<?php

namespace app\common\controller;

use PHPExcel;
use PHPExcel_IOFactory;
use PHPExcel_Worksheet_Drawing;
use think\Controller;
use think\Exception;

/**
 * 通用导出控制器，提供 Excel 导出与图片插入能力
 */
class ExportController extends Controller
{
    /**
     * @var array<string> 需要在请求结束时清理的临时文件
     */
    protected static $tempFiles = [];

    /**
     * 导出 Excel（支持指定列插入图片）
     *
     * @param string $fileName      输出文件名（可不带扩展名）
     * @param array  $headers       列定义，例如 ['name' => '姓名', 'phone' => '电话']
     * @param array  $rows          数据行，需与 $headers 的 key 对应
     * @param array  $imageColumns  需要渲染为图片的列 key 列表
     * @param string $sheetName     工作表名称
     *
     * @throws Exception
     */
    public static function exportExcelWithImages(
        $fileName,
        array $headers,
        array $rows,
        array $imageColumns = [],
        $sheetName = 'Sheet1'
    ) {
        if (empty($headers)) {
            throw new Exception('导出列定义不能为空');
        }
        if (empty($rows)) {
            throw new Exception('导出数据不能为空');
        }

        $excel = new PHPExcel();
        $sheet = $excel->getActiveSheet();
        $sheet->setTitle($sheetName);

        $columnKeys = array_keys($headers);

        // 写入表头
        foreach ($columnKeys as $index => $key) {
            $columnLetter = self::columnLetter($index);
            $sheet->setCellValue($columnLetter . '1', $headers[$key]);
            $sheet->getColumnDimension($columnLetter)->setAutoSize(true);
        }

        // 写入数据与图片
        foreach ($rows as $rowIndex => $rowData) {
            $excelRow = $rowIndex + 2; // 数据从第 2 行开始
            foreach ($columnKeys as $colIndex => $key) {
                $columnLetter = self::columnLetter($colIndex);
                $cell = $columnLetter . $excelRow;
                $value = isset($rowData[$key]) ? $rowData[$key] : '';

                if (in_array($key, $imageColumns, true) && !empty($value)) {
                    $imagePath = self::resolveImagePath($value);
                    if ($imagePath) {
                        $drawing = new PHPExcel_Worksheet_Drawing();
                        $drawing->setPath($imagePath);
                        $drawing->setCoordinates($cell);
                        $drawing->setOffsetX(5);
                        $drawing->setOffsetY(5);
                        $drawing->setHeight(60);
                        $drawing->setWorksheet($sheet);
                        $sheet->getRowDimension($excelRow)->setRowHeight(60);
                    } else {
                        $sheet->setCellValue($cell, $value);
                    }
                } else {
                    $sheet->setCellValue($cell, $value);
                }
            }
        }

        $safeName = preg_replace('/[^\w\-]/', '_', $fileName ?: 'export_' . date('Ymd_His'));
        if (stripos($safeName, '.xlsx') === false) {
            $safeName .= '.xlsx';
        }

        if (ob_get_length()) {
            ob_end_clean();
        }

        header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
        header('Cache-Control: max-age=0');
        header('Content-Disposition: attachment;filename="' . $safeName . '"');

        $writer = PHPExcel_IOFactory::createWriter($excel, 'Excel2007');
        $writer->save('php://output');

        self::cleanupTempFiles();
        exit;
    }

    /**
     * 根据列序号生成 Excel 列字母
     *
     * @param int $index
     * @return string
     */
    protected static function columnLetter($index)
    {
        $letters = '';
        do {
            $letters = chr($index % 26 + 65) . $letters;
            $index = intval($index / 26) - 1;
        } while ($index >= 0);

        return $letters;
    }

    /**
     * 将远程或本地图片路径转换为可用的本地文件路径
     *
     * @param string $path
     * @return string|null
     */
    protected static function resolveImagePath($path)
    {
        if (empty($path)) {
            return null;
        }

        if (preg_match('/^https?:\/\//i', $path)) {
            $tempFile = tempnam(sys_get_temp_dir(), 'export_img_');
            $stream = @file_get_contents($path);
            if ($stream === false) {
                return null;
            }
            file_put_contents($tempFile, $stream);
            self::$tempFiles[] = $tempFile;
            return $tempFile;
        }

        if (file_exists($path)) {
            return $path;
        }

        return null;
    }

    /**
     * 清理所有临时文件
     */
    protected static function cleanupTempFiles()
    {
        foreach (self::$tempFiles as $file) {
            if (file_exists($file)) {
                @unlink($file);
            }
        }
        self::$tempFiles = [];
    }
}