import os
import subprocess
import sys
import time

def run_command(command):
    process = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    output = []

    # Iterate over the output lines
    for line in iter(process.stdout.readline, b''):
        decoded_line = line.decode()
        output.append(decoded_line)
        sys.stdout.write(decoded_line)

    process.stdout.close()
    return_code = process.wait()
    if return_code:
        # Join the output list to create a single string
        full_output = ''.join(output)
        raise subprocess.CalledProcessError(return_code, command, output=full_output.encode())


def git_pull(directory):
    os.chdir(directory)
    print(f"Checking if the git repository in {directory} is up to date.")
    local = subprocess.check_output("git rev-parse @", shell=True).decode().strip()
    remote = subprocess.check_output("git rev-parse @{u}", shell=True).decode().strip()
    
    if local != remote:
        print("Repository is not up to date. Performing git pull.")
        run_command("git pull")
    else:
        print("Repository is already up to date.")
        
def get_image_digests(directory):
    compose_project = os.path.basename(directory)
    try:
        images_output = subprocess.check_output(
            f'docker images --format "{{{{.Repository}}}}:{{{{.Tag}}}}@{{{{.Digest}}}}" | grep {compose_project}', 
            shell=True
        ).decode().strip()
        return dict(line.split('@') for line in images_output.splitlines() if line)
    except subprocess.CalledProcessError as e:
        if e.returncode == 1:  # grep no match found
            return {}
        else:
            raise  # Other errors are still raised

def is_any_service_up(directory):
    os.chdir(directory)
    process = subprocess.Popen("docker-compose ps -q", shell=True, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    output, _ = process.communicate()
    service_ids = output.decode().strip().splitlines()

    # Check if there are any service containers up
    if not service_ids:
        return False  # No services are up
    return True  # At least one service is up


def update_docker(directory):
    print(f"Checking for updates to Docker images in {directory}.")
    os.chdir(directory)
    before_digests = get_image_digests(directory)
    print("Pulling docker images.")
    
    need_to_build=False
    
    try:
        run_command("docker-compose pull")
    except subprocess.CalledProcessError as e:
        if "pull access denied" in e.output.decode() or "must be built from source" in e.output.decode():
            print("Need to build the image from source.")
            need_to_build=True
        else:
            print("Failed to pull images with unexpected error.")
            raise

    
    after_digests = get_image_digests(directory)
    if before_digests != after_digests:
        print("Changes detected in image digests. Rebuilding containers.")
        need_to_build=True
        
    if need_to_build:
        run_command("docker-compose build")
        start_docker(directory)
    else:
        print("Docker images are up to date. No rebuild necessary.")

def update_nextcloud(directory):
    print("Updating Nextcloud apps.")
    max_attempts = 3
    for attempt in range(max_attempts):
        try:
            run_command("docker-compose exec -T -u www-data application /var/www/html/occ app:update --all")
            break  # If the command succeeds, exit the loop
        except subprocess.CalledProcessError as e:
            if attempt < max_attempts - 1:  # Check if it's not the last attempt
                print(f"Attempt {attempt + 1} failed, retrying in 60 seconds...")
                time.sleep(60)  # Wait for 60 seconds before retrying
            else:
                print("All attempts to update Nextcloud apps have failed.")
                raise  # Re-raise the last exception after all attempts fail


def start_docker(directory):
    if is_any_service_up(directory):
        print(f"Restarting containers in {directory}.")
        run_command("docker-compose up -d --force-recreate")
    else:
        print(f"Skipped starting. No service is up in {directory}.")

if __name__ == "__main__":
    if len(sys.argv) < 2:
        print("Please provide the path to the parent directory as a parameter.")
        sys.exit(1)

    parent_directory = sys.argv[1]
    for dir_entry in os.scandir(parent_directory):
        if dir_entry.is_dir():
            dir_path = dir_entry.path
            print(f"Checking for updates in: {dir_path}")
            
            if os.path.isdir(os.path.join(dir_path, ".git")):
                git_pull(dir_path)
            
            update_docker(dir_path)
            
            if os.path.basename(dir_path) == "nextcloud":
                update_nextcloud(dir_path)