add(taskwarrior): integrate uda for git integration

This implementation adds the necessary fields for the tasks of
taskwarrior to be synchronized with git. It provides the necessary
conversion of the taskwarrior times and the standard time.Time go
format. WIP for #3.

internal/taskwarrior/task.go

@@ -3,7 +3,11 @@ package taskwarrior
 import (
 	"bytes"
 	"encoding/json"
+	"fmt"
+	"os"
 	"os/exec"
+	"strings"
+	"time"
 )
 
 /// A task with an Id of 0 is either `completed` or `deleted` which is also
@@ -11,6 +15,8 @@ import (
 
 type Task struct {
 	Id          uint         `json:"id,omitempty"`
+	Git_id      float32      `json:"git_id,omitempty"`   // uda
+	Git_type    string       `json:"git_type,omitempty"` // uda
 	Project     string       `json:"project,omitempty"`
 	Tags        []string     `json:"tags,omitempty"`
 	Description string       `json:"description,omitempty"`
@@ -29,14 +35,55 @@ type Annotation struct {
 	Entry       string `json:"entry,omitempty"`
 }
 
-func NewTask(description string, project string, tags ...string) Task {
+func NewTask(description string, project string, git_id uint, git_type Type, tags ...string) Task {
+	// TODO: update task struct to include the new user defined value, which shall
+	// also be provided as an argument
 	return Task{
 		Project:     project,
-		Tags:        tags,
 		Description: description,
+		Git_id:      float32(git_id),
+		Git_type:    string(git_type),
+		Tags:        tags,
 	}
 }
 
+func TaskTimeToGoTime(t string) time.Time {
+	// TODO: apply required changes to the string for correct parsing
+	splits := strings.Split(t, "T")
+	if len(splits) != 2 {
+		fmt.Fprintf(os.Stderr, "Expected exactly 2 splits")
+		os.Exit(-1)
+	}
+	date := splits[0]
+	first := date[0:4]
+	second := date[4:6]
+	third := date[6:]
+	date = strings.Join([]string{first, second, third}, "-")
+	timestamp := splits[1]
+	first = timestamp[0:2]
+	second = timestamp[2:4]
+	third = timestamp[4 : len(timestamp)-1]
+	timestamp = strings.Join([]string{first, second, third}, ":")
+	value := fmt.Sprintf("%sT%s+02:00", date, timestamp)
+	result, err := time.Parse(time.RFC3339, value)
+	if err != nil {
+		fmt.Fprint(os.Stderr, err)
+		os.Exit(-1)
+	}
+	return result
+}
+
+func GoTimeToTaskTime(t time.Time) string {
+	result := t.Format(time.RFC3339)
+	// TODO: apply changes to the result
+	// go: 2023-10-10T19:57:22+02:00
+	// task: 20231010T195722Z
+	result = strings.Replace(result, "-", "", 2)
+	result = strings.Replace(result, ":", "", 2)
+	result = strings.ReplaceAll(result, "+02:00", "Z")
+	return result
+}
+
 func GetTasks(filter Filter) ([]Task, error) {
 	filter.filter = append(filter.filter, "export")
 	cmd := exec.Command("task", filter.filter...)