<?php

namespace App\Business;

use Illuminate\Http\UploadedFile;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;
use PhpOffice\PhpSpreadsheet\IOFactory;
use PhpOffice\PhpSpreadsheet\Shared\Date as ExcelDate;

class BusinessTableImporter
{
    public function import(
        UploadedFile $file,
        TableDescriptor $descriptor,
        string $section,
        string $page,
        ?string $tab = null,
    ): array {
        if ($section === 'fund-management' && $page === 'fund-forecast') {
            return app(FundForecastWorkbookImporter::class)->import(
                $file,
                (int) (company_id() ?: 1),
            );
        }

        $spreadsheet = IOFactory::load($file->getRealPath());
        [$rows, $headerRow, $columnMap] = $this->bestMatchingSheet($spreadsheet, $descriptor);

        if ($rows === null || $columnMap === []) {
            throw ValidationException::withMessages([
                'import' => '未找到可识别的表头，请使用当前页面显示的中文表头。',
            ]);
        }

        $created = 0;
        $updated = 0;
        $model = $descriptor->model;
        $identityFields = TableRegistry::importIdentityFields($section, $page);

        DB::transaction(function () use (
            $rows,
            $headerRow,
            $columnMap,
            $descriptor,
            $section,
            $page,
            $tab,
            $model,
            $identityFields,
            &$created,
            &$updated,
        ) {
            foreach (array_slice($rows, $headerRow + 1) as $offset => $row) {
                $data = [];

                foreach ($columnMap as $columnIndex => $field) {
                    $data[$field['name']] = $this->normalizeValue(
                        $row[$columnIndex] ?? null,
                        $field['type'],
                        $headerRow + $offset + 2,
                        $field['label'],
                    );
                }

                if (collect($data)->every(fn ($value) => $value === null || $value === '')) {
                    continue;
                }

                if ($descriptor->tabFilterColumn && $tab) {
                    $tabValue = TableRegistry::tabValue($section, $page, $tab);

                    if ($tabValue !== null) {
                        $data[$descriptor->tabFilterColumn] = $tabValue;
                    }
                }

                foreach (TableRegistry::fixedFilters($section, $page) as $column => $value) {
                    $data[$column] = $value;
                }

                $data['company_id'] = company_id() ?: 1;
                $identity = collect($identityFields)
                    ->filter(fn ($field) => array_key_exists($field, $data) && $data[$field] !== null && $data[$field] !== '')
                    ->mapWithKeys(fn ($field) => [$field => $data[$field]])
                    ->all();

                $record = count($identity) === count($identityFields) && $identity !== []
                    ? $model::query()->where($identity)->first()
                    : null;

                if ($record) {
                    $record->update($data);
                    $updated++;
                } else {
                    $model::create($data);
                    $created++;
                }
            }
        });

        if ($created + $updated === 0) {
            throw ValidationException::withMessages([
                'import' => '表格中没有可导入的数据行。',
            ]);
        }

        return compact('created', 'updated');
    }

    private function bestMatchingSheet($spreadsheet, TableDescriptor $descriptor): array
    {
        $fieldLookup = [];

        foreach ($descriptor->fields as $field) {
            $fieldLookup[$this->normalizeHeader($field['name'])] = $field;
            $fieldLookup[$this->normalizeHeader($field['label'])] = $field;
        }

        $best = [null, null, []];
        $bestScore = 0;

        foreach ($spreadsheet->getWorksheetIterator() as $worksheet) {
            $rows = $worksheet->toArray(null, true, false, false);

            foreach (array_slice($rows, 0, 20, true) as $rowIndex => $row) {
                $columnMap = [];

                foreach ($row as $columnIndex => $heading) {
                    $key = $this->normalizeHeader($heading);

                    if ($key !== '' && isset($fieldLookup[$key])) {
                        $columnMap[$columnIndex] = $fieldLookup[$key];
                    }
                }

                if (count($columnMap) > $bestScore) {
                    $best = [$rows, $rowIndex, $columnMap];
                    $bestScore = count($columnMap);
                }
            }
        }

        return $best;
    }

    private function normalizeHeader($value): string
    {
        return mb_strtolower(preg_replace('/[\s\x{FEFF}_\-（）()]+/u', '', trim((string) $value)));
    }

    private function normalizeValue($value, string $type, int $rowNumber, string $label)
    {
        if ($value === null || trim((string) $value) === '') {
            return null;
        }

        if ($type === 'date') {
            try {
                return is_numeric($value)
                    ? ExcelDate::excelToDateTimeObject($value)->format('Y-m-d')
                    : \Illuminate\Support\Carbon::parse($value)->format('Y-m-d');
            } catch (\Throwable $e) {
                throw ValidationException::withMessages([
                    'import' => "第 {$rowNumber} 行“{$label}”不是有效日期。",
                ]);
            }
        }

        if (in_array($type, ['number', 'currency'], true)) {
            $number = str_replace([',', '，', '￥', '¥'], '', (string) $value);

            if (! is_numeric($number)) {
                throw ValidationException::withMessages([
                    'import' => "第 {$rowNumber} 行“{$label}”不是有效数字。",
                ]);
            }

            return (float) $number;
        }

        if ($type === 'boolean') {
            return in_array(mb_strtolower(trim((string) $value)), ['1', '是', 'true', 'yes', 'y'], true) ? 1 : 0;
        }

        return trim((string) $value);
    }
}