from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
import requests
import time
from datetime import datetime
from fastapi.middleware.cors import CORSMiddleware
import os
app = FastAPI(title="IoT Traffic Monitor API", 
              description="API to get the latest traffic status from IoT devices",
              version="1.0.0")

# Enable CORS
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Firebase configuration - same as in your HTML file
firebase_config = {
    "apiKey": os.getenv('a'),
    "projectId": os.getenv('b')
}

class TrafficResponse(BaseModel):
    detected_count: int
    traffic_status: str
    timestamp: str

def get_traffic_status(detected_count):
    """Determine traffic status based on detected count."""
    if detected_count < 4:
        return "LIGHT TRAFFIC"
    elif detected_count < 7:
        return "MEDIUM TRAFFIC"
    else:
        return "HEAVY TRAFFIC"

def fetch_latest_data():
    """Fetch the latest data from the IOT collection using Firebase REST API."""
    try:
        # Firestore REST API endpoint for querying collections
        base_url = f"https://firestore.googleapis.com/v1/projects/{firebase_config['projectId']}/databases/(default)/documents/IOT"
        
        # Make the request to get all documents
        response = requests.get(base_url, params={"key": firebase_config["apiKey"]})
        
        if response.status_code == 200:
            data = response.json()
            if 'documents' in data and data['documents']:
                # Sort documents by timestamp field (if it exists)
                sorted_docs = sorted(
                    data['documents'], 
                    key=lambda doc: doc.get('fields', {}).get('timestamp', {}).get('stringValue', ''),
                    reverse=True  # Most recent first
                )
                
                # Get the most recent document
                if sorted_docs:
                    doc_data = parse_firestore_document(sorted_docs[0])
                    return doc_data
            
            return None
        else:
            raise HTTPException(status_code=503, detail=f"Error fetching data from Firebase: {response.status_code}")
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Internal server error: {str(e)}")

def parse_firestore_document(doc):
    """Parse Firestore document from REST API format to a simple dict."""
    result = {}
    
    if 'fields' in doc:
        for key, value in doc['fields'].items():
            # Extract the value based on its type
            for type_key, actual_value in value.items():
                if type_key == 'stringValue':
                    result[key] = actual_value
                elif type_key == 'integerValue':
                    result[key] = int(actual_value)
                elif type_key == 'doubleValue':
                    result[key] = float(actual_value)
                elif type_key == 'booleanValue':
                    result[key] = bool(actual_value)
                elif type_key == 'timestampValue':
                    result[key] = actual_value
                elif type_key == 'arrayValue':
                    # Handle array values if needed
                    result[key] = [parse_firestore_value(item) for item in actual_value.get('values', [])]
                elif type_key == 'mapValue':
                    # Handle nested maps if needed
                    if 'fields' in actual_value:
                        result[key] = {k: parse_firestore_value(v) for k, v in actual_value['fields'].items()}
                    else:
                        result[key] = {}
    
    return result

def parse_firestore_value(value_dict):
    """Helper function to parse Firestore values."""
    for type_key, actual_value in value_dict.items():
        if type_key == 'stringValue':
            return actual_value
        elif type_key == 'integerValue':
            return int(actual_value)
        elif type_key == 'doubleValue':
            return float(actual_value)
        elif type_key == 'booleanValue':
            return bool(actual_value)
        elif type_key == 'timestampValue':
            return actual_value
    return None

@app.get("/", response_model=TrafficResponse)
async def get_traffic():
    """
    Get the latest traffic information
    
    Returns:
        - detected_count: Number of objects detected by the IoT device
        - traffic_status: Current traffic status classification (LIGHT/MEDIUM/HEAVY)
        - timestamp: Timestamp of the detection
    """
    data = fetch_latest_data()
    
    if not data or 'detected_count' not in data:
        raise HTTPException(status_code=404, detail="No traffic data available")
    
    detected_count = data.get('detected_count', 0)
    traffic_status = get_traffic_status(detected_count)
    timestamp = data.get('timestamp', datetime.now().isoformat())
    
    return TrafficResponse(
        detected_count=detected_count,
        traffic_status=traffic_status,
        timestamp=timestamp
    )

@app.get("/health")
async def health_check():
    """Health check endpoint"""
    return {"status": "healthy", "timestamp": datetime.now().isoformat()}