import csv
import os
from django.core.management.base import BaseCommand
from django.db import connection
from inventory.models import CarTrim


class Command(BaseCommand):
    help = 'Add id_car_model column to CarTrim model and populate it using a CSV file.'

    def handle(self, *args, **options):
        # Define the file path relative to the project directory
        base_dir = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
        file_path = os.path.join(base_dir, 'data/mappings.csv')

        # Step 1: Add the new column if it does not exist
        with connection.cursor() as cursor:
            try:
                cursor.execute("ALTER TABLE inventory_cartrim ADD COLUMN id_car_model INTEGER")
                self.stdout.write(self.style.SUCCESS("Column 'id_car_model' added successfully."))
            except Exception as e:
                self.stdout.write(self.style.WARNING(f"Column 'id_car_model' might already exist: {e}"))

        # Step 2: Read and process the CSV file
        try:
            with open(file_path, mode='r', encoding='utf-8-sig') as csvfile:
                reader = csv.DictReader(csvfile)

                for row in reader:
                    # Extract id_car_serie and id_car_model from the current row
                    id_car_serie = row.get('id_car_serie')
                    id_car_model = row.get('id_car_model')

                    if not id_car_serie or not id_car_model:
                        self.stdout.write(self.style.WARNING(f"Skipping row with missing data: {row}"))
                        continue

                    # Step 3: Update CarTrim rows based on the id_car_serie
                    updated_count = CarTrim.objects.filter(id_car_serie=id_car_serie).update(id_car_model=id_car_model)

                    # Output progress
                    if updated_count > 0:
                        self.stdout.write(self.style.SUCCESS(
                            f"Updated {updated_count} rows for id_car_serie={id_car_serie} with id_car_model={id_car_model}."
                        ))
                    else:
                        self.stdout.write(self.style.WARNING(
                            f"No rows found for id_car_serie={id_car_serie}."
                        ))

            self.stdout.write(self.style.SUCCESS("All rows have been processed successfully!"))

        except FileNotFoundError:
            self.stdout.write(self.style.ERROR(f"File not found: {file_path}"))
        except Exception as e:
            self.stdout.write(self.style.ERROR(f"An error occurred: {e}"))