generate_code_node.py

"""
GenerateCodeNode Module
"""
from typing import Any, Dict, List, Optional
import ast
import sys
from io import StringIO
import re
import json
from pydantic import ValidationError
from langchain.prompts import PromptTemplate
from langchain.output_parsers import ResponseSchema, StructuredOutputParser
from langchain_core.output_parsers import StrOutputParser
from langchain_community.chat_models import ChatOllama
from bs4 import BeautifulSoup
from ..prompts import (
    TEMPLATE_INIT_CODE_GENERATION, TEMPLATE_SEMANTIC_COMPARISON
)
from ..utils import (transform_schema,
                    extract_code,
                    syntax_focused_analysis, syntax_focused_code_generation,
                    execution_focused_analysis, execution_focused_code_generation,
                    validation_focused_analysis, validation_focused_code_generation,
                    semantic_focused_analysis, semantic_focused_code_generation,
                    are_content_equal)
from .base_node import BaseNode
from jsonschema import validate, ValidationError

class GenerateCodeNode(BaseNode):
    """
    A node that generates Python code for a function that extracts data
    from HTML based on a output schema.

    Attributes:
        llm_model: An instance of a language model client, configured for generating answers.
        verbose (bool): A flag indicating whether to show print statements during execution.

    Args:
        input (str): Boolean expression defining the input keys needed from the state.
        output (List[str]): List of output keys to be updated in the state.
        node_config (dict): Additional configuration for the node.
        node_name (str): The unique identifier name for the node, defaulting to "GenerateAnswer".
    """

    def __init__(
        self,
        input: str,
        output: List[str],
        node_config: Optional[dict] = None,
        node_name: str = "GenerateCode",
    ):
        super().__init__(node_name, "node", input, output, 2, node_config)

        self.llm_model = node_config["llm_model"]

        if isinstance(node_config["llm_model"], ChatOllama):
            self.llm_model.format="json"

        self.verbose = (
            True if node_config is None else node_config.get("verbose", False)
        )
        self.force = (
            False if node_config is None else node_config.get("force", False)
        )
        self.script_creator = (
            False if node_config is None else node_config.get("script_creator", False)
        )
        self.is_md_scraper = (
            False if node_config is None else node_config.get("is_md_scraper", False)
        )

        self.additional_info = node_config.get("additional_info")

        self.max_iterations = node_config.get("max_iterations", {
            "overall": 10,
            "syntax": 3,
            "execution": 3,
            "validation": 3,
            "semantic": 3
        })

        self.output_schema = node_config.get("schema")

    def execute(self, state: dict) -> dict:
        """
        Generates Python code for a function that extracts data from HTML based on a output schema.

        Args:
            state (dict): The current state of the graph. The input keys will be used
                            to fetch the correct data from the state.

        Returns:
            dict: The updated state with the output key containing the generated answer.

        Raises:
            KeyError: If the input keys are not found in the state, indicating
                      that the necessary information for generating an answer is missing.
            RuntimeError: If the maximum number of iterations is
            reached without obtaining the desired code.
        """

        self.logger.info(f"--- Executing {self.node_name} Node ---")

        input_keys = self.get_input_keys(state)

        input_data = [state[key] for key in input_keys]

        user_prompt = input_data[0]
        refined_prompt = input_data[1]
        html_info = input_data[2]
        reduced_html = input_data[3]
        answer = input_data[4]

        self.raw_html = state['original_html'][0].page_content

        simplefied_schema = str(transform_schema(self.output_schema.schema()))

        reasoning_state = {
            "user_input": user_prompt,
            "json_schema": simplefied_schema,
            "initial_analysis": refined_prompt,
            "html_code": reduced_html,
            "html_analysis": html_info,
            "generated_code": "",
            "execution_result": None,
            "reference_answer": answer,
            "errors": {
                "syntax": [],
                "execution": [],
                "validation": [],
                "semantic": []
            },
            "iteration": 0
        }

        final_state = self.overall_reasoning_loop(reasoning_state)

        state.update({self.output[0]: final_state["generated_code"]})
        return state

    def overall_reasoning_loop(self, state: dict) -> dict:
        """
        Executes the overall reasoning loop to generate and validate the code.

        Args:
            state (dict): The current state of the reasoning process.

        Returns:
            dict: The final state after the reasoning loop.

        Raises:
            RuntimeError: If the maximum number of iterations 
            is reached without obtaining the desired code.
        """
        self.logger.info(f"--- (Generating Code) ---")
        state["generated_code"] = self.generate_initial_code(state)
        state["generated_code"] = extract_code(state["generated_code"])

        while state["iteration"] < self.max_iterations["overall"]:
            state["iteration"] += 1
            if self.verbose:
                self.logger.info(f"--- Iteration {state['iteration']} ---")

            self.logger.info(f"--- (Checking Code Syntax) ---")
            state = self.syntax_reasoning_loop(state)
            if state["errors"]["syntax"]:
                continue

            self.logger.info(f"--- (Executing the Generated Code) ---")
            state = self.execution_reasoning_loop(state)
            if state["errors"]["execution"]:
                continue

            self.logger.info(f"--- (Validate the Code Output Schema) ---")
            state = self.validation_reasoning_loop(state)
            if state["errors"]["validation"]:
                continue

            self.logger.info(f"""--- (Checking if the informations
                             exctrcated are the ones Requested) ---""")
            state = self.semantic_comparison_loop(state)
            if state["errors"]["semantic"]:
                continue
            break

        if state["iteration"] == self.max_iterations["overall"] and \
            (state["errors"]["syntax"] or state["errors"]["execution"] \
             or state["errors"]["validation"] or state["errors"]["semantic"]):
            raise RuntimeError("Max iterations reached without obtaining the desired code.")

        self.logger.info(f"--- (Code Generated Correctly) ---")

        return state

    def syntax_reasoning_loop(self, state: dict) -> dict:
        """
        Executes the syntax reasoning loop to ensure the generated code has correct syntax.

        Args:
            state (dict): The current state of the reasoning process.

        Returns:
            dict: The updated state after the syntax reasoning loop.
        """
        for _ in range(self.max_iterations["syntax"]):
            syntax_valid, syntax_message = self.syntax_check(state["generated_code"])
            if syntax_valid:
                state["errors"]["syntax"] = []
                return state

            state["errors"]["syntax"] = [syntax_message]
            self.logger.info(f"--- (Synax Error Found: {syntax_message}) ---")
            analysis = syntax_focused_analysis(state, self.llm_model)
            self.logger.info(f"""--- (Regenerating Code
                             to fix the Error) ---""")
            state["generated_code"] = syntax_focused_code_generation(state,
                                                                     analysis, self.llm_model)
            state["generated_code"] = extract_code(state["generated_code"])
        return state

    def execution_reasoning_loop(self, state: dict) -> dict:
        """
        Executes the execution reasoning loop to ensure the generated code runs without errors.

        Args:
            state (dict): The current state of the reasoning process.

        Returns:
            dict: The updated state after the execution reasoning loop.
        """
        for _ in range(self.max_iterations["execution"]):
            execution_success, execution_result = self.create_sandbox_and_execute(
                                                                                state["generated_code"])
            if execution_success:
                state["execution_result"] = execution_result
                state["errors"]["execution"] = []
                return state

            state["errors"]["execution"] = [execution_result]
            self.logger.info(f"--- (Code Execution Error: {execution_result}) ---")
            analysis = execution_focused_analysis(state, self.llm_model)
            self.logger.info(f"--- (Regenerating Code to fix the Error) ---")
            state["generated_code"] = execution_focused_code_generation(state,
                                                                        analysis, self.llm_model)
            state["generated_code"] = extract_code(state["generated_code"])
        return state

    def validation_reasoning_loop(self, state: dict) -> dict:
        """
        Executes the validation reasoning loop to ensure the 
        generated code's output matches the desired schema.

        Args:
            state (dict): The current state of the reasoning process.

        Returns:
            dict: The updated state after the validation reasoning loop.
        """
        for _ in range(self.max_iterations["validation"]):
            validation, errors = self.validate_dict(state["execution_result"],
                                                    self.output_schema.schema())
            if validation:
                state["errors"]["validation"] = []
                return state

            state["errors"]["validation"] = errors
            self.logger.info(f"--- (Code Output not compliant to the deisred Output Schema) ---")
            analysis = validation_focused_analysis(state, self.llm_model)
            self.logger.info(f"""--- (Regenerating Code to make the
                             Output compliant to the deisred Output Schema) ---""")
            state["generated_code"] = validation_focused_code_generation(state,
                                                                         analysis, self.llm_model)
            state["generated_code"] = extract_code(state["generated_code"])
        return state

    def semantic_comparison_loop(self, state: dict) -> dict:
        """
        Executes the semantic comparison loop to ensure the generated code's
          output is semantically equivalent to the reference answer.

        Args:
            state (dict): The current state of the reasoning process.

        Returns:
            dict: The updated state after the semantic comparison loop.
        """
        for _ in range(self.max_iterations["semantic"]):
            comparison_result = self.semantic_comparison(state["execution_result"],
                                                         state["reference_answer"])
            if comparison_result["are_semantically_equivalent"]:
                state["errors"]["semantic"] = []
                return state

            state["errors"]["semantic"] = comparison_result["differences"]
            self.logger.info(f"""--- (The informations exctrcated
                             are not the all ones requested) ---""")
            analysis = semantic_focused_analysis(state, comparison_result, self.llm_model)
            self.logger.info(f"""--- (Regenerating Code to
                                obtain all the infromation requested) ---""")
            state["generated_code"] = semantic_focused_code_generation(state,
                                                                       analysis, self.llm_model)
            state["generated_code"] = extract_code(state["generated_code"])
        return state

    def generate_initial_code(self, state: dict) -> str:
        """
        Generates the initial code based on the provided state.

        Args:
            state (dict): The current state of the reasoning process.

        Returns:
            str: The initially generated code.
        """
        prompt = PromptTemplate(
            template=TEMPLATE_INIT_CODE_GENERATION,
            partial_variables={
                "user_input": state["user_input"],
                "json_schema": state["json_schema"],
                "initial_analysis": state["initial_analysis"],
                "html_code": state["html_code"],
                "html_analysis": state["html_analysis"]
            })

        output_parser = StrOutputParser()

        chain =  prompt | self.llm_model | output_parser
        generated_code = chain.invoke({})
        return generated_code

    def semantic_comparison(self, generated_result: Any, reference_result: Any) -> Dict[str, Any]:
        """
        Performs a semantic comparison between the generated result and the reference result.

        Args:
            generated_result (Any): The result generated by the code.
            reference_result (Any): The reference result for comparison.

        Returns:
            Dict[str, Any]: A dictionary containing the comparison result, 
            differences, and explanation.
        """
        reference_result_dict = self.output_schema(**reference_result).dict()
        if are_content_equal(generated_result, reference_result_dict):
            return {
                "are_semantically_equivalent": True,
                "differences": [],
                "explanation": "The generated result and reference result are exactly equal."
            }

        response_schemas = [
            ResponseSchema(name="are_semantically_equivalent",
                           description="""Boolean indicating if the
                           results are semantically equivalent"""),
            ResponseSchema(name="differences",
                           description="""List of semantic differences
                           between the results, if any"""),
            ResponseSchema(name="explanation",
                           description="""Detailed explanation of the
                           comparison and reasoning""")
        ]
        output_parser = StructuredOutputParser.from_response_schemas(response_schemas)

        prompt = PromptTemplate(
            template=TEMPLATE_SEMANTIC_COMPARISON,
            input_variables=["generated_result", "reference_result"],
            partial_variables={"format_instructions": output_parser.get_format_instructions()}
        )

        chain = prompt | self.llm_model | output_parser
        return chain.invoke({
            "generated_result": json.dumps(generated_result, indent=2),
            "reference_result": json.dumps(reference_result_dict, indent=2)
        })

    def syntax_check(self, code):
        """
        Checks the syntax of the provided code.

        Args:
            code (str): The code to be checked for syntax errors.

        Returns:
            tuple: A tuple containing a boolean indicating if the syntax is correct and a message.
        """
        try:
            ast.parse(code)
            return True, "Syntax is correct."
        except SyntaxError as e:
            return False, f"Syntax error: {str(e)}"

    def create_sandbox_and_execute(self, function_code):
        """
        Creates a sandbox environment and executes the provided function code.

        Args:
            function_code (str): The code to be executed in the sandbox.

        Returns:
            tuple: A tuple containing a boolean indicating if 
            the execution was successful and the result or error message.
        """
        sandbox_globals = {
            'BeautifulSoup': BeautifulSoup,
            're': re,
            '__builtins__': __builtins__,
        }

        old_stdout = sys.stdout
        sys.stdout = StringIO()

        try:
            exec(function_code, sandbox_globals)

            extract_data = sandbox_globals.get('extract_data')

            if not extract_data:
                raise NameError("Function 'extract_data' not found in the generated code.")

            result = extract_data(self.raw_html)
            return True, result
        except Exception as e:
            return False, f"Error during execution: {str(e)}"
        finally:
            sys.stdout = old_stdout

    def validate_dict(self, data: dict, schema):
        """
        Validates the provided data against the given schema.

        Args:
            data (dict): The data to be validated.
            schema (dict): The schema against which the data is validated.

        Returns:
            tuple: A tuple containing a boolean indicating 
            if the validation was successful and a list of errors if any.
        """
        try:
            validate(instance=data, schema=schema)
            return True, None
        except ValidationError as e:
            errors = [e.message]
            return False, errors