import re
import openai
import os
from dotenv import load_dotenv
from utils.db import MongoDBUtil
from bson import ObjectId
from .moderation import check_moderation_text

# Load environment variables
load_dotenv()
openai.api_key = os.getenv("OPENAI_API_KEY")

mongo_util = MongoDBUtil()

# Function to use GPT for extracting details
def gpt_extract_trip_details(sentence):
    """
    Use OpenAI GPT to extract destination and number of days.
    """
    prompt = (
        f"Extract the following details from this sentence:\n"
        f"Sentence: '{sentence}'\n\n"
        f"Details to extract:\n"
        f"1. Destination: (The place the user wants to travel to, None if not mentioned)\n"
        f"2. Number of Days: (Always convert written numbers like 'ten', 'fifteen', 'twenty five' into digits like 10, 15, 25. Return None if not explicitly mentioned)\n\n"
        f"Format the response as:\n"
        f"Destination: [destination]\n"
        f"Number of Days: [days]\n"
    )
    try:
        client = openai.OpenAI() 
        response = client.chat.completions.create(
            model="gpt-4o-mini",
            messages=[
                {"role": "system", "content": "You are an assistant that extracts structured details from sentences."},
                {"role": "user", "content": prompt}
            ],
            max_tokens=150,
            temperature=0.5
        )
        return response.choices[0].message.content.strip()
    except Exception as e:
        print(f"OpenAI API Error: {e}")
        return None

# Function to parse GPT response
def parse_gpt_response(response):
    """
    Parse GPT response into a structured dictionary and handle missing values.
    """
    try:
        result = {"destination": None, "num_days": None}

        if not response:
            return result

        lines = response.split("\n")

        for line in lines:
            if ": " in line:
                key, value = line.split(": ", 1)
                key = key.lower().strip()
                value = value.strip()

                if key == "destination":
                    result["destination"] = value if value and value.lower() != "none" else None
                elif key == "number of days":
                    if value.isdigit():
                        num_days = int(value)
                        if 1 <= num_days <= 31:
                            result["num_days"] = num_days
                        else:
                            result["num_days"] = None
                    else:
                        result["num_days"] = None

        return result
    except Exception as e:
        print(f"Error parsing GPT response: {e}")
        return {"destination": None, "num_days": None}

# Regex-based extraction
def extract_trip_details(sentence):
    """
    Extract destination and number of days using regex.
    """
    destination_pattern = r'(?:to|for)\s+(\w+(?:\s+\w+)*)'
    days_pattern = r'(\d+)\s+(?:days|day)'

    destination_match = re.search(destination_pattern, sentence, re.IGNORECASE)
    destination = destination_match.group(1).strip() if destination_match else None

    days_match = re.search(days_pattern, sentence, re.IGNORECASE)
    num_days = int(days_match.group(1)) if days_match else None

    # If "from" is present, it indicates origin, not destination
    if "from" in sentence.lower():
        destination = None

    return {"destination": destination, "num_days": num_days}

# Main processing function
def extract_sentence(sentence, user):
    """
    Complete pipeline for extracting travel details with fallback to regex if GPT fails.
    """
    sentence = sentence.lower().strip()  # Convert the sentence to lowercase before processing

    print("Using GPT to extract travel details...")
    gpt_response = gpt_extract_trip_details(sentence)
    if gpt_response:
        mongo_util.get_collection("users").update_one({"_id": ObjectId(user["_id"])},{"$inc": {"ai_gpt": -1}})
        gpt_details = parse_gpt_response(gpt_response)
        if gpt_details["destination"] is None and "from" in sentence.lower():
            gpt_details["destination"] = None
        return gpt_details

    print("GPT extraction failed or returned no details. Falling back to regex extraction...")
    return extract_trip_details(sentence)

# Main entry point
if __name__ == "__main__":
    sentence = input("Enter a trip-related sentence: ")
    result = extract_sentence(sentence)
    print("Extracted Travel Details:")
    print(result)