<?php

namespace App\Business;

use App\Models\Business\FundForecast;
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 FundForecastWorkbookImporter
{
    private const HEADER_FIELDS = [
        '预策月份' => 'budget_month',
        '预测月份' => 'budget_month',
        '公司名称' => 'company_name',
        '余额/银行' => 'balance_bank',
        '余额/京东' => 'balance_jd',
        '余额/抖音' => 'balance_douyin',
        '余额/得物' => 'balance_dewu',
        '余额/淘系支付宝' => 'balance_taobao_alipay',
        '余额/微信' => 'balance_wechat',
        '收入/京东' => 'income_jd',
        '收入/抖音' => 'income_douyin',
        '收入/得物' => 'income_dewu',
        '收入/淘系支付宝' => 'income_taobao_alipay',
        '收入/货款' => 'income_goods_payment',
        '收入/其他收入' => 'income_other',
        '支出/供应商货款' => 'expense_supplier_goods',
        '支出/快递款' => 'expense_courier',
        '支出/纸厂压贴' => 'expense_paper_lamination',
        '支出/封边条' => 'expense_edge_band',
        '支出/日常报销' => 'expense_daily_reimbursement',
        '支出/淘宝红包' => 'expense_taobao_red_packet',
        '支出/板材' => 'expense_board',
        '支出/店铺充值' => 'expense_store_top_up',
        '支出/种菜' => 'expense_planting',
        '支出/工资' => 'expense_salary',
        '支出/税金' => 'expense_tax',
        '支出/店铺花费暂估10%' => 'expense_store_spend',
    ];

    public function import(UploadedFile $file, int $companyId): array
    {
        $spreadsheet = IOFactory::load($file->getRealPath());
        $worksheet = $spreadsheet->getSheet(0);
        $rows = $worksheet->toArray(null, true, false, false);
        $columnMap = $this->columnMap($rows[0] ?? [], $rows[1] ?? []);

        foreach (['budget_month', 'company_name'] as $required) {
            if (! in_array($required, $columnMap, true)) {
                throw ValidationException::withMessages([
                    'import' => '资金预测表缺少“预测月份”或“公司名称”表头。',
                ]);
            }
        }

        $created = 0;
        $updated = 0;

        DB::transaction(function () use ($rows, $columnMap, $companyId, &$created, &$updated): void {
            foreach (array_slice($rows, 2) as $offset => $row) {
                if (collect($row)->every(fn ($value): bool => $value === null || trim((string) $value) === '')) {
                    continue;
                }

                $rowNumber = $offset + 3;
                $data = [];
                foreach ($columnMap as $columnIndex => $field) {
                    $data[$field] = $this->value($row[$columnIndex] ?? null, $field, $rowNumber);
                }

                if (($data['budget_month'] ?? '') === '' || ($data['company_name'] ?? '') === '') {
                    throw ValidationException::withMessages([
                        'import' => "第 {$rowNumber} 行必须填写预测月份和公司名称。",
                    ]);
                }

                $identity = [
                    'company_id' => $companyId,
                    'budget_month' => $data['budget_month'],
                    'company_name' => $data['company_name'],
                ];
                $record = FundForecast::query()->where($identity)->first();
                $data['report_status'] = '待审核';

                if ($record) {
                    $record->update($data);
                    $updated++;
                } else {
                    FundForecast::create(array_merge($identity, $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 columnMap(array $groups, array $headers): array
    {
        $map = [];
        $group = '';
        $count = max(count($groups), count($headers));

        for ($index = 0; $index < $count; $index++) {
            $candidate = trim((string) ($groups[$index] ?? ''));
            if ($candidate !== '') {
                $group = $candidate;
            }
            $header = trim((string) ($headers[$index] ?? ''));
            $combined = $header === '' ? $group : ($group === '' ? $header : $group . '/' . $header);
            $field = self::HEADER_FIELDS[$this->normalizeHeader($combined)] ?? null;
            if ($field !== null) {
                $map[$index] = $field;
            }
        }

        return $map;
    }

    private function normalizeHeader(string $header): string
    {
        return preg_replace('/[\s_\-（）()]+/u', '', trim($header));
    }

    private function value(mixed $value, string $field, int $rowNumber): mixed
    {
        if ($value === null || trim((string) $value) === '') {
            return null;
        }
        if ($field === 'budget_month') {
            if (is_numeric($value)) {
                return ExcelDate::excelToDateTimeObject($value)->format('Y-m');
            }
            $text = trim((string) $value);
            if (preg_match('/^(\d{4})[年\/.\-](\d{1,2})(?:月)?$/u', $text, $matches) === 1) {
                $month = (int) $matches[2];
                if ($month >= 1 && $month <= 12) {
                    return sprintf('%04d-%02d', (int) $matches[1], $month);
                }
            }
            throw ValidationException::withMessages(['import' => "第 {$rowNumber} 行预测月份格式不正确。"]);
        }
        if ($field === 'company_name') {
            return mb_substr(trim((string) $value), 0, 191);
        }
        $number = str_replace([',', '，', '￥', '¥'], '', trim((string) $value));
        if (! is_numeric($number)) {
            throw ValidationException::withMessages(['import' => "第 {$rowNumber} 行包含无效金额。"]);
        }

        return (float) $number;
    }
}