pipeline {
    agent any
    environment {
        GIT_CREDENTIALS = 'jenkins-gitea-karel-token' // the ID of your Jenkins Gitea credentials
    }
    stages {
        stage('Checkout') {
            steps {
                // Clone repo
                git branch: 'main', credentialsId: env.GIT_CREDENTIALS, url: 'https://git.karel.one/karel/test.git'
            }
        }
        stage('Modify File') {
            steps {
                script {
                    // Append a line to test.txt (create if it doesn't exist)
                    def file = 'test.txt'
                    if (!fileExists(file)) {
                        writeFile file: file, text: 'This is the first line\n'
                    } else {
                        writeFile file: file, text: readFile(file) + "Updated by Jenkins at ${new Date()}\n"
                    }
                }
            }
        }
        stage('Commit & Push') {
            steps {
                withCredentials([usernamePassword(
                    credentialsId: env.GIT_CREDENTIALS, 
                    usernameVariable: 'GIT_USER', 
                    passwordVariable: 'GIT_PASS'
                )]) {
                    sh '''
                        git config user.name "jenkins"
                        git config user.email "jenkins@example.com"
                        git add test.txt
                        git commit -m "Update test.txt from Jenkins" || echo "No changes to commit"
                        git push https://$GIT_USER:$GIT_PASS@git.karel.one/karel/test.git main
                    '''
                }
            }
        }
    }
}