<?php

namespace App\Console\Commands;

use App\Models\AccountingEntry;
use App\Models\ChartOfAccount;
use App\Models\FinanceDocument;
use Illuminate\Console\Command;
use PhpOffice\PhpSpreadsheet\IOFactory;
use PhpOffice\PhpSpreadsheet\Shared\Date as ExcelDate;

class ImportAccountingData extends Command
{
    protected $signature = 'import:accounting-data
                            {file? : Path to Excel file}
                            {--dry-run : Preview without importing}';

    protected $description = 'Import accounting data from Excel files';

    protected $mapping;
    protected $expenseKeywords;
    protected $accountCache = [];
    protected $stats = [
        'income_count' => 0,
        'expense_count' => 0,
        'skipped_count' => 0,
        'error_count' => 0,
    ];

    public function handle()
    {
        $this->info('=== 會計資料匯入工具 ===');
        $this->newLine();

        // Load configuration
        $this->mapping = config('accounting_mapping.excel_to_system', []);
        $this->expenseKeywords = config('accounting_mapping.expense_keywords', []);

        // Get file path
        $filePath = $this->argument('file') ?? $this->askForFile();

        if (!file_exists($filePath)) {
            $this->error("檔案不存在: {$filePath}");
            return 1;
        }

        $this->info("📂 檔案: {$filePath}");
        $this->info("📅 檔案日期: " . date('Y-m-d H:i:s', filemtime($filePath)));
        $this->newLine();

        if ($this->option('dry-run')) {
            $this->warn('⚠️  DRY RUN MODE - 不會實際寫入資料庫');
            $this->newLine();
        }

        try {
            $spreadsheet = IOFactory::load($filePath);

            // Import income
            $this->info('📊 匯入收入資料...');
            $this->importIncome($spreadsheet);
            $this->newLine();

            // Import expenses
            $this->info('📊 匯入支出資料...');
            $this->importExpenses($spreadsheet);
            $this->newLine();

            // Show summary
            $this->showSummary();

            // Verify balance
            if (!$this->option('dry-run')) {
                $this->verifyBalance();
            }

            return 0;
        } catch (\Exception $e) {
            $this->error('匯入失敗: ' . $e->getMessage());
            $this->error($e->getTraceAsString());
            return 1;
        }
    }

    protected function askForFile(): string
    {
        $defaultPath = '協會行政資料/協會帳務/2025 收入支出總表 (含會計科目編號).xlsx';

        $this->info('可用檔案:');
        $this->line('1. ' . $defaultPath);

        return $this->ask('請輸入檔案路徑', $defaultPath);
    }

    protected function importIncome($spreadsheet)
    {
        // Find the "收入" sheet
        $sheet = null;
        foreach ($spreadsheet->getAllSheets() as $s) {
            if (in_array($s->getTitle(), ['收入', 'Income', '收入明細'])) {
                $sheet = $s;
                break;
            }
        }

        if (!$sheet) {
            $this->warn('找不到「收入」工作表，跳過');
            return;
        }

        $this->info("工作表: {$sheet->getTitle()}");

        // Read header row to find columns
        $headerRow = 1;
        $headers = [];
        $maxCol = $sheet->getHighestColumn();
        for ($col = 'A'; $col <= $maxCol; $col++) {
            $value = $sheet->getCell($col . $headerRow)->getValue();
            if ($value) {
                $headers[$col] = $value;
            }
        }

        $this->line('欄位: ' . implode(', ', $headers));

        // Detect columns
        $dateCol = $this->findColumn($headers, ['日期', 'Date']);
        $accountCodeCol = $this->findColumn($headers, ['科目編號', '科目代碼', 'Code']);
        $accountNameCol = $this->findColumn($headers, ['科目名稱', 'Account']);
        $amountCol = $this->findColumn($headers, ['收入金額', '金額', 'Amount']);
        $descCol = $this->findColumn($headers, ['收入來源備註', '備註', '說明', 'Description']);

        if (!$dateCol || !$amountCol) {
            $this->error('缺少必要欄位（日期、金額）');
            return;
        }

        // Import rows
        $highestRow = $sheet->getHighestRow();
        $bar = $this->output->createProgressBar($highestRow - 1);

        for ($row = $headerRow + 1; $row <= $highestRow; $row++) {
            $amount = $sheet->getCell($amountCol . $row)->getValue();

            if (empty($amount) || $amount == 0) {
                $this->stats['skipped_count']++;
                $bar->advance();
                continue;
            }

            try {
                $date = $this->parseDate($sheet->getCell($dateCol . $row)->getValue());
                $excelAccountCode = $accountCodeCol ? $sheet->getCell($accountCodeCol . $row)->getValue() : null;
                $description = $descCol ? $sheet->getCell($descCol . $row)->getValue() : '';

                // Map to system account
                $systemAccountCode = $this->mapAccountCode($excelAccountCode);
                $account = $this->getAccount($systemAccountCode);

                if (!$account) {
                    $this->stats['error_count']++;
                    $this->warn("\n找不到科目: {$systemAccountCode} (Excel: {$excelAccountCode})");
                    $bar->advance();
                    continue;
                }

                if (!$this->option('dry-run')) {
                    $this->createIncomeEntry($date, $account, $amount, $description);
                }

                $this->stats['income_count']++;
            } catch (\Exception $e) {
                $this->stats['error_count']++;
                $this->warn("\nRow {$row} 錯誤: " . $e->getMessage());
            }

            $bar->advance();
        }

        $bar->finish();
        $this->newLine();
    }

    protected function importExpenses($spreadsheet)
    {
        // Find the "支出" sheet
        $sheet = null;
        foreach ($spreadsheet->getAllSheets() as $s) {
            if (in_array($s->getTitle(), ['支出', 'Expense', '支出明細'])) {
                $sheet = $s;
                break;
            }
        }

        if (!$sheet) {
            $this->warn('找不到「支出」工作表，跳過');
            return;
        }

        $this->info("工作表: {$sheet->getTitle()}");

        // Read header row
        $headerRow = 1;
        $headers = [];
        $maxCol = $sheet->getHighestColumn();
        for ($col = 'A'; $col <= $maxCol; $col++) {
            $value = $sheet->getCell($col . $headerRow)->getValue();
            if ($value) {
                $headers[$col] = $value;
            }
        }

        $this->line('欄位: ' . implode(', ', $headers));

        // Detect columns
        $dateCol = $this->findColumn($headers, ['日期', 'Date']);
        $accountCodeCol = $this->findColumn($headers, ['科目編號', '科目代碼', 'Code']);
        $amountCol = $this->findColumn($headers, ['支出金額', '金額', 'Amount']);
        $descCol = $this->findColumn($headers, ['支出用途備註', '用途', '備註', 'Description']);

        if (!$dateCol || !$amountCol) {
            $this->error('缺少必要欄位（日期、金額）');
            return;
        }

        // Import rows
        $highestRow = $sheet->getHighestRow();
        $bar = $this->output->createProgressBar($highestRow - 1);

        for ($row = $headerRow + 1; $row <= $highestRow; $row++) {
            $amount = $sheet->getCell($amountCol . $row)->getValue();

            if (empty($amount) || $amount == 0) {
                $this->stats['skipped_count']++;
                $bar->advance();
                continue;
            }

            try {
                $date = $this->parseDate($sheet->getCell($dateCol . $row)->getValue());
                $excelAccountCode = $accountCodeCol ? $sheet->getCell($accountCodeCol . $row)->getValue() : '5100';
                $description = $descCol ? $sheet->getCell($descCol . $row)->getValue() : '';

                // For 5100, classify by keywords
                if ($excelAccountCode == '5100') {
                    $systemAccountCode = $this->classifyExpense($description);
                } else {
                    $systemAccountCode = $this->mapAccountCode($excelAccountCode);
                }

                $account = $this->getAccount($systemAccountCode);

                if (!$account) {
                    $this->stats['error_count']++;
                    $this->warn("\n找不到科目: {$systemAccountCode}");
                    $bar->advance();
                    continue;
                }

                if (!$this->option('dry-run')) {
                    $this->createExpenseEntry($date, $account, $amount, $description);
                }

                $this->stats['expense_count']++;
            } catch (\Exception $e) {
                $this->stats['error_count']++;
                $this->warn("\nRow {$row} 錯誤: " . $e->getMessage());
            }

            $bar->advance();
        }

        $bar->finish();
        $this->newLine();
    }

    protected function createIncomeEntry($date, $account, $amount, $description)
    {
        // Create finance document
        $document = FinanceDocument::create([
            'title' => '收入 - ' . $account->account_name_zh,
            'amount' => $amount,
            'description' => $description,
            'chart_of_account_id' => $account->id,
            'submitted_at' => $date,
            'status' => FinanceDocument::STATUS_APPROVED_CHAIR,
        ]);

        // Create accounting entries (double-entry)
        // Debit: Cash
        AccountingEntry::create([
            'finance_document_id' => $document->id,
            'chart_of_account_id' => $this->getAccount('1101')->id,
            'entry_type' => AccountingEntry::ENTRY_TYPE_DEBIT,
            'amount' => $amount,
            'entry_date' => $date,
            'description' => '收入 - ' . $description,
        ]);

        // Credit: Income account
        AccountingEntry::create([
            'finance_document_id' => $document->id,
            'chart_of_account_id' => $account->id,
            'entry_type' => AccountingEntry::ENTRY_TYPE_CREDIT,
            'amount' => $amount,
            'entry_date' => $date,
            'description' => $description,
        ]);
    }

    protected function createExpenseEntry($date, $account, $amount, $description)
    {
        // Create finance document
        $document = FinanceDocument::create([
            'title' => '支出 - ' . $account->account_name_zh,
            'amount' => $amount,
            'description' => $description,
            'chart_of_account_id' => $account->id,
            'submitted_at' => $date,
            'status' => FinanceDocument::STATUS_APPROVED_CHAIR,
        ]);

        // Create accounting entries (double-entry)
        // Debit: Expense account
        AccountingEntry::create([
            'finance_document_id' => $document->id,
            'chart_of_account_id' => $account->id,
            'entry_type' => AccountingEntry::ENTRY_TYPE_DEBIT,
            'amount' => $amount,
            'entry_date' => $date,
            'description' => $description,
        ]);

        // Credit: Cash
        AccountingEntry::create([
            'finance_document_id' => $document->id,
            'chart_of_account_id' => $this->getAccount('1101')->id,
            'entry_type' => AccountingEntry::ENTRY_TYPE_CREDIT,
            'amount' => $amount,
            'entry_date' => $date,
            'description' => '支出 - ' . $description,
        ]);
    }

    protected function mapAccountCode($excelCode)
    {
        return $this->mapping[$excelCode] ?? $excelCode;
    }

    protected function classifyExpense($description): string
    {
        foreach ($this->expenseKeywords as $rule) {
            if (empty($rule['keywords'])) {
                if ($rule['is_default'] ?? false) {
                    return $rule['account_code'];
                }
                continue;
            }

            foreach ($rule['keywords'] as $keyword) {
                if (mb_strpos($description, $keyword) !== false) {
                    return $rule['account_code'];
                }
            }
        }

        return '5901'; // Default: 雜項支出
    }

    protected function getAccount($accountCode)
    {
        if (!isset($this->accountCache[$accountCode])) {
            $this->accountCache[$accountCode] = ChartOfAccount::where('account_code', $accountCode)->first();
        }

        return $this->accountCache[$accountCode];
    }

    protected function parseDate($value)
    {
        if (is_numeric($value)) {
            return ExcelDate::excelToDateTimeObject($value);
        }

        if ($value instanceof \DateTime) {
            return $value;
        }

        return new \DateTime($value);
    }

    protected function findColumn($headers, $patterns)
    {
        foreach ($headers as $col => $header) {
            foreach ($patterns as $pattern) {
                if (mb_strpos($header, $pattern) !== false) {
                    return $col;
                }
            }
        }

        return null;
    }

    protected function showSummary()
    {
        $this->info('=== 匯入統計 ===');
        $this->table(
            ['項目', '數量'],
            [
                ['收入筆數', $this->stats['income_count']],
                ['支出筆數', $this->stats['expense_count']],
                ['跳過筆數', $this->stats['skipped_count']],
                ['錯誤筆數', $this->stats['error_count']],
            ]
        );
    }

    protected function verifyBalance()
    {
        $this->info('=== 驗證借貸平衡 ===');

        $debitTotal = AccountingEntry::where('entry_type', AccountingEntry::ENTRY_TYPE_DEBIT)->sum('amount');
        $creditTotal = AccountingEntry::where('entry_type', AccountingEntry::ENTRY_TYPE_CREDIT)->sum('amount');

        $this->line("借方總計: " . number_format($debitTotal, 2));
        $this->line("貸方總計: " . number_format($creditTotal, 2));

        if (bccomp((string)$debitTotal, (string)$creditTotal, 2) === 0) {
            $this->info('✅ 借貸平衡');
        } else {
            $diff = $debitTotal - $creditTotal;
            $this->error("❌ 借貸不平衡，差額: " . number_format($diff, 2));
        }
    }
}