import base64
from lxml import etree
import gzip
import shutil, os, io


def write_file_in_new_directory(directory, file_name, content):
    # Create the new directory if it doesn't exist
    os.makedirs(directory, exist_ok=True)
    
    # Define the file path
    file_path = os.path.join(directory, file_name)
    
    # Write content to the file
    with open(file_path, 'wb') as file:
        file.write(content)
    
    print(f"File '{file_name}' has been written in the directory '{directory}'")

def write_gunzip_bytestream_to_file(bytestream, output_directory, output_file):
    # Create the directory if it doesn't exist
    os.makedirs(output_directory, exist_ok=True)
    
    # Define the file path
    file_path = os.path.join(output_directory, output_file)
    
    # Decompress the GZIP bytestream
    with gzip.GzipFile(fileobj=io.BytesIO(bytestream), mode='rb') as gzip_file:
        decompressed_data = gzip_file.read()
    
    # Write the decompressed data to the file
    with open(file_path, 'wb') as file:
        file.write(decompressed_data)
    
    print(f"Decompressed data has been written to '{file_path}'")

# Parse the XML file
tree = etree.parse('incident.xml')
root = tree.getroot()

# Extract and save attachments
for attachment in root.findall(".//sys_attachment"):
    file_name_element = attachment.find('file_name')
    if file_name_element is None:
        continue
    file_name = file_name_element.text
    sys_id = attachment.find('sys_id').text

    previous_element =  None
    for sibling in attachment.itersiblings(preceding=True):
        if sibling.tag == 'incident':
            previous_element = sibling
            break

    incident = previous_element.find('number').text
    print(f"Processing attachment: {file_name}, sys_id: {sys_id} for incident: {incident}")

    # Find the corresponding attachment data chunks
    attachment_data_chunks = root.findall(f".//sys_attachment_doc[sys_attachment='{sys_id}']")
    combined_data = ""

    if not attachment_data_chunks:
        print(f"No data chunks found for sys_id: {sys_id}")
        continue

    # Save the attachment to a file
    # try:
    #     with open(f'./output/{file_name}.gz', 'wb') as file:
    #         for chunk in attachment_data_chunks:
    #             encoded_data = chunk.find('data').text

    #             # Decode the combined base64-encoded data
    #             try:
    #                 decoded_data = base64.b64decode(encoded_data)
    #                 file.write(decoded_data)
    #                 # write_file_in_new_directory(incident, file_name + ".gz", decoded_data)
    #             except Exception as e:
    #                 print(f"Error decoding data for sys_id: {sys_id}, Error: {e}")
    #                 continue

    try:
        # with open(f'./output/{file_name}.gz', 'wb') as file:
        decoded_data = b''
        for chunk in attachment_data_chunks:
            encoded_data = chunk.find('data').text

            # Decode the combined base64-encoded data
            try:
                decoded_data += base64.b64decode(encoded_data)
        
            except Exception as e:
                print(f"Error decoding data for sys_id: {sys_id}, Error: {e}")
                continue

        # write_file_in_new_directory(incident, file_name + ".gz", decoded_data)
        write_gunzip_bytestream_to_file(decoded_data, incident, file_name)

    except Exception as e:
        print(f"Error saving attachment: {file_name}, Error: {e}")

print("All attachments processed.")