import { Checker, CheckResult } from '@stryker-mutator/api/check';
import { StrykerOptions, Mutant } from '@stryker-mutator/api/core';
import { PluginKind, tokens, commonTokens } from '@stryker-mutator/api/plugin';
import { StrykerError } from '@stryker-mutator/util';

import { coreTokens, PluginCreator } from '../di/index.js';

import { CheckerResource } from './checker-resource.js';

export class CheckerWorker implements CheckerResource {
  private readonly innerCheckers: Map<string, Checker>;

  public static inject = tokens(commonTokens.options, coreTokens.pluginCreator);
  constructor(options: StrykerOptions, pluginCreator: PluginCreator) {
    this.innerCheckers = new Map(options.checkers.map((name) => [name, pluginCreator.create(PluginKind.Checker, name)]));
  }
  public async init(): Promise<void> {
    for await (const [name, checker] of this.innerCheckers.entries()) {
      try {
        await checker.init();
      } catch (error: unknown) {
        throw new StrykerError(`An error occurred during initialization of the "${name}" checker`, error);
      }
    }
  }
  public async check(checkerName: string, mutants: Mutant[]): Promise<Record<string, CheckResult>> {
    return this.perform(checkerName, (checker) => checker.check(mutants));
  }

  public async group(checkerName: string, mutants: Mutant[]): Promise<string[][]> {
    return this.perform(
      checkerName,
      (checker) =>
        checker.group?.(mutants) ??
        // Group one by one by default
        mutants.map(({ id }) => [id]),
    );
  }

  private perform<T>(checkerName: string, act: (checker: Checker) => T) {
    const checker = this.innerCheckers.get(checkerName);
    if (checker) {
      return act(checker);
    } else {
      throw new Error(`Checker ${checkerName} does not exist!`);
    }
  }
}