import json
import xml.etree.ElementTree as ET
from xml.dom import minidom

def create_element_with_id(tag, name, uid, parent_uid=None):
    """Create an XML element with a specific id and name."""
    if parent_uid:

        uid = f"{parent_uid}_{uid}"

    elem = ET.Element(tag)

    elem.set('xml:id', f"SPEASY_CDAWEB_{uid}")

    elem.set('name', name)
    return elem

def parse_dimensions(shape):
    dim1 = dim2 = None
    if shape.isdigit():
        dim1 = int(shape)
    elif shape.startswith("(") and shape.endswith(",)"):
        dim1 = int(shape[1:-2])  
    elif shape.startswith("(") and shape.endswith(")"):
        numbers = shape[1:-1].split(",")
        dim1 = int(numbers[0].strip())
        dim2 = int(numbers[1].strip())

    return dim1, dim2

def getParamInfo(parameter, paramInfo):

    """Get dims and type info from the json to the XML element."""

    shape = paramInfo.get('spz_shape', '')
    speasyUID = paramInfo.get('__spz_provider__','') + "/" + paramInfo.get('__spz_uid__','')

    dim1, dim2 = parse_dimensions(shape)  
    if not dim1 == None:
        parameter.set('dim1', str(dim1))
        if dim2 == None:
            parameter.set('dim2', "1")
        else:
            parameter.set('dim2', str(dim2))
    parameter.set('type', 'double')
    parameter.set('minSampling', '4')

    parameter.set('speasyUID', speasyUID)

def count_levels(data):
    """Recursively count the levels of nested dictionaries."""
    if isinstance(data, dict):
        return 1 + max((count_levels(v) for v in data.values()), default=0)
    return 0

def get_mission_levels(json_obj):
    """Create a dictionary with mission names as keys and nested levels as values."""
    levels_dict = {}
    for mission_key, mission_data in json_obj.items():
        if isinstance(mission_data, dict):
            levels_dict[mission_key] = count_levels(mission_data)
    return levels_dict

def add_instrument(observatory, observatory_data, mission_observatory_key):
    """Add the instrument, dataset and parameter to an observatory or a mission."""
    for instrument_key, instrument_data in observatory_data.items():
        if isinstance(instrument_data, dict) and '__spz_name__' in instrument_data:
            instrument = create_element_with_id('instrument', instrument_data.get('__spz_name__', ''), instrument_key, mission_observatory_key)
            observatory.append(instrument)

            for dataset_key, dataset_data in instrument_data.items():
                if isinstance(dataset_data, dict) and '__spz_name__' in dataset_data:

                    dataset = create_element_with_id('dataset', dataset_data.get('__spz_name__', ''), dataset_key, f"{mission_observatory_key}_{instrument_key}")

                    instrument.append(dataset)

                    for param_key, param_data in dataset_data.items():
                        if isinstance(param_data, dict) and param_data.get('__spz_type__') == 'ParameterIndex':

                            parameter = create_element_with_id('parameter', param_data.get('__spz_name__', ''), param_key, f"{mission_observatory_key}_{instrument_key}_{dataset_key}")
                            getParamInfo(parameter, param_data)

                            dataset.append(parameter)
    

def json_to_custom_xml(json_obj, levels):
    """Convert JSON object to custom XML format."""
    dataRoot = ET.Element('dataRoot')
    dataRoot.set('xml:id', "myRemoteData-treeRootNode")
    dataCenter = ET.Element('dataCenter')
    dataCenter.set('xml:id', "SPEASY_CDAWEB")
    dataCenter.set('name', "SPEASY_CDAWEB")
    dataRoot.append(dataCenter)

    for mission_key, mission_data in json_obj.items():
        if isinstance(mission_data, dict):
            mission = create_element_with_id('mission', mission_data.get('__spz_name__', ''), mission_key)
            dataCenter.append(mission)

    
            if(levels[mission_key] == 4):
                observatory_data = mission_data
                observatory = mission
                mission_observatory_key = mission_key
                add_instrument(observatory, observatory_data, mission_observatory_key)
            else:

                for observatory_key, data in mission_data.items():
                    if isinstance(data, dict):
                        observatory = create_element_with_id('observatory', data.get('__spz_name__', ''), observatory_key, mission_key)
                        observatory_data = data

                        mission_observatory_key = f"{mission_key}_{observatory_key}"

                        mission.append(observatory)

                        add_instrument(observatory, observatory_data, mission_observatory_key)       

    return ET.tostring(dataRoot, encoding='unicode')

def pretty_print_xml(xml_str):
    """Pretty print the XML string."""
    parsed_xml = minidom.parseString(xml_str)
    return parsed_xml.toprettyxml(indent="  ")

def convert_json_file_to_xml(json_file_path, xml_file_path):
    """Reads a JSON file and writes its content as pretty-printed XML to another file."""
    with open(json_file_path, 'r') as json_file:
        json_data = json.load(json_file)

    levels_dict = get_mission_levels(json_data)
    xml_data = json_to_custom_xml(json_data, levels_dict)
    pretty_xml = pretty_print_xml(xml_data)

    with open(xml_file_path, 'w') as xml_file:
        xml_file.write(pretty_xml)

convert_json_file_to_xml('data.json', 'base.xml')