const fs = require('fs');
const path = require('path');

class AlipayEventSourceFixPlugin {
  apply(compiler) {
    // 在构建完成后执行
    compiler.hooks.afterEmit.tapAsync('AlipayEventSourceFixPlugin', (compilation, callback) => {
      this.fixEventSource();
      callback();
    });
  }

  fixEventSource() {
    const taroJsPath = path.join(process.cwd(), 'dist', 'taro.js');
    
    if (!fs.existsSync(taroJsPath)) {
      console.log('AlipayEventSourceFixPlugin: dist/taro.js not found');
      return;
    }
    
    console.log('AlipayEventSourceFixPlugin: Fixing EventSource in dist/taro.js...');
    
    let content = fs.readFileSync(taroJsPath, 'utf8');
    
    // 检查是否存在EventSource相关的代码
    if (content.includes('EventSource')) {
      console.log('AlipayEventSourceFixPlugin: Found EventSource in dist/taro.js');
      
      // 新的EventSource实现（使用标准格式，确保语法正确）
      const newEventSource = 'class EventSource {\n  data = {};\n\n  get(id) {\n    return this.data[id];\n  }\n\n  set(id, value) {\n    this.data[id] = value;\n  }\n\n  delete(id) {\n    delete this.data[id];\n  }\n\n  has(id) {\n    return id in this.data;\n  }\n\n  removeNode(child) {\n    const { sid, uid } = child;\n    this.delete(sid);\n    if (uid !== sid && uid) this.delete(uid);\n  }\n\n  removeNodeTree(child) {\n    this.removeNode(child);\n    const { childNodes } = child;\n    childNodes.forEach((node) => this.removeNodeTree(node));\n  }\n}';
      
      let replaced = false;
      
      // 方式1：查找并替换event-source.js模块
      const eventSourceModulePattern = /\/\*\*\*\.\/node_modules\/@tarojs\/runtime\/dist\/dom\/event-source\.js[\s\S]*?class EventSource[\s\S]*?\/\*\*\*\/\s*\}\);/g;
      
      if (eventSourceModulePattern.test(content)) {
        console.log('AlipayEventSourceFixPlugin: Found event-source.js module');
        const matches = content.match(eventSourceModulePattern);
        if (matches && matches.length > 0) {
          const oldModule = matches[0];
          // 提取模块的开头部分
          const moduleStart = oldModule.substring(0, oldModule.indexOf('class EventSource'));
          // 提取模块的结尾部分
          const moduleEnd = oldModule.substring(oldModule.lastIndexOf('*/') + 2);
          // 构建新的模块内容
          const newModule = moduleStart + newEventSource + moduleEnd;
          // 替换整个模块
          content = content.replace(oldModule, newModule);
          fs.writeFileSync(taroJsPath, content, 'utf8');
          console.log('AlipayEventSourceFixPlugin: Success: EventSource module replaced');
          replaced = true;
        }
      }
      
      // 方式2：直接查找EventSource类定义
      if (!replaced) {
        const eventSourceStart = content.indexOf('class EventSource');
        if (eventSourceStart !== -1) {
          console.log('AlipayEventSourceFixPlugin: Found EventSource class');
          // 查找类的结束位置
          let braceCount = 0;
          let eventSourceEnd = eventSourceStart;
          let foundOpeningBrace = false;
          
          for (let i = eventSourceStart; i < content.length; i++) {
            if (content[i] === '{') {
              braceCount++;
              foundOpeningBrace = true;
            } else if (content[i] === '}') {
              braceCount--;
              if (foundOpeningBrace && braceCount === 0) {
                eventSourceEnd = i + 1; // 包含结束大括号
                break;
              }
            }
          }
          
          if (eventSourceEnd > eventSourceStart) {
            const oldEventSource = content.substring(eventSourceStart, eventSourceEnd);
            // 替换为新的实现
            content = content.replace(oldEventSource, newEventSource);
            fs.writeFileSync(taroJsPath, content, 'utf8');
            console.log('AlipayEventSourceFixPlugin: Success: EventSource class replaced');
            replaced = true;
          }
        }
      }
      
      // 方式3：处理压缩后的EventSource类
      if (!replaced) {
        const compressedPattern = /class EventSource[^{]*\{[^}]*\{[^}]*\{[^}]*\}[^}]*\}[^}]*\}/g;
        if (compressedPattern.test(content)) {
          console.log('AlipayEventSourceFixPlugin: Found compressed EventSource');
          const matches = content.match(compressedPattern);
          if (matches && matches.length > 0) {
            content = content.replace(matches[0], newEventSource);
            fs.writeFileSync(taroJsPath, content, 'utf8');
            console.log('AlipayEventSourceFixPlugin: Success: Compressed EventSource replaced');
            replaced = true;
          }
        }
      }
      
      // 方式4：处理语法错误的情况
      if (!replaced && content.includes('class EventSource') && (content.includes('sid, uid') || content.includes('childNodes'))) {
        console.log('AlipayEventSourceFixPlugin: Found EventSource with potential syntax errors');
        // 查找EventSource开始位置
        const eventSourceStart = content.indexOf('class EventSource');
        if (eventSourceStart !== -1) {
          // 查找一个合理的结束位置
          const eventSourceEnd = content.indexOf('eventSource', eventSourceStart);
          if (eventSourceEnd > eventSourceStart) {
            // 提取从EventSource开始到eventSource变量定义之间的内容
            const oldEventSource = content.substring(eventSourceStart, eventSourceEnd);
            // 替换为新的实现
            content = content.replace(oldEventSource, newEventSource);
            fs.writeFileSync(taroJsPath, content, 'utf8');
            console.log('AlipayEventSourceFixPlugin: Success: EventSource with syntax errors fixed');
            replaced = true;
          }
        }
      }
      
      if (!replaced) {
        console.log('AlipayEventSourceFixPlugin: Info: EventSource not found or could not be replaced');
      }
    } else {
      console.log('AlipayEventSourceFixPlugin: Info: No EventSource found in dist/taro.js');
    }
  }
}

module.exports = AlipayEventSourceFixPlugin;