from fastapi import HTTPException, Request
from loguru import logger
import json
import redis
from typing import Optional, List, Union
from pydantic import BaseModel, ConfigDict, field_validator
from datetime import datetime, timedelta
import time

from config import settings
from langfuse import Langfuse
from llm.models import JiraWebhookPayload, AnalysisFlags
from llm.chains import analysis_chain, validate_response

class BadRequestError(HTTPException):
    def __init__(self, detail: str):
        super().__init__(status_code=400, detail=detail)

class RateLimitError(HTTPException):
    def __init__(self, detail: str):
        super().__init__(status_code=429, detail=detail)

class ValidationError(HTTPException):
    def __init__(self, detail: str):
        super().__init__(status_code=422, detail=detail)

class JiraWebhookHandler:
    def __init__(self):
        self.analysis_chain = analysis_chain
        self.redis = None
        self.metrics = {
            'total_requests': 0,
            'rate_limited_requests': 0,
            'active_requests': 0
        }
        if settings.redis.enabled:
            self.redis = redis.Redis.from_url(settings.redis.url)
            
    async def check_rate_limit(self, ip: str) -> bool:
        """Check if request is within rate limit using sliding window algorithm"""
        if not self.redis:
            return True
            
        current_time = time.time()
        window_size = settings.redis.rate_limit.window
        max_requests = settings.redis.rate_limit.max_requests
        
        # Remove old requests outside the window
        self.redis.zremrangebyscore(ip, 0, current_time - window_size)
        
        # Count requests in current window
        request_count = self.redis.zcard(ip)
        self.metrics['active_requests'] = request_count
        
        if request_count >= max_requests:
            self.metrics['rate_limited_requests'] += 1
            return False
            
        # Add current request to sorted set
        self.redis.zadd(ip, {current_time: current_time})
        self.redis.expire(ip, window_size)
        return True

    async def handle_webhook(self, payload: JiraWebhookPayload, request: Request):
        try:
            self.metrics['total_requests'] += 1
            # Check rate limit
            if settings.redis.enabled:
                ip = request.client.host
                if not await self.check_rate_limit(ip):
                    raise RateLimitError(
                        f"Too many requests. Limit is {settings.redis.rate_limit.max_requests} "
                        f"requests per {settings.redis.rate_limit.window} seconds"
                    )
            if not payload.issueKey:
                raise BadRequestError("Missing required field: issueKey")
                
            if not payload.summary:
                raise BadRequestError("Missing required field: summary")
                
            logger.bind(
                issue_key=payload.issueKey,
                timestamp=datetime.utcnow().isoformat()
            ).info("Received webhook")
            
            # Create Langfuse trace if enabled
            trace = None
            if settings.langfuse.enabled:
                trace = settings.langfuse_client.start_span(
                    name="Jira Webhook",
                    input=payload.dict(),
                    metadata={
                        "trace_id": f"webhook-{payload.issueKey}",
                            "issue_key": payload.issueKey,
                            "timestamp": datetime.utcnow().isoformat()
                        }
                    )

            llm_input = {
                "issueKey": payload.issueKey,
                "summary": payload.summary,
                "description": payload.description if payload.description else "No description provided.",
                "status": payload.status if payload.status else "Unknown",
                "labels": ", ".join(payload.labels) if payload.labels else "None",
                "assignee": payload.assignee if payload.assignee else "Unassigned",
                "updated": payload.updated if payload.updated else "Unknown",
                "comment": payload.comment if payload.comment else "No new comment provided."
            }
            
            # Create Langfuse span for LLM processing if enabled
            llm_span = None
            if settings.langfuse.enabled and trace:
                llm_span = trace.start_span(
                    name="LLM Processing",
                    input=llm_input,
                    metadata={
                        "model": settings.llm.model if settings.llm.mode == 'openai' else settings.llm.ollama_model
                    }
                )

            try:
                analysis_result = await self.analysis_chain.ainvoke(llm_input)
                
                # Update Langfuse span with output if enabled
                if settings.langfuse.enabled and llm_span:
                    llm_span.update(output=analysis_result)
                    llm_span.end()
                
                # Validate LLM response
                if not validate_response(analysis_result):
                    logger.warning(f"Invalid LLM response format for {payload.issueKey}")
                    analysis_result = {
                        "hasMultipleEscalations": False,
                        "customerSentiment": "neutral"
                    }
                
                logger.debug(f"LLM Analysis Result for {payload.issueKey}: {json.dumps(analysis_result, indent=2)}")
                return {"status": "success", "analysis_flags": analysis_result}
                
            except Exception as e:
                logger.error(f"LLM processing failed for {payload.issueKey}: {str(e)}")
                
                # Log error to Langfuse if enabled
                if settings.langfuse.enabled and llm_span:
                    llm_span.error(e)
                    llm_span.end()
                return {
                    "status": "error",
                    "analysis_flags": {
                        "hasMultipleEscalations": False,
                        "customerSentiment": "neutral"
                    },
                    "error": str(e)
                }

        except Exception as e:
            logger.error(f"Error processing webhook: {str(e)}")
            import traceback
            logger.error(f"Stack trace: {traceback.format_exc()}")
            
            # Log error to Langfuse if enabled
            if settings.langfuse.enabled and trace:
                trace.end(error=e)
                
            raise HTTPException(status_code=500, detail=f"Internal Server Error: {str(e)}")