import type { Services } from '../../../services/mod.js'
import type { DeviceRegistrationManifest } from '../../../domain/device-registration-manifest.js'

import {
  isError,
  makeError,
  makeSuccess,
  unwrapResult,
} from '../../../framework/types/result.js'
import { BaseError } from '../../../framework/error/mod.js'

interface Options {
  deps: {
    services: Services
  }
}

export interface GetFeatureFlagDto<FlagKey> {
  manifest: DeviceRegistrationManifest
  key: FlagKey
}

export class GetFeatureFlagError extends BaseError {
  public readonly _tag = 'GetFeatureFlagError'
}

export function buildGetFeatureFlag(options: Options) {
  return async function getFeatureFlag<FlagKey>(
    dto: GetFeatureFlagDto<FlagKey>,
  ) {
    const {
      deps: { services },
    } = options

    const resultOfGettingLicense = await services.device.getLicense(
      dto.manifest,
    )

    if (isError(resultOfGettingLicense)) {
      return makeError(new GetFeatureFlagError())
    }

    const license = unwrapResult(resultOfGettingLicense)

    const flag = license.flags?.find((flag) => flag.key === dto.key)

    return makeSuccess(flag?.value)
  }
}