<?php

namespace App\Business;

use App\Models\Business\SystemizationTodo;
use Illuminate\Support\Carbon;
use Illuminate\Support\Facades\DB;
use Modules\EcommerceFinance\Services\PayablesWorkbookStreamReader;
use PhpOffice\PhpSpreadsheet\Shared\Date as ExcelDate;
use RuntimeException;

class SystemizationTodoWorkbookImporter
{
    private const REQUIRED_HEADERS = [
        'category' => '类型',
        'section' => '内容',
        'title' => '待办事项',
        'owner' => '总负责人',
        'assignee' => '责任人',
        'start' => '开始时间',
        'finish' => '完成时间',
        'progress' => '完成情况',
        'notes' => '备注',
    ];

    /**
     * 导入财务系统化待办。只新增系统中不存在的来源行，不覆盖日常维护后的状态与截图。
     *
     * @return array{created:int,skipped:int,sheet:string}
     */
    public function import(string $path, int $companyId, ?int $userId = null): array
    {
        if (! is_file($path)) {
            throw new RuntimeException('找不到待办 Excel 文件。');
        }

        $extension = strtolower(pathinfo($path, PATHINFO_EXTENSION));
        if ($extension !== 'xlsx') {
            throw new RuntimeException('系统化待办仅支持 .xlsx 文件。');
        }

        $reader = PayablesWorkbookStreamReader::forFile($path, $extension);
        foreach ($reader->sheetNames() as $sheetIndex => $sheetName) {
            $headerInfo = $this->headerMap($reader, $sheetIndex);
            if ($headerInfo === null) {
                continue;
            }
            $header = $headerInfo['columns'];
            $headerRow = $headerInfo['row'];

            $created = 0;
            $skipped = 0;
            DB::transaction(function () use (
                $reader,
                $sheetIndex,
                $sheetName,
                $header,
                $headerRow,
                $companyId,
                $userId,
                &$created,
                &$skipped
            ): void {
                $category = '';
                $section = '';
                foreach ($reader->rows($sheetIndex) as $rowNumber => $cells) {
                    if ($rowNumber <= $headerRow) {
                        continue;
                    }
                    $categoryValue = $this->cell($cells, $header['category'] ?? null);
                    if ($categoryValue !== '') {
                        $category = $categoryValue;
                    }
                    $sectionValue = $this->cell($cells, $header['section'] ?? null);
                    if ($sectionValue !== '') {
                        $section = $sectionValue;
                    }

                    $title = $this->cell($cells, $header['title'] ?? null);
                    if ($title === '') {
                        continue;
                    }

                    $owner = $this->cell($cells, $header['owner'] ?? null);
                    $assignee = $this->cell($cells, $header['assignee'] ?? null);
                    $sourceKey = hash(
                        'sha256',
                        implode('|', [$companyId, $sheetName, $rowNumber, $category, $section, $title, $owner, $assignee])
                    );
                    $exists = SystemizationTodo::withoutGlobalScopes()
                        ->where('company_id', $companyId)
                        ->where('source_key', $sourceKey)
                        ->exists();
                    if ($exists) {
                        $skipped++;
                        continue;
                    }

                    $startText = $this->cell($cells, $header['start'] ?? null);
                    $finishText = $this->cell($cells, $header['finish'] ?? null);
                    [$startDate, $startNote] = $this->dateParts($startText);
                    [$finishDate, $finishNote] = $this->dateParts($finishText);
                    $progress = $this->cell($cells, $header['progress'] ?? null);
                    $status = $this->status($progress, $startText, $finishText);
                    $completedAt = $status === SystemizationTodo::STATUS_COMPLETED
                        ? ($finishDate ?? now()->toDateString())
                        : null;

                    SystemizationTodo::withoutGlobalScopes()->create([
                        'company_id' => $companyId,
                        'category' => $category !== '' ? $category : null,
                        'section' => $section !== '' ? $section : null,
                        'title' => $title,
                        'owner' => $owner !== '' ? $owner : null,
                        'assignee' => $assignee !== '' ? $assignee : null,
                        'start_date' => $startDate,
                        'start_note' => $startNote !== '' ? $startNote : null,
                        'due_date' => $finishDate,
                        'due_note' => $finishNote !== '' ? $finishNote : null,
                        'status' => $status,
                        'completed_at' => $completedAt,
                        'progress' => $progress !== '' ? $progress : null,
                        'notes' => ($notes = $this->cell($cells, $header['notes'] ?? null)) !== '' ? $notes : null,
                        'sort_order' => $rowNumber,
                        'source_key' => $sourceKey,
                        'imported_at' => now(),
                        'created_by' => $userId,
                        'updated_by' => $userId,
                    ]);
                    $created++;
                }
            });

            return ['created' => $created, 'skipped' => $skipped, 'sheet' => $sheetName];
        }

        throw new RuntimeException(
            '未找到待办表头。请确认工作表包含：类型、内容、待办事项、总负责人、责任人、开始时间、完成时间、完成情况、备注。'
        );
    }

    /**
     * @return array{row:int,columns:array<string,int>}|null
     */
    private function headerMap(PayablesWorkbookStreamReader $reader, int $sheetIndex): ?array
    {
        foreach ($reader->rows($sheetIndex, null, 12) as $rowNumber => $cells) {
            $normalized = [];
            foreach ($cells as $column => $value) {
                $value = $this->normalizeHeader($this->text($value));
                if ($value !== '') {
                    $normalized[$value] = $column;
                }
            }

            $mapped = [];
            foreach (self::REQUIRED_HEADERS as $field => $label) {
                $needle = $this->normalizeHeader($label);
                foreach ($normalized as $header => $column) {
                    if ($header === $needle || str_starts_with($header, $needle)) {
                        $mapped[$field] = $column;
                        break;
                    }
                }
            }

            if (isset($mapped['title'])
                && isset($mapped['owner'])
                && isset($mapped['assignee'])) {
                return ['row' => $rowNumber, 'columns' => $mapped];
            }
        }

        return null;
    }

    private function normalizeHeader(string $value): string
    {
        return preg_replace('/[\s　（）()]+/u', '', $value) ?? '';
    }

    /**
     * @param  array<int,mixed>  $cells
     */
    private function cell(array $cells, ?int $column): string
    {
        return $column === null ? '' : $this->text($cells[$column] ?? null);
    }

    private function text(mixed $value): string
    {
        if ($value === null) {
            return '';
        }
        if (is_bool($value)) {
            return $value ? '1' : '0';
        }

        return trim(str_replace("\u{00A0}", ' ', (string) $value));
    }

    /**
     * @return array{0:string|null,1:string}
     */
    private function dateParts(string $value): array
    {
        $value = trim($value);
        if ($value === '' || $value === '已完成') {
            return [null, ''];
        }

        if (is_numeric($value)) {
            $serial = (float) $value;
            if ($serial >= 20000 && $serial <= 80000) {
                return [ExcelDate::excelToDateTimeObject($serial)->format('Y-m-d'), ''];
            }
        }

        foreach (['Y-m-d', 'Y/m/d', 'Y.m.d', 'Y年n月j日'] as $format) {
            try {
                $date = Carbon::createFromFormat($format, $value);
                if ($date !== false) {
                    return [$date->format('Y-m-d'), ''];
                }
            } catch (\Throwable) {
                // 不是标准日期，保留原值作为时间备注。
            }
        }

        return [null, mb_substr($value, 0, 100)];
    }

    private function status(string $progress, string $startNote, string $finishNote): string
    {
        if (str_contains($progress, '已完成')) {
            return SystemizationTodo::STATUS_COMPLETED;
        }
        if ($progress !== '') {
            return str_contains($progress, '延期')
                ? SystemizationTodo::STATUS_DELAYED
                : SystemizationTodo::STATUS_IN_PROGRESS;
        }
        if (str_contains($startNote, '延期') || str_contains($finishNote, '延期')) {
            return SystemizationTodo::STATUS_DELAYED;
        }

        return SystemizationTodo::STATUS_PENDING;
    }
}