"""Fill the checked-in layout; preserve every other DOCX part byte for byte."""
import io
import json
import re
import zipfile
from pathlib import Path
from xml.dom import minidom

W = 'http://schemas.openxmlformats.org/wordprocessingml/2006/main'
W14 = 'http://schemas.microsoft.com/office/word/2010/wordml'
TITLE_TOKEN, DATE_TOKEN, BODY_TOKEN = TOKENS = (
    '[[AUSHANG_TITLE]]', '[[AUSHANG_DATE]]', '[[AUSHANG_BODY]]',
)
FONT_FACES = json.loads((Path(__file__).with_name('renderer') / 'fonts.json').read_text())


class TemplateError(ValueError):
    pass


def _placeholders(document):
    found = {}
    for token in TOKENS:
        matches = [p for p in document.getElementsByTagNameNS(W, 'p')
                   if ''.join(t.firstChild.data if t.firstChild else ''
                              for t in p.getElementsByTagNameNS(W, 't')) == token]
        if len(matches) != 1:
            raise TemplateError(f'Vorlage muss genau einen Absatz {token} enthalten.')
        found[token] = matches[0]
    return found


def validate_template(template: Path) -> None:
    with zipfile.ZipFile(template) as archive:
        _placeholders(minidom.parseString(archive.read('word/document.xml')))


def _set_text(paragraph, text):
    if any(ord(char) < 32 and char not in '\t\n\r' for char in text):
        raise TemplateError('Text enthält ungültige Steuerzeichen.')
    nodes = paragraph.getElementsByTagNameNS(W, 't')
    for node in nodes:
        while node.firstChild:
            node.removeChild(node.firstChild)
    document, anchor = paragraph.ownerDocument, nodes[0]
    text = text.replace('\r\n', '\n').replace('\r', '\n')
    for part in re.split(r'(\n|\t)', text):
        if part in ('\n', '\t'):
            node = document.createElementNS(W, 'w:br' if part == '\n' else 'w:tab')
        else:
            node = document.createElementNS(W, 'w:t')
            node.setAttribute('xml:space', 'preserve')
            node.appendChild(document.createTextNode(part))
        anchor.parentNode.insertBefore(node, anchor)
    anchor.parentNode.removeChild(anchor)
    # Preserve verse/signature lines without stretching them to the full width.
    if '\n' in text:
        for alignment in paragraph.getElementsByTagNameNS(W, 'jc'):
            alignment.setAttributeNS(W, 'w:val', 'left')


def fill_template(template: Path, output: Path, title: str, date_label: str, paragraphs: list[str]) -> None:
    paragraphs = [p.strip() for p in paragraphs if p.strip()]
    if not title.strip() or not date_label.strip() or not paragraphs:
        raise TemplateError('Titel, Datum und Inhalt dürfen nicht leer sein.')
    with zipfile.ZipFile(template) as source:
        document = minidom.parseString(source.read('word/document.xml'))
        placeholders = _placeholders(document)
        _set_text(placeholders[TITLE_TOKEN], title.strip())
        _set_text(placeholders[DATE_TOKEN], date_label.strip())
        body = placeholders[BODY_TOKEN]
        used = {p.getAttributeNS(W14, 'paraId') for p in document.getElementsByTagNameNS(W, 'p')}
        index = 1
        for text in paragraphs:
            paragraph = body.cloneNode(deep=True)
            while f'{index:08X}' in used:
                index += 1
            paragraph.setAttributeNS(W14, 'w14:paraId', f'{index:08X}')
            used.add(f'{index:08X}')
            _set_text(paragraph, text)
            body.parentNode.insertBefore(paragraph, body)
        body.parentNode.removeChild(body)
        output.parent.mkdir(parents=True, exist_ok=True)
        with zipfile.ZipFile(output, 'w') as target:
            for info in source.infolist():
                data = document.toxml(encoding='utf-8') if info.filename == 'word/document.xml' else source.read(info)
                target.writestr(info, data)


def renderer_document(document: Path) -> bytes:
    # BetterOffice 0.1.0 emits unquoted CSS font names: alias the apostrophe in
    # Suisse Int'l only in this disposable render copy, never in the Word file.
    aliases = {face['family']: face['alias'] for face in FONT_FACES}
    output = io.BytesIO()
    with zipfile.ZipFile(document) as source, zipfile.ZipFile(output, 'w') as target:
        for info in source.infolist():
            data = source.read(info)
            if info.filename.startswith('word/') and info.filename.endswith('.xml'):
                xml = minidom.parseString(data)
                changed = False
                for tag in ('rFonts', 'font'):
                    for node in xml.getElementsByTagNameNS(W, tag):
                        for attr in node.attributes.values():
                            if attr.value in aliases:
                                attr.value = aliases[attr.value]
                                changed = True
                if changed:
                    data = xml.toxml(encoding='utf-8')
            target.writestr(info, data)
    return output.getvalue()