<?php

namespace App\Business;

use Illuminate\Http\UploadedFile;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;
use Modules\EcommerceFinance\Repositories\StoreViolationRecordRepository;
use PhpOffice\PhpSpreadsheet\IOFactory;
use Throwable;

/**
 * 店铺违规信息预警：导入文件按统一表头映射到 store_violation_records。
 *
 * preview() 只解析和校验，不写库；commit() 按 (platform, violation_no) 幂等写入。
 */
class StoreViolationWorkbookImporter
{
    public function __construct(
        private readonly StoreViolationMapper $mapper,
        private readonly StoreViolationRecordRepository $repository,
        private readonly StoreViolationAlertCalculator $alerts,
    ) {
    }

    /**
     * @return array{platform:string,sheet:string,columns:list<array{key:string,label:string}>,unknown_headers:list<string>,rows:list<array>,summary:array,existing_checked:bool}
     */
    public function preview(UploadedFile $file, string $platform): array
    {
        $platforms = (array) config('store_violations.platforms', []);
        if (! array_key_exists($platform, $platforms)) {
            throw ValidationException::withMessages(['import' => '未知平台，请刷新页面后重试。']);
        }

        if (! $this->repository->available()) {
            throw ValidationException::withMessages(['import' => '导入功能尚未就绪：统一表尚未建立，请联系管理员完成迁移。']);
        }

        try {
            $spreadsheet = IOFactory::load($file->getRealPath());
        } catch (Throwable $exception) {
            report($exception);

            throw ValidationException::withMessages(['import' => '无法读取该文件，请上传 xlsx / xls / csv 格式的表格。']);
        }

        $worksheet = $spreadsheet->getActiveSheet();
        $matrix = $worksheet->toArray(null, true, true, false);

        [$headerIndex, $columnMap, $unknownHeaders] = $this->detectHeaders($matrix);
        if ($headerIndex === null) {
            throw ValidationException::withMessages([
                'import' => '未找到可识别的表头行，请使用统一表头或下载导入模板。',
            ]);
        }

        $missing = [];
        foreach (['shop_name', 'violation_no'] as $required) {
            if (! in_array($required, $columnMap, true)) {
                $missing[] = $this->labelFor($required);
            }
        }
        if ($missing !== []) {
            throw ValidationException::withMessages([
                'import' => '缺少必填列：' . implode('、', $missing) . '。请使用统一表头或下载导入模板。',
            ]);
        }

        $maxRows = (int) config('store_violations.import.max_rows', 20000);
        $dataRows = array_slice($matrix, $headerIndex + 1);
        if (count($dataRows) > $maxRows) {
            throw ValidationException::withMessages([
                'import' => '单次最多导入 ' . number_format($maxRows) . ' 行，请拆分文件后重试。',
            ]);
        }

        $rows = [];
        $seen = [];
        $invalid = 0;

        foreach ($dataRows as $offset => $row) {
            $rowNumber = $headerIndex + 2 + $offset;
            $raw = $this->rowToFields($row, $columnMap);
            if ($this->isEmptyRow($raw)) {
                continue;
            }

            $item = $this->normalizeRow($raw, $platform, $rowNumber, $columnMap);

            if ($item['status'] === 'valid') {
                $key = $platform . '|' . $item['data']['violation_no'];
                if (isset($seen[$key])) {
                    $item = $seen[$key]['data'] === $item['data']
                        ? $this->markRow($item, 'same', '与文件内前一行重复，将跳过')
                        : $this->markRow($item, 'invalid', '与文件内前一行的数据冲突，请先合并');
                } else {
                    $seen[$key] = $item;
                }
            }

            if ($item['status'] === 'invalid') {
                $invalid++;
            }

            $rows[] = $item;
        }

        $summary = ['new' => 0, 'update' => 0, 'same' => 0, 'invalid' => $invalid];
        $this->compareWithExisting($rows, $platform, $summary);

        return [
            'platform' => $platform,
            'sheet' => $worksheet->getTitle(),
            'columns' => collect((array) config('store_violations.columns', []))
                ->map(fn (array $column): array => ['key' => $column['key'], 'label' => $column['label']])
                ->all(),
            'unknown_headers' => $unknownHeaders,
            'provided_columns' => array_values($columnMap),
            'rows' => $rows,
            'summary' => $summary,
        ];
    }

    /** @param array{rows:list<array>} $preview */
    public function commit(array $preview): array
    {
        $platform = (string) ($preview['platform'] ?? '');
        $rows = $preview['rows'] ?? [];
        $provided = array_values(array_unique((array) ($preview['provided_columns'] ?? [])));
        $now = now();

        $unifiedColumns = array_map(
            static fn (array $column): string => (string) $column['key'],
            (array) config('store_violations.columns', []),
        );
        $updateColumns = array_values(array_intersect($unifiedColumns, $provided));
        if (! in_array('violation_category', $updateColumns, true) && in_array('violation_type', $provided, true)) {
            $updateColumns[] = 'violation_category';
        }
        $updateColumns[] = 'source';
        $updateColumns[] = 'updated_at';
        // 预警派生字段（级别/责任人/处理截止等）：导入时按当前字典自动计算写入。
        $updateColumns = array_values(array_unique(array_merge(
            $updateColumns,
            StoreViolationRecordRepository::ALERT_DERIVED_COLUMNS,
        )));

        $payload = [];
        $created = 0;
        $updated = 0;

        foreach ($rows as $row) {
            $status = $row['status'] ?? '';
            if (! in_array($status, ['new', 'update'], true)) {
                continue;
            }

            $data = $row['data'] ?? [];
            if (($data['platform'] ?? null) !== $platform || ($data['violation_no'] ?? '') === '') {
                continue;
            }

            $matchType = trim((string) ($data['violation_type'] ?? '')) !== ''
                ? (string) $data['violation_type']
                : ($data['violation_reason'] ?? null);
            $data = array_merge($data, $this->alerts->calculate(
                $platform,
                (string) ($data['shop_name'] ?? ''),
                $matchType,
                $data['violation_date'] ?? null,
                $data['appeal_deadline'] ?? null,
            ));

            foreach (array_values(array_diff($updateColumns, ['source', 'updated_at'])) as $column) {
                if (! array_key_exists($column, $data)) {
                    $data[$column] = null;
                }
            }

            $payload[] = $data + [
                'source' => 'import',
                'created_at' => $now,
                'updated_at' => $now,
            ];

            $status === 'new' ? $created++ : $updated++;
        }

        $affected = $this->repository->upsertRows($payload, $updateColumns);

        return ['created' => $created, 'updated' => $updated, 'affected' => $affected];
    }

    /**
     * @param  list<list<mixed>>  $matrix
     * @return array{0:?int,1:list<string>,2:list<string>}
     */
    private function detectHeaders(array $matrix): array
    {
        $bestIndex = null;
        $bestMap = [];
        $bestUnknown = [];
        $bestScore = 0;

        foreach ($matrix as $index => $row) {
            $map = [];
            $unknown = [];
            foreach ($row as $cell) {
                $label = trim((string) $cell);
                if ($label === '') {
                    continue;
                }
                $key = $this->matchHeader($label);
                if ($key === null) {
                    $unknown[] = $label;
                    continue;
                }
                if (! in_array($key, $map, true)) {
                    $map[] = $key;
                }
            }

            if (count($map) > $bestScore) {
                $bestIndex = $index;
                $bestMap = $map;
                $bestUnknown = $unknown;
                $bestScore = count($map);
            }

            // 命中 6 列以上视为表头，避免把数据行误判为表头
            if ($bestScore >= 6) {
                break;
            }
        }

        if ($bestIndex === null || $bestScore < 2) {
            return [null, [], []];
        }

        return [$bestIndex, $bestMap, array_values(array_unique($bestUnknown))];
    }

    private function matchHeader(string $label): ?string
    {
        $normalized = mb_strtolower(preg_replace('/[\s"*　]/u', '', $label) ?? $label);

        foreach ((array) config('store_violations.header_aliases', []) as $key => $aliases) {
            foreach ((array) $aliases as $alias) {
                $alias = mb_strtolower(preg_replace('/[\s"*　]/u', '', (string) $alias) ?? (string) $alias);
                if ($alias !== '' && $normalized === $alias) {
                    return (string) $key;
                }
            }
        }

        return null;
    }

    /**
     * @param  list<mixed>  $row
     * @param  list<string>  $columnMap
     * @return array<string,mixed>
     */
    private function rowToFields(array $row, array $columnMap): array
    {
        $fields = [];
        foreach ($row as $index => $cell) {
            $key = $columnMap[$index] ?? null;
            if ($key !== null) {
                $fields[$key] = $cell;
            }
        }

        return $fields;
    }

    /** @param array<string,mixed> $fields */
    private function isEmptyRow(array $fields): bool
    {
        foreach ($fields as $value) {
            if (trim((string) $value) !== '') {
                return false;
            }
        }

        return true;
    }

    /**
     * @param  array<string,mixed>  $raw
     * @return array{row_number:int,status:string,message:string,data:array<string,mixed>}
     */
    private function normalizeRow(array $raw, string $platform, int $rowNumber, array $provided): array
    {
        $errors = [];
        $data = ['platform' => $platform];
        $has = static fn (string $key): bool => in_array($key, $provided, true);

        if ($has('shop_name')) {
            $shopName = trim((string) ($raw['shop_name'] ?? ''));
            if ($shopName === '') {
                $errors[] = '店铺名不能为空';
            } elseif (mb_strlen($shopName) > 191) {
                $errors[] = '店铺名超过 191 字';
            }
            $data['shop_name'] = mb_substr($shopName, 0, 191);
        }

        if ($has('violation_no')) {
            $violationNo = trim((string) ($raw['violation_no'] ?? ''));
            if ($violationNo === '') {
                $errors[] = '违规单号不能为空';
            } elseif (mb_strlen($violationNo) > 100) {
                $errors[] = '违规单号超过 100 字';
            }
            $data['violation_no'] = mb_substr($violationNo, 0, 100);
        }

        $type = $has('violation_type') ? trim((string) ($raw['violation_type'] ?? '')) : null;
        if ($has('violation_type')) {
            $data['violation_type'] = $type === '' ? null : mb_substr($type, 0, 500);
        }

        $reason = $has('violation_reason') ? trim((string) ($raw['violation_reason'] ?? '')) : null;
        if ($has('violation_reason')) {
            $data['violation_reason'] = $reason === '' ? null : mb_substr($reason, 0, 500);
        }

        if ($has('disposition')) {
            $disposition = trim((string) ($raw['disposition'] ?? ''));
            $data['disposition'] = $disposition === '' ? null : mb_substr($disposition, 0, 500);
        }

        if ($has('violation_category')) {
            $categorySource = ($type !== null && $type !== '') ? $type : (string) $reason;
            $category = trim((string) ($raw['violation_category'] ?? ''));
            $data['violation_category'] = $category === ''
                ? $this->mapper->categoryForContent($categorySource)
                : mb_substr($category, 0, 64);
        } elseif ($has('violation_type') || $has('violation_reason')) {
            $categorySource = ($type !== null && $type !== '') ? $type : (string) $reason;
            $data['violation_category'] = $this->mapper->categoryForContent($categorySource);
        }

        if ($has('violation_date')) {
            try {
                $data['violation_date'] = $this->mapper->normalizeDate($raw['violation_date'] ?? null);
            } catch (Throwable $exception) {
                $errors[] = '违规日期：' . $exception->getMessage();
                $data['violation_date'] = null;
            }
        }

        if ($has('points_deducted')) {
            try {
                $data['points_deducted'] = $this->mapper->normalizePoints($raw['points_deducted'] ?? null);
            } catch (Throwable $exception) {
                $errors[] = '扣分：' . $exception->getMessage();
                $data['points_deducted'] = null;
            }
        }

        if ($has('status')) {
            $status = trim((string) ($raw['status'] ?? ''));
            $data['status'] = $status === '' ? null : mb_substr($status, 0, 64);
        }

        if ($has('penalty_date')) {
            try {
                $data['penalty_date'] = $this->mapper->normalizeDate($raw['penalty_date'] ?? null);
            } catch (Throwable $exception) {
                $errors[] = '处罚日期：' . $exception->getMessage();
                $data['penalty_date'] = null;
            }
        }

        if ($has('appeal_deadline')) {
            try {
                $data['appeal_deadline'] = $this->mapper->normalizeDate($raw['appeal_deadline'] ?? null);
            } catch (Throwable $exception) {
                $errors[] = '申诉截止日期：' . $exception->getMessage();
                $data['appeal_deadline'] = null;
            }
        }

        if ($has('handling_status')) {
            $handling = trim((string) ($raw['handling_status'] ?? ''));
            $legacyMap = (array) config('store_violations.handling_status_legacy', []);
            $handling = (string) ($legacyMap[$handling] ?? $handling);
            $options = (array) config('store_violations.handling_statuses', []);
            if ($handling === '') {
                $data['handling_status'] = (string) config('store_violations.default_handling_status', '未处理');
            } elseif (! in_array($handling, $options, true)) {
                $errors[] = '处理状态必须是：' . implode('、', $options);
                $data['handling_status'] = $handling;
            } else {
                $data['handling_status'] = $handling;
            }
        }

        if ($has('ignore_reason')) {
            $ignoreReason = trim((string) ($raw['ignore_reason'] ?? ''));
            $data['ignore_reason'] = $ignoreReason === '' ? null : mb_substr($ignoreReason, 0, 191);
        }

        if (($data['handling_status'] ?? null) === '已忽略' && trim((string) ($data['ignore_reason'] ?? '')) === '') {
            $errors[] = '处理状态为“已忽略”时必须填写忽略原因';
        }

        return [
            'row_number' => $rowNumber,
            'status' => $errors === [] ? 'valid' : 'invalid',
            'message' => $errors === [] ? '待导入' : implode('；', $errors),
            'data' => $data,
        ];
    }

    private function markRow(array $row, string $status, string $message): array
    {
        $row['status'] = $status;
        $row['message'] = $message;

        return $row;
    }

    /**
     * 与库内已有记录比对：无 → new，字段完全一致 → same，否则 → update。
     *
     * @param  list<array>  $rows
     */
    private function compareWithExisting(array &$rows, string $platform, array &$summary): void
    {
        $keys = collect($rows)
            ->filter(fn (array $row): bool => $row['status'] === 'valid' && ($row['data']['violation_no'] ?? '') !== '')
            ->pluck('data.violation_no')
            ->unique()
            ->values();

        if ($keys->isEmpty()) {
            return;
        }

        $existing = collect();
        foreach ($keys->chunk(500) as $chunk) {
            $existing = $existing->merge(
                DB::connection((string) config('upstream_mirrors.connection', 'business_mirror'))
                    ->table(StoreViolationRecordRepository::TABLE)
                    ->where('platform', $platform)
                    ->whereIn('violation_no', $chunk->all())
                    ->get()
                    ->keyBy('violation_no'),
            );
        }

        foreach ($rows as $index => $row) {
            if ($row['status'] !== 'valid') {
                continue;
            }

            $record = $existing->get($row['data']['violation_no']);
            if ($record === null) {
                $summary['new']++;
                $rows[$index] = $this->markRow($row, 'new', '新增记录');

                continue;
            }

            $rows[$index] = $this->sameAsExisting($row['data'], $record)
                ? $this->markRow($row, 'same', '与库内记录一致，将跳过')
                : $this->markRow($row, 'update', '库内已有该单号，将按文件内容更新');
            $rows[$index]['status'] === 'same' ? $summary['same']++ : $summary['update']++;
        }
    }

    private function sameAsExisting(array $data, object $record): bool
    {
        $normalizePoints = static function (mixed $value): string {
            if ($value === null || $value === '') {
                return '';
            }

            return number_format((float) $value, 2, '.', '');
        };

        foreach ($data as $key => $value) {
            if ($key === 'platform') {
                continue;
            }

            $current = $record->{$key} ?? null;

            if ($key === 'points_deducted') {
                if ($normalizePoints($value) !== $normalizePoints($current)) {
                    return false;
                }

                continue;
            }

            if (trim((string) $value) !== trim((string) $current)) {
                return false;
            }
        }

        return true;
    }

    private function labelFor(string $key): string
    {
        foreach ((array) config('store_violations.columns', []) as $column) {
            if (($column['key'] ?? null) === $key) {
                return (string) $column['label'];
            }
        }

        return $key;
    }
}