import openai
from config import PROJECT_ID, DATASET_ID
from utils.bigquery_utils import get_bigquery_schema_info

def sql_generation_agent(state):
    """Generates a SQL query based on the natural language query and sample data."""
    natural_language_query = state["sql_query"]
    relevant_tables = state.get("relevant_tables", [])
    sample_data = state.get("sample_data", {})
    client = state["client"]
    
    if client is None:
        return {"generated_sql": "-- Error: Failed to connect to BigQuery."}
    
    schema_info = get_bigquery_schema_info(client, PROJECT_ID, DATASET_ID)
    
    # Format the schema for the prompt
    schema_text = ""
    for table_name, columns in schema_info.items():
        if f"{DATASET_ID}.{table_name}" in relevant_tables:
            schema_text += f"- **{DATASET_ID}.{table_name}** ({', '.join(columns)})\n"
    
    # Format sample data for the prompt
    sample_data_text = ""
    for table, rows in sample_data.items():
        if isinstance(rows, list) and rows:
            sample_data_text += f"\n**Sample data from {table}:**\n"
            # Get column names from the first row
            columns = list(rows[0].keys())
            sample_data_text += "| " + " | ".join(columns) + " |\n"
            sample_data_text += "| " + " | ".join(["---"] * len(columns)) + " |\n"
            
            # Add row data
            for row in rows:
                sample_data_text += "| " + " | ".join([str(row.get(col, "")) for col in columns]) + " |\n"
    
    prompt = f"""
    Generate a BigQuery SQL query to answer the following question:
    
    **Question:** "{natural_language_query}"
    
    **Relevant Tables Schema:**
    {schema_text}
    
    **Sample Data:**
    {sample_data_text}
    
    **Rules:**
    - Use only the provided tables with their full dataset.table_name format (e.g., {DATASET_ID}.users).
    - Ensure correct column names as shown in the schema.
    - Use appropriate joins based on the relationships visible in the sample data.
    - Use BigQuery SQL syntax.
    - Return ONLY the SQL query without any explanations or markdown formatting.
    """
    
    response = openai.chat.completions.create(
        model="gpt-4o-mini",
        messages=[{"role": "user", "content": prompt}],
        temperature=0.0
    )
    
    generated_sql = response.choices[0].message.content.strip()
    
    # Remove markdown code block formatting if present
    if generated_sql.startswith("```sql"):
        generated_sql = generated_sql.replace("```sql", "").replace("```", "").strip()
    
    return {"generated_sql": generated_sql}