import {
  BuilderComponentPlugin,
  IChunkBuilder,
  ICodeChunk,
  ICodeStruct,
} from '../types';

import { COMMON_SUB_MODULE_NAME } from '../const/generator';

export const groupChunks = (chunks: ICodeChunk[]): ICodeChunk[][] => {
  const col = chunks.reduce(
    (chunksSet: Record<string, ICodeChunk[]>, chunk) => {
      const fileKey = `${chunk.subModule || COMMON_SUB_MODULE_NAME}.${
        chunk.fileType
      }`;
      if (!chunksSet[fileKey]) {
        chunksSet[fileKey] = [];
      }
      chunksSet[fileKey].push(chunk);
      return chunksSet;
    },
    {},
  );

  return Object.keys(col).map(key => col[key]);
};

/**
 * 代码片段构建器
 *
 * @export
 * @class ChunkBuilder
 * @template T
 */
export default class ChunkBuilder implements IChunkBuilder {
  private plugins: BuilderComponentPlugin[];

  constructor(plugins: BuilderComponentPlugin[] = []) {
    this.plugins = plugins;
  }

  public async run(
    ir: unknown,
    initialStructure: ICodeStruct = {
      ir,
      chunks: [],
      depNames: [],
    },
  ) {
    const structure = initialStructure;

    const finalStructure: ICodeStruct = await this.plugins.reduce(
      async (previousPluginOperation: Promise<ICodeStruct>, plugin) => {
        const modifiedStructure = await previousPluginOperation;
        return plugin(modifiedStructure);
      },
      Promise.resolve(structure),
    );

    const chunks = groupChunks(finalStructure.chunks);

    return {
      chunks,
    };
  }

  public getPlugins() {
    return this.plugins;
  }

  public addPlugin(plugin: BuilderComponentPlugin) {
    this.plugins.push(plugin);
  }
}