import type { Release } from '@dify/contracts/enterprise/types.gen'

export type ReleaseDeploymentAction = 'deploy' | 'deployExistingRelease' | 'promote' | 'rollback'

function releaseCreatedAt(release: Release) {
  const time = Date.parse(release.createdAt)
  return Number.isFinite(time) ? time : undefined
}

function releaseById(releaseRows: Release[], releaseId?: string) {
  return releaseRows.find((release) => release.id === releaseId)
}

function releaseOrderIndex(releaseRows: Release[], releaseId?: string) {
  return releaseRows.findIndex((release) => release.id === releaseId)
}

function compareReleaseOrder(
  targetRelease: Release | undefined,
  currentRelease: Release,
  releaseRows: Release[],
) {
  if (!targetRelease) return undefined
  if (targetRelease.id === currentRelease.id) return 0

  const normalizedTargetRelease = releaseById(releaseRows, targetRelease.id) ?? targetRelease
  const normalizedCurrentRelease = releaseById(releaseRows, currentRelease.id) ?? currentRelease
  const targetCreatedAt = releaseCreatedAt(normalizedTargetRelease)
  const currentCreatedAt = releaseCreatedAt(normalizedCurrentRelease)

  if (
    targetCreatedAt !== undefined &&
    currentCreatedAt !== undefined &&
    targetCreatedAt !== currentCreatedAt
  )
    return targetCreatedAt > currentCreatedAt ? 1 : -1

  const targetIndex = releaseOrderIndex(releaseRows, targetRelease.id)
  const currentIndex = releaseOrderIndex(releaseRows, currentRelease.id)
  if (targetIndex >= 0 && currentIndex >= 0 && targetIndex !== currentIndex)
    return targetIndex < currentIndex ? 1 : -1

  return undefined
}

export function releaseDeploymentAction({
  targetRelease,
  currentRelease,
  releaseRows,
  isExistingRelease,
}: {
  targetRelease?: Release
  currentRelease?: Release
  releaseRows: Release[]
  isExistingRelease?: boolean
}): ReleaseDeploymentAction {
  if (!currentRelease) return isExistingRelease ? 'deployExistingRelease' : 'deploy'

  const order = compareReleaseOrder(targetRelease, currentRelease, releaseRows)
  if (order === -1) return 'rollback'
  if (order === 1) return 'promote'

  return targetRelease && targetRelease.id !== currentRelease.id
    ? 'promote'
    : isExistingRelease
      ? 'deployExistingRelease'
      : 'deploy'
}