<?php

namespace App\Exports;

use App\Exceptions\RepositoryException;
use App\Models\BillModel;
use App\Models\ProductCategoryModel;
use App\Models\ProductModel;
use App\Services\BillDetailService;
use Illuminate\Support\Collection;
use Maatwebsite\Excel\Concerns\FromCollection;
use Maatwebsite\Excel\Concerns\WithStyles;
use PhpOffice\PhpSpreadsheet\Style\Alignment;
use PhpOffice\PhpSpreadsheet\Style\Border;
use PhpOffice\PhpSpreadsheet\Style\Fill;
use PhpOffice\PhpSpreadsheet\Worksheet\Worksheet;

/**
 * 门店账单合并导出：勾选账单跨账单按商品合并明细（可按一级分类过滤），
 * 表尾汇总商品金额/配送费/附加金额/售后金额/总金额
 */
class BillExport implements FromCollection, WithStyles
{
    /** 数量列填充色（浅黄） */
    private const string QUANTITY_FILL = 'FFFFF2CC';

    /** 金额列填充色（浅红） */
    private const string AMOUNT_FILL = 'FFFFCCCC';

    /** 金额格式：￥ + 两位小数 */
    private const string CURRENCY_FORMAT = '"￥"#,##0.00';

    private ?Collection $rows = null;

    /** @var array<int, string> 特殊行索引（1 起）=> 类型（title/scope/header/summary/grand） */
    private array $specialRows = [];

    /** @var array<int, int> 标签需左合并 A:G 的合计行索引 */
    private array $mergeRows = [];

    /** @var array<int, array{row: int, column: string, value: float}> 条件填色单元格（F=数量浅黄，H=金额浅红，非 0 填色） */
    private array $fillCells = [];

    /** 列头所在行索引 */
    private int $headerRow = 1;

    /** 数据末行索引 */
    private int $lastRow = 1;

    /**
     * @param Collection<int, BillModel> $bills 勾选账单（已按 bill_date/id 排序，with store）
     * @param int $categoryId 一级分类ID（0=全部）
     */
    public function __construct(
        private readonly Collection $bills,
        private readonly int $categoryId = 0,
    ) {
    }

    /**
     * 导出行：标题/范围/列头/明细/合计全部手工构建（行位置不固定，不用 WithHeadings）
     */
    public function collection(): Collection
    {
        if ($this->rows !== null) {
            return $this->rows;
        }

        $items = app(BillDetailService::class)->mergedItemsOfBills(
            $this->bills->pluck('id')->map(static fn ($id): int => (int) $id)->all()
        );

        $categoryName = '全部';
        if ($this->categoryId > 0) {
            [$items, $categoryName] = $this->filterByRootCategory($items);
        }

        $rows = [];
        $rowIndex = 0;

        // 标题行
        $rows[] = ['门店账单合并导出（共 ' . $this->bills->count() . ' 张）'];
        $this->specialRows[++$rowIndex] = 'title';

        // 范围行：账单号 / 门店 / 分类 / 导出时间
        $billNos = $this->bills->pluck('bill_no')->all();
        $billNoText = count($billNos) > 8
            ? implode('、', array_slice($billNos, 0, 8)) . ' 等 ' . count($billNos) . ' 张'
            : implode('、', $billNos);
        $storeNames = $this->bills
            ->map(static fn (BillModel $bill): string => $bill->store->name ?? ('门店#' . $bill->store_id))
            ->unique()
            ->values()
            ->all();
        $rows[] = ['账单号：' . $billNoText];
        $this->specialRows[++$rowIndex] = 'scope';
        $rows[] = ['门店：' . implode('、', $storeNames) . '    分类：' . $categoryName . '    导出时间：' . now('Asia/Shanghai')->format('Y-m-d H:i:s')];
        $this->specialRows[++$rowIndex] = 'scope';

        // 空行
        $rows[] = [''];
        $rowIndex++;

        // 列头
        $rows[] = ['序号', '品名', '包规', '单位', '单价', '数量', '重量(斤)', '金额'];
        $this->specialRows[++$rowIndex] = 'header';
        $this->headerRow = $rowIndex;

        // 明细行（跨账单同商品已合并，单价为加权平均）
        $totalQuantity = 0;
        $totalWeight = '0';
        $totalAmount = '0';
        foreach (array_values($items) as $sort => $item) {
            $rows[] = [
                $sort + 1,
                $item['product_name'],
                $item['product_spec'],
                $item['unit'],
                (float) $item['price'],
                (int) $item['quantity'],
                (float) $item['weight'],
                (float) $item['amount'],
            ];
            $rowIndex++;
            $this->fillCells[] = ['row' => $rowIndex, 'column' => 'F', 'value' => (float) $item['quantity']];
            $this->fillCells[] = ['row' => $rowIndex, 'column' => 'H', 'value' => (float) $item['amount']];
            $totalQuantity += (int) $item['quantity'];
            $totalWeight = bcadd($totalWeight, $item['weight'], 3);
            $totalAmount = bcadd($totalAmount, $item['amount'], 2);
        }

        // 商品合计行
        $rows[] = ['', '合计', '', '', '', $totalQuantity, (float) $totalWeight, (float) $totalAmount];
        $this->specialRows[++$rowIndex] = 'summary';
        $this->fillCells[] = ['row' => $rowIndex, 'column' => 'F', 'value' => (float) $totalQuantity];
        $this->fillCells[] = ['row' => $rowIndex, 'column' => 'H', 'value' => (float) $totalAmount];

        // 配送费/附加金额/售后金额/总金额（账单级费用全额汇总，不受分类过滤影响）
        $deliveryTotal = '0';
        $addedTotal = '0';
        $afterSaleTotal = '0';
        $boxNum = 0;
        $trayNum = 0;
        foreach ($this->bills as $bill) {
            $deliveryTotal = bcadd($deliveryTotal, (string) $bill->delivery_fee, 2);
            $addedTotal = bcadd($addedTotal, (string) $bill->added_amount, 2);
            $afterSaleTotal = bcadd($afterSaleTotal, (string) $bill->after_sale, 2);
            $boxNum += (int) $bill->box_num;
            $trayNum += (int) $bill->tray_num;
        }
        $grandTotal = bcadd(bcadd(bcadd($totalAmount, $deliveryTotal, 2), $addedTotal, 2), $afterSaleTotal, 2);

        $rows[] = ['配送费合计', '', '', '', '', '', '', (float) $deliveryTotal];
        $this->specialRows[++$rowIndex] = 'summary';
        $this->mergeRows[] = $rowIndex;
        $this->fillCells[] = ['row' => $rowIndex, 'column' => 'H', 'value' => (float) $deliveryTotal];

        $rows[] = ['附加金额合计（周转筐 ' . $boxNum . ' 个 / 周转托盘 ' . $trayNum . ' 个）', '', '', '', '', '', '', (float) $addedTotal];
        $this->specialRows[++$rowIndex] = 'summary';
        $this->mergeRows[] = $rowIndex;
        $this->fillCells[] = ['row' => $rowIndex, 'column' => 'H', 'value' => (float) $addedTotal];

        $rows[] = ['售后金额合计（可正负）', '', '', '', '', '', '', (float) $afterSaleTotal];
        $this->specialRows[++$rowIndex] = 'summary';
        $this->mergeRows[] = $rowIndex;
        $this->fillCells[] = ['row' => $rowIndex, 'column' => 'H', 'value' => (float) $afterSaleTotal];

        $rows[] = ['总金额（商品金额+配送费+附加金额+售后金额）', '', '', '', '', '', '', (float) $grandTotal];
        $this->specialRows[++$rowIndex] = 'grand';
        $this->mergeRows[] = $rowIndex;
        $this->fillCells[] = ['row' => $rowIndex, 'column' => 'H', 'value' => (float) $grandTotal];
        $this->lastRow = $rowIndex;

        return $this->rows = collect($rows);
    }

    /**
     * 标题/列头/合计行加粗，合计行标签左合并 A:G；全表居中 + 全边框；金额类列货币格式；
     * 数量（浅黄）/金额（浅红）非 0 条件填色（0 不填、列头固定填色），冻结列头
     */
    public function styles(Worksheet $sheet): array
    {
        $this->collection();

        $sheet->freezePane('A' . ($this->headerRow + 1));
        $sheet->getColumnDimension('A')->setWidth(6);
        $sheet->getColumnDimension('B')->setWidth(24);
        $sheet->getColumnDimension('C')->setWidth(14);
        $sheet->getColumnDimension('D')->setWidth(8);
        $sheet->getColumnDimension('E')->setWidth(10);
        $sheet->getColumnDimension('F')->setWidth(10);
        $sheet->getColumnDimension('G')->setWidth(12);
        $sheet->getColumnDimension('H')->setWidth(12);

        foreach ($this->mergeRows as $row) {
            $sheet->mergeCells('A' . $row . ':G' . $row);
        }

        // 全部单元格水平/垂直居中（合计行标签保持左对齐）
        $sheet->getStyle('A1:H' . $this->lastRow)
            ->getAlignment()
            ->setHorizontal(Alignment::HORIZONTAL_CENTER)
            ->setVertical(Alignment::VERTICAL_CENTER);
        foreach ($this->mergeRows as $row) {
            $sheet->getStyle('A' . $row)->getAlignment()->setHorizontal(Alignment::HORIZONTAL_LEFT);
        }

        // 表格区域（列头 → 末行）添加所有边框
        $sheet->getStyle('A' . $this->headerRow . ':H' . $this->lastRow)
            ->getBorders()
            ->getAllBorders()
            ->setBorderStyle(Border::BORDER_THIN);

        // 金额类列（单价/金额）货币格式：￥ + 两位小数
        foreach (['E', 'H'] as $column) {
            $sheet->getStyle($column . ($this->headerRow + 1) . ':' . $column . $this->lastRow)
                ->getNumberFormat()
                ->setFormatCode(self::CURRENCY_FORMAT);
        }

        // 列头固定填色：数量列（F）浅黄、金额列（H）浅红
        $this->fillCell($sheet, 'F' . $this->headerRow, self::QUANTITY_FILL);
        $this->fillCell($sheet, 'H' . $this->headerRow, self::AMOUNT_FILL);

        // 数据区条件填色：非 0 填色，0 无背景（金额含负值）
        foreach ($this->fillCells as $cell) {
            if ((float) $cell['value'] !== 0.0) {
                $this->fillCell(
                    $sheet,
                    $cell['column'] . $cell['row'],
                    $cell['column'] === 'F' ? self::QUANTITY_FILL : self::AMOUNT_FILL
                );
            }
        }

        $styles = [];
        foreach ($this->specialRows as $row => $type) {
            $style = match ($type) {
                'title' => ['font' => ['bold' => true, 'size' => 14]],
                'header', 'summary' => ['font' => ['bold' => true]],
                'grand' => ['font' => ['bold' => true, 'size' => 12]],
                default => [],
            };
            if ($style !== []) {
                $styles[$row] = $style;
            }
        }

        return $styles;
    }

    /**
     * 单元格纯色填充
     */
    private function fillCell(Worksheet $sheet, string $coordinate, string $argb): void
    {
        $sheet->getStyle($coordinate)
            ->getFill()
            ->setFillType(Fill::FILL_SOLID)
            ->getStartColor()
            ->setARGB($argb);
    }

    /**
     * 按一级分类过滤明细：沿 parent_id 上溯取根分类（商品含软删除，保证历史账单可导出），
     * 仅保留根分类为所选分类的行
     *
     * @param array<int, array> $items 合并后的商品明细
     * @return array{0: array<int, array>, 1: string} [过滤后明细, 一级分类名]
     */
    private function filterByRootCategory(array $items): array
    {
        $categories = ProductCategoryModel::all()->keyBy('id');
        $categoryName = $categories->get($this->categoryId)->name ?? ('分类#' . $this->categoryId);

        $productCategoryIds = ProductModel::withTrashed()
            ->whereIn('id', array_column($items, 'product_id'))
            ->pluck('category_id', 'id');

        // 商品ID => 根分类ID（与采购单导出同口径的上溯解析）
        $rootIds = [];
        foreach ($productCategoryIds as $productId => $categoryId) {
            $rootId = 0;
            $cursor = (int) $categoryId;
            $guard = 0;
            while ($cursor > 0 && $guard++ < 20) {
                $category = $categories->get($cursor);
                if ($category === null) {
                    break;
                }
                $rootId = (int) $category->id;
                $cursor = (int) $category->parent_id;
            }
            $rootIds[(int) $productId] = $rootId;
        }

        $categoryId = $this->categoryId;
        $filtered = array_values(array_filter(
            $items,
            static fn (array $row): bool => ($rootIds[$row['product_id']] ?? 0) === $categoryId
        ));

        if ($filtered === []) {
            throw new RepositoryException('所选账单在「' . $categoryName . '」分类下无商品明细');
        }

        return [$filtered, $categoryName];
    }
}