import QRCode from 'qrcode';

/**
 * 通用js方法封装处理
 * Copyright (c) 2019 klp
 */

// 日期格式化
export function parseTime(time, pattern) {
  if (arguments.length === 0 || !time) {
    return null
  }
  const format = pattern || '{y}-{m}-{d} {h}:{i}:{s}'
  let date
  if (typeof time === 'object') {
    date = time
  } else {
    if ((typeof time === 'string') && (/^[0-9]+$/.test(time))) {
      time = parseInt(time)
    } else if (typeof time === 'string') {
      time = time.replace(new RegExp(/-/gm), '/').replace('T', ' ').replace(new RegExp(/\.[\d]{3}/gm), '');
    }
    if ((typeof time === 'number') && (time.toString().length === 10)) {
      time = time * 1000
    }
    date = new Date(time)
  }
  const formatObj = {
    y: date.getFullYear(),
    m: date.getMonth() + 1,
    d: date.getDate(),
    h: date.getHours(),
    i: date.getMinutes(),
    s: date.getSeconds(),
    a: date.getDay()
  }
  const time_str = format.replace(/{(y|m|d|h|i|s|a)+}/g, (result, key) => {
    let value = formatObj[key]
    // Note: getDay() returns 0 on Sunday
    if (key === 'a') { return ['日', '一', '二', '三', '四', '五', '六'][value] }
    if (result.length > 0 && value < 10) {
      value = '0' + value
    }
    return value || 0
  })
  return time_str
}

// 表单重置
export function resetForm(refName) {
  if (this.$refs[refName]) {
    this.$refs[refName].resetFields();
  }
}

// 添加日期范围
export function addDateRange(params, dateRange, propName) {
  let search = params;
  search.params = typeof (search.params) === 'object' && search.params !== null && !Array.isArray(search.params) ? search.params : {};
  dateRange = Array.isArray(dateRange) ? dateRange : [];
  if (typeof (propName) === 'undefined') {
    search.params['beginTime'] = dateRange[0];
    search.params['endTime'] = dateRange[1];
  } else {
    search.params['begin' + propName] = dateRange[0];
    search.params['end' + propName] = dateRange[1];
  }
  return search;
}

// 回显数据字典
export function selectDictLabel(datas, value) {
  if (value === undefined) {
    return "";
  }
  var actions = [];
  Object.keys(datas).some((key) => {
    if (datas[key].value == ('' + value)) {
      actions.push(datas[key].label);
      return true;
    }
  })
  if (actions.length === 0) {
    actions.push(value);
  }
  return actions.join('');
}

// 回显数据字典（字符串、数组）
export function selectDictLabels(datas, value, separator) {
  if (value === undefined || value.length ===0) {
    return "";
  }
  if (Array.isArray(value)) {
    value = value.join(",");
  }
  var actions = [];
  var currentSeparator = undefined === separator ? "," : separator;
  var temp = value.split(currentSeparator);
  Object.keys(value.split(currentSeparator)).some((val) => {
    var match = false;
    Object.keys(datas).some((key) => {
      if (datas[key].value == ('' + temp[val])) {
        actions.push(datas[key].label + currentSeparator);
        match = true;
      }
    })
    if (!match) {
      actions.push(temp[val] + currentSeparator);
    }
  })
  return actions.join('').substring(0, actions.join('').length - 1);
}

// 字符串格式化(%s )
export function sprintf(str) {
  var args = arguments, flag = true, i = 1;
  str = str.replace(/%s/g, function () {
    var arg = args[i++];
    if (typeof arg === 'undefined') {
      flag = false;
      return '';
    }
    return arg;
  });
  return flag ? str : '';
}

// 转换字符串，undefined,null等转化为""
export function parseStrEmpty(str) {
  if (!str || str == "undefined" || str == "null") {
    return "";
  }
  return str;
}

// 数据合并
export function mergeRecursive(source, target) {
  for (var p in target) {
    try {
      if (target[p].constructor == Object) {
        source[p] = mergeRecursive(source[p], target[p]);
      } else {
        source[p] = target[p];
      }
    } catch (e) {
      source[p] = target[p];
    }
  }
  return source;
};

/**
 * 构造树型结构数据
 * @param {*} data 数据源
 * @param {*} id id字段 默认 'id'
 * @param {*} parentId 父节点字段 默认 'parentId'
 * @param {*} children 孩子节点字段 默认 'children'
 */
export function handleTree(data, id, parentId, children) {
  let config = {
    id: id || 'id',
    parentId: parentId || 'parentId',
    childrenList: children || 'children'
  };

  var childrenListMap = {};
  var nodeIds = {};
  var tree = [];

  for (let d of data) {
    let parentId = d[config.parentId];
    if (childrenListMap[parentId] == null) {
      childrenListMap[parentId] = [];
    }
    nodeIds[d[config.id]] = d;
    childrenListMap[parentId].push(d);
  }

  for (let d of data) {
    let parentId = d[config.parentId];
    if (nodeIds[parentId] == null) {
      tree.push(d);
    }
  }

  for (let t of tree) {
    adaptToChildrenList(t);
  }

  function adaptToChildrenList(o) {
    if (childrenListMap[o[config.id]] !== null) {
      o[config.childrenList] = childrenListMap[o[config.id]];
    }
    if (o[config.childrenList]) {
      for (let c of o[config.childrenList]) {
        adaptToChildrenList(c);
      }
    }
  }
  return tree;
}

/**
* 参数处理
* @param {*} params  参数
*/
export function tansParams(params) {
  let result = ''
  for (const propName of Object.keys(params)) {
    const value = params[propName];
    var part = encodeURIComponent(propName) + "=";
    if (value !== null && value !== "" && typeof (value) !== "undefined") {
      if (typeof value === 'object') {
        for (const key of Object.keys(value)) {
          if (value[key] !== null && value[key] !== "" && typeof (value[key]) !== 'undefined') {
            let params = propName + '[' + key + ']';
            var subPart = encodeURIComponent(params) + "=";
            result += subPart + encodeURIComponent(value[key]) + "&";
          }
        }
      } else {
        result += part + encodeURIComponent(value) + "&";
      }
    }
  }
  return result
}

// 验证是否为blob格式
export function blobValidate(data) {
  return data.type !== 'application/json'
}

/**
 * 保存二维码为图片
 * @param {string} code 二维码内容
 * @param {string} text 下方文字
 * @param {number} index 索引，用于生成文件名
 * @param {Object} context Vue组件实例上下文（需要包含$message、barcodeWidth、barcodeHeight）
 */
export async function saveAsImage(code, text, index, context) {
  // 确保上下文存在
  if (!context) {
    console.error('缺少组件上下文，请传入Vue实例');
    return;
  }

  try {
    // 检查QRCode库是否加载
    if (typeof QRCode === 'undefined') {
      throw new Error('QRCode库未加载，请确保已引入');
    }

    // 创建临时canvas用于绘制二维码和文字
    const canvas = document.createElement('canvas');
    const ctx = canvas.getContext('2d');
    if (!ctx) {
      throw new Error('无法获取canvas上下文');
    }
    
    // 从上下文获取尺寸参数，提供默认值
    const barcodeWidth = context.barcodeWidth || 200;
    const barcodeHeight = context.barcodeHeight || 200;
    const textHeight = 30; // 文字区域高度
    
    canvas.width = barcodeWidth;
    canvas.height = barcodeHeight + textHeight;
    
    // 绘制二维码
    const qrCanvas = document.createElement('canvas');
    qrCanvas.width = barcodeWidth;
    qrCanvas.height = barcodeHeight;
    
    // 等待二维码绘制完成
    await new Promise((resolve, reject) => {
      QRCode.toCanvas(qrCanvas, code, {
        width: barcodeWidth,
        height: barcodeHeight,
        margin: 0,
        errorCorrectionLevel: 'M'
      }, (error) => {
        if (error) reject(error);
        else resolve();
      });
    });
    
    // 将二维码绘制到主canvas
    ctx.drawImage(qrCanvas, 0, 0);
    
    // 绘制文字（处理文字过长情况）
    ctx.fillStyle = '#000';
    ctx.font = '14px Arial, sans-serif';
    ctx.textAlign = 'center';
    ctx.textBaseline = 'top';
    
    // 处理过长文字，最多显示2行
    const maxTextWidth = barcodeWidth - 20; // 预留边距
    let displayText = text;
    if (ctx.measureText(text).width > maxTextWidth) {
      // 尝试截断并添加省略号
      let i = text.length;
      while (ctx.measureText(text.substring(0, i)).width > maxTextWidth && i > 0) {
        i--;
      }
      displayText = text.substring(0, i) + '...';
    }
    ctx.fillText(displayText, barcodeWidth / 2, barcodeHeight + 5);
    
    // 创建图片链接并下载
    canvas.toBlob(blob => {
      if (!blob) {
        throw new Error('无法生成图片blob对象');
      }
      
      try {
        const url = URL.createObjectURL(blob);
        const a = document.createElement('a');
        
        // 处理文件名特殊字符
        a.download = `二维码_${index + 1}.png`;
        a.href = url;
        
        // 模拟点击下载
        document.body.appendChild(a);
        const event = new MouseEvent('click');
        a.dispatchEvent(event);
        
        // 清理资源
        setTimeout(() => {
          document.body.removeChild(a);
          URL.revokeObjectURL(url);
        }, 100);
        
        context.$message.success('图片保存成功');
      } catch (urlError) {
        console.error('创建下载链接失败:', urlError);
        context.$message.error('创建下载链接失败');
      }
    }, 'image/png'); // 明确指定MIME类型
    
  } catch (error) {
    console.error('保存图片失败:', error);
    context.$message.error(`保存图片失败: ${error.message || '未知错误'}`);
  }
}