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

class AlipayEventSourceFixPlugin {
  apply(compiler) {
    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');
    let replaced = false;

    // 新策略: Taro 4.x 压缩后的 EventSource (class X extends Map with removeNode)
    if (content.includes('extends Map{removeNode(')) {
      console.log('AlipayEventSourceFixPlugin: Found minified EventSource (extends Map with removeNode)');

      const minifiedPattern =
        /class \w+ extends Map\{removeNode\([\s\S]*?removeNodeTree\([\s\S]*?\}\}const r=new \w+/g;

      if (minifiedPattern.test(content)) {
        const replacement =
          'class EventSource{data={};get(e){return this.data[e]};set(e,t){this.data[e]=t};delete(e){delete this.data[e]};has(e){return e in this.data};removeNode(e){const{sid:t,uid:n}=e;this.delete(t);n!==t&&n&&this.delete(n)};removeNodeTree(e){this.removeNode(e);const{childNodes:t}=e;t.forEach(e=>this.removeNodeTree(e))}}const r=new EventSource';

        content = content.replace(minifiedPattern, replacement);
        fs.writeFileSync(taroJsPath, content, 'utf8');
        console.log('AlipayEventSourceFixPlugin: Success: Minified EventSource replaced');
        replaced = true;
      }
    }

    // 原有策略: 处理未压缩的 EventSource
    if (!replaced && content.includes('EventSource')) {
      console.log('AlipayEventSourceFixPlugin: Found EventSource in dist/taro.js');

      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}';

      // 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];
          const moduleStart = oldModule.substring(0, oldModule.indexOf('class EventSource'));
          const moduleEnd = oldModule.substring(oldModule.lastIndexOf('*/') + 2);
          const newModule = moduleStart + newEventSource + moduleEnd;
          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');
          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;
                break;
              }
            }
          }

          if (eventSourceEnd > eventSourceStart) {
            const oldEventSource = content.substring(eventSourceStart, eventSourceEnd);
            content = content.replace(oldEventSource, newEventSource);
            fs.writeFileSync(taroJsPath, content, 'utf8');
            console.log('AlipayEventSourceFixPlugin: Success: EventSource class replaced');
            replaced = true;
          }
        }
      }

      if (!replaced) {
        console.log('AlipayEventSourceFixPlugin: Info: EventSource not found or could not be replaced');
      }
    }

    if (!replaced) {
      console.log('AlipayEventSourceFixPlugin: Info: No EventSource pattern found in dist/taro.js');
    }
  }
}

module.exports = AlipayEventSourceFixPlugin;