E2E List cmd and added API calls (#3)

* Completed List cmd and added API calls

* Minor comments and add delete code to pass linting

* Typo in descriptions

* Minor comments

* Validations

* Validations-1

* improved branch flag validation

* removed build

* Minor comments and Readme

cmd/utils.go

@@ -0,0 +1,69 @@
+package cmd
+
+import (
+	"fmt"
+	"net/url"
+	"strconv"
+	"strings"
+
+	gh "github.com/cli/go-gh"
+	ghRepo "github.com/cli/go-gh/pkg/repository"
+)
+
+const MB_IN_BYTES = 1024 * 1024
+const GB_IN_BYTES = 1024 * 1024 * 1024
+
+var SORT_INPUT_TO_QUERY_MAP = map[string]string{
+	"created-at": "created_at",
+	"last-used": "last_accessed_at",
+	"size": "size_in_bytes",
+}
+
+func generateQueryParams(branch string, limit int, key string, order string, sort string) url.Values {
+	query := url.Values{}
+	if branch != "" {
+		if strings.HasPrefix(branch, "refs/"){
+			query.Add("ref", branch)
+		} else {
+			query.Add("ref", fmt.Sprintf("refs/heads/%s", branch))
+		}
+	}
+	if limit != 30 {
+		query.Add("per_page", strconv.Itoa(limit))
+	}
+	if key != "" {
+		query.Add("key", key)
+	}
+	if order != "" {
+		query.Add("direction", order)
+	}
+	if sort != "" {
+		query.Add("sort", SORT_INPUT_TO_QUERY_MAP[sort])
+	}
+
+	return query
+}
+
+func getRepo(r string) (ghRepo.Repository, error) {
+	if r != "" {
+		return ghRepo.Parse(r)
+	}
+
+	return gh.CurrentRepository()
+}
+
+func formatCacheSize(size_in_bytes float64) string {
+	if size_in_bytes < 1024 {
+		return fmt.Sprintf("%.2f B", size_in_bytes)
+	}
+
+	if size_in_bytes < MB_IN_BYTES {
+		return fmt.Sprintf("%.2f KB", size_in_bytes/1024)
+	}
+
+	if size_in_bytes < GB_IN_BYTES {
+		return fmt.Sprintf("%.2f MB", size_in_bytes/MB_IN_BYTES)
+	}
+
+	return fmt.Sprintf("%.2f GB", size_in_bytes/GB_IN_BYTES)
+}