package roles

const (
	Owner  = "owner"
	Admin  = "admin"
	Editor = "editor"
	Member = "member"
	Viewer = "viewer"
)

var rank = map[string]int{
	Viewer: 0,
	Member: 1,
	Editor: 2,
	Admin:  3,
	Owner:  4,
}

func Rank(r string) int { return rank[r] }

func ValidMemberRole(r string) bool {
	switch r {
	case Admin, Editor, Member, Viewer:
		return true
	}
	return false
}

func CanUpload(r string) bool {
	switch r {
	case Owner, Admin, Editor, Member:
		return true
	}
	return false
}

func CanComment(r string) bool {
	return CanUpload(r)
}

func CanDeleteAnyPhoto(r string) bool {
	return r == Owner || r == Admin
}

func CanDeleteOwnPhoto(r string) bool {
	return CanUpload(r)
}

func CanEditAlbum(r string) bool {
	return r == Owner || r == Admin
}

func CanManageShares(r string) bool {
	return r == Owner || r == Admin
}

func CanInvite(actorRole, targetRole string) bool {
	if actorRole == Editor {
		return targetRole == Member || targetRole == Viewer
	}
	if actorRole != Owner && actorRole != Admin {
		return false
	}
	if targetRole == Owner {
		return false
	}
	return Rank(targetRole) <= Rank(actorRole)
}

func CanChangeRole(actorRole, targetCurrent, newRole string) bool {
	if targetCurrent == Owner || newRole == Owner {
		return false
	}
	if !ValidMemberRole(newRole) {
		return false
	}
	switch actorRole {
	case Owner:
		return true
	case Admin:
		if targetCurrent == Admin {
			return false
		}
		return newRole == Editor || newRole == Member || newRole == Viewer
	default:
		return false
	}
}

func CanRemoveMember(actorRole, targetRole string) bool {
	if actorRole != Owner && actorRole != Admin {
		return false
	}
	if targetRole == Owner || targetRole == Admin {
		return false
	}
	return true
}