<?php

namespace Modules\EcommerceFinance\Services;

use Illuminate\Http\UploadedFile;
use Illuminate\Validation\ValidationException;
use PhpOffice\PhpSpreadsheet\IOFactory;
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Style\Alignment;
use PhpOffice\PhpSpreadsheet\Style\Border;
use PhpOffice\PhpSpreadsheet\Style\Fill;
use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
use Symfony\Component\HttpFoundation\StreamedResponse;
use Throwable;

/** 读取和生成「是否包邮厂家」导入文件。 */
class SupplierFreeShippingWorkbook
{
    public const SUPPLIER_CODE_HEADER = '供应商代码';

    public const FIELD_HEADER = '是否包邮厂家';

    /**
     * 返回供应商代码 => 是否包邮厂家。空白或“-”表示否。
     *
     * @return array<string,bool>
     */
    public function read(UploadedFile $file): array
    {
        try {
            $reader = IOFactory::createReader(match (mb_strtolower($file->getClientOriginalExtension())) {
                'xlsx' => 'Xlsx',
                'xls' => 'Xls',
                'csv' => 'Csv',
                default => throw new \RuntimeException('Unsupported workbook format.'),
            });
            $book = $reader->load($file->getRealPath());
        } catch (Throwable) {
            throw ValidationException::withMessages([
                'import' => '无法读取导入文件，请确认文件未损坏且格式为 xlsx、xls 或 csv。',
            ]);
        }

        try {
            [$sheet, $headerRow, $codeColumn, $fieldColumn] = $this->locateColumns($book);
            $highestRow = $sheet->getHighestDataRow();
            if ($highestRow > 5001) {
                throw ValidationException::withMessages(['import' => '单次最多导入 5,000 条供应商记录，请拆分文件后重试。']);
            }

            $records = [];
            $lineByCode = [];
            for ($row = $headerRow + 1; $row <= $highestRow; $row++) {
                $code = $this->text($sheet, $codeColumn, $row);
                if (str_starts_with($code, "'")) {
                    $code = substr($code, 1);
                }
                $field = $this->text($sheet, $fieldColumn, $row);
                if ($code === '' && $field === '') {
                    continue;
                }
                if ($code === '') {
                    throw ValidationException::withMessages(['import' => "第 {$row} 行供应商代码为空。"]);
                }
                if (mb_strlen($code) > 191) {
                    throw ValidationException::withMessages(['import' => "第 {$row} 行供应商代码超过 191 个字符。"]);
                }
                $codeKey = mb_strtolower($code);
                if (isset($lineByCode[$codeKey])) {
                    throw ValidationException::withMessages([
                        'import' => "第 {$row} 行供应商代码“{$code}”与第 {$lineByCode[$codeKey]} 行重复。",
                    ]);
                }

                $records[$code] = $this->parseFlag($field, $row);
                $lineByCode[$codeKey] = $row;
            }

            if ($records === []) {
                throw ValidationException::withMessages(['import' => '表格中没有可导入的供应商记录。']);
            }

            return $records;
        } finally {
            $book->disconnectWorksheets();
        }
    }

    public function template(): StreamedResponse
    {
        return response()->streamDownload(function (): void {
            $book = new Spreadsheet();
            $sheet = $book->getActiveSheet();
            $sheet->setTitle('是否包邮厂家');
            $sheet->fromArray([self::SUPPLIER_CODE_HEADER, '供应商名称', self::FIELD_HEADER], null, 'A1');
            $sheet->getStyle('A1:C1')->applyFromArray([
                'font' => ['bold' => true, 'color' => ['rgb' => 'FFFFFF']],
                'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => ['rgb' => '856632']],
                'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER],
                'borders' => ['allBorders' => ['borderStyle' => Border::BORDER_THIN, 'color' => ['rgb' => 'D8D2C7']]],
            ]);
            $sheet->getRowDimension(1)->setRowHeight(24);
            $sheet->freezePane('A2');
            $sheet->setAutoFilter('A1:C1');
            foreach (['A' => 22, 'B' => 34, 'C' => 20] as $column => $width) {
                $sheet->getColumnDimension($column)->setWidth($width);
            }
            $sheet->getStyle('A2:A5001')->getNumberFormat()->setFormatCode('@');

            $instructions = $book->createSheet();
            $instructions->setTitle('填写说明');
            $instructions->fromArray([
                ['项目', '说明'],
                [self::SUPPLIER_CODE_HEADER, '必填。请填写供应商管理页面中的供应商代码，按代码精确关联。'],
                [self::FIELD_HEADER, '填写“包邮”表示是包邮厂家；空白或“-”表示不是包邮厂家。'],
                ['兼容导出表', '也可以使用本页面导出的文件，在此列补充后直接导入。'],
                ['覆盖规则', '同一供应商再次导入会更新该字段；其他列不会修改。'],
            ], null, 'A1');
            $instructions->getStyle('A1:B1')->applyFromArray([
                'font' => ['bold' => true, 'color' => ['rgb' => 'FFFFFF']],
                'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => ['rgb' => '856632']],
            ]);
            $instructions->getColumnDimension('A')->setWidth(22);
            $instructions->getColumnDimension('B')->setWidth(76);
            $instructions->getStyle('A1:B5')->getAlignment()->setVertical(Alignment::VERTICAL_CENTER)->setWrapText(true);
            foreach (range(1, 5) as $row) {
                $instructions->getRowDimension($row)->setRowHeight($row === 1 ? 24 : 34);
            }

            $book->setActiveSheetIndex(0);
            (new Xlsx($book))->save('php://output');
            $book->disconnectWorksheets();
        }, '供应商是否包邮厂家_导入模板_' . now()->format('Ymd') . '.xlsx', [
            'Content-Type' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
            'Cache-Control' => 'private, no-store',
        ]);
    }

    /** @return array{0:Worksheet,1:int,2:int,3:int} */
    private function locateColumns(Spreadsheet $book): array
    {
        $best = null;
        foreach ($book->getWorksheetIterator() as $sheet) {
            $rows = $sheet->toArray(null, false, false, false);
            foreach (array_slice($rows, 0, 20, true) as $rowIndex => $row) {
                $headers = [];
                foreach ($row as $columnIndex => $value) {
                    $header = $this->header($value);
                    if ($header !== '') {
                        $headers[$header] = $columnIndex + 1;
                    }
                }
                if (isset($headers[self::SUPPLIER_CODE_HEADER], $headers[self::FIELD_HEADER])) {
                    $candidate = [$sheet, $rowIndex + 1, $headers[self::SUPPLIER_CODE_HEADER], $headers[self::FIELD_HEADER]];
                    $best = $candidate;
                    break 2;
                }
            }
        }

        if ($best === null) {
            throw ValidationException::withMessages([
                'import' => '缺少表头：需要“供应商代码”和“是否包邮厂家”两列。',
            ]);
        }

        return $best;
    }

    private function parseFlag(string $value, int $row): bool
    {
        $normalized = mb_strtolower(preg_replace('/[\s\x{FEFF}]+/u', '', $value));
        if (in_array($normalized, ['', '-', '否', '不是', '0', 'false', 'no'], true)) {
            return false;
        }
        if (in_array($normalized, ['包邮', '是', '是包邮厂家', '1', 'true', 'yes'], true)) {
            return true;
        }

        throw ValidationException::withMessages([
            'import' => "第 {$row} 行“是否包邮厂家”只能填写“包邮”，或留空表示否。",
        ]);
    }

    private function text(Worksheet $sheet, int $column, int $row): string
    {
        $cell = $sheet->getCell([$column, $row]);
        if ($cell->getDataType() === 'f') {
            throw ValidationException::withMessages(['import' => "第 {$row} 行含公式，请填写实际值。"]);
        }

        return trim((string) $cell->getFormattedValue());
    }

    private function header(mixed $value): string
    {
        return str_replace([' ', '　', "\n", "\r", "\t", "\x{FEFF}"], '', trim((string) $value));
    }
}