feat: new Github helper

cmd/github.go

@@ -0,0 +1,101 @@
+package cmd
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"regexp"
+	"sort"
+
+	"github.com/Masterminds/semver"
+)
+
+// GitHubHelper is a utility class for interacting with GitHub
+type GitHubHelper struct {
+	validPrereleaseRegex *regexp.Regexp
+	validReleaseRegex    *regexp.Regexp
+}
+
+// NewGitHubHelper returns a new GitHub Helper
+func NewGitHubHelper() *GitHubHelper {
+	const SemVerRegex string = `v?([0-9]+)(\.[0-9]+)?(\.[0-9]+)?`
+	const SemPreVerRegex string = `v?([0-9]+)(\.[0-9]+)?(\.[0-9]+)?-([0-9A-Za-z\-]+(\.[0-9A-Za-z\-]+)*)`
+
+	return &GitHubHelper{
+		validPrereleaseRegex: regexp.MustCompile(SemPreVerRegex),
+		validReleaseRegex:    regexp.MustCompile(SemVerRegex),
+	}
+}
+
+// GetVersionTags gets the list of tags on the Wails repo
+// It retuns a list of sorted tags in descending order
+func (g *GitHubHelper) GetVersionTags() ([]*semver.Version, error) {
+
+	result := []*semver.Version{}
+
+	// Test data
+	v0_14_0, _ := semver.NewVersion("v0.12.4")
+	result = append(result, v0_14_0)
+	v0_13_0pre, _ := semver.NewVersion("v0.12.3-pre1")
+	result = append(result, v0_13_0pre)
+	v0_13_1pre, _ := semver.NewVersion("v0.12.3-pre2")
+	result = append(result, v0_13_1pre)
+
+	var err error
+
+	resp, err := http.Get("https://api.github.com/repos/wailsapp/wails/tags")
+	if err != nil {
+		return result, err
+	}
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return result, err
+	}
+
+	data := []map[string]interface{}{}
+	err = json.Unmarshal(body, &data)
+	if err != nil {
+		return result, err
+	}
+
+	// Convert tag data to Version structs
+	for _, tag := range data {
+		version := tag["name"].(string)
+		semver, err := semver.NewVersion(version)
+		if err != nil {
+			return result, err
+		}
+		result = append(result, semver)
+	}
+
+	// Reverse Sort
+	sort.Sort(sort.Reverse(semver.Collection(result)))
+
+	return result, err
+}
+
+func (g *GitHubHelper) isRelease(tag *semver.Version) bool {
+	return g.validReleaseRegex.MatchString(tag.String())
+}
+
+func (g *GitHubHelper) isPreRelease(tag *semver.Version) bool {
+	return g.validPrereleaseRegex.MatchString(tag.String())
+}
+
+// GetLatestStableRelease gets the latest stable release on GitHub
+func (g *GitHubHelper) GetLatestStableRelease() (result string, err error) {
+
+	tags, err := g.GetVersionTags()
+	if err != nil {
+		return "", err
+	}
+
+	for _, tag := range tags {
+		if g.isRelease(tag) {
+			return "v" + tag.String(), nil
+		}
+	}
+
+	return "", fmt.Errorf("no release tag found")
+}