<?php

namespace App\Http\Controllers;

use App\Models\ItemTransaksi;
use App\Models\Produk;
use App\Models\Transaksi;
use App\Models\Sales;
use App\Models\Nampan;
use Carbon\Carbon;
use Carbon\CarbonPeriod;
use Illuminate\Http\Request;
use Illuminate\Pagination\LengthAwarePaginator;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Log;
use Maatwebsite\Excel\Facades\Excel;
use Barryvdh\DomPDF\Facade\Pdf;
use App\Exports\RingkasanExport;

class LaporanController extends Controller
{
    private const CURRENCY_SYMBOL = 'Rp ';
    private const WEIGHT_UNIT = ' g';
    private const DEFAULT_DISPLAY = '-';
    private const CACHE_TTL = 300; // 5 menit
    private const DEFAULT_PER_PAGE = 15;
    private const MAX_PER_PAGE = 100;
    private const DAILY_PER_PAGE = 7;
    private const MONTHLY_PER_PAGE = 12;
    private const PAGINATION_DAYS_LIMIT = 365;

    /**
     * Endpoint untuk ringkasan laporan dengan caching
     */
    public function ringkasan(Request $request)
    {
        try {
            $filter = $request->query('filter', 'bulan');
            $page = (int) $request->query('page', 1);

            // Validasi filter
            if (!in_array($filter, ['hari', 'bulan'])) {
                return response()->json(['error' => 'Filter harus "hari" atau "bulan"'], 400);
            }

            // Cache key berdasarkan filter dan page
            $cacheKey = "laporan_ringkasan_{$filter}_page_{$page}";
            
            $data = Cache::remember($cacheKey, self::CACHE_TTL, function () use ($filter, $page) {
                $allSalesNames = $this->getAllSalesNames();

                if ($filter === 'hari') {
                    return $this->processLaporanHarian($allSalesNames, $page, true);
                }
                
                return $this->processLaporanBulanan($allSalesNames, $page, true);
            });

            return response()->json($data);

        } catch (\Exception $e) {
            Log::error('Error in ringkasan method: ' . $e->getMessage());
            return response()->json(['error' => 'Terjadi kesalahan saat mengambil data'], 500);
        }
    }

    /**
     * Detail laporan per produk dengan validasi dan error handling yang lebih baik
     */
    public function detailPerProduk(Request $request)
    {
        try {
            $validatedData = $request->validate([
                'tanggal' => 'required|date_format:Y-m-d|before_or_equal:today',
                'sales_id' => 'nullable|integer|exists:sales,id',
                'nampan_id' => 'nullable|integer',
                'nama_pembeli' => 'nullable|string|max:255',
                'page' => 'nullable|integer|min:1',
                'per_page' => 'nullable|integer|min:1|max:' . self::MAX_PER_PAGE,
            ]);

            $tanggal = $validatedData['tanggal'];
            $salesId = $request->query('sales_id');
            $nampanId = $request->query('nampan_id');
            $namaPembeli = $request->query('nama_pembeli');
            $page = (int) $request->query('page', 1);
            $perPage = (int) $request->query('per_page', self::DEFAULT_PER_PAGE);

            $carbonDate = Carbon::parse($tanggal);

            // Validasi nampan_id jika ada
            if ($nampanId && $nampanId != 0) {
                if (!Nampan::where('id', $nampanId)->exists()) {
                    return response()->json(['error' => 'Nampan tidak ditemukan'], 404);
                }
            }

            $produkTerjualQuery = $this->buildBaseItemQuery($carbonDate);
            $this->applyFilters($produkTerjualQuery, $salesId, $nampanId, $namaPembeli);

            $produkTerjual = $produkTerjualQuery
                ->select(
                    'produks.id as id_produk',
                    'produks.nama as nama_produk',
                    DB::raw('COUNT(item_transaksis.id) as jumlah_item_terjual'),
                    DB::raw('COALESCE(SUM(produks.berat), 0) as berat_terjual'),
                    DB::raw('COALESCE(SUM(item_transaksis.harga_deal), 0) as pendapatan')
                )
                ->groupBy('produks.id', 'produks.nama')
                ->get()
                ->keyBy('id_produk');

            $totals = $this->calculateTotals($produkTerjual);
            $semuaProdukPaginated = Produk::select('id', 'nama')
                ->orderBy('nama')
                ->paginate($perPage, ['*'], 'page', $page);
            
            $detailItem = $this->mapProductsWithSalesData($semuaProdukPaginated, $produkTerjual);
            $filterInfo = $this->buildFilterInfo($carbonDate, $salesId, $nampanId, $namaPembeli);

            return response()->json([
                'filter' => $filterInfo,
                'rekap_harian' => $totals,
                'produk' => $detailItem->values(),
                'pagination' => $this->buildPaginationInfo($semuaProdukPaginated),
            ]);

        } catch (\Exception $e) {
            Log::error('Error in detailPerProduk method: ' . $e->getMessage());
            return response()->json(['error' => 'Terjadi kesalahan saat mengambil data produk'], 500);
        }
    }

    /**
     * Detail laporan per nampan dengan perbaikan validasi dan error handling
     */
    public function detailPerNampan(Request $request)
    {
        try {
            $validatedData = $request->validate([
                'tanggal' => 'required|date_format:Y-m-d|before_or_equal:today',
                'sales_id' => 'nullable|integer|exists:sales,id',
                'produk_id' => 'nullable|integer|exists:produks,id',
                'nama_pembeli' => 'nullable|string|max:255',
                'page' => 'nullable|integer|min:1',
                'per_page' => 'nullable|integer|min:1|max:' . self::MAX_PER_PAGE,
            ]);

            $tanggal = $validatedData['tanggal'];
            $salesId = $request->query('sales_id');
            $produkId = $request->query('produk_id');
            $namaPembeli = $request->query('nama_pembeli');
            $page = (int) $request->query('page', 1);
            $perPage = (int) $request->query('per_page', self::DEFAULT_PER_PAGE);

            $carbonDate = Carbon::parse($tanggal);

            $nampanTerjualQuery = $this->buildBaseItemQuery($carbonDate);
            $this->applyNampanFilters($nampanTerjualQuery, $salesId, $produkId, $namaPembeli);

            $nampanTerjual = $nampanTerjualQuery
                ->leftJoin('nampans', 'items.id_nampan', '=', 'nampans.id')
                ->select(
                    DB::raw('COALESCE(items.id_nampan, 0) as id_nampan'),
                    DB::raw('COALESCE(nampans.nama, "Brankas") as nama_nampan'),
                    DB::raw('COUNT(item_transaksis.id) as jumlah_item_terjual'),
                    DB::raw('COALESCE(SUM(produks.berat), 0) as berat_terjual'),
                    DB::raw('COALESCE(SUM(item_transaksis.harga_deal), 0) as pendapatan')
                )
                ->groupBy('id_nampan', 'nama_nampan')
                ->get()
                ->keyBy('id_nampan');

            $totals = $this->calculateTotals($nampanTerjual);
            $semuaNampanPaginated = $this->getAllNampanWithPagination($page, $perPage);
            $detailItem = $this->mapNampanWithSalesData($semuaNampanPaginated, $nampanTerjual);
            $filterInfo = $this->buildNampanFilterInfo($carbonDate, $salesId, $produkId, $namaPembeli);

            return response()->json([
                'filter' => $filterInfo,
                'rekap_harian' => $totals,
                'nampan' => $detailItem->values(),
                'pagination' => $this->buildPaginationInfo($semuaNampanPaginated),
            ]);

        } catch (\Exception $e) {
            Log::error('Error in detailPerNampan method: ' . $e->getMessage());
            return response()->json(['error' => 'Terjadi kesalahan saat mengambil data nampan'], 500);
        }
    }

    /**
     * Export laporan ringkasan dengan validasi format
     */
    public function exportRingkasan(Request $request)
    {
        try {
            $validatedData = $request->validate([
                'filter' => 'required|in:hari,bulan',
                'format' => 'required|in:pdf,xlsx,csv',
            ]);

            $filter = $validatedData['filter'];
            $format = $validatedData['format'];

            $allSalesNames = $this->getAllSalesNames();
            
            if ($filter === 'hari') {
                $data = $this->processLaporanHarian($allSalesNames, 1, false);
            } else {
                $data = $this->processLaporanBulanan($allSalesNames, 1, false);
            }

            $fileName = "laporan_ringkasan_{$filter}_" . Carbon::now()->format('Ymd') . ".{$format}";

            if ($format === 'pdf') {
                $pdf = PDF::loadView('exports.ringkasan_pdf', [
                    'data' => $data,
                    'filter' => $filter
                ]);
                $pdf->setPaper('a4', 'landscape');
                return $pdf->download($fileName);
            }

            // Format XLSX atau CSV
            return Excel::download(new RingkasanExport($data), $fileName);

        } catch (\Exception $e) {
            Log::error('Error in exportRingkasan method: ' . $e->getMessage());
            return response()->json(['error' => 'Terjadi kesalahan saat export data'], 500);
        }
    }

    /**
     * Helper method untuk mendapatkan semua nama sales dengan caching
     */
    private function getAllSalesNames(): Collection
    {
        return Cache::remember('all_sales_names', self::CACHE_TTL, function () {
            return Transaksi::select('nama_sales')->distinct()->pluck('nama_sales');
        });
    }

    /**
     * Helper method untuk mendapatkan semua nampan dengan pagination
     */
    private function getAllNampanWithPagination(int $page, int $perPage): LengthAwarePaginator
    {
        $semuaNampan = Nampan::select('id', 'nama')->orderBy('nama')->get();
        $brankasEntry = (object) ['id' => 0, 'nama' => 'Brankas'];
        $semuaNampanCollection = $semuaNampan->prepend($brankasEntry);

        $offset = ($page - 1) * $perPage;
        $itemsForCurrentPage = $semuaNampanCollection->slice($offset, $perPage);

        return new LengthAwarePaginator(
            $itemsForCurrentPage,
            $semuaNampanCollection->count(),
            $perPage,
            $page,
            ['path' => request()->url(), 'query' => request()->query()]
        );
    }

    /**
     * Logika inti untuk menghasilkan data laporan harian yang sudah dioptimasi
     */
    private function processLaporanHarian(Collection $allSalesNames, int $page = 1, bool $limitPagination = true)
    {
        $perPage = self::DAILY_PER_PAGE;

        if ($limitPagination) {
            $endDate = Carbon::today()->subDays(($page - 1) * $perPage);
            $startDate = $endDate->copy()->subDays($perPage - 1);
            $totalHariUntukPaginasi = self::PAGINATION_DAYS_LIMIT;
        } else {
            $endDate = Carbon::today();
            $startDate = $endDate->copy()->subYear()->addDay();
            $totalHariUntukPaginasi = $endDate->diffInDays($startDate) + 1;
        }

        $transaksis = Transaksi::with(['itemTransaksi.item.produk'])
            ->whereBetween('created_at', [$startDate->startOfDay(), $endDate->endOfDay()])
            ->orderBy('created_at', 'desc')
            ->get();

        $transaksisByDay = $transaksis->groupBy(function ($transaksi) {
            return Carbon::parse($transaksi->created_at)->format('Y-m-d');
        });

        $period = CarbonPeriod::create($startDate, $endDate);
        $laporan = [];

        foreach ($period as $date) {
            $dateString = $date->format('Y-m-d');
            $tanggalFormatted = $date->isoFormat('dddd, D MMMM Y');

            if (isset($transaksisByDay[$dateString])) {
                $transaksisPerTanggal = $transaksisByDay[$dateString];
                $salesDataTransaksi = $transaksisPerTanggal->groupBy('nama_sales')
                    ->map(fn($transaksisPerSales) => $this->hitungDataSales($transaksisPerSales));

                $fullSalesData = $allSalesNames->map(function ($namaSales) use ($salesDataTransaksi) {
                    return $salesDataTransaksi->get($namaSales) ?? $this->defaultSalesData($namaSales);
                });

                $totalItem = $fullSalesData->sum('item_terjual');
                $totalBerat = $fullSalesData->sum('berat_terjual_raw');
                $totalPendapatan = $fullSalesData->sum('pendapatan_raw');

                $laporan[$dateString] = [
                    'tanggal' => $tanggalFormatted,
                    'total_item_terjual' => $totalItem > 0 ? $totalItem : self::DEFAULT_DISPLAY,
                    'total_berat' => $totalBerat > 0 ? $this->formatWeight($totalBerat) : self::DEFAULT_DISPLAY,
                    'total_pendapatan' => $totalPendapatan > 0 ? $this->formatCurrency($totalPendapatan) : self::DEFAULT_DISPLAY,
                    'sales' => $this->formatSalesDataValues($fullSalesData)->values(),
                ];
            } else {
                $laporan[$dateString] = [
                    'tanggal' => $tanggalFormatted,
                    'total_item_terjual' => self::DEFAULT_DISPLAY,
                    'total_berat' => self::DEFAULT_DISPLAY,
                    'total_pendapatan' => self::DEFAULT_DISPLAY,
                    'sales' => [],
                ];
            }
        }

        if ($limitPagination) {
            return new LengthAwarePaginator(
                array_reverse(array_values($laporan)),
                $totalHariUntukPaginasi,
                $perPage,
                $page,
                ['path' => request()->url(), 'query' => request()->query()]
            );
        }

        return collect(array_reverse(array_values($laporan)));
    }

    /**
     * Logika inti untuk menghasilkan data laporan bulanan yang sudah dioptimasi
     */
    private function processLaporanBulanan(Collection $allSalesNames, int $page = 1, bool $limitPagination = true)
    {
        $perPage = self::MONTHLY_PER_PAGE;

        $transaksis = Transaksi::with(['itemTransaksi.item.produk'])
            ->orderBy('created_at', 'desc')
            ->get();

        $laporan = $transaksis->groupBy(function ($transaksi) {
            return Carbon::parse($transaksi->created_at)->format('F Y');
        })->map(function ($transaksisPerTanggal, $tanggal) use ($allSalesNames) {
            $salesDataTransaksi = $transaksisPerTanggal
                ->groupBy('nama_sales')
                ->map(fn($transaksisPerSales) => $this->hitungDataSales($transaksisPerSales));

            $fullSalesData = $allSalesNames->map(function ($namaSales) use ($salesDataTransaksi) {
                return $salesDataTransaksi->get($namaSales) ?? $this->defaultSalesData($namaSales);
            });

            $totalItem = $fullSalesData->sum('item_terjual');
            $totalBerat = $fullSalesData->sum('berat_terjual_raw');
            $totalPendapatan = $fullSalesData->sum('pendapatan_raw');

            return [
                'tanggal' => $tanggal,
                'total_item_terjual' => $totalItem > 0 ? $totalItem : self::DEFAULT_DISPLAY,
                'total_berat' => $totalBerat > 0 ? $this->formatWeight($totalBerat) : self::DEFAULT_DISPLAY,
                'total_pendapatan' => $totalPendapatan > 0 ? $this->formatCurrency($totalPendapatan) : self::DEFAULT_DISPLAY,
                'sales' => $this->formatSalesDataValues($fullSalesData)->values(),
            ];
        });

        if ($limitPagination) {
            return new LengthAwarePaginator(
                $laporan->forPage($page, $perPage)->values(),
                $laporan->count(),
                $perPage,
                $page,
                ['path' => request()->url(), 'query' => request()->query()]
            );
        }

        return $laporan->values();
    }

    /**
     * Membangun query dasar untuk item transaksi
     */
    private function buildBaseItemQuery(Carbon $carbonDate)
    {
        return ItemTransaksi::query()
            ->join('items', 'item_transaksis.id_item', '=', 'items.id')
            ->join('produks', 'items.id_produk', '=', 'produks.id')
            ->join('transaksis', 'item_transaksis.id_transaksi', '=', 'transaksis.id')
            ->whereDate('transaksis.created_at', $carbonDate);
    }

    /**
     * Menerapkan filter untuk query produk
     */
    private function applyFilters($query, $salesId, $nampanId, $namaPembeli): void
    {
        if ($salesId) {
            $query->join('sales', 'transaksis.id_sales', '=', 'sales.id')
                ->where('sales.id', $salesId);
        }

        if ($nampanId !== null) {
            if ($nampanId == 0) {
                $query->whereNull('items.id_nampan');
            } else {
                $query->where('items.id_nampan', $nampanId);
            }
        }

        if ($namaPembeli) {
            $query->where('transaksis.nama_pembeli', 'like', "%{$namaPembeli}%");
        }
    }

    /**
     * Menerapkan filter untuk query nampan
     */
    private function applyNampanFilters($query, $salesId, $produkId, $namaPembeli): void
    {
        if ($salesId) {
            $query->join('sales', 'transaksis.id_sales', '=', 'sales.id')
                ->where('sales.id', $salesId);
        }

        if ($produkId) {
            $query->where('produks.id', $produkId);
        }

        if ($namaPembeli) {
            $query->where('transaksis.nama_pembeli', 'like', "%{$namaPembeli}%");
        }
    }

    /**
     * Menghitung total dari data penjualan
     */
    private function calculateTotals(Collection $data): array
    {
        $totalPendapatan = $data->sum('pendapatan');
        $totalItemTerjual = $data->sum('jumlah_item_terjual');
        $totalBeratTerjual = $data->sum('berat_terjual');

        return [
            'total_item_terjual' => $totalItemTerjual,
            'total_berat_terjual' => $this->formatWeight($totalBeratTerjual),
            'total_pendapatan' => $this->formatCurrency($totalPendapatan),
        ];
    }

    /**
     * Memetakan produk dengan data penjualan
     */
    private function mapProductsWithSalesData($paginatedData, Collection $salesData): Collection
    {
        return $paginatedData->getCollection()->map(function ($item) use ($salesData) {
            if ($salesData->has($item->id)) {
                $dataTerjual = $salesData->get($item->id);
                return [
                    'nama_produk' => $item->nama,
                    'jumlah_item_terjual' => (int) $dataTerjual->jumlah_item_terjual,
                    'berat_terjual' => $this->formatWeight($dataTerjual->berat_terjual),
                    'pendapatan' => $this->formatCurrency($dataTerjual->pendapatan),
                ];
            }

            return [
                'nama_produk' => $item->nama,
                'jumlah_item_terjual' => self::DEFAULT_DISPLAY,
                'berat_terjual' => self::DEFAULT_DISPLAY,
                'pendapatan' => self::DEFAULT_DISPLAY,
            ];
        });
    }

    /**
     * Memetakan nampan dengan data penjualan
     */
    private function mapNampanWithSalesData($paginatedData, Collection $salesData): Collection
    {
        return $paginatedData->getCollection()->map(function ($item) use ($salesData) {
            if ($salesData->has($item->id)) {
                $dataTerjual = $salesData->get($item->id);
                return [
                    'nama_nampan' => $item->nama,
                    'jumlah_item_terjual' => (int) $dataTerjual->jumlah_item_terjual,
                    'berat_terjual' => $this->formatWeight($dataTerjual->berat_terjual),
                    'pendapatan' => $this->formatCurrency($dataTerjual->pendapatan),
                ];
            }

            return [
                'nama_nampan' => $item->nama,
                'jumlah_item_terjual' => self::DEFAULT_DISPLAY,
                'berat_terjual' => self::DEFAULT_DISPLAY,
                'pendapatan' => self::DEFAULT_DISPLAY,
            ];
        });
    }

    /**
     * Membangun informasi filter untuk produk
     */
    private function buildFilterInfo(Carbon $carbonDate, $salesId, $nampanId, $namaPembeli): array
    {
        $filterInfo = [
            'tanggal' => $carbonDate->isoFormat('dddd, D MMMM Y'),
            'nama_sales' => null,
            'nampan' => null,
            'nama_pembeli' => $namaPembeli,
        ];

        if ($salesId) {
            $sales = Sales::find($salesId);
            $filterInfo['nama_sales'] = $sales?->nama;
        }

        if ($nampanId !== null) {
            if ($nampanId == 0) {
                $filterInfo['nampan'] = 'Brankas';
            } else {
                $nampan = Nampan::find($nampanId);
                $filterInfo['nampan'] = $nampan?->nama;
            }
        }

        return $filterInfo;
    }

    /**
     * Membangun informasi filter untuk nampan
     */
    private function buildNampanFilterInfo(Carbon $carbonDate, $salesId, $produkId, $namaPembeli): array
    {
        $filterInfo = [
            'tanggal' => $carbonDate->isoFormat('dddd, D MMMM Y'),
            'nama_sales' => null,
            'produk' => null,
            'nama_pembeli' => $namaPembeli,
        ];

        if ($salesId) {
            $sales = Sales::find($salesId);
            $filterInfo['nama_sales'] = $sales?->nama;
        }

        if ($produkId) {
            $produk = Produk::find($produkId);
            $filterInfo['produk'] = $produk?->nama;
        }

        return $filterInfo;
    }

    /**
     * Membangun informasi pagination
     */
    private function buildPaginationInfo($paginatedData): array
    {
        return [
            'current_page' => $paginatedData->currentPage(),
            'last_page' => $paginatedData->lastPage(),
            'per_page' => $paginatedData->perPage(),
            'total' => $paginatedData->total(),
            'from' => $paginatedData->firstItem(),
            'to' => $paginatedData->lastItem(),
        ];
    }

    /**
     * Menghitung data sales dari transaksi
     */
    private function hitungDataSales(Collection $transaksisPerSales): array
    {
        $itemTerjual = $transaksisPerSales->sum(fn($t) => $t->itemTransaksi->count());
        $beratTerjual = $transaksisPerSales->sum(
            fn($t) => $t->itemTransaksi->sum(fn($it) => $it->item->produk->berat ?? 0)
        );
        $pendapatan = $transaksisPerSales->sum('total_harga');

        return [
            'nama' => $transaksisPerSales->first()->nama_sales,
            'item_terjual' => $itemTerjual,
            'berat_terjual_raw' => $beratTerjual,
            'pendapatan_raw' => $pendapatan,
        ];
    }

    /**
     * Default data untuk sales yang tidak ada transaksi
     */
    private function defaultSalesData(string $namaSales): array
    {
        return [
            'nama' => $namaSales,
            'item_terjual' => 0,
            'berat_terjual_raw' => 0,
            'pendapatan_raw' => 0,
        ];
    }

    /**
     * Format nilai data sales untuk tampilan
     */
    private function formatSalesDataValues(Collection $salesData): Collection
    {
        return $salesData->map(function ($sale) {
            $sale['item_terjual'] = $sale['item_terjual'] > 0 ? $sale['item_terjual'] : self::DEFAULT_DISPLAY;
            $sale['berat_terjual'] = $sale['berat_terjual_raw'] > 0 ? 
                $this->formatWeight($sale['berat_terjual_raw']) : self::DEFAULT_DISPLAY;
            $sale['pendapatan'] = $sale['pendapatan_raw'] > 0 ? 
                $this->formatCurrency($sale['pendapatan_raw']) : self::DEFAULT_DISPLAY;

            unset($sale['berat_terjual_raw'], $sale['pendapatan_raw']);
            return $sale;
        });
    }

    /**
     * Format mata uang
     */
    private function formatCurrency(float $amount): string
    {
        return self::CURRENCY_SYMBOL . number_format($amount, 2, ',', '.');
    }

    /**
     * Format berat
     */
    private function formatWeight(float $weight): string
    {
        return number_format($weight, 2, ',', '.') . self::WEIGHT_UNIT;
    }
}