BREAKING CHANGE: Setup refactor and code cleanup

This MR makes several major tweaks to the codebase. Primarily it adjusts
the setup steps for the application so that rather than providing just
the project ID in the `.gitlab.nvim` file, users can also provide a
vareity of other settings, such as auth_token, base_branch, and so
forth. This is to make the project more extensible in the future.

This MR also fixes a variety of issues with error handling in the code,
primarily in the request/response model between the Lua jobs and the
Golang server.

BREAKING CHANGE: Modifies `.gitlab.nvim` and setup steps

cmd/client.go

@@ -1,8 +1,10 @@
 package main
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
+	"net/http"
 	"os"
 	"strconv"
 
@@ -10,10 +12,12 @@ import (
 )
 
 type Client struct {
-	command   string
-	projectId string
-	mergeId   int
-	git       *gitlab.Client
+	command        string
+	projectId      string
+	mergeId        int
+	gitlabInstance string
+	authToken      string
+	git            *gitlab.Client
 }
 
 type Logger struct {
@@ -22,7 +26,9 @@ type Logger struct {
 
 func (l Logger) Printf(s string, args ...interface{}) {
 	logString := fmt.Sprintf(s+"\n", args...)
-	file, err := os.OpenFile("./logs", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+	logPath := os.Args[len(os.Args)-1]
+
+	file, err := os.OpenFile(logPath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
 	if err != nil {
 		panic(err)
 	}
@@ -31,21 +37,36 @@ func (l Logger) Printf(s string, args ...interface{}) {
 }
 
 /* This will initialize the client with the token and check for the basic project ID and command arguments */
-func (c *Client) Init(branchName string) error {
+func (c *Client) init(branchName string) error {
 
-	if len(os.Args) < 2 {
-		return errors.New("Must provide project ID!")
+	if len(os.Args) < 5 {
+		return errors.New("Must provide project ID, gitlab instance, port, and auth token!")
 	}
 
 	projectId := os.Args[1]
-	c.projectId = projectId
+	gitlabInstance := os.Args[2]
+	authToken := os.Args[4]
 
 	if projectId == "" {
 		return errors.New("Project ID cannot be empty")
 	}
 
+	if gitlabInstance == "" {
+		return errors.New("GitLab instance URL cannot be empty")
+	}
+
+	if authToken == "" {
+		return errors.New("Auth token cannot be empty")
+	}
+
+	c.gitlabInstance = gitlabInstance
+	c.projectId = projectId
+	c.authToken = authToken
+
 	var l Logger
-	git, err := gitlab.NewClient(os.Getenv("GITLAB_TOKEN"), gitlab.WithCustomLogger(l))
+	var apiCustUrl = fmt.Sprintf(c.gitlabInstance + "/api/v4")
+
+	git, err := gitlab.NewClient(authToken, gitlab.WithBaseURL(apiCustUrl), gitlab.WithCustomLogger(l))
 
 	if err != nil {
 		return fmt.Errorf("Failed to create client: %v", err)
@@ -77,3 +98,12 @@ func (c *Client) Init(branchName string) error {
 
 	return nil
 }
+
+func (c *Client) handleError(w http.ResponseWriter, err error, message string, status int) {
+	w.WriteHeader(status)
+	response := ErrorResponse{
+		Message: message,
+		Details: err.Error(),
+	}
+	json.NewEncoder(w).Encode(response)
+}