''' Utility functions '''
import copy
import json
import re
from io import BytesIO
from zipfile import ZipFile

# Name for JSON inside Exteor files archive
EXTEOR_INNER_FILENAME = 'document.json'

# Old style reference pattern
_REF_OLD_PATTERN = re.compile(r'@{([^0-9\-][^\}\|\{]*?)\|([^\}\|\{]*?)\|([^\}\|\{]*?)}')


def read_zipped_json(data, json_filename: str) -> dict:
    ''' Read JSON from zipped data '''
    with ZipFile(data, 'r') as archive:
        json_data = archive.read(json_filename)
    result: dict = json.loads(json_data)
    return result


def write_zipped_json(json_data: dict, json_filename: str) -> bytes:
    ''' Write json JSON to bytes buffer '''
    content = BytesIO()
    data = json.dumps(json_data, indent=4, ensure_ascii=False)
    with ZipFile(content, 'w') as archive:
        archive.writestr(json_filename, data=data)
    return content.getvalue()


def apply_pattern(text: str, mapping: dict[str, str], pattern: re.Pattern[str]) -> str:
    ''' Apply mapping to matching in regular expression pattern subgroup 1 '''
    if text == '' or pattern == '':
        return text
    pos_input: int = 0
    output: str = ''
    for segment in re.finditer(pattern, text):
        entity = segment.group(1)
        if entity in mapping:
            output += text[pos_input: segment.start(1)]
            output += mapping[entity]
            output += text[segment.end(1): segment.end(0)]
            pos_input = segment.end(0)
    output += text[pos_input: len(text)]
    return output


def fix_old_references(text: str) -> str:
    ''' Fix reference format: @{X1|nomn|sing} -> {X1|nomn,sing} '''
    if text == '':
        return text
    pos_input: int = 0
    output: str = ''
    for segment in re.finditer(_REF_OLD_PATTERN, text):
        output += text[pos_input: segment.start(0)]
        output += f'@{{{segment.group(1)}|{segment.group(2)},{segment.group(3)}}}'
        pos_input = segment.end(0)
    output += text[pos_input: len(text)]
    return output


def filename_for_schema(alias: str) -> str:
    ''' Generate filename for schema from alias. '''
    if alias == '' or not alias.isascii():
        # Note: non-ascii symbols in Content-Disposition
        # are not supported by some browsers
        return 'Schema.trs'
    return alias + '.trs'


def clone_rsform(rsform):
    rsform_copy = copy.deepcopy(rsform)
    rsform_copy.item.pk = None
    # rsform_copy.item.owner = "System"
    rsform_copy.item.comment = "Temporary cloned rsform"
    rsform_copy.item.save()

    rsform_copy.insert_copy(items=rsform.item.constituenta_set.all(), position=1)
    rsform_copy.item.save()
    return rsform_copy