import os
import sys
import re
import logging
import pandas as pd
from datetime import datetime
from collections import Counter
from thefuzz import fuzz
from helpers import normalize_company_name, simple_normalize_url, serp_website_lookup
from config import Config
from google_sheet_handler import GoogleSheetHandler

# duplicate_checker.py v2.15
# Quality-first ++: Domain-Gate, Location-Penalties, Smart Blocking (IDF-light),
# Serp-Trust, Weak-Threshold, City-Bias-Guard, Prefilter tightened, Metrics
# Build timestamp is injected into logfile name.

# --- Konfiguration ---
CRM_SHEET_NAME      = "CRM_Accounts"
MATCHING_SHEET_NAME = "Matching_Accounts"
SCORE_THRESHOLD     = 80      # Standard-Schwelle
SCORE_THRESHOLD_WEAK= 95      # Schwelle, wenn weder Domain noch (City&Country) matchen
MIN_NAME_FOR_DOMAIN = 70      # Domain-Score nur, wenn Name >= 70 ODER Ort+Land matchen
CITY_MISMATCH_PENALTY    = 30
COUNTRY_MISMATCH_PENALTY = 40
PREFILTER_MIN_PARTIAL    = 70  # (vorher 60)
PREFILTER_LIMIT          = 30  # (vorher 50)
LOG_DIR                  = "Log"
now = datetime.now().strftime('%Y-%m-%d_%H-%M')
LOG_FILE                 = f"{now}_duplicate_check_v2.15.txt"

# --- Logging Setup ---
if not os.path.exists(LOG_DIR):
    os.makedirs(LOG_DIR, exist_ok=True)
log_path = os.path.join(LOG_DIR, LOG_FILE)
root = logging.getLogger()
root.setLevel(logging.DEBUG)
for h in list(root.handlers):
    root.removeHandler(h)
formatter = logging.Formatter("%(asctime)s - %(levelname)-8s - %(message)s")
ch = logging.StreamHandler(sys.stdout)
ch.setLevel(logging.INFO)
ch.setFormatter(formatter)
root.addHandler(ch)
fh = logging.FileHandler(log_path, mode='a', encoding='utf-8')
fh.setLevel(logging.DEBUG)
fh.setFormatter(formatter)
root.addHandler(fh)
logger = logging.getLogger(__name__)
logger.info(f"Logging to console and file: {log_path}")
logger.info(f"Starting duplicate_checker.py v2.15 | Build: {now}")

# --- SerpAPI Key laden ---
try:
    Config.load_api_keys()
    serp_key = Config.API_KEYS.get('serpapi')
    if not serp_key:
        logger.warning("SerpAPI Key nicht gefunden; Serp-Fallback deaktiviert.")
except Exception as e:
    logger.warning(f"Fehler beim Laden API-Keys: {e}")
    serp_key = None

# --- Stop-/City-Tokens ---
STOP_TOKENS_BASE = {
    'gmbh','mbh','ag','kg','ug','ohg','se','co','kgaa','inc','llc','ltd','sarl',
    'holding','gruppe','group','international','solutions','solution','service','services',
    'deutschland','austria','germany','technik','technology','technologies','systems','systeme',
    'logistik','logistics','industries','industrie','management','consulting','vertrieb','handel',
    'international','company','gesellschaft','mbh&co','mbhco','werke','werk','renkhoff','sonnenschutztechnik'
}
CITY_TOKENS = set()  # dynamisch befüllt nach Datennormalisierung

# --- Utilities ---
def _tokenize(s: str):
    if not s:
        return []
    return re.split(r"[^a-z0-9]+", str(s).lower())

def split_tokens(name: str):
    """Tokens für Indexing/Scoring (Basis-Stop + dynamische City-Tokens)."""
    if not name:
        return []
    tokens = [t for t in _tokenize(name) if len(t) >= 3]
    stop_union = STOP_TOKENS_BASE | CITY_TOKENS
    return [t for t in tokens if t not in stop_union]

def clean_name_for_scoring(norm_name: str):
    """Entfernt Stop- & City-Tokens. Leerer Output => kein sinnvoller Namevergleich."""
    toks = split_tokens(norm_name)
    return " ".join(toks), set(toks)

def assess_serp_trust(company_name: str, url: str) -> str:
    """Vertrauen 'hoch/mittel/niedrig' anhand Token-Vorkommen in Domain."""
    if not url:
        return 'n/a'
    host = simple_normalize_url(url) or ''
    host = host.replace('www.', '')
    name_toks = [t for t in split_tokens(normalize_company_name(company_name)) if len(t) >= 3]
    if any(t in host for t in name_toks if len(t) >= 4):
        return 'hoch'
    if any(t in host for t in name_toks if len(t) == 3):
        return 'mittel'
    return 'niedrig'

# --- Similarity ---
def calculate_similarity(mrec: dict, crec: dict, token_freq: Counter):
    n1 = mrec.get('normalized_name','')
    n2 = crec.get('normalized_name','')
    
    # NEU: Direkte Prämierung für exakten Namens-Match
    if n1 and n1 == n2:
        return 300, {'name': 100, 'exact_match': 1}

    # Domain (mit Gate)
    dom1 = mrec.get('normalized_domain','')
    dom2 = crec.get('normalized_domain','')
    m_domain_use = mrec.get('domain_use_flag', 0)
    domain_flag_raw = 1 if (m_domain_use == 1 and dom1 and dom1 == dom2) else 0

    # Location flags
    city_match = 1 if (mrec.get('CRM Ort') and crec.get('CRM Ort') and mrec.get('CRM Ort') == crec.get('CRM Ort')) else 0
    country_match = 1 if (mrec.get('CRM Land') and crec.get('CRM Land') and mrec.get('CRM Land') == crec.get('CRM Land')) else 0

    # Name (nur sinnvolle Tokens)
    n1 = mrec.get('normalized_name','')
    n2 = crec.get('normalized_name','')
    clean1, toks1 = clean_name_for_scoring(n1)
    clean2, toks2 = clean_name_for_scoring(n2)

    # Overlaps
    overlap_clean = toks1 & toks2
    # city-only overlap check (wenn nach Clean nichts übrig, aber Roh-Overlap evtl. Städte; wir cappen Score)
    raw_overlap = set(_tokenize(n1)) & set(_tokenize(n2))
    city_only_overlap = (not overlap_clean) and any(t in CITY_TOKENS for t in raw_overlap)

    # Name-Score
    if clean1 and clean2:
        ts = fuzz.token_set_ratio(clean1, clean2)
        pr = fuzz.partial_ratio(clean1, clean2)
        ss = fuzz.token_sort_ratio(clean1, clean2)
        name_score = max(ts, pr, ss)
    else:
        name_score = 0

    if city_only_overlap and name_score > 70:
        name_score = 70  # cap

    # Rare-token-overlap (IDF-light): benutze seltensten Token aus mrec
    rtoks_sorted = sorted(list(toks1), key=lambda t: (token_freq.get(t, 10**9), -len(t)))
    rare_token = rtoks_sorted[0] if rtoks_sorted else None
    rare_overlap = 1 if (rare_token and rare_token in toks2) else 0

    # Domain Gate
    domain_gate_ok = (name_score >= MIN_NAME_FOR_DOMAIN) or (city_match and country_match)
    domain_used = 1 if (domain_flag_raw and domain_gate_ok) else 0

    # Basisscore
    total = domain_used*100 + name_score*1.0 + (1 if (city_match and country_match) else 0)*20

    # Penalties
    penalties = 0
    if mrec.get('CRM Land') and crec.get('CRM Land') and not country_match:
        penalties += COUNTRY_MISMATCH_PENALTY
    if mrec.get('CRM Ort') and crec.get('CRM Ort') and not city_match:
        penalties += CITY_MISMATCH_PENALTY
    total -= penalties

    # Bonus für starke Name-only Fälle
    name_bonus = 1 if (domain_used == 0 and not (city_match and country_match) and name_score >= 85 and rare_overlap==1) else 0
    if name_bonus:
        total += 20

    comp = {
        'domain_raw': domain_flag_raw,
        'domain_used': domain_used,
        'domain_gate_ok': int(domain_gate_ok),
        'name': round(name_score,1),
        'city_match': city_match,
        'country_match': country_match,
        'penalties': penalties,
        'name_bonus': name_bonus,
        'rare_overlap': rare_overlap,
        'city_only_overlap': int(city_only_overlap),
        'is_parent_child': 0 # Standardwert
    }

    # Prüfen auf Parent-Child-Beziehung
    n1_norm = mrec.get('normalized_name','')
    n2_norm = crec.get('normalized_name','')
    p1_norm = mrec.get('normalized_parent_name','')
    p2_norm = crec.get('normalized_parent_name','')

    if (n1_norm and p2_norm and n1_norm == p2_norm) or \
       (n2_norm and p1_norm and n2_norm == p1_norm):
        comp['is_parent_child'] = 1
        # Wenn es eine Parent-Child-Beziehung ist, geben wir einen sehr hohen Score zurück,
        # aber mit dem Flag, damit es später ignoriert werden kann.
        return 500, comp # Sehr hoher Score, um es leicht erkennbar zu machen

    return round(total), comp

# --- Indexe ---
def build_indexes(crm_df: pd.DataFrame):
    records = list(crm_df.to_dict('records'))
    # Domain-Index
    domain_index = {}
    for r in records:
        d = r.get('normalized_domain')
        if d:
            domain_index.setdefault(d, []).append(r)
    # Token-Frequenzen (auf gereinigten Tokens)
    token_freq = Counter()
    for r in records:
        _, toks = clean_name_for_scoring(r.get('normalized_name',''))
        for t in set(toks):
            token_freq[t] += 1
    # Token-Index
    token_index = {}
    for r in records:
        _, toks = clean_name_for_scoring(r.get('normalized_name',''))
        for t in set(toks):
            token_index.setdefault(t, []).append(r)
    return records, domain_index, token_freq, token_index


def choose_rarest_token(norm_name: str, token_freq: Counter):
    _, toks = clean_name_for_scoring(norm_name)
    if not toks:
        return None
    lst = sorted(list(toks), key=lambda x: (token_freq.get(x, 10**9), -len(x)))
    return lst[0] if lst else None

def build_city_tokens(df1: pd.DataFrame, df2: pd.DataFrame = None):
    """Baut dynamisch ein Set von City-Tokens aus den Orts-Spalten."""
    dfs = [df1]
    if df2 is not None:
        dfs.append(df2)
    cities = set()
    for s in pd.concat([df['CRM Ort'] for df in dfs], ignore_index=True).dropna().unique():
        for t in _tokenize(s):
            if len(t) >= 3:
                cities.add(t)
    return cities

def run_internal_deduplication():
    """Führt die interne Deduplizierung auf dem CRM_Accounts-Sheet durch."""
    logger.info("Modus 'Interne Deduplizierung' gewählt.")
    try:
        sheet = GoogleSheetHandler()
        logger.info("GoogleSheetHandler initialisiert")
    except Exception as e:
        logger.critical(f"Init GoogleSheetHandler fehlgeschlagen: {e}")
        sys.exit(1)

    # Daten laden
    crm_df = sheet.get_sheet_as_dataframe(CRM_SHEET_NAME)
    if crm_df is None or crm_df.empty:
        logger.critical("CRM-Sheet ist leer. Abbruch.")
        return
    
    # Eindeutige ID hinzufügen, um Zeilen zu identifizieren
    crm_df['unique_id'] = crm_df.index
    logger.info(f"{len(crm_df)} CRM-Datensätze geladen.")

    # Normalisierung
    crm_df['normalized_name']        = crm_df['CRM Name'].astype(str).apply(normalize_company_name)
    crm_df['normalized_domain']      = crm_df['CRM Website'].astype(str).apply(simple_normalize_url)
    crm_df['CRM Ort']                = crm_df['CRM Ort'].astype(str).str.lower().str.strip()
    crm_df['CRM Land']               = crm_df['CRM Land'].astype(str).str.lower().str.strip()
    crm_df['Parent Account']         = crm_df.get('Parent Account', pd.Series(index=crm_df.index, dtype=object)).astype(str).fillna('').str.strip()
    crm_df['normalized_parent_name'] = crm_df['Parent Account'].apply(normalize_company_name)
    crm_df['domain_use_flag']        = 1  # CRM-Domain gilt als vertrauenswürdig

    # City-Tokens und Blocking-Indizes
    global CITY_TOKENS
    CITY_TOKENS = build_city_tokens(crm_df)
    logger.info(f"City tokens gesammelt: {len(CITY_TOKENS)}")
    
    crm_records, domain_index, token_freq, token_index = build_indexes(crm_df)
    logger.info(f"Blocking: Domains={len(domain_index)} | TokenKeys={len(token_index)}")

    # --- Selbst-Vergleich ---
    found_pairs = []
    processed_pairs = set() # Verhindert (A,B) und (B,A)
    total = len(crm_records)
    logger.info("Starte internen Abgleich...")

    for i, record1 in enumerate(crm_records):
        if i % 100 == 0:
            logger.info(f"Verarbeite Datensatz {i}/{total}...")

        candidate_records = {}
        # Kandidaten via Domain finden
        domain = record1.get('normalized_domain')
        if domain:
            for record2 in domain_index.get(domain, []):
                candidate_records[record2['unique_id']] = record2
        
        # Kandidaten via seltenstem Token finden
        rtok = choose_rarest_token(record1.get('normalized_name',''), token_freq)
        if rtok:
            for record2 in token_index.get(rtok, []):
                candidate_records[record2['unique_id']] = record2

        if not candidate_records:
            continue

        for record2 in candidate_records.values():
            # Vergleiche nicht mit sich selbst
            if record1['unique_id'] == record2['unique_id']:
                continue

            # Verhindere doppelte Vergleiche (A,B) vs (B,A)
            pair_key = tuple(sorted((record1['unique_id'], record2['unique_id'])))
            if pair_key in processed_pairs:
                continue
            processed_pairs.add(pair_key)

            score, comp = calculate_similarity(record1, record2, token_freq)

            # Wenn es eine bekannte Parent-Child-Beziehung ist, ignorieren wir sie.
            if comp.get('is_parent_child') == 1:
                logger.debug(f"  -> Ignoriere bekannte Parent-Child-Beziehung: '{record1['CRM Name']}' <-> '{record2['CRM Name']}'")
                continue

            # Akzeptanzlogik (hier könnte man den Threshold anpassen)
            if score >= SCORE_THRESHOLD:
                duplicate_hint = ''
                # Prüfen, ob beide Accounts keinen Parent Account haben
                if not record1.get('Parent Account') and not record2.get('Parent Account'):
                    duplicate_hint = 'Potenziell fehlende Parent-Account-Beziehung'

                pair_info = {
                    'id1': record1['unique_id'], 'name1': record1['CRM Name'],
                    'id2': record2['unique_id'], 'name2': record2['CRM Name'],
                    'score': score,
                    'details': str(comp),
                    'hint': duplicate_hint
                }
                found_pairs.append(pair_info)
                logger.info(f"  -> Potenzielles Duplikat gefunden: '{record1['CRM Name']}' <-> '{record2['CRM Name']}' (Score: {score}, Hint: {duplicate_hint})")

    logger.info("\n===== Interner Abgleich abgeschlossen ====")
    logger.info(f"Insgesamt {len(found_pairs)} potenzielle Duplikatspaare gefunden.")
    
    if not found_pairs:
        logger.info("Keine weiteren Schritte nötig.")
        return

    groups = group_duplicate_pairs(found_pairs)
    logger.info(f"{len(groups)} eindeutige Duplikatsgruppen gebildet.")

    if not groups:
        logger.info("Keine Duplikate gefunden, die geschrieben werden müssen.")
        return

    # Schritt 4: IDs zuweisen und in Tabelle schreiben
    crm_df['Duplicate_ID'] = ''
    crm_df['Duplicate_Hint'] = '' # Neue Spalte für Hinweise
    dup_counter = 1
    for group in groups:
        dup_id = f"Dup_{dup_counter:04d}"
        dup_counter += 1
        
        # IDs der Gruppe im DataFrame aktualisieren
        crm_df.loc[crm_df['unique_id'].isin(group), 'Duplicate_ID'] = dup_id

        # Hinweise für die Gruppe sammeln und setzen
        group_hints = [p['hint'] for p in found_pairs if p['id1'] in group or p['id2'] in group and p['hint']]
        if group_hints:
            # Nur den ersten eindeutigen Hinweis pro Gruppe setzen, oder eine Zusammenfassung
            unique_hints = list(set(group_hints))
            crm_df.loc[crm_df['unique_id'].isin(group), 'Duplicate_Hint'] = "; ".join(unique_hints)
        
        # Namen der Gruppenmitglieder für Log-Ausgabe sammeln
        member_names = crm_df[crm_df['unique_id'].isin(group)]['CRM Name'].tolist()
        logger.info(f"Gruppe {dup_id}: {member_names}")

    # Bereinigen der Hilfsspalten vor dem Schreiben
    crm_df.drop(columns=['unique_id', 'normalized_name', 'normalized_domain', 'domain_use_flag', 'normalized_parent_name'], inplace=True)

    # Ergebnisse zurückschreiben
    logger.info("Schreibe Ergebnisse mit Duplikats-IDs ins Sheet...")
    backup_path = os.path.join(LOG_DIR, f"{now}_backup_internal_{CRM_SHEET_NAME}.csv")
    try:
        crm_df.to_csv(backup_path, index=False, encoding='utf-8')
        logger.info(f"Lokales Backup geschrieben: {backup_path}")
    except Exception as e:
        logger.warning(f"Backup fehlgeschlagen: {e}")

    data = [crm_df.columns.tolist()] + crm_df.fillna('').values.tolist()
    ok = sheet.clear_and_write_data(CRM_SHEET_NAME, data)
    if ok:
        logger.info("Ergebnisse erfolgreich ins Google Sheet geschrieben.")
    else:
        logger.error("Fehler beim Schreiben der Ergebnisse ins Google Sheet.")


def group_duplicate_pairs(pairs: list) -> list:
    """Fasst eine Liste von Duplikatspaaren zu Gruppen zusammen."""
    groups = []
    for pair in pairs:
        id1, id2 = pair['id1'], pair['id2']
        group1_found = None
        group2_found = None
        for group in groups:
            if id1 in group:
                group1_found = group
            if id2 in group:
                group2_found = group
        
        if group1_found and group2_found:
            if group1_found is not group2_found: # Zwei unterschiedliche Gruppen verschmelzen
                group1_found.update(group2_found)
                groups.remove(group2_found)
        elif group1_found: # Zu Gruppe 1 hinzufügen
            group1_found.add(id2)
        elif group2_found: # Zu Gruppe 2 hinzufügen
            group2_found.add(id1)
        else: # Neue Gruppe erstellen
            groups.append({id1, id2})
            
    return [set(g) for g in groups]


def run_external_comparison():
    """Führt den Vergleich zwischen CRM_Accounts und Matching_Accounts durch."""
    logger.info("Modus 'Externer Vergleich' gewählt.")
    try:
        sheet = GoogleSheetHandler()
        logger.info("GoogleSheetHandler initialisiert")
    except Exception as e:
        logger.critical(f"Init GoogleSheetHandler fehlgeschlagen: {e}")
        sys.exit(1)

    # Daten laden
    crm_df = sheet.get_sheet_as_dataframe(CRM_SHEET_NAME)
    match_df = sheet.get_sheet_as_dataframe(MATCHING_SHEET_NAME)
    logger.info(f"{0 if crm_df is None else len(crm_df)} CRM-Datensätze | {0 if match_df is None else len(match_df)} Matching-Datensätze")
    if crm_df is None or crm_df.empty or match_df is None or match_df.empty:
        logger.critical("Leere Daten in einem der Sheets. Abbruch.")
        return

    # SerpAPI nur für Matching (B und E leer)
    if serp_key:
        if 'Gefundene Website' not in match_df.columns:
            match_df['Gefundene Website'] = ''
        b_empty = match_df['CRM Website'].fillna('').astype(str).str.strip().str.lower().isin(['','k.a.','k.a','n/a','na'])
        e_empty = match_df['Gefundene Website'].fillna('').astype(str).str.strip().str.lower().isin(['','k.a.','k.a','n/a','na'])
        empty_mask = b_empty & e_empty
        empty_count = int(empty_mask.sum())
        if empty_count > 0:
            logger.info(f"Serp-Fallback für Matching: {empty_count} Firmen ohne URL in B/E")
            found_cnt = 0
            trust_stats = Counter()
            for idx, row in match_df[empty_mask].iterrows():
                company = row['CRM Name']
                try:
                    url = serp_website_lookup(company)
                    if url and 'k.A.' not in url:
                        if not str(url).startswith(('http://','https://')):
                            url = 'https://' + str(url).lstrip()
                        trust = assess_serp_trust(company, url)
                        match_df.at[idx, 'Gefundene Website'] = url
                        match_df.at[idx, 'Serp Vertrauen'] = trust
                        trust_stats[trust] += 1
                        logger.info(f"  ✓ URL gefunden: '{company}' -> {url} (Vertrauen: {trust})")
                        found_cnt += 1
                    else:
                        logger.debug(f"  ✗ Keine eindeutige URL: '{company}' -> {url}")
                except Exception as e:
                    logger.warning(f"  ! Serp-Fehler für '{company}': {e}")
            logger.info(f"Serp-Fallback beendet: {found_cnt}/{empty_count} URLs ergänzt | Trust: {dict(trust_stats)}")
        else:
            logger.info("Serp-Fallback übersprungen: B oder E bereits befüllt (keine fehlenden Matching-URLs)")

    # Normalisierung CRM
    crm_df['normalized_name']        = crm_df['CRM Name'].astype(str).apply(normalize_company_name)
    crm_df['normalized_domain']      = crm_df['CRM Website'].astype(str).apply(simple_normalize_url)
    crm_df['CRM Ort']                = crm_df['CRM Ort'].astype(str).str.lower().str.strip()
    crm_df['CRM Land']               = crm_df['CRM Land'].astype(str).str.lower().str.strip()
    crm_df['Parent Account']         = crm_df.get('Parent Account', pd.Series(index=crm_df.index, dtype=object)).astype(str).fillna('').str.strip()
    crm_df['normalized_parent_name'] = crm_df['Parent Account'].apply(normalize_company_name)
    crm_df['block_key']              = crm_df['normalized_name'].apply(lambda x: x.split()[0] if x else None)
    crm_df['domain_use_flag']        = 1  # CRM-Domain gilt als vertrauenswürdig

    # Normalisierung Matching
    match_df['Gefundene Website'] = match_df.get('Gefundene Website', pd.Series(index=match_df.index, dtype=object))
    match_df['Serp Vertrauen']    = match_df.get('Serp Vertrauen', pd.Series(index=match_df.index, dtype=object))
    match_df['Effektive Website'] = match_df['CRM Website'].fillna('').astype(str).str.strip()
    mask_eff = match_df['Effektive Website'] == ''
    match_df.loc[mask_eff, 'Effektive Website'] = match_df['Gefundene Website'].fillna('').astype(str).str.strip()

    match_df['normalized_name']   = match_df['CRM Name'].astype(str).apply(normalize_company_name)
    match_df['normalized_domain'] = match_df['Effektive Website'].astype(str).apply(simple_normalize_url)
    match_df['CRM Ort']           = match_df['CRM Ort'].astype(str).str.lower().str.strip()
    match_df['CRM Land']          = match_df['CRM Land'].astype(str).str.lower().str.strip()
    match_df['block_key']         = match_df['normalized_name'].apply(lambda x: x.split()[0] if x else None)

    # Domain-Vertrauen/Use-Flag
    def _domain_use(row):
        if str(row.get('CRM Website','')).strip():
            return 1
        trust = str(row.get('Serp Vertrauen','')).lower()
        return 1 if trust == 'hoch' else 0
    match_df['domain_use_flag'] = match_df.apply(_domain_use, axis=1)

    # City-Tokens dynamisch bauen (nach Normalisierung von Ort)
    global CITY_TOKENS
    CITY_TOKENS = build_city_tokens(crm_df, match_df)
    logger.info(f"City tokens gesammelt: {len(CITY_TOKENS)}")

    # Blocking-Indizes (nachdem CITY_TOKENS gesetzt wurde)
    crm_records, domain_index, token_freq, token_index = build_indexes(crm_df)
    logger.info(f"Blocking: Domains={len(domain_index)} | TokenKeys={len(token_index)}")

    # Matching
    results = []
    metrics = Counter()
    total = len(match_df)
    logger.info("Starte Matching-Prozess…")
    processed = 0

    for idx, mrow in match_df.to_dict('index').items():
        processed += 1
        name_disp = mrow.get('CRM Name','')
        
        # --- NEUE KANDIDATEN-SAMMELLOGIK ---
        candidate_records = {} # Dict, um Duplikate zu vermeiden und Records zu speichern
        used_blocks = []

        # 1. Priorität: Exakter Namens-Match
        mrec_norm_name = mrow.get('normalized_name')
        if mrec_norm_name:
            exact_matches = crm_df[crm_df['normalized_name'] == mrec_norm_name]
            if not exact_matches.empty:
                for _, record in exact_matches.to_dict('index').items():
                    candidate_records[record['CRM Name']] = record
                used_blocks.append('exact_name')

        # 2. Domain-Match
        if mrow.get('normalized_domain') and mrow.get('domain_use_flag') == 1:
            domain_cands = domain_index.get(mrow['normalized_domain'], [])
            if domain_cands:
                for record in domain_cands:
                    candidate_records[record['CRM Name']] = record
                used_blocks.append('domain')

        # 3. Rarest-Token-Match
        rtok = choose_rarest_token(mrow.get('normalized_name',''), token_freq)
        if rtok:
            token_cands = token_index.get(rtok, [])
            if token_cands:
                for record in token_cands:
                    candidate_records[record['CRM Name']] = record
                used_blocks.append('token')
        
        # 4. Prefilter als Fallback, wenn wenige Kandidaten gefunden wurden
        if len(candidate_records) < PREFILTER_LIMIT:
            pf = []
            n1 = mrow.get('normalized_name','')
            rtok = choose_rarest_token(n1, token_freq)
            clean1, toks1 = clean_name_for_scoring(n1)
            if clean1:
                for r in crm_records:
                    if r['CRM Name'] in candidate_records: continue # Nicht erneut prüfen
                    n2 = r.get('normalized_name','')
                    clean2, toks2 = clean_name_for_scoring(n2)
                    if not clean2 or (rtok and rtok not in toks2):
                        continue
                    pr = fuzz.partial_ratio(clean1, clean2)
                    if pr >= PREFILTER_MIN_PARTIAL:
                        pf.append((pr, r))
            pf.sort(key=lambda x: x[0], reverse=True)
            for _, record in pf[:PREFILTER_LIMIT]:
                candidate_records[record['CRM Name']] = record
            if pf: used_blocks.append('prefilter')

        candidates = list(candidate_records.values())
        logger.info(f"Prüfe {processed}/{total}: '{name_disp}' -> {len(candidates)} Kandidaten (Blocks={','.join(used_blocks)})")

        if not candidates:
            results.append({'Match':'', 'Score':0, 'Match_Grund':'keine Kandidaten'})
            continue

        scored = []
        for cr in candidates:
            score, comp = calculate_similarity(mrow, cr, token_freq)
            scored.append((cr.get('CRM Name',''), score, comp))
        scored.sort(key=lambda x: x[1], reverse=True)

        # Log Top5
        for cand_name, sc, comp in scored[:5]:
            logger.debug(f"  Kandidat: {cand_name} | Score={sc} | Comp={comp}")

        best_name, best_score, best_comp = scored[0]

        # Akzeptanzlogik (Weak-Threshold + Guard)
        weak = (best_comp.get('domain_used') == 0 and not (best_comp.get('city_match') and best_comp.get('country_match')))
        applied_threshold = SCORE_THRESHOLD_WEAK if weak else SCORE_THRESHOLD
        weak_guard_fail = (weak and best_comp.get('rare_overlap') == 0)

        if not weak_guard_fail and best_score >= applied_threshold:
            results.append({'Match': best_name, 'Score': best_score, 'Match_Grund': str(best_comp)})
            metrics['matches_total'] += 1
            if best_comp.get('domain_used') == 1:
                metrics['matches_domain'] += 1
            if best_comp.get('city_match') and best_comp.get('country_match'):
                metrics['matches_with_loc'] += 1
            if best_comp.get('domain_used') == 0 and best_comp.get('name') >= 85 and not (best_comp.get('city_match') and best_comp.get('country_match')):
                metrics['matches_name_only'] += 1
            logger.info(f" --> Match: '{best_name}' ({best_score}) {best_comp} | TH={applied_threshold}{' weak' if weak else ''}")
        else:
            reason = 'weak_guard_no_rare' if weak_guard_fail else 'below_threshold'
            results.append({'Match':'', 'Score': best_score, 'Match_Grund': f"{best_comp} | {reason} TH={applied_threshold}"})
            logger.info(f" --> Kein Match (Score={best_score}) {best_comp} | {reason} TH={applied_threshold}")

    # Ergebnisse zurückschreiben (SAFE)
    logger.info("Schreibe Ergebnisse ins Sheet (SAFE in-place, keine Spaltenverluste)…")
    res_df = pd.DataFrame(results, index=match_df.index)
    write_df = match_df.copy()
    write_df['Match'] = res_df['Match']
    write_df['Score'] = res_df['Score']
    write_df['Match_Grund'] = res_df['Match_Grund']

    drop_cols = ['normalized_name','normalized_domain','block_key','Effektive Website','domain_use_flag', 'normalized_parent_name']
    for c in drop_cols:
        if c in write_df.columns:
            write_df.drop(columns=[c], inplace=True)

    backup_path = os.path.join(LOG_DIR, f"{now}_backup_{MATCHING_SHEET_NAME}.csv")
    try:
        write_df.to_csv(backup_path, index=False, encoding='utf-8')
        logger.info(f"Lokales Backup geschrieben: {backup_path}")
    except Exception as e:
        logger.warning(f"Backup fehlgeschlagen: {e}")

    data = [write_df.columns.tolist()] + write_df.fillna('').values.tolist()
    ok = sheet.clear_and_write_data(MATCHING_SHEET_NAME, data)
    if ok:
        logger.info("Ergebnisse erfolgreich geschrieben")
    else:
        logger.error("Fehler beim Schreiben ins Google Sheet")

    # Summary
    serp_counts = Counter((str(x).lower() for x in write_df.get('Serp Vertrauen', [])))
    logger.info("===== Summary =====")
    logger.info(f"Matches total: {metrics['matches_total']} | mit Domain: {metrics['matches_domain']} | mit Ort: {metrics['matches_with_loc']} | nur Name: {metrics['matches_name_only']}")
    logger.info(f"Serp Vertrauen: {dict(serp_counts)}")
    logger.info(f"Config: TH={SCORE_THRESHOLD}, TH_WEAK={SCORE_THRESHOLD_WEAK}, MIN_NAME_FOR_DOMAIN={MIN_NAME_FOR_DOMAIN}, Penalties(city={CITY_MISMATCH_PENALTY},country={COUNTRY_MISMATCH_PENALTY}), Prefilter(partial>={PREFILTER_MIN_PARTIAL}, limit={PREFILTER_LIMIT})")


# --- Hauptfunktion ---
def main():
    logger.info("Starte Duplikats-Check v3.0")
    
    while True:
        print("\nBitte wählen Sie den gewünschten Modus:")
        print("1: Externer Vergleich (gleicht CRM_Accounts mit Matching_Accounts ab)")
        print("2: Interne Deduplizierung (findet Duplikate innerhalb von CRM_Accounts)")
        choice = input("Ihre Wahl (1 oder 2): ")
        
        if choice == '1':
            run_external_comparison()
            break
        elif choice == '2':
            run_internal_deduplication()
            break
        else:
            print("Ungültige Eingabe. Bitte geben Sie 1 oder 2 ein.")

if __name__=='__main__':
    main()