import * as Promise  from 'bluebird'
import { gte as greaterThanOrEqual, lt as lessThan, valid as isValidVersion }  from 'semver'
import getCobaltVersion from '@cobalt-engine/get-cov'

const NPM_STRUCTURE_MIN_VERSION = '2.0.0'
const ZERO_MAJOR_VERSION = 'ZERO_MAJOR_VERSION'

export function isBowerStructure (presentationDir: string): Promise<boolean> {
  return getCobaltVersion(presentationDir)
    .then(isBower)
}

export function isNpmStructure (presentationDir: string): Promise<boolean> {
  return getCobaltVersion(presentationDir)
    .then(isNpm)
}

export function isMajorZeroStructure (presentationDir: string): Promise<boolean> {
  return getCobaltVersion(presentationDir)
    .then((cobaltVersion: string) => cobaltVersion === ZERO_MAJOR_VERSION)
}

function isBower(cobaltVersion: string): boolean {
  return !!isValidVersion(cobaltVersion) && lessThan(cobaltVersion, NPM_STRUCTURE_MIN_VERSION)
}
function isNpm (cobaltVersion: string): boolean {
  return !!isValidVersion(cobaltVersion) && greaterThanOrEqual(cobaltVersion, NPM_STRUCTURE_MIN_VERSION)
}