<?php

namespace Modules\Lpj\Imports;

use Modules\Lpj\Models\Slik;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;
use Maatwebsite\Excel\Concerns\ToCollection;
use Maatwebsite\Excel\Concerns\WithStartRow;
use Maatwebsite\Excel\Concerns\WithChunkReading;
use Maatwebsite\Excel\Concerns\WithBatchInserts;
use Maatwebsite\Excel\Concerns\WithCustomCsvSettings;


/**
 * Class SlikImport
 *
 * Handle import data Excel untuk modul Slik
 * Menggunakan Laravel Excel package untuk membaca file Excel
 * dengan optimasi memory dan chunk processing
 *
 * @package Modules\Lpj\app\Imports
 */
class SlikImport implements ToCollection, WithStartRow, WithBatchInserts, WithChunkReading, WithCustomCsvSettings
{
    /**
     * Mulai membaca dari baris ke-5 (skip header)
     *
     * @return int
     */
    public function startRow(): int
    {
        return 5;
    }

    /**
     * Batch size untuk insert data dari konfigurasi
     *
     * @return int
     */
    public function batchSize(): int
    {
        return config('import.slik.batch_size', 50);
    }

    /**
     * Chunk size untuk membaca file dari konfigurasi
     *
     * @return int
     */
    public function chunkSize(): int
    {
        return config('import.slik.chunk_size', 50);
    }

    /**
     * Custom CSV settings untuk optimasi pembacaan file
     *
     * @return array
     */
    public function getCsvSettings(): array
    {
        return [
            'input_encoding' => 'UTF-8',
            'delimiter' => ',',
            'enclosure' => '"',
            'escape_character' => '\\',
        ];
    }

    /**
     * Process collection data dari Excel dengan optimasi memory
     *
     * @param Collection $collection
     * @return void
     */
    public function collection(Collection $collection)
    {
        // Set memory limit dari konfigurasi
        $memoryLimit = config('import.slik.memory_limit', 1024);
        $currentMemoryLimit = ini_get('memory_limit');

        if ($currentMemoryLimit !== '-1' && $this->convertToBytes($currentMemoryLimit) < $memoryLimit * 1024 * 1024) {
            ini_set('memory_limit', $memoryLimit . 'M');
        }

        // Set timeout handler
        $timeout = config('import.slik.timeout', 1800);
        set_time_limit($timeout);

        // Force garbage collection sebelum memulai
        if (config('import.slik.enable_gc', true)) {
            gc_collect_cycles();
        }

        Log::info('SlikImport: Memulai import data', [
            'total_rows' => $collection->count(),
            'memory_usage' => memory_get_usage(true),
            'memory_peak' => memory_get_peak_usage(true),
            'memory_limit' => ini_get('memory_limit'),
            'php_version' => PHP_VERSION,
            'memory_limit_before' => $currentMemoryLimit,
            'config' => [
                'memory_limit' => $memoryLimit,
                'chunk_size' => $this->chunkSize(),
                'batch_size' => $this->batchSize()
            ]
        ]);

        DB::beginTransaction();

        try {
            $processedRows = 0;
            $skippedRows = 0;
            $errorRows = 0;
            $totalRows = $collection->count();

            foreach ($collection as $index => $row) {
                // Log progress setiap 25 baris untuk chunk lebih kecil
                if ($index % 25 === 0) {
                    Log::info('SlikImport: Processing chunk', [
                        'current_row' => $index + 5,
                        'progress' => round(($index / max($totalRows, 1)) * 100, 2) . '%',
                        'processed' => $processedRows,
                        'skipped' => $skippedRows,
                        'errors' => $errorRows,
                        'memory_usage' => memory_get_usage(true),
                        'memory_peak' => memory_get_peak_usage(true),
                        'memory_diff' => memory_get_peak_usage(true) - memory_get_usage(true)
                    ]);
                }

                // Skip baris kosong
                if ($this->isEmptyRow($row)) {
                    $skippedRows++;
                    Log::debug('SlikImport: Skipping empty row', ['row_number' => $index + 5]);
                    continue;
                }

                // Validasi data
                if (!$this->validateRow($row)) {
                    $errorRows++;
                    Log::warning('SlikImport: Invalid row data', [
                        'row_number' => $index + 5,
                        'data' => $row->toArray()
                    ]);
                    continue;
                }

                try {
                    // Map data dari Excel ke model
                    $slikData = $this->mapRowToSlik($row);

                    // Update atau create berdasarkan no_rekening dan cif
                    $slik = Slik::updateOrCreate(
                        [
                            'no_rekening' => $slikData['no_rekening'],
                            'cif' => $slikData['cif']
                        ],
                        $slikData
                    );

                    $processedRows++;

                    // Log detail untuk baris pertama sebagai sample
                    if ($index === 0) {
                        Log::info('SlikImport: Sample data processed', [
                            'slik_id' => $slik->id,
                            'no_rekening' => $slik->no_rekening,
                            'cif' => $slik->cif,
                            'was_recently_created' => $slik->wasRecentlyCreated
                        ]);
                    }

                    // Force garbage collection setiap 25 baris untuk mengurangi memory
                    if (config('import.slik.enable_gc', true) && $index > 0 && $index % 25 === 0) {
                        gc_collect_cycles();
                    }

                    // Unset data yang sudah tidak digunakan untuk mengurangi memory
                    if ($index > 0 && $index % 25 === 0) {
                        unset($slikData, $slik);
                    }

                    // Reset collection internal untuk mengurangi memory
                    if ($index > 0 && $index % 100 === 0) {
                        $collection = collect($collection->slice($index + 1)->values());
                    }

                } catch (\Exception $e) {
                    $errorRows++;
                    Log::error('SlikImport: Error processing row', [
                        'row_number' => $index + 5,
                        'error' => $e->getMessage(),
                        'data' => $row->toArray(),
                        'memory_usage' => memory_get_usage(true)
                    ]);
                }
            }

            DB::commit();

            // Force garbage collection setelah selesai
            if (config('import.slik.enable_gc', true)) {
                gc_collect_cycles();
            }

            // Cleanup variables
            unset($collection);

            Log::info('SlikImport: Import berhasil diselesaikan', [
                'total_rows' => $totalRows,
                'processed_rows' => $processedRows,
                'skipped_rows' => $skippedRows,
                'error_rows' => $errorRows,
                'final_memory_usage' => memory_get_usage(true),
                'peak_memory_usage' => memory_get_peak_usage(true),
                'memory_saved' => memory_get_peak_usage(true) - memory_get_usage(true),
                'memory_efficiency' => ($processedRows > 0) ? round(memory_get_peak_usage(true) / $processedRows, 2) : 0
            ]);

        } catch (\Exception $e) {
            DB::rollBack();

            // Force garbage collection jika error
            if (config('import.slik.enable_gc', true)) {
                gc_collect_cycles();
            }

            $errorType = 'general';
            if (str_contains(strtolower($e->getMessage()), 'memory')) {
                $errorType = 'memory';
            } elseif (str_contains(strtolower($e->getMessage()), 'timeout') || str_contains(strtolower($e->getMessage()), 'maximum execution time')) {
                $errorType = 'timeout';
            }

            Log::error('SlikImport: Error during import', [
                'error' => $e->getMessage(),
                'error_type' => $errorType,
                'exception_type' => get_class($e),
                'trace' => $e->getTraceAsString(),
                'file' => $e->getFile(),
                'line' => $e->getLine(),
                'memory_usage' => memory_get_usage(true),
                'memory_peak' => memory_get_peak_usage(true),
                'memory_limit' => ini_get('memory_limit'),
                'timeout_limit' => ini_get('max_execution_time'),
                'is_memory_error' => str_contains(strtolower($e->getMessage()), 'memory'),
                'is_timeout_error' => str_contains(strtolower($e->getMessage()), 'timeout') || str_contains(strtolower($e->getMessage()), 'maximum execution time')
            ]);
            throw $e;
        }
    }

    /**
     * Convert memory limit string ke bytes
     *
     * @param string $memoryLimit
     * @return int
     */
    private function convertToBytes(string $memoryLimit): int
    {
        $memoryLimit = trim($memoryLimit);
        $lastChar = strtolower(substr($memoryLimit, -1));
        $number = (int) substr($memoryLimit, 0, -1);

        switch ($lastChar) {
            case 'g':
                return $number * 1024 * 1024 * 1024;
            case 'm':
                return $number * 1024 * 1024;
            case 'k':
                return $number * 1024;
            default:
                return (int) $memoryLimit;
        }
    }

    /**
     * Cek apakah baris kosong
     *
     * @param Collection $row
     * @return bool
     */
    private function isEmptyRow(Collection $row): bool
    {
        return $row->filter(function ($value) {
            return !empty(trim($value));
        })->isEmpty();
    }

    /**
     * Validasi data baris
     *
     * @param Collection $row
     * @return bool
     */
    private function validateRow(Collection $row): bool
    {
        // Validasi minimal: sandi_bank, no_rekening, dan cif harus ada
        return !empty(trim($row[0])) && // sandi_bank
               !empty(trim($row[5])) && // no_rekening
               !empty(trim($row[6]));   // cif
    }

    /**
     * Map data dari baris Excel ke array untuk model Slik
     *
     * @param Collection $row
     * @return array
     */
    private function mapRowToSlik(Collection $row): array
    {
        return [
            'sandi_bank' => trim($row[0]) ?: null,
            'tahun' => $this->parseInteger($row[1]),
            'bulan' => $this->parseInteger($row[2]),
            'flag_detail' => trim($row[3]) ?: null,
            'kode_register_agunan' => trim($row[4]) ?: null,
            'no_rekening' => trim($row[5]) ?: null,
            'cif' => trim($row[6]) ?: null,
            'kolektibilitas' => trim($row[7]) ?: null,
            'fasilitas' => trim($row[8]) ?: null,
            'jenis_segmen_fasilitas' => trim($row[9]) ?: null,
            'status_agunan' => trim($row[10]) ?: null,
            'jenis_agunan' => trim($row[11]) ?: null,
            'peringkat_agunan' => trim($row[12]) ?: null,
            'lembaga_pemeringkat' => trim($row[13]) ?: null,
            'jenis_pengikatan' => trim($row[14]) ?: null,
            'tanggal_pengikatan' => $this->parseDate($row[15]),
            'nama_pemilik_agunan' => trim($row[16]) ?: null,
            'bukti_kepemilikan' => trim($row[17]) ?: null,
            'alamat_agunan' => trim($row[18]) ?: null,
            'lokasi_agunan' => trim($row[19]) ?: null,
            'nilai_agunan' => $this->parseDecimal($row[20]),
            'nilai_agunan_menurut_ljk' => $this->parseDecimal($row[21]),
            'tanggal_penilaian_ljk' => $this->parseDate($row[22]),
            'nilai_agunan_penilai_independen' => $this->parseDecimal($row[23]),
            'nama_penilai_independen' => trim($row[24]) ?: null,
            'tanggal_penilaian_penilai_independen' => $this->parseDate($row[25]),
            'jumlah_hari_tunggakan' => $this->parseInteger($row[26]),
            'status_paripasu' => trim($row[27]) ?: null,
            'prosentase_paripasu' => $this->parseDecimal($row[28]),
            'status_kredit_join' => trim($row[29]) ?: null,
            'diasuransikan' => trim($row[30]) ?: null,
            'keterangan' => trim($row[31]) ?: null,
            'kantor_cabang' => trim($row[32]) ?: null,
            'operasi_data' => trim($row[33]) ?: null,
            'kode_cabang' => trim($row[34]) ?: null,
            'nama_debitur' => trim($row[35]) ?: null,
            'nama_cabang' => trim($row[36]) ?: null,
            'flag' => trim($row[37]) ?: null,
        ];
    }

    /**
     * Parse integer value
     *
     * @param mixed $value
     * @return int|null
     */
    private function parseInteger($value): ?int
    {
        if (empty(trim($value))) {
            return null;
        }

        return (int) $value;
    }

    /**
     * Parse decimal value
     *
     * @param mixed $value
     * @return float|null
     */
    private function parseDecimal($value): ?float
    {
        if (empty(trim($value))) {
            return null;
        }

        // Remove currency formatting
        $cleaned = str_replace([',', '.'], ['', '.'], $value);
        $cleaned = preg_replace('/[^0-9.]/', '', $cleaned);

        return (float) $cleaned;
    }

    /**
     * Parse date value
     *
     * @param mixed $value
     * @return string|null
     */
    private function parseDate($value): ?string
    {
        if (empty(trim($value))) {
            return null;
        }

        try {
            // Try to parse various date formats
            $date = \Carbon\Carbon::parse($value);
            return $date->format('Y-m-d');
        } catch (\Exception $e) {
            Log::warning('SlikImport: Invalid date format', [
                'value' => $value,
                'error' => $e->getMessage()
            ]);
            return null;
        }
    }
}