package system
 
 import (
 	"fmt"
 	"runtime"
 	"strings"
 
 	specs "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
 // IsPlatformEmpty determines if an OCI image-spec platform structure is not populated.
 // TODO This is a temporary function - can be replaced by parsing from
 // https://github.com/containerd/containerd/pull/1403/files at a later date.
 // @jhowardmsft
 func IsPlatformEmpty(platform specs.Platform) bool {
 	if platform.Architecture == "" &&
 		platform.OS == "" &&
 		len(platform.OSFeatures) == 0 &&
 		platform.OSVersion == "" &&
 		platform.Variant == "" {
 		return true
 	}
 	return false
 }
 
 // ValidatePlatform determines if a platform structure is valid.
 // TODO This is a temporary function - can be replaced by parsing from
 // https://github.com/containerd/containerd/pull/1403/files at a later date.
 // @jhowardmsft
 func ValidatePlatform(platform *specs.Platform) error {
 	platform.Architecture = strings.ToLower(platform.Architecture)
 	platform.OS = strings.ToLower(platform.OS)
 	if platform.Architecture != "" && platform.Architecture != runtime.GOARCH {
 		return fmt.Errorf("invalid platform architecture %q", platform.Architecture)
 	}
 	if platform.OS != "" {
 		if !(platform.OS == runtime.GOOS || (LCOWSupported() && platform.OS == "linux")) {
 			return fmt.Errorf("invalid platform os %q", platform.OS)
 		}
 	}
 	if len(platform.OSFeatures) != 0 {
 		return fmt.Errorf("invalid platform osfeatures %q", platform.OSFeatures)
 	}
 	if platform.OSVersion != "" {
 		return fmt.Errorf("invalid platform osversion %q", platform.OSVersion)
 	}
 	if platform.Variant != "" {
 		return fmt.Errorf("invalid platform variant %q", platform.Variant)
 	}
 	return nil
 }
 
 // ParsePlatform parses a platform string in the format os[/arch[/variant]
 // into an OCI image-spec platform structure.
 // TODO This is a temporary function - can be replaced by parsing from
 // https://github.com/containerd/containerd/pull/1403/files at a later date.
 // @jhowardmsft
 func ParsePlatform(in string) *specs.Platform {
 	p := &specs.Platform{}
 	elements := strings.SplitN(strings.ToLower(in), "/", 3)
 	if len(elements) == 3 {
 		p.Variant = elements[2]
 	}
 	if len(elements) >= 2 {
 		p.Architecture = elements[1]
 	}
 	if len(elements) >= 1 {
 		p.OS = elements[0]
 	}
 	return p
 }