<?php

namespace App\Http\Controllers;

use App\Models\Cat;
use App\Models\Treatment;
use App\Models\Medicine;
use App\Traits\LogsActivity;
use Illuminate\Http\Request;
use Illuminate\View\View;
use Illuminate\Http\RedirectResponse;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Storage;
use Exception;

class TreatmentController extends Controller
{
    use LogsActivity;

    /**
     * Menampilkan daftar rekam medis dengan optimasi Eager Loading.
     */
    public function index(): View
    {
        $treatments = Treatment::with([
                'cat:id,nama_kucing,foto', 
                'medicine:id,nama_obat,unit', 
                'user:id,name' 
            ])
            ->latest('tanggal')
            ->paginate(15);

        return view('pages.treatments.index', compact('treatments'));
    }

    /**
     * Form tambah rekam medis.
     */
    public function create(Request $request): View
    {
        $selectedCat = $request->filled('cat_id') ? Cat::findOrFail($request->cat_id) : null;
        $cats = Cat::select('id', 'nama_kucing', 'ras')->get();
        $medicines = Medicine::where('qty', '>', 0)->get();

        return view('pages.treatments.create', compact('selectedCat', 'cats', 'medicines'));
    }

    /**
     * Simpan rekam medis baru & potong stok (mendukung desimal).
     */
    public function store(Request $request): RedirectResponse
    {
        $validated = $this->validateTreatment($request);

        try {
            DB::transaction(function () use ($request, &$validated) {
                $medicine = Medicine::findOrFail($request->medicine_id);

                // Validasi kecukupan stok desimal
                if ($medicine->qty < $request->qty_used) {
                    throw new Exception("Stok {$medicine->nama_obat} tidak mencukupi (Sisa: {$medicine->qty} {$medicine->unit}).");
                }

                if ($request->hasFile('foto_bukti')) {
                    $validated['foto_bukti'] = $request->file('foto_bukti')->store('treatments', 'public');
                }

                // Otomatisasi data sistem
                $validated['user_id'] = auth()->id(); 
                $validated['nama_obat'] = $medicine->nama_obat; 
                
                $treatment = Treatment::create($validated);

                // Potong stok (decrement mendukung nilai float/decimal)
                $medicine->decrement('qty', $request->qty_used);

                $this->logAction('TREATED', $treatment, "Mencatat pengobatan oleh " . auth()->user()->name);
            });

            return redirect()->route('cats.show', $request->cat_id)
                ->with('success', 'Rekam medis berhasil dicatat dengan presisi.');

        } catch (Exception $e) {
            if (isset($validated['foto_bukti'])) {
                Storage::disk('public')->delete($validated['foto_bukti']);
            }
            return back()->withInput()->with('error', 'Gagal menyimpan: ' . $e->getMessage());
        }
    }

    /**
     * Form edit rekam medis.
     */
    public function edit(Treatment $treatment): View
    {
        $cats = Cat::select('id', 'nama_kucing', 'ras')->get();
        $medicines = Medicine::all();
        return view('pages.treatments.edit', compact('treatment', 'cats', 'medicines'));
    }

    /**
     * Update rekam medis & sinkronisasi ulang stok desimal.
     */
    public function update(Request $request, Treatment $treatment): RedirectResponse
    {
        $validated = $this->validateTreatment($request);

        try {
            DB::transaction(function () use ($request, $treatment, &$validated) {
                // 1. Kembalikan stok lama (Desimal Revert)
                $oldMedicine = Medicine::find($treatment->medicine_id);
                if ($oldMedicine) {
                    $oldMedicine->increment('qty', $treatment->qty_used);
                }

                // 2. Potong stok baru
                $newMedicine = Medicine::findOrFail($request->medicine_id);
                if ($newMedicine->qty < $request->qty_used) {
                    throw new Exception("Stok {$newMedicine->nama_obat} tidak mencukupi untuk perubahan ini.");
                }
                $newMedicine->decrement('qty', $request->qty_used);

                // 3. Kelola Foto
                if ($request->hasFile('foto_bukti')) {
                    if ($treatment->foto_bukti) Storage::disk('public')->delete($treatment->foto_bukti);
                    $validated['foto_bukti'] = $request->file('foto_bukti')->store('treatments', 'public');
                }

                // 4. Update data sistem
                $validated['user_id'] = auth()->id();
                $validated['nama_obat'] = $newMedicine->nama_obat;
                $treatment->update($validated);

                $this->logAction('UPDATED_TREATMENT', $treatment, "Diperbarui oleh " . auth()->user()->name);
            });

            return redirect()->route('cats.show', $request->cat_id)->with('success', 'Rekam medis & inventori berhasil di-sinkronisasi.');

        } catch (Exception $e) {
            return back()->withInput()->with('error', 'Gagal memperbarui: ' . $e->getMessage());
        }
    }

    /**
     * Hapus rekam medis & kembalikan stok.
     */
    public function destroy(Treatment $treatment): RedirectResponse
    {
        try {
            DB::transaction(function () use ($treatment) {
                if ($treatment->medicine_id) {
                    Medicine::where('id', $treatment->medicine_id)->increment('qty', $treatment->qty_used);
                }
                if ($treatment->foto_bukti) Storage::disk('public')->delete($treatment->foto_bukti);
                
                $this->logAction('DELETED_TREATMENT', $treatment, "Menghapus catatan medis kucing: {$treatment->cat->nama_kucing}");
                $treatment->delete();
            });

            return back()->with('success', 'Data rekam medis dihapus dan stok dikembalikan.');
        } catch (Exception $e) {
            return back()->with('error', 'Gagal menghapus data.');
        }
    }

    /**
     * Helper Validasi: Terpusat untuk Clean Code & Mendukung Desimal.
     */
    private function validateTreatment(Request $request)
    {
        return $request->validate([
            'cat_id'      => 'required|exists:cats,id',
            'medicine_id' => 'required|exists:medicines,id',
            // 'numeric' mengizinkan input desimal (koma)
            'qty_used'    => 'required|numeric|min:0.01', 
            'tanggal'     => 'required|date',
            'keluhan'     => 'required|string|max:255',
            'diagnosa'    => 'required|string',
            'dosis'       => 'required|string',
            'keterangan'  => 'nullable|string',
            'foto_bukti'  => 'nullable|image|max:2048',
        ]);
    }
}