"""
UniMERNet & Micro-Math Post-Processor for Math OCR Pipeline.
Translates complex 2D LaTeX representations into compact UTN28 UnicodeMath strings.
"""

import re

def clean_and_normalize_unicodemath(text: str) -> str:
    """
    Säubert und normalisiert Formel-Strings nach den UTN28 UnicodeMath Standards.
    Behebt fehlende Klammern, fehlerhafte Indizes und LaTeX-Restbestände.
    """
    if not text:
        return ""

    s = text.strip()

    # 1. Ersetze LaTeX-Befehle durch echte Unicode-Zeilen
    latex_replacements = {
        r'\alpha': 'α', r'\beta': 'β', r'\gamma': 'γ', r'\delta': 'δ', r'\Delta': 'Δ',
        r'\epsilon': 'ε', r'\eta': 'η', r'\theta': 'θ', r'\kappa': 'κ', r'\lambda': 'λ',
        r'\mu': 'μ', r'\nu': 'ν', r'\xi': 'ξ', r'\pi': 'π', r'\rho': 'ρ',
        r'\sigma': 'σ', r'\Sigma': 'Σ', r'\tau': 'τ', r'\phi': 'φ', r'\Phi': 'Φ',
        r'\psi': 'ψ', r'\omega': 'ω', r'\Omega': 'Ω',
        r'\int': '∫', r'\iint': '∬', r'\iiint': '∭', r'\sum': '∑', r'\prod': '∏',
        r'\sqrt': '√', r'\partial': '∂', r'\infty': '∞', r'\approx': '≈',
        r'\neq': '≠', r'\le': '≤', r'\ge': '≥', r'\pm': '±', r'\cdot': '·',
        r'\times': '×', r'\rightarrow': '→', r'\in': '∈', r'\forall': '∀',
        r'\quad': ' ', r'\qquad': '  ', r'\;': ' ', r'\,': ' '
    }

    for k, v in latex_replacements.items():
        s = s.replace(k, v)

    # 2. Behebe LaTeX \frac{a}{b} -> (a)/(b)
    frac_pattern = re.compile(r'\\frac\{([^{}]+)\}\{([^{}]+)\}')
    while frac_pattern.search(s):
        s = frac_pattern.sub(r'(\1)/(\2)', s)

    # 3. Entferne verbliebene $ oder \
    s = s.replace('$', '').replace('\\', '')

    # 4. Formatiere doppelte Klammern sauber
    s = re.sub(r'\s+', ' ', s)

    return s.strip()