import type { Compiler } from '@rspack/core'
import { rspack } from '@rspack/core'

export interface ChunkLoadRetryPluginOptions {
  /** 每个 chunk 的最大重试次数，不包含首次请求 */
  maxRetries?: number
  /** 每次重试之间的等待时间（毫秒） */
  retryDelay?: number
  /** 重试时追加时间戳参数，避免命中失败缓存 */
  cacheBust?: boolean
}

const PLUGIN_NAME = 'ChunkLoadRetryPlugin'

class ChunkLoadRetryRuntimeModule extends rspack.RuntimeModule {
  constructor(private readonly options: Required<ChunkLoadRetryPluginOptions>) {
    super('webpack/runtime/edu-scripts_chunk_load_retry', rspack.RuntimeModule.STAGE_TRIGGER)
  }

  override generate() {
    const { maxRetries, retryDelay, cacheBust } = this.options

    return `
var __eduMaxRetries__ = ${JSON.stringify(maxRetries)};
var __eduRetryDelay__ = ${JSON.stringify(retryDelay)};
var __eduCacheBust__ = ${JSON.stringify(cacheBust)};

var __eduLoadScript__ = __webpack_require__.l;
if (typeof __eduLoadScript__ === 'function' && !__eduLoadScript__.__eduChunkRetryPatched__) {
  __webpack_require__.l = function(url, done, key, chunkId) {
    var retries = 0;

    var attempt = function(requestUrl) {
      __eduLoadScript__(requestUrl, function(event) {
        if (!event || event.type === 'load') {
          done(event);
          return;
        }

        if (retries >= __eduMaxRetries__) {
          done(event);
          return;
        }

        retries += 1;

        var nextUrl = url;
        if (__eduCacheBust__) {
          nextUrl = url + (url.indexOf('?') >= 0 ? '&' : '?') + 'retry=' + retries + '&t=' + Date.now();
        }

        if (__eduRetryDelay__ > 0) {
          setTimeout(function() {
            attempt(nextUrl);
          }, __eduRetryDelay__);
        } else {
          attempt(nextUrl);
        }
      }, key ? key + '-retry-' + retries : key, chunkId);
    };

    attempt(url);
  };

  __webpack_require__.l.__eduChunkRetryPatched__ = true;
}
`
  }
}

export default class ChunkLoadRetryPlugin {
  private readonly options: Required<ChunkLoadRetryPluginOptions>

  constructor(options: ChunkLoadRetryPluginOptions = {}) {
    this.options = {
      maxRetries: Math.max(0, options.maxRetries ?? 3),
      retryDelay: Math.max(0, options.retryDelay ?? 100),
      cacheBust: options.cacheBust ?? true,
    }
  }

  apply(compiler: Compiler) {
    compiler.hooks.thisCompilation.tap(PLUGIN_NAME, (compilation) => {
      compilation.hooks.runtimeRequirementInTree
        .for(rspack.RuntimeGlobals.loadScript)
        .tap(PLUGIN_NAME, (chunk) => {
          compilation.addRuntimeModule(chunk, new ChunkLoadRetryRuntimeModule(this.options))
        })
    })
  }
}