from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
from transformers import pipeline

app = FastAPI()

# Initialize the text generation pipeline
pipe = pipeline("text-generation", model="defog/sqlcoder-7b-2", pad_token_id=2)

class QueryRequest(BaseModel):
    text: str

@app.get("/")
def home():
    return {"message": "SQL Generation Server is running"}
@app.post("/generate")
def generate(request: QueryRequest):
    try:
        text = request.text
        prompt = f"Generate a valid SQL query for the following request. Only return the SQL query, nothing else:\n\n{text}\n\nSQL query:"
        output = pipe(prompt, max_new_tokens=100)
        
        generated_text = output[0]['generated_text']
        sql_query = generated_text.split("SQL query:")[-1].strip()
        # Basic validation to ensure it's a valid SQL query
        if not sql_query.lower().startswith(('select', 'show', 'describe', 'insert', 'update', 'delete')):
            raise ValueError("Generated text is not a valid SQL query")
        
        # Further validation to ensure no additional text
        sql_query = sql_query.split(';')[0].strip()

        # Comprehensive list of SQL keywords
        allowed_keywords = {
            'select', 'insert', 'update', 'delete', 'show', 'describe', 'from', 'where', 'and', 'or', 'like', 'limit', 'order by', 'group by', 'join', 'inner join', 'left join', 'right join', 'full join', 'on', 'using', 'union', 'union all', 'distinct', 'having', 'into', 'values', 'set', 'create', 'alter', 'drop', 'table', 'database', 'index', 'view', 'trigger', 'procedure', 'function', 'if', 'exists', 'primary key', 'foreign key', 'references', 'check', 'constraint', 'default', 'auto_increment', 'null', 'not null', 'in', 'is', 'is not', 'between', 'case', 'when', 'then', 'else', 'end', 'asc', 'desc', 'count', 'sum', 'avg', 'min', 'max', 'timestamp', 'date', 'time', 'varchar', 'char', 'int', 'integer', 'smallint', 'bigint', 'decimal', 'numeric', 'float', 'real', 'double', 'boolean', 'enum', 'text', 'blob', 'clob'
        }
        # Ensure the query only contains allowed keywords
        tokens = sql_query.lower().split()
        for token in tokens:
            if not any(token.startswith(keyword) for keyword in allowed_keywords):
                raise ValueError("Generated text contains invalid SQL syntax")

        return {"output": sql_query}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))



if __name__ == "__main__":
    import uvicorn
    uvicorn.run(app, host="0.0.0.0", port=7860)