import * as path from 'path'
import {
  Matchable,
  Replacement,
  Result,
  Compiler,
  NormalModuleFactory,
} from './typings'

const pluginName = 'NormalModuleReplacementPlugin'
export class ModuleReplacementOverridePlugin {
  resourceRegExp: Matchable
  newResource: Replacement
  constructor(resourceRegExp: Matchable, newResource: Replacement) {
    this.resourceRegExp = resourceRegExp
    this.newResource = newResource
  }

  beforeResolve = (result: Result) => {
    if (!result) {
      return undefined
    }

    if (this.resourceRegExp.test(result.request)) {
      if (typeof this.newResource === 'function') {
        this.newResource(result)
      } else {
        result.request = this.newResource
      }
    }

    return result
  }

  afterResolve = (result: Result) => {
    if (!result) {
      return undefined
    }

    if (this.resourceRegExp.test(result.resource)) {
      if (typeof this.newResource === 'function') {
        this.newResource(result)
      } else {
        result.resource = path.resolve(
          path.dirname(result.resource),
          this.newResource
        )
      }
    }

    return result
  }

  apply(compiler: Compiler): void {
    compiler.hooks.normalModuleFactory.tap(
      pluginName,
      (normalModuleFactory: NormalModuleFactory) => {
        normalModuleFactory.hooks.beforeResolve.tap(
          pluginName,
          this.beforeResolve
        )
        normalModuleFactory.hooks.afterResolve.tap(
          pluginName,
          this.afterResolve
        )
      }
    )
  }
}