<?php

namespace App\Business;

use App\Models\Business\CourierSurchargeQuote;
use Illuminate\Http\UploadedFile;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;
use PhpOffice\PhpSpreadsheet\Cell\Coordinate;
use PhpOffice\PhpSpreadsheet\IOFactory;
use PhpOffice\PhpSpreadsheet\Shared\Date as ExcelDate;
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Style\Alignment;
use PhpOffice\PhpSpreadsheet\Style\Border;
use PhpOffice\PhpSpreadsheet\Style\Fill;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
use Symfony\Component\HttpFoundation\StreamedResponse;
use Throwable;

class CourierSurchargeQuoteWorkbookImporter
{
    public const MAX_ROWS = 500;

    public const DUPLICATE_SKIP = 'skip';

    public const DUPLICATE_UPDATE = 'update';

    public const HEADERS = [
        '快递名称',
        '快递归属',
        '对账人',
        '供应商',
        '附加费类型',
        '结算方式',
        '计价标准',
        '生效条件',
        '生效日期',
        '状态',
        '备注',
    ];

    public function __construct(private readonly CourierSurchargeQuoteRepository $quotes)
    {
    }

    public function template(): StreamedResponse
    {
        $types = $this->quotes->activeTypeNames();

        return response()->streamDownload(function () use ($types): void {
            $spreadsheet = new Spreadsheet();
            $sheet = $spreadsheet->getActiveSheet();
            $sheet->setTitle('附加费报价');
            $sheet->fromArray(self::HEADERS, null, 'A1');

            $lastColumn = Coordinate::stringFromColumnIndex(count(self::HEADERS));
            $headerRange = 'A1:' . $lastColumn . '1';
            $sheet->getStyle($headerRange)->applyFromArray([
                'font' => ['bold' => true, 'color' => ['rgb' => 'FFFFFF']],
                'fill' => ['fillType' => Fill::FILL_SOLID, 'startColor' => ['rgb' => '856632']],
                'alignment' => ['horizontal' => Alignment::HORIZONTAL_CENTER, 'vertical' => Alignment::VERTICAL_CENTER],
                'borders' => ['allBorders' => ['borderStyle' => Border::BORDER_THIN, 'color' => ['rgb' => 'D8D2C7']]],
            ]);
            $sheet->getRowDimension(1)->setRowHeight(24);
            $sheet->freezePane('A2');
            $sheet->setAutoFilter($headerRange);

            $widths = [18, 14, 14, 20, 24, 18, 30, 32, 14, 12, 30];
            foreach ($widths as $index => $width) {
                $column = Coordinate::stringFromColumnIndex($index + 1);
                $sheet->getColumnDimension($column)->setWidth($width);
                $sheet->getStyle($column . '2:' . $column . (self::MAX_ROWS + 1))
                    ->getNumberFormat()
                    ->setFormatCode('@');
            }

            $instructions = $spreadsheet->createSheet();
            $instructions->setTitle('填写说明');
            $instructions->fromArray([
                ['项目', '填写要求'],
                ['必填字段', '快递名称、快递归属、对账人、附加费类型、结算方式、计价标准、生效条件、生效日期、状态。'],
                ['供应商', '选填；没有供应商时保持空白。'],
                ['附加费类型', '多种类型使用“、”分隔；只能填写当前已启用类型。当前可选：' . implode('、', $types)],
                ['快递归属', '自有快递 或 代发仓。'],
                ['结算方式', implode('、', CourierSurchargeQuoteRepository::MODES)],
                ['生效日期', '使用 YYYY-MM-DD，例如 2026-09-22。'],
                ['状态', '已启用 或 已停用；也可填写 active 或 inactive。'],
                ['重复规则', '预览后必须明确选择跳过已有规则或更新已有规则，系统不会静默覆盖。'],
                ['单次上限', '最多 ' . self::MAX_ROWS . ' 条非空数据。'],
            ], 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(18);
            $instructions->getColumnDimension('B')->setWidth(90);
            $instructions->getStyle('A1:B10')->getAlignment()->setVertical(Alignment::VERTICAL_CENTER)->setWrapText(true);
            foreach (range(1, 10) as $row) {
                $instructions->getRowDimension($row)->setRowHeight($row === 1 ? 24 : 34);
            }

            $spreadsheet->setActiveSheetIndex(0);
            (new Xlsx($spreadsheet))->save('php://output');
            $spreadsheet->disconnectWorksheets();
        }, '附加费报价导入模板_' . now()->format('Ymd') . '.xlsx', [
            'Content-Type' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
            'Cache-Control' => 'private, no-store',
        ]);
    }

    /**
     * @return array{
     *   rows:list<array{line:int,data:array<string,mixed>,display:array<string,string>,errors:list<string>,result:string,result_label:string,existing_id:?int}>,
     *   summary:array{total:int,valid:int,new:int,duplicate:int,invalid:int}
     * }
     */
    public function preview(UploadedFile $file): array
    {
        $extension = mb_strtolower($file->getClientOriginalExtension());
        if (! in_array($extension, ['xlsx', 'xls', 'csv'], true)) {
            throw ValidationException::withMessages(['import' => '仅支持 xlsx、xls 或 csv 文件。']);
        }

        try {
            $reader = IOFactory::createReader(match ($extension) {
                'xlsx' => 'Xlsx',
                'xls' => 'Xls',
                'csv' => 'Csv',
            });
            $reader->setReadDataOnly(true);
            $spreadsheet = $reader->load($file->getRealPath());
            $rows = $spreadsheet->getActiveSheet()->toArray(null, false, false, false);
        } catch (Throwable) {
            throw ValidationException::withMessages([
                'import' => '无法读取导入文件，请确认文件未损坏且格式为 xlsx、xls 或 csv。',
            ]);
        } finally {
            if (isset($spreadsheet)) {
                $spreadsheet->disconnectWorksheets();
            }
        }

        $headers = array_map(fn (mixed $value): string => $this->text($value), $rows[0] ?? []);
        while ($headers !== [] && end($headers) === '') {
            array_pop($headers);
        }
        if ($headers !== self::HEADERS) {
            throw ValidationException::withMessages([
                'import' => '表头不正确。请下载最新模板，并保持 11 个字段名称及顺序不变。',
            ]);
        }

        $dataRows = [];
        foreach (array_slice($rows, 1, null, true) as $index => $row) {
            $row = array_slice(array_pad($row, count(self::HEADERS), null), 0, count(self::HEADERS));
            if (collect($row)->every(fn (mixed $value): bool => $this->text($value) === '')) {
                continue;
            }
            $dataRows[] = ['line' => $index + 1, 'values' => $row];
            if (count($dataRows) > self::MAX_ROWS) {
                throw ValidationException::withMessages([
                    'import' => '单次最多导入 ' . self::MAX_ROWS . ' 条非空数据，请拆分文件后重试。',
                ]);
            }
        }

        if ($dataRows === []) {
            throw ValidationException::withMessages(['import' => '表格中没有可预览的数据行。']);
        }

        $previewRows = array_map(fn (array $row): array => $this->normalizeRow($row['values'], $row['line']), $dataRows);
        $signatures = [];
        foreach ($previewRows as $index => $row) {
            if ($row['errors'] === []) {
                $signatures[$this->quotes->importIdentity($row['data'])][] = $index;
            }
        }
        foreach ($signatures as $indexes) {
            if (count($indexes) < 2) {
                continue;
            }
            $lines = implode('、', array_map(fn (int $index): int => $previewRows[$index]['line'], $indexes));
            foreach ($indexes as $index) {
                $previewRows[$index]['errors'][] = '文件内规则重复（行号：' . $lines . '）。';
            }
        }

        foreach ($previewRows as &$row) {
            if ($row['errors'] !== []) {
                $row['result'] = 'invalid';
                $row['result_label'] = '校验失败';
                continue;
            }
            $existing = $this->quotes->findImportDuplicate($row['data']);
            $row['existing_id'] = $existing?->id;
            $row['result'] = $existing ? 'duplicate' : 'new';
            $row['result_label'] = $existing ? '已有规则' : '可新增';
        }
        unset($row);

        $collection = collect($previewRows);

        return [
            'rows' => $previewRows,
            'summary' => [
                'total' => $collection->count(),
                'valid' => $collection->where('result', '!=', 'invalid')->count(),
                'new' => $collection->where('result', 'new')->count(),
                'duplicate' => $collection->where('result', 'duplicate')->count(),
                'invalid' => $collection->where('result', 'invalid')->count(),
            ],
        ];
    }

    /**
     * @param list<array{line:int,data:array<string,mixed>,errors:list<string>}> $rows
     * @return array{created:int,updated:int,skipped:int,total:int}
     */
    public function commit(array $rows, string $duplicatePolicy, int $userId): array
    {
        if (! in_array($duplicatePolicy, [self::DUPLICATE_SKIP, self::DUPLICATE_UPDATE], true)) {
            throw ValidationException::withMessages(['duplicate_policy' => '请选择已有规则的处理方式。']);
        }
        if ($rows === [] || count($rows) > self::MAX_ROWS || collect($rows)->contains(fn (array $row): bool => ($row['errors'] ?? []) !== [])) {
            throw ValidationException::withMessages(['import' => '预览数据无效或包含错误，请重新上传文件。']);
        }

        $activeTypes = $this->quotes->activeTypeNames();
        foreach ($rows as $row) {
            $inactive = array_values(array_diff((array) ($row['data']['types'] ?? []), $activeTypes));
            if ($inactive !== []) {
                throw ValidationException::withMessages([
                    'import' => '附加费类型“' . implode('、', $inactive) . '”已停用或不存在，请重新预览。',
                ]);
            }
        }

        $counts = ['created' => 0, 'updated' => 0, 'skipped' => 0, 'total' => count($rows)];
        DB::transaction(function () use ($rows, $duplicatePolicy, $userId, &$counts): void {
            foreach ($rows as $row) {
                $data = $row['data'];
                $status = $data['status'];
                unset($data['status']);

                $existing = $this->quotes->findImportDuplicate($data, true);
                if ($existing && $duplicatePolicy === self::DUPLICATE_SKIP) {
                    $counts['skipped']++;
                    continue;
                }

                if ($existing) {
                    $quote = $this->quotes->update($existing, $data, $userId);
                    $counts['updated']++;
                } else {
                    $quote = $this->quotes->create($data, $userId);
                    $counts['created']++;
                }

                if ($quote->status !== $status) {
                    $this->quotes->setStatus($quote, $status, $userId);
                }
            }
        });

        return $counts;
    }

    /** @return array{line:int,data:array<string,mixed>,display:array<string,string>,errors:list<string>,result:string,result_label:string,existing_id:?int} */
    private function normalizeRow(array $values, int $line): array
    {
        $raw = array_combine(self::HEADERS, $values);
        $display = [];
        foreach ($raw as $header => $value) {
            $display[$header] = $this->text($value);
        }

        $errors = [];
        foreach (['快递名称', '快递归属', '对账人', '附加费类型', '结算方式', '计价标准', '生效条件', '生效日期', '状态'] as $header) {
            if ($display[$header] === '') {
                $errors[] = $header . '不能为空。';
            }
        }

        $this->checkLength($display, '快递名称', 191, $errors);
        $this->checkLength($display, '对账人', 100, $errors);
        $this->checkLength($display, '供应商', 191, $errors);
        $this->checkLength($display, '计价标准', 2000, $errors);
        $this->checkLength($display, '生效条件', 2000, $errors);
        $this->checkLength($display, '备注', 2000, $errors);

        $types = array_values(array_unique(array_filter(array_map(
            'trim',
            preg_split('/[、,，;；]+/u', $display['附加费类型']) ?: [],
        ))));
        if (count($types) > 50) {
            $errors[] = '附加费类型最多 50 项。';
        }
        $validTypes = $this->quotes->validTypeNames();
        $activeTypes = $this->quotes->activeTypeNames();
        $unknownTypes = array_values(array_diff($types, $validTypes));
        $inactiveTypes = array_values(array_diff(array_intersect($types, $validTypes), $activeTypes));
        if ($unknownTypes !== []) {
            $errors[] = '附加费类型不存在：' . implode('、', $unknownTypes) . '。';
        }
        if ($inactiveTypes !== []) {
            $errors[] = '附加费类型已停用：' . implode('、', $inactiveTypes) . '。';
        }
        if ($display['快递归属'] !== '' && ! in_array($display['快递归属'], CourierSurchargeQuoteRepository::SCOPES, true)) {
            $errors[] = '快递归属只能填写“自有快递”或“代发仓”。';
        }
        if ($display['结算方式'] !== '' && ! in_array($display['结算方式'], CourierSurchargeQuoteRepository::MODES, true)) {
            $errors[] = '结算方式不在允许范围内。';
        }

        $effectiveAt = $this->date($raw['生效日期']);
        if ($display['生效日期'] !== '' && $effectiveAt === null) {
            $errors[] = '生效日期必须是有效的 YYYY-MM-DD 日期。';
        }

        $status = match (mb_strtolower($display['状态'])) {
            '已启用', CourierSurchargeQuote::STATUS_ACTIVE => CourierSurchargeQuote::STATUS_ACTIVE,
            '已停用', CourierSurchargeQuote::STATUS_INACTIVE => CourierSurchargeQuote::STATUS_INACTIVE,
            default => null,
        };
        if ($display['状态'] !== '' && $status === null) {
            $errors[] = '状态只能填写“已启用/active”或“已停用/inactive”。';
        }

        if ($effectiveAt !== null) {
            $display['生效日期'] = $effectiveAt;
        }

        return [
            'line' => $line,
            'data' => [
                'courier' => $display['快递名称'],
                'scope' => $display['快递归属'],
                'reconciler' => $display['对账人'],
                'supplier' => $display['供应商'] !== '' ? $display['供应商'] : null,
                'types' => $types,
                'mode' => $display['结算方式'],
                'standard' => $display['计价标准'],
                'condition' => $display['生效条件'],
                'effective_at' => $effectiveAt,
                'status' => $status,
                'remark' => $display['备注'],
            ],
            'display' => $display,
            'errors' => array_values(array_unique($errors)),
            'result' => 'invalid',
            'result_label' => '校验失败',
            'existing_id' => null,
        ];
    }

    /** @param array<string,string> $values @param list<string> $errors */
    private function checkLength(array $values, string $field, int $max, array &$errors): void
    {
        if (mb_strlen($values[$field]) > $max) {
            $errors[] = $field . '不能超过 ' . $max . ' 个字符。';
        }
    }

    private function date(mixed $value): ?string
    {
        if (is_numeric($value) && (float) $value > 0) {
            try {
                return ExcelDate::excelToDateTimeObject((float) $value)->format('Y-m-d');
            } catch (Throwable) {
                return null;
            }
        }

        $value = $this->text($value);
        if (! preg_match('/^(\d{4})-(\d{2})-(\d{2})$/', $value, $matches)) {
            return null;
        }

        return checkdate((int) $matches[2], (int) $matches[3], (int) $matches[1]) ? $value : null;
    }

    private function text(mixed $value): string
    {
        return trim(str_replace("\xEF\xBB\xBF", '', (string) ($value ?? '')));
    }
}