if ($cocok) {
                $hasil[] = [
                    'nama'       => $disease->name,
                    'persentase' => round($cfCombine * 100, 2),
                ];
            }
        }

        usort($hasil, fn($a, $b) => $b['persentase'] <=> $a['persentase']);

        return $hasil;
    }

    private function level(float $persen): string
    {
        if ($persen <= 20) return 'Sangat Rendah';
        if ($persen <= 40) return 'Rendah';
        if ($persen <= 60) return 'Sedang';
        if ($persen <= 80) return 'Tinggi';
        return 'Sangat Tinggi';
    }
}