import re
import litellm
from typing import List, Dict, Any, Optional

# Import the necessary functions
from prompts import PROMPTS, format_prompt
from utils import save_results, generate_user_id


def generate_strategies(query: str, selected_strategy: Optional[str], k: int) -> List[str]:
    """
    Generate k strategy options using the LLM.

    Args:
        query: The original user query
        selected_strategy: Previously selected strategy (if any)
        k: Number of strategies to generate

    Returns:
        List of strategy options
    """
    # Choose the appropriate prompt template
    if selected_strategy:
        prompt_key = "continuation_strategies"
        format_args = {
            "query": query,
            "selected_strategy": selected_strategy,
            "k": k
        }
    else:
        prompt_key = "initial_strategies"
        format_args = {
            "query": query,
            "k": k
        }

    # Format the prompts
    system_template = PROMPTS["ibfs"][prompt_key]["system"]
    user_template = PROMPTS["ibfs"][prompt_key]["user"]

    system_message = format_prompt(system_template, **format_args)
    user_message = format_prompt(user_template, **format_args)

    messages = [
        {"role": "system", "content": system_message},
        {"role": "user", "content": user_message}
    ]

    # Get response from LLM
    response = litellm.completion(
        model="gpt-4o",
        messages=messages,
        temperature=0.7,
        max_tokens=1000
    )

    content = response.choices[0].message.content

    # Parse strategies using regex (simplified)
    strategies = re.findall(r'\d+\.\s*(.+?)(?=\n\d+\.|\Z)', content, re.DOTALL)

    # Ensure we have exactly k strategies
    strategies = [s.strip() for s in strategies[:k]]

    # Fill in missing strategies if needed
    while len(strategies) < k:
        strategies.append(f"Strategy option #{len(strategies) + 1}")

    return strategies


def answer_query(query: str, final_strategy: str) -> str:
    """
    Generate the final answer based on the selected strategy.

    Args:
        query: The original user query
        final_strategy: The final selected strategy

    Returns:
        The final answer
    """
    # Get prompt templates
    system_template = PROMPTS["ibfs"]["final_answer"]["system"]
    user_template = PROMPTS["ibfs"]["final_answer"]["user"]

    # Format the prompts
    format_args = {
        "query": query,
        "final_strategy": final_strategy
    }

    system_message = format_prompt(system_template, **format_args)
    user_message = format_prompt(user_template, **format_args)

    messages = [
        {"role": "system", "content": system_message},
        {"role": "user", "content": user_message}
    ]

    response = litellm.completion(
        model="gpt-4o",
        messages=messages,
        temperature=0.3,
        max_tokens=2000
    )

    return response.choices[0].message.content


def start_ibfs(query: str, k: int, m: int) -> tuple:
    """
    Start the IBFS process with a new query.

    Args:
        query: User's query
        k: Branching factor
        m: Depth

    Returns:
        Initial state and chat history
    """
    if not query or not query.strip():
        return None, [{"role": "assistant", "content": "Please enter a query."}]

    # Generate a unique user ID
    user_id = generate_user_id()

    # Initialize chat history
    chat_history = []

    # Add the original query to chat history
    chat_history.append({"role": "user", "content": f"Query: {query}"})

    # Welcome message
    welcome_msg = format_prompt(
        PROMPTS["ibfs"]["ui_messages"]["welcome"],
        m=m,
        k=k
    )
    chat_history.append({"role": "assistant", "content": welcome_msg})

    # Generating message
    generating_msg = PROMPTS["ibfs"]["ui_messages"]["generating"]
    chat_history.append({"role": "assistant", "content": generating_msg})

    try:
        # Generate initial strategies
        strategies = generate_strategies(query, None, k)

        # Format strategies for display
        valid_options = ", ".join(map(str, range(1, len(strategies) + 1)))
        select_msg = format_prompt(
            PROMPTS["ibfs"]["ui_messages"]["select_strategy"],
            current_step=1,
            max_steps=m,
            valid_options=valid_options
        )

        options_text = f"{select_msg}\n\n"
        for idx, strategy in enumerate(strategies):
            options_text += f"{idx + 1}. {strategy}\n\n"

        chat_history.append({"role": "assistant", "content": options_text})

        # Create state
        state = {
            "user_id": user_id,
            "query": query,
            "k": k,
            "m": m,
            "current_step": 0,
            "strategy_path": [],
            "chat_history": chat_history,
            "strategies": strategies,
        }

        return state, chat_history

    except Exception as e:
        error_msg = format_prompt(
            PROMPTS["ibfs"]["ui_messages"]["error_general"],
            error_message=str(e)
        )
        print(error_msg)
        return None, [
            {"role": "user", "content": f"Query: {query}"},
            {"role": "assistant", "content": "I encountered an error while starting the IBFS process."},
            {"role": "system", "content": error_msg}
        ]


def handle_choice(state: Dict[str, Any], choice: str) -> tuple:
    """
    Handle the user's choice of strategy.

    Args:
        state: Current state
        choice: The user's selected option (1-based index as string)

    Returns:
        Updated state and chat history
    """
    if not state:
        return state, []

    chat_history = state.get("chat_history", [])

    # Validate choice input
    if not choice or not choice.strip():
        chat_history.append({"role": "system", "content": PROMPTS["ibfs"]["ui_messages"]["error_missing_choice"]})
        return state, chat_history

    try:
        choice_idx = int(choice.strip()) - 1  # Convert to 0-based index
        strategies = state.get("strategies", [])

        # Check if we have strategies and if choice is valid
        if not strategies:
            chat_history.append({"role": "system", "content": PROMPTS["ibfs"]["ui_messages"]["error_no_strategies"]})
            return state, chat_history

        if choice_idx < 0 or choice_idx >= len(strategies):
            error_msg = format_prompt(
                PROMPTS["ibfs"]["ui_messages"]["error_invalid_choice"],
                max_option=len(strategies)
            )
            chat_history.append({"role": "system", "content": error_msg})
            return state, chat_history

        # Get the selected strategy and update path
        selected_strategy = strategies[choice_idx]
        strategy_path = state.get("strategy_path", [])
        strategy_path.append(selected_strategy)

        # Record user's choice
        chat_history.append({"role": "user", "content": f"I choose option {choice_idx + 1}: {selected_strategy}"})

        # Update current step
        current_step = state.get("current_step", 0) + 1
        m = state.get("m", 2)

        # Check if we've reached the final step
        if current_step >= m:
            # Generate final answer
            final_processing_msg = PROMPTS["ibfs"]["ui_messages"]["final_processing"]
            chat_history.append({"role": "assistant", "content": final_processing_msg})

            query = state.get("query", "")
            final_answer = answer_query(query, selected_strategy)

            # Format final result
            result_msg = format_prompt(
                PROMPTS["ibfs"]["ui_messages"]["final_result"],
                final_strategy=selected_strategy,
                final_answer=final_answer
            )
            chat_history.append({"role": "assistant", "content": result_msg})

            # Save results
            user_id = state.get("user_id", "")
            save_path = save_results(
                user_id=user_id,
                query=query,
                final_answer=final_answer,
                method="ibfs",
                strategy_path=strategy_path
            )

            saved_msg = format_prompt(
                PROMPTS["ibfs"]["ui_messages"]["saved_result"],
                save_path=save_path,
                user_id=user_id
            )
            chat_history.append({"role": "system", "content": saved_msg})

            # Reset state for a new query
            state = {
                "user_id": user_id,
                "current_step": 0,
                "strategy_path": [],
                "strategies": [],
                "chat_history": chat_history,
            }

            return state, chat_history

        # If we're not at the final step, generate new strategies
        k = state.get("k", 3)
        query = state.get("query", "")

        # Generate sub-strategies for next step
        sub_strategies = generate_strategies(query, selected_strategy, k)

        # Format strategies for display
        valid_options = ", ".join(map(str, range(1, len(sub_strategies) + 1)))
        select_msg = format_prompt(
            PROMPTS["ibfs"]["ui_messages"]["select_strategy"],
            current_step=current_step + 1,
            max_steps=m,
            valid_options=valid_options
        )

        options_text = f"{select_msg}\n\n"
        for idx, strategy in enumerate(sub_strategies):
            options_text += f"{idx + 1}. {strategy}\n\n"

        chat_history.append({"role": "assistant", "content": options_text})

        # Update state
        state.update({
            "current_step": current_step,
            "strategy_path": strategy_path,
            "chat_history": chat_history,
            "strategies": sub_strategies,
        })

        return state, chat_history

    except ValueError:
        error_msg = format_prompt(
            PROMPTS["ibfs"]["ui_messages"]["error_invalid_number"],
            choice=choice
        )
        chat_history.append({"role": "system", "content": error_msg})
        return state, chat_history

    except Exception as e:
        error_msg = format_prompt(
            PROMPTS["ibfs"]["ui_messages"]["error_general"],
            error_message=str(e)
        )
        print(error_msg)
        chat_history.append({"role": "system", "content": error_msg})
        return state, chat_history