<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\Penugasan;
use App\Models\User;
use App\Exports\PenugasanExport;
use Maatwebsite\Excel\Facades\Excel;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\Storage;
use Illuminate\Support\Facades\Notification;
use App\Notifications\PenugasanStatusNotification;

class PenugasanController extends Controller
{
    /**
     * 1. DASHBOARD STATS
     */
    public function dashboard()
    {
        try {
            $user = Auth::user();
            
            $query = Penugasan::query()->where('is_archived', false);

            if ($user && $user->role === 'user') {
                $query->whereHas('petugas', function($q) use ($user) {
                    $q->where('users.id', $user->id);
                });
            }

            $totalTugas    = (clone $query)->where('status', '!=', 'dibatalkan')->count();
            $proses        = (clone $query)->where('status', 'proses')->count();
            $selesai       = (clone $query)->where('status', 'selesai')->count();
            $telahDitinjau = (clone $query)->where('status', 'telah_ditinjau')->count();
            $dibatalkan    = (clone $query)->where('status', 'dibatalkan')->count();

            // Ambil 5 tugas terbaru beserta data petugasnya, kecuali yang dibatalkan
            $terbaru = (clone $query)->with('petugas')->where('status', '!=', 'dibatalkan')->latest()->limit(5)->get();

            return response()->json([
                'success' => true,
                'data' => [
                    'stats' => [
                        'total_tugas'     => $totalTugas,
                        'status_proses'   => $proses,
                        'status_selesai'  => $selesai,
                        'status_ditinjau' => $telahDitinjau,
                        'status_batal'    => $dibatalkan,
                    ],
                    'recent_activities' => $terbaru
                ]
            ]);
        } catch (\Exception $e) {
            return response()->json(['success' => false, 'message' => $e->getMessage()], 500);
        }
    }

    /**
     * 2. LIST SEMUA TUGAS
     */
    public function index(Request $request)
    {
        $user = Auth::user();
        $query = Penugasan::with(['petugas', 'pembuat', 'progress.user']);

        if ($user && $user->role === 'user') {
            $query->whereHas('petugas', function($q) use ($user) {
                $q->where('users.id', $user->id);
            });
        }

        if ($request->has('is_archived') && $request->is_archived == 'true') {
            $query->where('is_archived', true);
        } else {
            $query->where('is_archived', false);
        }

        $data = $query->latest()->get();
        return response()->json(['success' => true, 'data' => $data]);
    }

    /**
     * 3. SIMPAN TUGAS BARU (SINKRON DENGAN FRONTEND)
     */
    public function store(Request $request)
    {
        $request->validate([
            'nomor_surat'   => 'nullable|string|unique:penugasan,nomor_surat',
            'kegiatan'      => 'required|string',
            'tanggal_mulai' => 'required|date',
            'pegawai_ids'   => 'required|array|min:1',
        ], [
            'nomor_surat.unique'   => 'Nomor surat ini sudah terdaftar di sistem (termasuk yang sudah dihapus/dibatalkan). Harap gunakan nomor yang berbeda.',
            'pegawai_ids.required' => 'Pilih minimal satu petugas.',
            'pegawai_ids.min'      => 'Pilih minimal satu petugas.',
        ]);

        DB::beginTransaction();

        try {

            $adminId = Auth::id() ?? 1;

            $lampiranPath = null;
            if ($request->hasFile('lampiran')) {
                $lampiranPath = $request->file('lampiran')->store('lampiran', 'public');
            }

            $penugasan = Penugasan::create([
                'nomor_surat'     => $request->nomor_surat,
                'kegiatan'        => $request->kegiatan,
                'lokasi'          => $request->lokasi,
                'keterangan'      => $request->keterangan,
                'lampiran'        => $lampiranPath,
                'tanggal_mulai'   => $request->tanggal_mulai,
                'tanggal_selesai' => $request->tanggal_selesai,
                'status_note'     => $request->status_note,
                'status'          => 'proses',
                'created_by'      => $adminId,
            ]);

            // SIMPAN MULTIPLE PEGAWAI
            $penugasan->petugas()->sync($request->pegawai_ids);

            DB::commit();

            return response()->json([
                'success' => true,
                'message' => 'Penugasan berhasil dibuat!',
                'data' => $penugasan->load('petugas')
            ], 201);
        } catch (\Exception $e) {

            DB::rollback();

            return response()->json([
                'success' => false,
                'message' => $e->getMessage()
            ], 500);
        }
    }

    /**
     * 3b. SHOW DETAIL TUGAS
     */
    public function show($id)
    {
        try {
            $penugasan = Penugasan::with(['petugas', 'pembuat', 'penyetuju', 'progress.user'])->findOrFail($id);
            return response()->json([
                'success' => true,
                'data' => $penugasan
            ]);
        } catch (\Exception $e) {
            return response()->json(['success' => false, 'message' => 'Data tidak ditemukan: ' . $e->getMessage()], 404);
        }
    }

    /**
     * 3c. UPDATE TUGAS
     */
    public function update(Request $request, $id)
    {
        $request->validate([
            'nomor_surat'   => 'nullable|string|unique:penugasan,nomor_surat,' . $id,
            'kegiatan'      => 'required|string',
            'tanggal_mulai' => 'required|date',
            'pegawai_ids'   => 'required|array|min:1',
        ], [
            'nomor_surat.unique'   => 'Nomor surat ini sudah terdaftar di sistem (termasuk yang sudah dihapus/dibatalkan). Harap gunakan nomor yang berbeda.',
            'pegawai_ids.required' => 'Pilih minimal satu petugas.',
            'pegawai_ids.min'      => 'Pilih minimal satu petugas.',
        ]);

        DB::beginTransaction();
        try {
            $penugasan = Penugasan::findOrFail($id);

            $lampiranPath = $penugasan->lampiran;
            if ($request->hasFile('lampiran')) {
                if ($lampiranPath && Storage::disk('public')->exists($lampiranPath)) {
                    Storage::disk('public')->delete($lampiranPath);
                }
                $lampiranPath = $request->file('lampiran')->store('lampiran', 'public');
            }

            $penugasan->update([
                'nomor_surat'     => $request->nomor_surat,
                'kegiatan'        => $request->kegiatan,
                'lokasi'          => $request->lokasi,
                'keterangan'      => $request->keterangan,
                'lampiran'        => $lampiranPath,
                'tanggal_mulai'   => $request->tanggal_mulai,
                'tanggal_selesai' => $request->tanggal_selesai,
                'status_note'     => $request->status_note,
                // tidak update status/created_by
            ]);

            $penugasan->petugas()->sync($request->pegawai_ids);

            DB::commit();
            return response()->json([
                'success' => true,
                'message' => 'Penugasan berhasil diperbarui!',
                'data' => $penugasan->load('petugas')
            ]);
        } catch (\Exception $e) {
            DB::rollback();
            return response()->json(['success' => false, 'message' => $e->getMessage()], 500);
        }
    }

    /**
     * 4. UPDATE STATUS (TINJAU)
     */
    public function updateStatus(Request $request, $id)
    {
        try {
            $penugasan = Penugasan::findOrFail($id);

            if ($request->status == 'telah_ditinjau') {
                $penugasan->update([
                    'status'      => 'telah_ditinjau',
                    'approved_by' => Auth::id() ?? $request->approved_by,
                    'approved_at' => now(),
                    'status_note' => $request->has('status_note') ? $request->status_note : null
                ]);
            } else {
                $updateData = ['status' => $request->status];
                if ($request->has('status_note')) {
                    $updateData['status_note'] = $request->status_note;
                }
                $penugasan->update($updateData);
                
                // Kirim notifikasi
                if (in_array($request->status, ['selesai', 'dibatalkan', 'proses'])) {
                    $action = 'diperbarui';
                    if ($request->status === 'selesai') $action = 'disetujui';
                    if ($request->status === 'dibatalkan') $action = 'dibatalkan';
                    if ($request->status === 'proses') $action = 'dikembalikan (revisi)';
                    
                    if ($penugasan->petugas->isNotEmpty()) {
                        Notification::send($penugasan->petugas, new PenugasanStatusNotification($penugasan, $request->status, $action));
                    }
                }
            }

            return response()->json(['success' => true, 'message' => 'Status diperbarui!']);
        } catch (\Exception $e) {
            return response()->json(['success' => false, 'message' => $e->getMessage()], 500);
        }
    }

    /**
     * 5. BATALKAN TUGAS
     */
    public function destroy(Request $request, $id)
    {
        $request->validate([
            'alasan' => 'required|string' // Frontend kirim 'alasan'
        ]);

        try {
            $penugasan = Penugasan::findOrFail($id);

            $penugasan->update([
                'status'       => 'dibatalkan',
                'alasan_hapus' => $request->alasan
            ]);

            if ($penugasan->petugas->isNotEmpty()) {
                Notification::send($penugasan->petugas, new PenugasanStatusNotification($penugasan, 'dibatalkan', 'dihapus'));
            }

            return response()->json([
                'success' => true,
                'message' => 'Kegiatan berhasil dibatalkan.'
            ]);
        } catch (\Exception $e) {
            return response()->json(['success' => false, 'message' => $e->getMessage()], 500);
        }
    }

    /**
     * 6. NOTIFIKASI
     */
    public function notifications()
    {
        // Contoh implementasi: kirim kegiatan yang sudah 'telah_ditinjau' untuk user ini
        try {
            $user = Auth::user();
            $notifications = [];
            
            if ($user && $user->role === 'user') {
                // Pegawai id mungkin sama dengan user_id
                $pegawai = \App\Models\Pegawai::where('user_id', $user->id)->first();
                if ($pegawai) {
                    $notifications = $pegawai->penugasan()
                        ->where('status', 'telah_ditinjau')
                        ->orderBy('approved_at', 'desc')
                        ->limit(5)
                        ->get()
                        ->map(function($p) {
                            return [
                                'id' => $p->id,
                                'text' => "Penugasan '{$p->kegiatan}' telah ditinjau.",
                                'is_read' => false
                            ];
                        });
                }
            }

            return response()->json([
                'success' => true,
                'data' => $notifications
            ]);
        } catch (\Exception $e) {
            return response()->json(['success' => false, 'message' => $e->getMessage()], 500);
        }
    }

    /**
     * 7. EXCEL EXPORT
     */
    public function export(Request $request)
    {
        try {
            $columns = $request->input('columns', []);
            return Excel::download(new PenugasanExport($columns), 'Laporan_Penugasan.xlsx');
        } catch (\Exception $e) {
            return response()->json(['success' => false, 'message' => 'Export Gagal: ' . $e->getMessage()], 500);
        }
    }

    public function toggleArchive($id)
    {
        try {
            $penugasan = Penugasan::findOrFail($id);
            $penugasan->is_archived = !$penugasan->is_archived;
            $penugasan->save();

            $status = $penugasan->is_archived ? 'diarsipkan' : 'dikembalikan dari arsip';

            return response()->json([
                'success' => true,
                'message' => "Laporan berhasil $status."
            ]);
        } catch (\Exception $e) {
            return response()->json(['success' => false, 'message' => 'Gagal mengarsipkan laporan: ' . $e->getMessage()], 500);
        }
    }

    public function storeProgress(Request $request, $id)
    {
        try {
            $request->validate([
                'note' => 'required|string',
                'attachment' => 'nullable|file|mimes:jpg,jpeg,png,pdf|max:2048'
            ]);
            
            $penugasan = Penugasan::findOrFail($id);
            
            $path = null;
            if ($request->hasFile('attachment')) {
                $file = $request->file('attachment');
                $filename = time() . '_' . $file->getClientOriginalName();
                $file->move(public_path('uploads/progress'), $filename);
                $path = 'uploads/progress/' . $filename;
            }

            $progress = $penugasan->progress()->create([
                'user_id' => Auth::id(),
                'note'    => $request->note,
                'attachment' => $path
            ]);

            return response()->json([
                'success' => true,
                'message' => 'Progress log added successfully',
                'data'    => $progress->load('user')
            ]);
        } catch (\Exception $e) {
            return response()->json(['success' => false, 'message' => 'Failed to add progress: ' . $e->getMessage()], 500);
        }
    }
}