import re
import pandas as pd
import recordlinkage
from rapidfuzz import fuzz
from google_sheet_handler import GoogleSheetHandler

# --- Konfiguration ---
CRM_SHEET_NAME      = "CRM_Accounts"
MATCHING_SHEET_NAME = "Matching_Accounts"
SCORE_THRESHOLD     = 0.8
WEIGHTS = {
    'domain': 0.5,
    'name':   0.4,
    'city':   0.1,
}

# --- Hilfsfunktionen ---
def normalize_company_name(name: str) -> str:
    """
    Vereinfacht Firmennamen:
    - Unicode-safe Kleinschreibung
    - Umlaute in ae/oe/ue, ß in ss
    - Entfernen von Rechtsformen/Stop-Wörtern
    """
    s = str(name).casefold()
    for src, dst in [('ä','ae'), ('ö','oe'), ('ü','ue'), ('ß','ss')]:
        s = s.replace(src, dst)
    s = re.sub(r'[^a-z0-9\s]', ' ', s)
    stops = ['gmbh','ag','kg','ug','ohg','holding','group','international']
    tokens = [t for t in s.split() if t and t not in stops]
    return ' '.join(tokens)


def normalize_domain(url: str) -> str:
    """Extrahiere Root-Domain, entferne Protokoll und www-Präfix"""
    s = str(url).casefold().strip()
    s = re.sub(r'^https?://', '', s)
    s = s.split('/')[0]
    if s.startswith('www.'):
        s = s[4:]
    return s


def main():
    # Google Sheets laden
    sheet_handler = GoogleSheetHandler()
    crm_df   = sheet_handler.get_sheet_as_dataframe(CRM_SHEET_NAME)
    match_df = sheet_handler.get_sheet_as_dataframe(MATCHING_SHEET_NAME)
    if crm_df is None or crm_df.empty or match_df is None or match_df.empty:
        print("Fehler: Leere Daten in einem der Tabs. Abbruch.")
        return

    # Normalisierung
    for df in (crm_df, match_df):
        df['norm_name']   = df['CRM Name'].fillna('').apply(normalize_company_name)
        df['norm_domain'] = df['CRM Website'].fillna('').apply(normalize_domain)
        df['city']        = df['CRM Ort'].fillna('').apply(lambda x: str(x).casefold().strip())

    # Blocking per Domain
    indexer = recordlinkage.Index()
    indexer.block('norm_domain')
    candidate_pairs = indexer.index(crm_df, match_df)

    # Vergleichsregeln definieren
    compare = recordlinkage.Compare()
    compare.exact('norm_domain', 'norm_domain', label='domain')
    compare.string('norm_name', 'norm_name', method='jarowinkler', label='name_sim')
    compare.exact('city', 'city', label='city')
    features = compare.compute(candidate_pairs, crm_df, match_df)

    # Gewichte und Score
    features['score'] = (
        WEIGHTS['domain'] * features['domain'] +
        WEIGHTS['name']   * features['name_sim'] +
        WEIGHTS['city']   * features['city']
    )

    # Bestes Match pro neuer Zeile
    matches = features.reset_index()
    best = matches.sort_values(['level_1','score'], ascending=[True, False]) \
                 .drop_duplicates('level_1')
    best = best[best['score'] >= SCORE_THRESHOLD] \
               .rename(columns={'level_0':'crm_idx','level_1':'match_idx'})

    # Merges
    crm_df   = crm_df.reset_index()
    match_df = match_df.reset_index()
    merged = (best
        .merge(crm_df,   left_on='crm_idx',   right_on='index')
        .merge(match_df, left_on='match_idx', right_on='index', suffixes=('_CRM','_NEW'))
    )

    # Ausgabe aufbauen
    output = match_df[['CRM Name','CRM Website','CRM Ort','CRM Land']].copy()
    output['Matched CRM Name']    = ''
    output['Matched CRM Website'] = ''
    output['Matched CRM Ort']     = ''
    output['Matched CRM Land']    = ''
    output['Score']               = 0.0

    for _, row in merged.iterrows():
        i = int(row['match_idx'])
        output.at[i, 'Matched CRM Name']    = row['CRM Name_CRM']
        output.at[i, 'Matched CRM Website'] = row['CRM Website_CRM']
        output.at[i, 'Matched CRM Ort']     = row['CRM Ort_CRM']
        output.at[i, 'Matched CRM Land']    = row['CRM Land_CRM']
        output.at[i, 'Score']               = row['score']

    # Zurückschreiben ins Google Sheet
    data = [output.columns.tolist()] + output.values.tolist()
    success = sheet_handler.clear_and_write_data(MATCHING_SHEET_NAME, data)
    if success:
        print(f"Erfolgreich: {len(best)} Matches mit Score ≥ {SCORE_THRESHOLD}")
    else:
        print("Fehler beim Schreiben ins Google Sheet.")

if __name__ == '__main__':
    main()