import sys
import os
import csv
import argparse
from datetime import datetime

# Setup Environment
sys.path.append(os.path.join(os.path.dirname(__file__), "../../"))

from backend.database import SessionLocal, RawJobTitle, init_db, engine, Base

def import_titles(file_path: str, delimiter: str = ';'):
    print(f"🚀 Starting Import from {file_path}...")
    
    # Ensure Table Exists
    RawJobTitle.__table__.create(bind=engine, checkfirst=True)
    
    db = SessionLocal()
    total_rows = 0
    new_titles = 0
    updated_titles = 0
    
    try:
        with open(file_path, 'r', encoding='utf-8-sig') as f: # utf-8-sig handles BOM from Excel
            # Try to detect header
            sample = f.read(1024)
            has_header = csv.Sniffer().has_header(sample)
            f.seek(0)
            
            reader = csv.reader(f, delimiter=delimiter)
            
            if has_header:
                headers = next(reader)
                print(f"ℹ️ Header detected: {headers}")
                # Try to find the right column index
                col_idx = 0
                for i, h in enumerate(headers):
                    if h.lower() in ['funktion', 'jobtitle', 'title', 'position', 'rolle']:
                        col_idx = i
                        print(f"  -> Using column '{h}' (Index {i})")
                        break
            else:
                col_idx = 0
                print("ℹ️ No header detected, using first column.")

            # Process Rows
            for row in reader:
                if not row: continue
                if len(row) <= col_idx: continue
                
                raw_title = row[col_idx].strip()
                if not raw_title: continue # Skip empty
                
                total_rows += 1
                
                # Check existance
                existing = db.query(RawJobTitle).filter(RawJobTitle.title == raw_title).first()
                
                if existing:
                    existing.count += 1
                    existing.updated_at = datetime.utcnow()
                    updated_titles += 1
                else:
                    db.add(RawJobTitle(title=raw_title, count=1))
                    new_titles += 1
                
                if total_rows % 100 == 0:
                    db.commit()
                    print(f"  Processed {total_rows} rows...", end='\r')

            db.commit()
            
    except Exception as e:
        print(f"\n❌ Error: {e}")
        db.rollback()
    finally:
        db.close()

    print(f"\n✅ Import Complete.")
    print(f"   Total Processed: {total_rows}")
    print(f"   New Unique Titles: {new_titles}")
    print(f"   Updated Frequencies: {updated_titles}")

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Import Job Titles from CSV")
    parser.add_argument("file", help="Path to CSV file")
    parser.add_argument("--delimiter", default=";", help="CSV Delimiter (default: ';')")
    
    args = parser.parse_args()
    
    if not os.path.exists(args.file):
        print(f"❌ File not found: {args.file}")
        sys.exit(1)
        
    import_titles(args.file, args.delimiter)