<?php

namespace Modules\EcommerceFinance\Services;

use Illuminate\Database\ConnectionInterface;
use Illuminate\Database\DatabaseManager;
use Illuminate\Support\Carbon;
use Illuminate\Support\Facades\Schema;
use PhpOffice\PhpSpreadsheet\Cell\Coordinate;
use PhpOffice\PhpSpreadsheet\IOFactory;
use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;
use RuntimeException;

/**
 * 「一般纳税人内部流转」工作簿导入器。
 *
 * 源表使用三行合并表头（抬头 / 标签 / 预计9月销量 / 开票 / 所需进项成本 /
 * 收票 / 剩余缺口 / 开票比例），导入时按表头标签匹配列，不依赖列位置；
 * 合计行与空行不进入明细表。
 */
class InternalFlowWorkbookImporter
{
    public const TABLE = 'business_internal_flow_records';

    public const SHEET_TITLE = '一般纳税人内部流转';

    /** 页面表头契约：与 Excel 表头顺序一致。 */
    public const COLUMNS = [
        ['field' => 'company_name', 'label' => '抬头', 'type' => 'text'],
        ['field' => 'tag', 'label' => '标签', 'type' => 'text'],
        ['field' => 'projected_sales', 'label' => '预计9月销量', 'type' => 'amount'],
        ['field' => 'invoiced_to_buyer', 'label' => '开票-给买家开票', 'type' => 'amount'],
        ['field' => 'internal_invoiced', 'label' => '开票-内部开票', 'type' => 'amount'],
        ['field' => 'required_input_cost', 'label' => '所需进项成本', 'type' => 'amount'],
        ['field' => 'receipt_from_supplier', 'label' => '收票-供应商', 'type' => 'amount'],
        ['field' => 'receipt_from_suofeiya', 'label' => '收票-索菲亚', 'type' => 'amount'],
        ['field' => 'receipt_from_gujia', 'label' => '收票-顾家', 'type' => 'amount'],
        ['field' => 'internal_transfer_1', 'label' => '收票-内部流转（来源）1', 'type' => 'amount'],
        ['field' => 'internal_transfer_2', 'label' => '收票-内部流转（来源）2', 'type' => 'amount'],
        ['field' => 'internal_transfer_3', 'label' => '收票-内部流转（来源）3', 'type' => 'amount'],
        ['field' => 'receipt_total', 'label' => '收票-合计', 'type' => 'amount'],
        ['field' => 'remaining_gap', 'label' => '剩余缺口', 'type' => 'amount'],
        ['field' => 'invoicing_ratio', 'label' => '开票比例', 'type' => 'text'],
    ];

    private const HEADER_ROWS = 3;

    private readonly ConnectionInterface $connection;

    public function __construct(DatabaseManager $databases)
    {
        $this->connection = $databases->connection(
            (string) config('upstream_mirrors.connection', 'business_mirror'),
        );
    }

    /**
     * @return array{imported:int,skipped:int,source_file:string}
     */
    public function import(string $path): array
    {
        $realPath = realpath($path);

        if ($realPath === false || ! is_file($realPath) || ! is_readable($realPath)) {
            throw new RuntimeException('内部流转工作簿不存在或不可读：' . $path);
        }

        if (! Schema::connection($this->connection->getName())->hasTable(self::TABLE)) {
            throw new RuntimeException('内部流转数据表尚未创建，请先执行数据库迁移。');
        }

        [$rows, $skipped] = $this->readRows($realPath);

        if ($rows === []) {
            throw new RuntimeException('表格中没有可导入的数据行，请检查“' . self::SHEET_TITLE . '”工作表。');
        }

        $now = Carbon::now();
        $sourceFile = basename($realPath);

        $this->connection->transaction(function () use ($rows, $now, $sourceFile): void {
            // 该报表是一份整体替换的月度数据集，重新导入时先清空上一版。
            $this->connection->table(self::TABLE)->delete();

            foreach (array_chunk($rows, 200) as $chunk) {
                $this->connection->table(self::TABLE)->insert(array_map(
                    static fn (array $row): array => $row + [
                        'source_file' => $sourceFile,
                        'imported_at' => $now,
                        'created_at' => $now,
                        'updated_at' => $now,
                    ],
                    $chunk,
                ));
            }
        });

        return [
            'imported' => count($rows),
            'skipped' => $skipped,
            'source_file' => $sourceFile,
        ];
    }

    /**
     * @return array{0: list<array<string,mixed>>, 1: int}
     */
    private function readRows(string $path): array
    {
        $spreadsheet = IOFactory::load($path);
        $sheet = $this->resolveSheet($spreadsheet->getAllSheets());

        $grid = $sheet->toArray(null, true, false, false);
        $this->expandMergedCells($grid, $sheet);

        $headerRow = $this->resolveHeaderRow($grid);
        $columnMap = $this->resolveColumnMap($grid, $headerRow);
        $missing = array_values(array_diff(
            array_column(self::COLUMNS, 'field'),
            array_values($columnMap),
        ));

        if ($missing !== []) {
            $labels = implode('、', array_map(
                static fn (string $field): string => (string) (collect(self::COLUMNS)->firstWhere('field', $field)['label'] ?? $field),
                $missing,
            ));

            throw new RuntimeException('内部流转表头缺少列：' . $labels . '。');
        }

        $types = array_column(self::COLUMNS, 'type', 'field');
        $rows = [];
        $skipped = 0;
        $sortOrder = 0;

        foreach (array_slice($grid, $headerRow + self::HEADER_ROWS) as $line) {
            $values = [];

            foreach ($columnMap as $columnIndex => $field) {
                $values[$field] = $this->normalizeValue($line[$columnIndex] ?? null, $types[$field] ?? 'text');
            }

            $title = trim((string) ($values['company_name'] ?? ''));

            if ($title === '' || $title === '合计') {
                if ($title !== '' || collect($values)->filter(static fn ($value): bool => $value !== null && $value !== '')->isNotEmpty()) {
                    $skipped++;
                }

                continue;
            }

            $values['company_name'] = $title;
            $values['sort_order'] = ++$sortOrder;
            $rows[] = $values;
        }

        return [$rows, $skipped];
    }

    /**
     * @param  list<Worksheet>  $sheets
     */
    private function resolveSheet(array $sheets): Worksheet
    {
        foreach ($sheets as $sheet) {
            if ($sheet->getTitle() === self::SHEET_TITLE) {
                return $sheet;
            }
        }

        throw new RuntimeException('未找到“' . self::SHEET_TITLE . '”工作表。');
    }

    /**
     * @param  list<list<mixed>>  $grid
     */
    private function expandMergedCells(array &$grid, Worksheet $sheet): void
    {
        foreach ($sheet->getMergeCells() as $range) {
            try {
                [[$startColumn, $startRow], [$endColumn, $endRow]] = Coordinate::rangeBoundaries($range);
            } catch (\Throwable) {
                continue;
            }

            $value = $grid[$startRow - 1][$startColumn - 1] ?? null;

            for ($row = $startRow; $row <= $endRow; $row++) {
                for ($column = $startColumn; $column <= $endColumn; $column++) {
                    $grid[$row - 1][$column - 1] = $value;
                }
            }
        }
    }

    /**
     * @param  list<list<mixed>>  $grid
     */
    private function resolveHeaderRow(array $grid): int
    {
        foreach (array_slice($grid, 0, 10, true) as $index => $line) {
            if (collect($line)->contains(fn ($value): bool => $this->normalizeHeader($value) === '抬头')) {
                return (int) $index;
            }
        }

        throw new RuntimeException('未找到以“抬头”开头的工作簿表头。');
    }

    /**
     * 按三行表头的标签路径匹配目标字段，允许列位置变化。
     *
     * @param  list<list<mixed>>  $grid
     * @return array<int,string> 列下标 => 字段名
     */
    private function resolveColumnMap(array $grid, int $headerRow): array
    {
        $map = [];
        $columnCount = 0;

        foreach (array_slice($grid, $headerRow, self::HEADER_ROWS) as $line) {
            $columnCount = max($columnCount, count($line));
        }

        for ($column = 0; $column < $columnCount; $column++) {
            $path = [];

            for ($row = $headerRow; $row < $headerRow + self::HEADER_ROWS; $row++) {
                $value = $this->normalizeHeader($grid[$row][$column] ?? null);

                if ($value !== '') {
                    $path[] = $value;
                }
            }

            $field = $this->matchField($path);

            if ($field !== null) {
                $map[$column] = $field;
            }
        }

        return $map;
    }

    /**
     * @param  list<string>  $path
     */
    private function matchField(array $path): ?string
    {
        if ($path === []) {
            return null;
        }

        $leaf = (string) end($path);

        return match (true) {
            $leaf === '抬头' => 'company_name',
            $leaf === '标签' => 'tag',
            preg_match('/^预计\d+月销量$/u', $leaf) === 1 => 'projected_sales',
            $leaf === '给买家开票' => 'invoiced_to_buyer',
            $leaf === '内部开票' => 'internal_invoiced',
            $leaf === '所需进项成本' => 'required_input_cost',
            $leaf === '供应商' => 'receipt_from_supplier',
            $leaf === '索菲亚' => 'receipt_from_suofeiya',
            $leaf === '顾家' => 'receipt_from_gujia',
            $leaf === '合计' => 'receipt_total',
            $leaf === '剩余缺口' => 'remaining_gap',
            $leaf === '开票比例' => 'invoicing_ratio',
            in_array($leaf, ['1', '2', '3'], true) && in_array('内部流转(来源)', $path, true) => 'internal_transfer_' . $leaf,
            default => null,
        };
    }

    private function normalizeHeader(mixed $value): string
    {
        if ($value === null || is_bool($value) || is_array($value)) {
            return '';
        }

        $text = trim((string) $value);
        $text = str_replace(['（', '）', '　', ' '], ['(', ')', '', ''], $text);

        return $text;
    }

    private function normalizeValue(mixed $value, string $type): ?string
    {
        if ($value === null) {
            return null;
        }

        if ($type === 'text') {
            if (is_float($value) && floor($value) === $value) {
                return (string) (int) $value;
            }

            $text = trim((string) $value);

            return $text === '' ? null : $text;
        }

        if (is_int($value) || is_float($value)) {
            return $this->decimal($value);
        }

        $text = trim((string) $value);

        if ($text === '' || in_array($text, ['/', '—', '-', 'N/A'], true)) {
            return null;
        }

        $normalized = str_replace([',', '，'], '', $text);

        return is_numeric($normalized) ? $this->decimal((float) $normalized) : null;
    }

    private function decimal(float $value): string
    {
        $formatted = rtrim(rtrim(number_format($value, 6, '.', ''), '0'), '.');

        return $formatted === '' || $formatted === '-' ? '0' : $formatted;
    }
}