import pandas as pd
import re

def _is_hub_pattern(tagname):
    """Check if TAGNAME matches hub patterns like FIO1H1, FIO2H3, etc."""
    # Match patterns like FIO1H1, FIO2H3, etc.
    hub_pattern = re.compile(r'FIO(\d+)?H\d+', re.IGNORECASE)
    return bool(hub_pattern.search(tagname))

def normalize_io_term(term):
    """Handle IO term variations like IO1 vs IO01"""
    if pd.isna(term):
        return []
    
    term_str = str(term).upper()
    variations = [term_str]
    
    # Handle IO padding variations
    if term_str.startswith('IO') and len(term_str) > 2:
        num_part = term_str[2:]
        if num_part.isdigit():
            # Add both padded and unpadded versions
            unpadded = f"IO{int(num_part)}"  # Remove leading zeros
            padded = f"IO{num_part.zfill(2)}"  # Ensure 2-digit padding
            variations.extend([unpadded, padded])
    
    return list(set(variations))  # Remove duplicates

def normalize_name(name):
    if pd.isna(name):
        return name
    return re.sub(r'\d+', lambda m: str(int(m.group(0))), str(name))

def normalize_vfd_name(name):
    """Only normalize VFD names, preserve others as-is"""
    if pd.isna(name):
        return name
    name_str = str(name).upper()
    if 'VFD' in name_str:
        return normalize_name(name)
    return str(name)

def normalize_io_path(path):
    if pd.isna(path):
        return path
    path_str = str(path)
    if ':' in path_str:
        prefix, suffix = path_str.split(':', 1)
        # Only normalize VFD paths
        if 'VFD' in prefix.upper():
            normalized_prefix = normalize_name(prefix)
            return f"{normalized_prefix}:{suffix}"
        return path_str
    return path_str

def assign_partnumber(row):
    tagname = str(row['TAGNAME']).upper()
    existing_partnumber = row['PARTNUMBER']
    
    # If there's already a valid part number, keep it
    if pd.notna(existing_partnumber) and existing_partnumber != '':
        return existing_partnumber
    
    # Only assign default part numbers if no existing part number
    # Hub devices (FIOH or FIO1H1, FIO2H3 patterns)
    if 'FIOH' in tagname or _is_hub_pattern(tagname):
        return 'TBIL-M1-16DXP'
    # DPM devices (only if contains DPM but NOT FIO)
    elif 'DPM' in tagname and 'FIO' not in tagname:
        return 'OS30-002404-2S'
    # PMM devices
    elif 'PMM' in tagname:
        return '1420-V2-ENT'
    # SIO devices
    elif 'SIO' in tagname:
        return '0980SSL3131-121-007D-202'
    # IB16S devices (check before IB16 to avoid conflict)
    elif 'IB16S' in tagname:
        return '1756-IB16S'
    # IB16 devices
    elif 'IB16' in tagname:
        return '1756-IB16'
    # OB16E devices
    elif 'OB16E' in tagname:
        return '1756-OB16E'
    else:
        return ''

def combine_desc(row):
    desca = str(row['DESCA']) if pd.notna(row['DESCA']) and row['DESCA'] != '' else ''
    descb = str(row['DESCB']) if pd.notna(row['DESCB']) and row['DESCB'] != '' else ''
    
    if desca and descb:
        return f"{desca} {descb}"
    elif desca:
        return desca
    elif descb:
        return descb
    else:
        return ''