feat: prerequisite checking (osx)

cmd/prerequisites.go

@@ -0,0 +1,79 @@
+package cmd
+
+import (
+	"fmt"
+	"runtime"
+)
+
+// binaryPrerequisite defines a binaryPrerequisite
+type binaryPrerequisite struct {
+	Name string
+	Help string
+	Path string
+}
+
+func newBinaryPrerequisite(name, help string) *binaryPrerequisite {
+	return &binaryPrerequisite{Name: name, Help: help}
+}
+
+// binaryPrerequisites is a list of binaryPrerequisites
+type binaryPrerequisites []*binaryPrerequisite
+
+// Add given prereq object to list
+func (p *binaryPrerequisites) Add(prereq *binaryPrerequisite) {
+	*p = append(*p, prereq)
+}
+
+func (p *binaryPrerequisites) check() (success *binaryPrerequisites, failed *binaryPrerequisites) {
+	success = &binaryPrerequisites{}
+	failed = &binaryPrerequisites{}
+	programHelper := NewProgramHelper()
+	for _, prereq := range *p {
+		bin := programHelper.FindProgram(prereq.Name)
+		if bin == nil {
+			failed.Add(prereq)
+		} else {
+			path, err := bin.GetFullPathToBinary()
+			if err != nil {
+				failed.Add(prereq)
+			} else {
+				prereq.Path = path
+				success.Add(prereq)
+			}
+		}
+	}
+
+	return success, failed
+}
+
+var platformbinaryPrerequisites = make(map[string]*binaryPrerequisites)
+
+func init() {
+	platformbinaryPrerequisites["darwin"] = &binaryPrerequisites{}
+	newDarwinbinaryPrerequisite("clang", "Please install with `xcode-select --install` and try again")
+}
+
+func newDarwinbinaryPrerequisite(name, help string) {
+	prereq := newBinaryPrerequisite(name, help)
+	platformbinaryPrerequisites["darwin"].Add(prereq)
+}
+
+func CheckBinaryPrerequisites() (*binaryPrerequisites, *binaryPrerequisites, error) {
+	platformPreReqs := platformbinaryPrerequisites[runtime.GOOS]
+	if platformPreReqs == nil {
+		return nil, nil, fmt.Errorf("Platform '%s' is not supported at this time", runtime.GOOS)
+	}
+	success, failed := platformPreReqs.check()
+	return success, failed, nil
+}
+
+func CheckNonBinaryPrerequisites() error {
+
+	var err error
+
+	// Check non-binaries
+	if runtime.GOOS == "linux" {
+
+	}
+	return err
+}