import os
import sys

# Add the project root to sys.path so we can import 'features'
sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

import subprocess
import tempfile
import psycopg2
from psycopg2.extras import RealDictCursor
from urllib.parse import urlparse
from dotenv import load_dotenv

# Import Schema logic
from features.schema import Schema

def main():
    # Load environment variables from .env
    load_dotenv()

    database_url = os.environ.get('DATABASE_URL')
    if not database_url:
        print("Error: DATABASE_URL not set in environment.")
        return

    # Connect to the database
    db_url = urlparse(database_url)
    conn = psycopg2.connect(
        database=db_url.path[1:],
        user=db_url.username,
        password=db_url.password,
        host=db_url.hostname,
        port=db_url.port
    )

    def execute_func(query, args=()):
        cur = conn.cursor(cursor_factory=RealDictCursor)
        cur.execute(query, args)
        rv = None
        if cur.description is not None:
            rv = cur.fetchall()
        cur.close()
        return rv

    # Initialize Schema logic
    schema_logic = Schema(execute_func)

    print("Fetching schema information...")
    schema_info = schema_logic.get_schema_info()
    
    print("Generating Mermaid code...")
    mermaid_code = schema_logic.generate_mermaid_er(schema_info)

    print("Rendering SVG via mermaid-cli...")
    try:
        with tempfile.TemporaryDirectory() as tmpdir:
            input_file = os.path.join(tmpdir, "input.mmd")
            output_file = os.path.join(tmpdir, "schema.svg")
            
            # Destination path
            target_file = os.path.abspath(os.path.join("static", "img", "schema.svg"))
            os.makedirs(os.path.dirname(target_file), exist_ok=True)

            with open(input_file, "w") as f:
                f.write(mermaid_code)

            # Run mmdc
            subprocess.run(
                ["bun", "x", "mmdc", "-i", input_file, "-o", target_file],
                check=True
            )
            print(f"Successfully generated {target_file}")

    except Exception as e:
        print(f"Error during SVG generation: {e}")
    finally:
        conn.close()

if __name__ == "__main__":
    main()