import csv
import io
from datetime import datetime
from flask import send_file
import xlsxwriter
from flask import current_app

def export_to_csv(data, headers):
    """导出数据到CSV文件"""
    output = io.StringIO()
    writer = csv.writer(output)
    writer.writerow(headers)
    
    for row in data:
        writer.writerow([row.get(header.lower().replace(' ', '_')) for header in headers])
    
    output.seek(0)
    return send_file(
        io.BytesIO(output.getvalue().encode('utf-8')),
        mimetype='text/csv',
        as_attachment=True,
        download_name=f'export_{datetime.now().strftime("%Y%m%d_%H%M%S")}.csv'
    )

def export_to_excel(data, headers, sheet_name='Sheet1'):
    """导出数据到Excel文件"""
    try:
        # 创建一个内存中的Excel文件
        output = io.BytesIO()
        workbook = xlsxwriter.Workbook(output)
        worksheet = workbook.add_worksheet(sheet_name)
        
        # 设置表头格式
        header_format = workbook.add_format({
            'bold': True,
            'align': 'center',
            'valign': 'vcenter',
            'fg_color': '#D7E4BC',
            'border': 1
        })
        
        # 设置数据格式
        data_format = workbook.add_format({
            'align': 'left',
            'valign': 'vcenter',
            'border': 1
        })
        
        # 写入表头
        for col, header in enumerate(headers):
            worksheet.write(0, col, header, header_format)
            worksheet.set_column(col, col, 15)  # 设置列宽
        
        # 写入数据
        for row, item in enumerate(data, start=1):
            for col, header in enumerate(headers):
                try:
                    # 确保数据类型正确
                    value = item.get(header, '')
                    if isinstance(value, (int, float)):
                        worksheet.write_number(row, col, value, data_format)
                    else:
                        worksheet.write_string(row, col, str(value), data_format)
                except Exception as e:
                    current_app.logger.error(f"Error writing cell [{row},{col}]: {str(e)}")
                    worksheet.write_string(row, col, str(value), data_format)
        
        workbook.close()
        output.seek(0)
        
        # 设置响应头
        response = send_file(
            output,
            mimetype='application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
            as_attachment=True,
            download_name=f'inventory_{datetime.now().strftime("%Y%m%d_%H%M%S")}.xlsx'
        )
        
        # 添加CORS头
        response.headers.add('Access-Control-Allow-Origin', '*')
        response.headers.add('Access-Control-Allow-Headers', 'Content-Type,Authorization')
        response.headers.add('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE,OPTIONS')
        response.headers.add('Access-Control-Expose-Headers', 'Content-Disposition')
        
        return response
        
    except Exception as e:
        current_app.logger.error(f"Error in export_to_excel: {str(e)}")
        raise