"""
Flare – Chat Handler  (v1.7 · parameter parsing düzeltmesi)
==========================================
"""

import re, json, sys, httpx
from datetime import datetime
from typing import Dict, List, Optional
from fastapi import APIRouter, HTTPException, Header
from pydantic import BaseModel
import requests

from prompt_builder import build_intent_prompt, build_parameter_prompt
from utils import log
from api_executor import call_api as execute_api  
from config_provider import ConfigProvider
from validation_engine import validate
from session import session_store, Session

# ─────────────────────────  HELPERS ───────────────────────── #
def _trim_response(raw: str) -> str:
    """
    Remove everything after the first logical assistant block or intent tag.
    Also strips trailing 'assistant' artifacts and prompt injections.
    """
    # Stop at our own rules if model leaked them
    for stop in ["#DETECTED_INTENT", "⚠️", "\nassistant", "assistant\n", "assistant"]:
        idx = raw.find(stop)
        if idx != -1:
            raw = raw[:idx]
    # Normalise selamlama
    raw = re.sub(r"Hoş[\s-]?geldin(iz)?", "Hoş geldiniz", raw, flags=re.IGNORECASE)
    return raw.strip()

def _safe_intent_parse(raw: str) -> tuple[str, str]:
    """Extract intent name and extra tail."""
    m = re.search(r"#DETECTED_INTENT:\s*([A-Za-z0-9_-]+)", raw)
    if not m:
        return "", raw
    name = m.group(1)
    # Remove 'assistant' suffix if exists
    if name.endswith("assistant"):
        name = name[:-9]  # Remove last 9 chars ("assistant")
        log(f"🔧 Removed 'assistant' suffix from intent name")
    tail = raw[m.end():]
    log(f"🎯 Parsed intent: {name}")
    return name, tail

# ─────────────────────────  CONFIG ───────────────────────── #
cfg = ConfigProvider.get()
SPARK_URL = str(cfg.global_config.spark_endpoint).rstrip("/")
ALLOWED_INTENTS = {"flight-booking", "flight-info", "booking-cancel"}

# ─────────────────────────  SPARK ───────────────────────── #
async def spark_generate(s: Session, prompt: str, user_msg: str) -> str:
    """Call Spark with proper error handling"""
    try:
        project = next((p for p in cfg.projects if p.name == s.project_name), None)
        if not project:
            raise ValueError(f"Project not found: {s.project_name}")
        
        version = next((v for v in project.versions if v.published), None)
        if not version:
            raise ValueError("No published version found")
        
        payload = {
            "project_name": s.project_name,
            "user_input": user_msg,
            "context": s.chat_history[-10:],
            "system_prompt": prompt
        }
        
        log(f"🚀 Calling Spark for session {s.session_id[:8]}...")
        log(f"📋 Prompt preview (first 200 chars): {prompt[:200]}...")
        
        async with httpx.AsyncClient(timeout=60) as client:
            response = await client.post(SPARK_URL + "/generate", json=payload)
            response.raise_for_status()
            data = response.json()
            raw = (data.get("assistant") or data.get("model_answer") or data.get("text", "")).strip()
            log(f"🪄 Spark raw: {raw[:120]!r}")
            return raw
            
    except httpx.TimeoutException:
        log(f"⏱️ Spark timeout for session {s.session_id[:8]}")
        raise
    except Exception as e:
        log(f"❌ Spark error: {e}")
        raise

# ─────────────────────────  FASTAPI ───────────────────────── #
router = APIRouter()

@router.get("/")
def health(): 
    return {"status": "ok", "sessions": len(session_store._sessions)}

class StartRequest(BaseModel): 
    project_name: str

class ChatRequest(BaseModel):  
    user_input: str

class ChatResponse(BaseModel):  
    session_id: str
    answer: str

@router.post("/start_session", response_model=ChatResponse)
async def start_session(req: StartRequest):
    """Create new session"""
    try:
        # Validate project exists
        project = next((p for p in cfg.projects if p.name == req.project_name and p.enabled), None)
        if not project:
            raise HTTPException(404, f"Project '{req.project_name}' not found or disabled")
        
        # Create session
        session = session_store.create_session(req.project_name)
        greeting = "Hoş geldiniz! Size nasıl yardımcı olabilirim?"
        session.add_turn("assistant", greeting)
        
        return ChatResponse(session_id=session.session_id, answer=greeting)
        
    except Exception as e:
        log(f"❌ Error creating session: {e}")
        raise HTTPException(500, str(e))

@router.post("/chat", response_model=ChatResponse)
async def chat(body: ChatRequest, x_session_id: str = Header(...)):
    """Process chat message"""
    try:
        # Get session
        session = session_store.get_session(x_session_id)
        if not session:
            raise HTTPException(404, "Session not found")
        
        user_input = body.user_input.strip()
        if not user_input:
            raise HTTPException(400, "Empty message")
            
        log(f"💬 User input: {user_input}")
        log(f"📊 Session state: {session.state}, last_intent: {session.last_intent}")
        
        session.add_turn("user", user_input)
        
        # Get project config
        project = next((p for p in cfg.projects if p.name == session.project_name), None)
        if not project:
            raise HTTPException(500, "Project configuration lost")
            
        version = next((v for v in project.versions if v.published), None)
        if not version:
            raise HTTPException(500, "No published version")

        # Handle based on state
        if session.state == "await_param":
            log(f"🔄 Handling parameter followup for missing: {session.awaiting_parameters}")
            answer = await _handle_parameter_followup(session, user_input, version)
        else:
            log("🆕 Handling new message")
            answer = await _handle_new_message(session, user_input, version)
        
        session.add_turn("assistant", answer)
        return ChatResponse(session_id=session.session_id, answer=answer)
        
    except HTTPException:
        raise
    except Exception as e:
        log(f"❌ Chat error: {e}")
        session.reset_flow()
        error_msg = "Bir hata oluştu. Lütfen tekrar deneyin."
        session.add_turn("assistant", error_msg)
        return ChatResponse(session_id=x_session_id, answer=error_msg)

# ─────────────────────────  MESSAGE HANDLERS ───────────────────────── #
async def _handle_new_message(session: Session, user_input: str, version) -> str:
    """Handle new message (not parameter followup)"""
    # Build intent detection prompt
    prompt = build_intent_prompt(
        version.general_prompt,
        session.chat_history,
        user_input,
        version.intents
    )
    
    # Get Spark response
    raw = await spark_generate(session, prompt, user_input)
    
    # Empty response fallback
    if not raw:
        log("⚠️ Empty response from Spark")
        return "Üzgünüm, mesajınızı anlayamadım. Lütfen tekrar dener misiniz?"
    
    # Check for intent
    if not raw.startswith("#DETECTED_INTENT"):
        # Small talk response
        log("💬 No intent detected, returning small talk")
        return _trim_response(raw)
    
    # Parse intent
    intent_name, tail = _safe_intent_parse(raw)
    
    # Validate intent
    if intent_name not in ALLOWED_INTENTS:
        log(f"⚠️ Invalid intent: {intent_name}")
        return _trim_response(tail) if tail else "Size nasıl yardımcı olabilirim?"
    
    # Short message guard (less than 3 words usually means incomplete request)
    if len(user_input.split()) < 3 and intent_name != "flight-info":
        log(f"⚠️ Message too short ({len(user_input.split())} words) for intent {intent_name}")
        return _trim_response(tail) if tail else "Lütfen talebinizi biraz daha detaylandırır mısınız?"
    
    # Find intent config
    intent_config = next((i for i in version.intents if i.name == intent_name), None)
    if not intent_config:
        log(f"❌ Intent config not found for: {intent_name}")
        return "Üzgünüm, bu işlemi gerçekleştiremiyorum."
    
    # Set intent in session
    session.last_intent = intent_name
    log(f"✅ Intent set: {intent_name}")
    
    # Log intent parameters
    log(f"📋 Intent parameters: {[p.name for p in intent_config.parameters]}")
    
    # Extract parameters
    return await _extract_parameters(session, intent_config, user_input)

async def _handle_parameter_followup(session: Session, user_input: str, version) -> str:
    """Handle parameter collection followup"""
    if not session.last_intent:
        log("⚠️ No last intent in session")
        session.reset_flow()
        return "Üzgünüm, hangi işlem için bilgi istediğimi unuttum. Baştan başlayalım."
    
    # Get intent config
    intent_config = next((i for i in version.intents if i.name == session.last_intent), None)
    if not intent_config:
        log(f"❌ Intent config not found for: {session.last_intent}")
        session.reset_flow()
        return "Bir hata oluştu. Lütfen tekrar deneyin."
    
    # Try to extract missing parameters
    missing = session.awaiting_parameters
    log(f"🔍 Trying to extract missing params: {missing}")
    
    prompt = build_parameter_prompt(intent_config, missing, user_input, session.chat_history)
    raw = await spark_generate(session, prompt, user_input)
    
    # Try parsing with or without #PARAMETERS: prefix
    success = _process_parameters(session, intent_config, raw)
    
    if not success:
        # Increment miss count
        session.missing_ask_count += 1
        log(f"⚠️ No parameters extracted, miss count: {session.missing_ask_count}")
        
        if session.missing_ask_count >= 3:
            session.reset_flow()
            return "Üzgünüm, istediğiniz bilgileri anlayamadım. Başka bir konuda yardımcı olabilir miyim?"
        return "Üzgünüm, anlayamadım. Lütfen tekrar söyler misiniz?"
    
    # Check if we have all required parameters
    missing = _get_missing_parameters(session, intent_config)
    log(f"📊 Still missing params: {missing}")
    
    if missing:
        session.awaiting_parameters = missing
        param = next(p for p in intent_config.parameters if p.name == missing[0])
        return f"{param.caption} bilgisini alabilir miyim?"
    
    # All parameters collected, call API
    log("✅ All parameters collected, calling API")
    session.state = "call_api"
    return await _execute_api_call(session, intent_config)

# ─────────────────────────  PARAMETER HANDLING ───────────────────────── #
async def _extract_parameters(session: Session, intent_config, user_input: str) -> str:
    """Extract parameters from user input"""
    missing = _get_missing_parameters(session, intent_config)
    log(f"🔍 Missing parameters: {missing}")
    
    if not missing:
        # All parameters already available
        log("✅ All parameters already available")
        return await _execute_api_call(session, intent_config)
    
    # Build parameter extraction prompt
    prompt = build_parameter_prompt(intent_config, missing, user_input, session.chat_history)
    raw = await spark_generate(session, prompt, user_input)
    
    # Try processing with flexible parsing
    success = _process_parameters(session, intent_config, raw)
    
    if success:
        missing = _get_missing_parameters(session, intent_config)
        log(f"📊 After extraction, missing: {missing}")
    else:
        log("⚠️ Failed to extract parameters from response")
    
    if missing:
        # Still missing parameters
        session.state = "await_param"
        session.awaiting_parameters = missing
        session.missing_ask_count = 0
        param = next(p for p in intent_config.parameters if p.name == missing[0])
        log(f"❓ Asking for parameter: {param.name} ({param.caption})")
        return f"{param.caption} bilgisini alabilir miyim?"
    
    # All parameters collected
    log("✅ All parameters collected after extraction")
    return await _execute_api_call(session, intent_config)

def _get_missing_parameters(session: Session, intent_config) -> List[str]:
    """Get list of missing required parameters"""
    missing = [
        p.name for p in intent_config.parameters 
        if p.required and p.variable_name not in session.variables
    ]
    log(f"📊 Session variables: {list(session.variables.keys())}")
    return missing

def _process_parameters(session: Session, intent_config, raw: str) -> bool:
    """Process parameter extraction response with flexible parsing"""
    try:
        # Try to parse JSON, handling both with and without #PARAMETERS: prefix
        json_str = raw
        if raw.startswith("#PARAMETERS:"):
            json_str = raw[len("#PARAMETERS:"):]
            log(f"🔍 Found #PARAMETERS: prefix, removing it")
        
        # Clean up any trailing content after JSON
        # Find the closing brace for the JSON object
        brace_count = 0
        json_end = -1
        in_string = False
        escape_next = False
        
        for i, char in enumerate(json_str):
            if escape_next:
                escape_next = False
                continue
                
            if char == '\\':
                escape_next = True
                continue
                
            if char == '"' and not escape_next:
                in_string = not in_string
                continue
                
            if not in_string:
                if char == '{':
                    brace_count += 1
                elif char == '}':
                    brace_count -= 1
                    if brace_count == 0:
                        json_end = i + 1
                        break
        
        if json_end > 0:
            json_str = json_str[:json_end]
            log(f"🔍 Cleaned JSON string: {json_str[:200]}")
        
        data = json.loads(json_str)
        
        extracted = data.get("extracted", [])
        log(f"📦 Extracted data: {extracted}")
        
        any_valid = False
        
        for param_data in extracted:
            param_name = param_data.get("name")
            param_value = param_data.get("value")
            
            if not param_name or not param_value:
                log(f"⚠️ Invalid param data: {param_data}")
                continue
            
            # Find parameter config
            param_config = next(
                (p for p in intent_config.parameters if p.name == param_name),
                None
            )
            if not param_config:
                log(f"⚠️ Parameter config not found for: {param_name}")
                continue
            
            # Validate parameter
            if validate(str(param_value), param_config):
                session.variables[param_config.variable_name] = str(param_value)
                any_valid = True
                log(f"✅ Extracted {param_name}={param_value} → {param_config.variable_name}")
            else:
                log(f"❌ Invalid {param_name}={param_value}")
        
        return any_valid
        
    except json.JSONDecodeError as e:
        log(f"❌ JSON parsing error: {e}")
        log(f"❌ Failed to parse: {raw[:200]}")
        return False
    except Exception as e:
        log(f"❌ Parameter processing error: {e}")
        return False

# ─────────────────────────  API EXECUTION ───────────────────────── #
async def _execute_api_call(session: Session, intent_config) -> str:
    """Execute API call and return humanized response"""
    try:
        session.state = "call_api"
        api_name = intent_config.action
        api_config = cfg.get_api(api_name)
        
        if not api_config:
            log(f"❌ API config not found: {api_name}")
            session.reset_flow()
            return intent_config.fallback_error_prompt or "İşlem başarısız oldu."
        
        log(f"📡 Calling API: {api_name}")
        log(f"📦 API variables: {session.variables}")
        
        # Execute API call with session
        response = execute_api(api_config, session)
        api_json = response.json()
        log(f"✅ API response: {api_json}")
        
        # Humanize response
        session.state = "humanize"
        if api_config.response_prompt:
            prompt = api_config.response_prompt.replace(
                "{{api_response}}", 
                json.dumps(api_json, ensure_ascii=False)
            )
            human_response = await spark_generate(session, prompt, json.dumps(api_json))
            session.reset_flow()
            return human_response if human_response else f"İşlem sonucu: {api_json}"
        else:
            session.reset_flow()
            return f"İşlem tamamlandı: {api_json}"
            
    except requests.exceptions.Timeout:
        log(f"⏱️ API timeout: {api_name}")
        session.reset_flow()
        return intent_config.fallback_timeout_prompt or "İşlem zaman aşımına uğradı."
    except Exception as e:
        log(f"❌ API call error: {e}")
        session.reset_flow()
        return intent_config.fallback_error_prompt or "İşlem sırasında bir hata oluştu."