"""
GraphIterator Module
"""

from typing import List, Optional
import copy
from tqdm import tqdm
from .base_node import BaseNode


class GraphIteratorNode(BaseNode):
    """
    A node responsible for instantiating and running multiple graph instances in parallel.
    It creates as many graph instances as the number of elements in the input list.

    Attributes:
        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 "Parse".
    """

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

        self.verbose = False if node_config is None else node_config.get("verbose", False)

    def execute(self,  state: dict) -> dict:
        """
        Executes the node's logic to instantiate and run multiple graph instances in parallel.

        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 results of the graph instances.

        Raises:
            KeyError: If the input keys are not found in the state, indicating that the
                        necessary information for running the graph instances is missing.
        """

        if self.verbose:
            print(f"--- Executing {self.node_name} Node ---")

        # Interpret input keys based on the provided input expression
        input_keys = self.get_input_keys(state)

        # Fetching data from the state based on the input keys
        input_data = [state[key] for key in input_keys]

        user_prompt = input_data[0]
        urls = input_data[1]

        graph_instance = self.node_config.get("graph_instance", None)
        if graph_instance is None:
            raise ValueError("Graph instance is required for graph iteration.")
        
        # set the prompt and source for each url
        graph_instance.prompt = user_prompt
        graphs_instances = []
        for url in urls:
            # make a copy of the graph instance
            copy_graph_instance = copy.copy(graph_instance)
            copy_graph_instance.source = url
            graphs_instances.append(copy_graph_instance)

        # run the graph for each url and use tqdm for progress bar
        graphs_answers = []
        for graph in tqdm(graphs_instances, desc="Processing Graph Instances", disable=not self.verbose):
            result = graph.run()
            graphs_answers.append(result)

        state.update({self.output[0]: graphs_answers})
        return state