Implement debug command

Author: juho05

cmd/debug.go

@@ -0,0 +1,97 @@
+package cmd
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/Bananenpro/cli"
+	"github.com/adrg/xdg"
+	"github.com/code-game-project/go-utils/exec"
+	"github.com/code-game-project/go-utils/external"
+	"github.com/code-game-project/go-utils/semver"
+	"github.com/code-game-project/go-utils/server"
+	"github.com/spf13/cobra"
+)
+
+var cgDebugPath = filepath.Join(xdg.DataHome, "codegame", "bin", "cg-debug")
+
+// debugCmd represents the debug command
+var debugCmd = &cobra.Command{
+	Use:   "debug",
+	Short: "View debug logs of a game server.",
+	Args:  cobra.RangeArgs(0, 1),
+	Run: func(cmd *cobra.Command, args []string) {
+		var url string
+		var err error
+		if len(args) == 0 {
+			url, err = cli.Input("Game server URL:")
+			if err != nil {
+				return
+			}
+		} else {
+			url = args[0]
+		}
+
+		api, err := server.NewAPI(url)
+		if err != nil {
+			abort(fmt.Errorf("%s is not a CodeGame game server.", external.TrimURL(url)))
+		}
+
+		info, err := api.FetchGameInfo()
+		abortf("Failed to fetch game info: %s", err)
+
+		version, err := findDebugVersion(info.CGVersion)
+		abortf("Failed to determine the correct cg-debug version to use: %s", err)
+
+		exeName, err := installDebug(version)
+		_, err = exec.Execute(false, filepath.Join(cgDebugPath, exeName), url)
+		if err != nil {
+			os.Exit(1)
+		}
+	},
+}
+
+func findDebugVersion(cgVersion string) (string, error) {
+	if cgVersion == "latest" {
+		version, err := external.LatestGithubTag("code-game-project", "cg-debug")
+		return strings.TrimPrefix(version, "v"), err
+	}
+
+	body, err := external.LoadVersionsJSON("code-game-project", "cg-debug")
+	if err != nil {
+		cli.Warn("Couldn't fetch versions.json. Using latest cg-debug version.")
+		version, err := external.LatestGithubTag("code-game-project", "cg-debug")
+		return strings.TrimPrefix(version, "v"), err
+	}
+	defer body.Close()
+
+	var versions map[string]string
+
+	err = json.NewDecoder(body).Decode(&versions)
+	if err != nil {
+		cli.Warn("Invalid versions.json. Using latest cg-debug version.")
+		version, err := external.LatestGithubTag("code-game-project", "cg-debug")
+		return strings.TrimPrefix(version, "v"), err
+	}
+
+	v := semver.CompatibleVersion(versions, cgVersion)
+
+	if v == "latest" {
+		version, err := external.LatestGithubTag("code-game-project", "cg-debug")
+		return strings.TrimPrefix(version, "v"), err
+	}
+
+	v, err = external.GithubTagFromVersion("code-game-project", "cg-debug", v)
+	return strings.TrimPrefix(v, "v"), err
+}
+
+func installDebug(version string) (string, error) {
+	return external.InstallProgram("cg-debug", "cg-debug", "https://github.com/code-game-project/cg-debug", version, cgDebugPath)
+}
+
+func init() {
+	rootCmd.AddCommand(debugCmd)
+}