<?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'];

            $rows = $this->workbookRows(
                $reader,
                $sheetIndex,
                $sheetName,
                $header,
                $headerRow,
                $companyId,
            );
            $created = 0;
            $skipped = 0;
            DB::transaction(function () use ($rows, $companyId, $userId, &$created, &$skipped): void {
                foreach ($rows as $row) {
                    $exists = SystemizationTodo::withoutGlobalScopes()
                        ->where('company_id', $companyId)
                        ->where('source_key', $row['data']['source_key'])
                        ->exists();
                    if ($exists) {
                        $skipped++;
                        continue;
                    }

                    SystemizationTodo::withoutGlobalScopes()->create([
                        ...$row['data'],
                        'company_id' => $companyId,
                        '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。'
        );
    }

    /**
     * 将新版工作簿同步到已有来源记录。保留截图和来源中已不在工作簿的事项，只新增和更新。
     *
     * @return array{created:int,updated:int,retained:int,sheet:string}
     */
    public function sync(string $path, int $companyId, ?int $userId = null, bool $dryRun = false): array
    {
        if (! is_file($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;
            }

            $rows = $this->workbookRows(
                $reader,
                $sheetIndex,
                $sheetName,
                $headerInfo['columns'],
                $headerInfo['row'],
                $companyId,
            );
            $existing = SystemizationTodo::withoutGlobalScopes()
                ->where('company_id', $companyId)
                ->whereNull('deleted_at')
                ->whereNotNull('imported_at')
                ->orderBy('sort_order')
                ->orderBy('id')
                ->get();
            [$matches, $newIndexes] = $this->matchRows($rows, $existing);
            $matchedIds = array_values($matches);
            $retained = $existing
                ->filter(static fn (SystemizationTodo $todo): bool => ! in_array($todo->id, $matchedIds, true))
                ->sortBy(static fn (SystemizationTodo $todo): string =>
                    sprintf('%010d-%010d', (int) $todo->sort_order, (int) $todo->id)
                )
                ->values();
            $retainedSortOrder = max(
                (int) $existing->max('sort_order'),
                ...array_map(
                    static fn (array $row): int => (int) $row['data']['sort_order'],
                    $rows,
                ),
            ) + 1;
            $oldSourceKeys = $existing->pluck('source_key', 'id')->all();
            $updated = 0;
            foreach ($matches as $rowIndex => $todoId) {
                $todo = $existing->firstWhere('id', $todoId);
                if ($todo && $this->contentDiffers($todo, $rows[$rowIndex]['data'])) {
                    $updated++;
                }
            }

            if ($dryRun) {
                return [
                    'created' => count($newIndexes),
                    'updated' => $updated,
                    'retained' => $retained->count(),
                    'sheet' => $sheetName,
                ];
            }

            $created = 0;
            $updated = 0;
            DB::transaction(function () use (
                $rows,
                $matches,
                $newIndexes,
                $existing,
                $retained,
                $oldSourceKeys,
                $retainedSortOrder,
                $companyId,
                $userId,
                &$created,
                &$updated,
            ): void {
                SystemizationTodo::withoutGlobalScopes()
                    ->where('company_id', $companyId)
                    ->whereNull('deleted_at')
                    ->whereNotNull('imported_at')
                    ->update(['source_key' => null]);

                foreach ($matches as $rowIndex => $todoId) {
                    $todo = $existing->firstWhere('id', $todoId);
                    if (! $todo) {
                        continue;
                    }
                    $todo->source_key = null;
                    $todo->syncOriginalAttribute('source_key');
                    $todo->fill($rows[$rowIndex]['data']);
                    $contentChanged = $todo->isDirty([
                        'category',
                        'section',
                        'title',
                        'owner',
                        'assignee',
                        'start_date',
                        'start_note',
                        'due_date',
                        'due_note',
                        'status',
                        'completed_at',
                        'progress',
                        'notes',
                    ]);
                    $todo->updated_by = $userId;
                    $todo->save();
                    if ($contentChanged) {
                        $updated++;
                    }
                }

                foreach ($newIndexes as $rowIndex) {
                    SystemizationTodo::withoutGlobalScopes()->create([
                        ...$rows[$rowIndex]['data'],
                        'company_id' => $companyId,
                        'imported_at' => now(),
                        'created_by' => $userId,
                        'updated_by' => $userId,
                    ]);
                    $created++;
                }

                foreach ($retained as $todo) {
                    SystemizationTodo::withoutGlobalScopes()
                        ->whereKey($todo->id)
                        ->update([
                            'sort_order' => $retainedSortOrder++,
                            'source_key' => $oldSourceKeys[$todo->id] ?? null,
                        ]);
                }
            });

            return [
                'created' => $created,
                'updated' => $updated,
                'retained' => $retained->count(),
                '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。'
        );
    }

    /**
     * @param  array<int,int>  $columns
     * @return array<int,array{
     *     row:int,
     *     title_index:int,
     *     title_count:int,
     *     source_title:string,
     *     category:string,
     *     section:string,
     *     title:string,
     *     data:array<string,mixed>
     * }>
     */
    private function workbookRows(
        PayablesWorkbookStreamReader $reader,
        int $sheetIndex,
        string $sheetName,
        array $columns,
        int $headerRow,
        int $companyId,
    ): array {
        $rows = [];
        $category = '';
        $section = '';
        foreach ($reader->rows($sheetIndex) as $rowNumber => $cells) {
            if ($rowNumber <= $headerRow) {
                continue;
            }
            $categoryValue = $this->cell($cells, $columns['category'] ?? null);
            if ($categoryValue !== '') {
                $category = $categoryValue;
            }
            $sectionValue = $this->cell($cells, $columns['section'] ?? null);
            if ($sectionValue !== '') {
                $section = $sectionValue;
            }

            $sourceTitle = $this->cell($cells, $columns['title'] ?? null);
            if ($sourceTitle === '') {
                continue;
            }
            $titles = $this->titleSegments($sourceTitle);
            $titleCount = count($titles);
            $owner = $this->cell($cells, $columns['owner'] ?? null);
            $assignee = $this->cell($cells, $columns['assignee'] ?? null);
            $startText = $this->cell($cells, $columns['start'] ?? null);
            $finishText = $this->cell($cells, $columns['finish'] ?? null);
            [$startDate, $startNote] = $this->dateParts($startText);
            [$finishDate, $finishNote] = $this->dateParts($finishText);
            $progress = $this->cell($cells, $columns['progress'] ?? null);
            $notes = $this->cell($cells, $columns['notes'] ?? null);
            $status = $this->status($progress, $startText, $finishText);

            foreach ($titles as $offset => $title) {
                $titleIndex = $offset + 1;
                $sortOrder = ($rowNumber * 100) + $titleIndex;
                $rows[] = [
                    'row' => $rowNumber,
                    'title_index' => $titleIndex,
                    'title_count' => $titleCount,
                    'source_title' => $sourceTitle,
                    'category' => $category,
                    'section' => $section,
                    'title' => $title,
                    'data' => [
                        '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' => $status === SystemizationTodo::STATUS_COMPLETED
                            ? ($finishDate ?? now()->toDateString())
                            : null,
                        'progress' => $progress !== '' ? $progress : null,
                        'notes' => $notes !== '' ? $notes : null,
                        'sort_order' => $sortOrder,
                        'source_key' => hash(
                            'sha256',
                            implode('|', [
                                $companyId,
                                $sheetName,
                                $rowNumber,
                                $titleIndex,
                                $category,
                                $section,
                                $title,
                                $owner,
                                $assignee,
                            ])
                        ),
                    ],
                ];
            }
        }

        return $rows;
    }

    /**
     * Split a cell into separate tasks only when it contains multiple numbered lines.
     *
     * @return array<int,string>
     */
    private function titleSegments(string $value): array
    {
        $value = trim(str_replace(["\r\n", "\r"], "\n", $value));
        $marker = '/^\s*(?:\d+|[一二三四五六七八九十百]+)\s*[、,，.．:：;；)]\s*/u';
        $lines = preg_split('/\n/u', $value) ?: [];
        $numberedLines = array_filter(
            $lines,
            static fn (string $line): bool => preg_match($marker, trim($line)) === 1,
        );
        if (count($numberedLines) < 2) {
            return [$value];
        }

        $segments = [];
        $current = '';
        foreach ($lines as $line) {
            $line = trim($line);
            if ($line === '') {
                continue;
            }
            if (preg_match($marker, $line) === 1) {
                if ($current !== '') {
                    $segments[] = trim($current);
                }
                $current = trim((string) preg_replace($marker, '', $line));
                continue;
            }
            $current = $current === '' ? $line : $current . "\n" . $line;
        }
        if ($current !== '') {
            $segments[] = trim($current);
        }

        return $segments !== [] ? $segments : [$value];
    }

    /**
     * @param  array<int,array{
     *     row:int,
     *     title_index:int,
     *     title_count:int,
     *     source_title:string,
     *     category:string,
     *     section:string,
     *     title:string,
     *     data:array<string,mixed>
     * }>  $rows
     * @return array{0:array<int,int>,1:array<int,int>}
     */
    private function matchRows(array $rows, \Illuminate\Support\Collection $existing): array
    {
        $matches = [];
        $usedIds = [];
        $candidates = [];
        foreach ($existing as $todo) {
            $candidates[$this->matchTitleKey($todo->title)][] = $todo;
        }

        foreach ($rows as $rowIndex => $row) {
            if ($row['title_count'] < 2 || $row['title_index'] !== 1) {
                continue;
            }
            $sourceKey = $this->matchTitleKey($row['source_title']);
            $available = array_values(array_filter(
                $candidates[$sourceKey] ?? [],
                fn (SystemizationTodo $todo): bool =>
                    ! in_array($todo->id, $usedIds, true)
                    && $this->matchText($todo->category) === $this->matchText($row['category'])
                    && $this->matchText($todo->section) === $this->matchText($row['section']),
            ));
            if ($available === []) {
                continue;
            }
            usort($available, static fn (SystemizationTodo $a, SystemizationTodo $b): int =>
                abs($a->sort_order - $row['data']['sort_order'])
                <=> abs($b->sort_order - $row['data']['sort_order'])
            );
            $matches[$rowIndex] = $available[0]->id;
            $usedIds[] = $available[0]->id;
        }

        foreach ($rows as $rowIndex => $row) {
            if (isset($matches[$rowIndex])) {
                continue;
            }
            $key = $this->matchTitleKey($row['title']);
            $available = array_values(array_filter(
                $candidates[$key] ?? [],
                static fn (SystemizationTodo $todo): bool => ! in_array($todo->id, $usedIds, true),
            ));
            if ($available === []) {
                continue;
            }
            usort($available, static fn (SystemizationTodo $a, SystemizationTodo $b): int =>
                abs($a->sort_order - $row['data']['sort_order'])
                <=> abs($b->sort_order - $row['data']['sort_order'])
            );
            $todo = $available[0];
            $matches[$rowIndex] = $todo->id;
            $usedIds[] = $todo->id;
        }

        $remainingIds = $existing
            ->pluck('id')
            ->reject(static fn (int $id): bool => in_array($id, $usedIds, true))
            ->values();
        $todoById = $existing->keyBy('id');
        $pairs = [];
        foreach ($rows as $rowIndex => $row) {
            if (isset($matches[$rowIndex])) {
                continue;
            }
            foreach ($remainingIds as $todoId) {
                $todo = $todoById->get($todoId);
                if (! $todo
                    || $this->matchText($todo->category) !== $this->matchText($row['category'])
                    || $this->matchText($todo->section) !== $this->matchText($row['section'])) {
                    continue;
                }
                $similarity = $this->titleSimilarity((string) $todo->title, $row['title']);
                if ($similarity >= 0.55) {
                    $pairs[] = [
                        'rowIndex' => $rowIndex,
                        'todoId' => $todoId,
                        'score' => $similarity - abs($todo->sort_order - $row['data']['sort_order']) / 1000,
                    ];
                }
            }
        }
        usort($pairs, static fn (array $a, array $b): int => $b['score'] <=> $a['score']);
        foreach ($pairs as $pair) {
            if (isset($matches[$pair['rowIndex']]) || in_array($pair['todoId'], $usedIds, true)) {
                continue;
            }
            $matches[$pair['rowIndex']] = $pair['todoId'];
            $usedIds[] = $pair['todoId'];
        }

        return [
            $matches,
            array_values(array_filter(
                array_keys($rows),
                static fn (int $rowIndex): bool => ! isset($matches[$rowIndex]),
            )),
        ];
    }

    private function matchTitleKey(?string $value): string
    {
        $value = preg_replace(
            '/^\s*(?:\d+|[一二三四五六七八九十百]+)\s*[、,，.．:：;；)]\s*/u',
            '',
            (string) $value,
        ) ?? '';

        return $this->matchText($value);
    }

    private function matchText(?string $value): string
    {
        return mb_strtolower(
            preg_replace('/[\s　“”"\'，。；、,.!?：:；（）()【】\[\]—-]+/u', '', (string) $value) ?? '',
            'UTF-8',
        );
    }

    /**
     * @param  array<string,mixed>  $data
     */
    private function contentDiffers(SystemizationTodo $todo, array $data): bool
    {
        foreach ([
            'category',
            'section',
            'title',
            'owner',
            'assignee',
            'start_date',
            'start_note',
            'due_date',
            'due_note',
            'status',
            'completed_at',
            'progress',
            'notes',
        ] as $field) {
            $current = $todo->{$field};
            $incoming = $data[$field] ?? null;
            if ($current instanceof \DateTimeInterface && $incoming !== null) {
                $current = $current->format('Y-m-d');
            }
            if ((string) ($current ?? '') !== (string) ($incoming ?? '')) {
                return true;
            }
        }

        return false;
    }

    private function titleSimilarity(string $left, string $right): float
    {
        $left = $this->matchTitleKey($left);
        $right = $this->matchTitleKey($right);
        if ($left === '' || $right === '') {
            return 0.0;
        }
        if ($left === $right) {
            return 1.0;
        }

        $leftChars = mb_str_split($left);
        $rightChars = mb_str_split($right);
        $leftPairs = [];
        $rightPairs = [];
        for ($index = 0; $index < count($leftChars) - 1; $index++) {
            $leftPairs[$leftChars[$index] . $leftChars[$index + 1]] = true;
        }
        for ($index = 0; $index < count($rightChars) - 1; $index++) {
            $rightPairs[$rightChars[$index] . $rightChars[$index + 1]] = true;
        }
        $leftPairs = array_keys($leftPairs);
        $rightPairs = array_keys($rightPairs);
        $containment = str_contains($left, $right) || str_contains($right, $left) ? 0.95 : 0.0;

        $dice = ($leftPairs === [] || $rightPairs === [])
            ? 0.0
            : 2 * count(array_intersect($leftPairs, $rightPairs)) / (count($leftPairs) + count($rightPairs));

        return max($containment, $dice);
    }

    /**
     * @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;
    }
}