#!/usr/bin/env python3
"""
FastAPI web interface for water monitoring system
"""

import asyncio
import threading
from datetime import datetime, timedelta
from typing import List, Dict, Any, Optional
from contextlib import asynccontextmanager

from fastapi import FastAPI, HTTPException, BackgroundTasks, Depends
from fastapi.responses import HTMLResponse, JSONResponse
from fastapi.staticfiles import StaticFiles
from fastapi.middleware.cors import CORSMiddleware
from pydantic import BaseModel, Field

from .water_scraper_v3 import EnhancedWaterMonitorScraper
from .config import Config
from .models import WaterMeasurement, StationInfo, ScrapingResult, StationCreateRequest, StationUpdateRequest, StationStatus
from .health_check import HealthCheckManager, DatabaseHealthCheck, APIHealthCheck, MemoryHealthCheck
from .metrics import get_metrics_collector, increment_counter, set_gauge
from .logging_config import setup_logging, get_logger

logger = get_logger(__name__)

# Pydantic models for API responses
class StationResponse(BaseModel):
    station_id: int
    station_code: str
    thai_name: str
    english_name: str
    latitude: Optional[float] = None
    longitude: Optional[float] = None
    geohash: Optional[str] = None
    status: str = "active"

class StationCreateModel(BaseModel):
    station_code: str = Field(..., description="Station code (e.g., P.1, P.20)")
    thai_name: str = Field(..., description="Thai name of the station")
    english_name: str = Field(..., description="English name of the station")
    latitude: Optional[float] = Field(None, ge=-90, le=90, description="Latitude coordinate")
    longitude: Optional[float] = Field(None, ge=-180, le=180, description="Longitude coordinate")
    geohash: Optional[str] = Field(None, description="Geohash for the location")
    status: str = Field("active", description="Station status")

class StationUpdateModel(BaseModel):
    thai_name: Optional[str] = Field(None, description="Thai name of the station")
    english_name: Optional[str] = Field(None, description="English name of the station")
    latitude: Optional[float] = Field(None, ge=-90, le=90, description="Latitude coordinate")
    longitude: Optional[float] = Field(None, ge=-180, le=180, description="Longitude coordinate")
    geohash: Optional[str] = Field(None, description="Geohash for the location")
    status: Optional[str] = Field(None, description="Station status")

class MeasurementResponse(BaseModel):
    timestamp: datetime
    station_code: str
    station_name_en: str
    station_name_th: str
    water_level: float
    discharge: float
    discharge_percent: Optional[float] = None
    status: str = "active"

class HealthResponse(BaseModel):
    overall_status: str
    timestamp: str
    checks: Dict[str, Dict[str, Any]]

class MetricsResponse(BaseModel):
    counters: Dict[str, float]
    gauges: Dict[str, float]
    histograms: Dict[str, Dict[str, float]]

class ScrapingStatusResponse(BaseModel):
    is_running: bool
    last_run: Optional[datetime] = None
    next_run: Optional[datetime] = None
    total_runs: int = 0
    successful_runs: int = 0
    failed_runs: int = 0

# Global application state
app_state = {
    "scraper": None,
    "health_manager": None,
    "scraping_task": None,
    "is_scraping": False,
    "scraping_stats": {
        "total_runs": 0,
        "successful_runs": 0,
        "failed_runs": 0,
        "last_run": None,
        "next_run": None
    }
}

@asynccontextmanager
async def lifespan(app: FastAPI):
    """Application lifespan manager"""
    # Startup
    logger.info("Starting Water Monitor API...")
    
    # Initialize configuration
    try:
        Config.validate_config()
        logger.info("Configuration validated successfully")
    except Exception as e:
        logger.error(f"Configuration validation failed: {e}")
        raise
    
    # Initialize scraper
    db_config = Config.get_database_config()
    app_state["scraper"] = EnhancedWaterMonitorScraper(db_config)
    
    # Initialize health checks
    health_manager = HealthCheckManager()
    health_manager.add_check(DatabaseHealthCheck(app_state["scraper"].db_adapter))
    health_manager.add_check(APIHealthCheck(Config.API_URL, app_state["scraper"].session))
    health_manager.add_check(MemoryHealthCheck(max_memory_mb=1000))
    app_state["health_manager"] = health_manager
    
    # Start background scraping task
    app_state["scraping_task"] = asyncio.create_task(background_scraping_task())
    
    logger.info("Water Monitor API started successfully")
    
    yield
    
    # Shutdown
    logger.info("Shutting down Water Monitor API...")
    
    if app_state["scraping_task"]:
        app_state["scraping_task"].cancel()
        try:
            await app_state["scraping_task"]
        except asyncio.CancelledError:
            pass
    
    logger.info("Water Monitor API shutdown complete")

# Create FastAPI app
app = FastAPI(
    title="Northern Thailand Ping River Monitor API",
    description="Real-time water level monitoring system for Northern Thailand's Ping River Basin stations",
    version="3.1.3",
    lifespan=lifespan
)

# Add CORS middleware
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # Configure appropriately for production
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

async def background_scraping_task():
    """Background task for periodic data scraping"""
    while True:
        try:
            if not app_state["is_scraping"]:
                app_state["is_scraping"] = True
                
                # Run scraping cycle
                scraper = app_state["scraper"]
                if scraper:
                    logger.info("Starting background scraping cycle")
                    start_time = datetime.now()
                    
                    try:
                        result = scraper.run_scraping_cycle()
                        
                        # Update stats
                        app_state["scraping_stats"]["total_runs"] += 1
                        app_state["scraping_stats"]["last_run"] = start_time
                        
                        if result:
                            app_state["scraping_stats"]["successful_runs"] += 1
                            increment_counter("scraping_cycles_successful")
                            logger.info("Background scraping cycle completed successfully")
                        else:
                            app_state["scraping_stats"]["failed_runs"] += 1
                            increment_counter("scraping_cycles_failed")
                            logger.warning("Background scraping cycle completed with no new data")
                        
                        # Update metrics
                        set_gauge("last_scraping_timestamp", start_time.timestamp())
                        
                    except Exception as e:
                        app_state["scraping_stats"]["failed_runs"] += 1
                        increment_counter("scraping_cycles_failed")
                        logger.error(f"Background scraping cycle failed: {e}")
                
                app_state["is_scraping"] = False
            
            # Calculate next run time
            interval_seconds = Config.SCRAPING_INTERVAL_HOURS * 3600
            app_state["scraping_stats"]["next_run"] = datetime.now() + timedelta(seconds=interval_seconds)
            
            # Wait for next cycle
            await asyncio.sleep(interval_seconds)
            
        except asyncio.CancelledError:
            logger.info("Background scraping task cancelled")
            break
        except Exception as e:
            logger.error(f"Error in background scraping task: {e}")
            await asyncio.sleep(60)  # Wait a minute before retrying

# API Routes

@app.get("/", response_class=HTMLResponse)
async def root():
    """Root endpoint with basic dashboard"""
    html_content = """
    <!DOCTYPE html>
    <html>
    <head>
        <title>Northern Thailand Ping River Monitor</title>
        <style>
            body { font-family: Arial, sans-serif; margin: 40px; }
            .header { color: #2c3e50; border-bottom: 2px solid #3498db; padding-bottom: 10px; }
            .section { margin: 20px 0; padding: 15px; border: 1px solid #ddd; border-radius: 5px; }
            .status-healthy { color: #27ae60; }
            .status-degraded { color: #f39c12; }
            .status-unhealthy { color: #e74c3c; }
            .endpoint { background: #f8f9fa; padding: 10px; margin: 5px 0; border-radius: 3px; }
            .endpoint code { color: #2c3e50; }
        </style>
    </head>
    <body>
        <div class="header">
            <h1>🏔️ Northern Thailand Ping River Monitor API</h1>
            <p>Real-time water level monitoring system for the Ping River Basin in Northern Thailand</p>
        </div>
        
        <div class="section">
            <h2>📊 Quick Status</h2>
            <p>API is running and monitoring 16 water stations along the Ping River</p>
            <p>Coverage: From Chiang Dao to Nakhon Sawan</p>
            <p>Data collection interval: Every hour</p>
        </div>
        
        <div class="section">
            <h2>🔗 API Endpoints</h2>
            <div class="endpoint"><code>GET /health</code> - System health status</div>
            <div class="endpoint"><code>GET /metrics</code> - Application metrics</div>
            <div class="endpoint"><code>GET /stations</code> - List all monitoring stations</div>
            <div class="endpoint"><code>POST /stations</code> - Add new monitoring station</div>
            <div class="endpoint"><code>PUT /stations/{station_id}</code> - Update station information</div>
            <div class="endpoint"><code>GET /measurements/latest</code> - Latest measurements</div>
            <div class="endpoint"><code>GET /measurements/station/{station_code}</code> - Station-specific data</div>
            <div class="endpoint"><code>POST /scrape/trigger</code> - Trigger manual data collection</div>
            <div class="endpoint"><code>GET /scraping/status</code> - Scraping status</div>
            <div class="endpoint"><code>GET /docs</code> - Interactive API documentation</div>
        </div>
        
        <div class="section">
            <h2>📈 Monitoring</h2>
            <p>• Grafana dashboards available for data visualization</p>
            <p>• Health checks monitor database, API, and system resources</p>
            <p>• Metrics collection for performance monitoring</p>
        </div>
    </body>
    </html>
    """
    return HTMLResponse(content=html_content)

@app.get("/health", response_model=HealthResponse)
async def get_health():
    """Get system health status"""
    increment_counter("api_requests", labels={"endpoint": "health"})
    
    health_manager = app_state["health_manager"]
    if not health_manager:
        raise HTTPException(status_code=503, detail="Health manager not initialized")
    
    # Run health checks
    results = health_manager.run_all_checks()
    summary = health_manager.get_health_summary()
    
    return HealthResponse(**summary)

@app.get("/metrics", response_model=MetricsResponse)
async def get_metrics():
    """Get application metrics"""
    increment_counter("api_requests", labels={"endpoint": "metrics"})
    
    metrics_collector = get_metrics_collector()
    metrics = metrics_collector.get_all_metrics()
    
    return MetricsResponse(**metrics)

@app.get("/stations", response_model=List[StationResponse])
async def get_stations():
    """Get list of all monitoring stations"""
    increment_counter("api_requests", labels={"endpoint": "stations"})
    
    scraper = app_state["scraper"]
    if not scraper:
        raise HTTPException(status_code=503, detail="Scraper not initialized")
    
    stations = []
    for station_id, station_info in scraper.station_mapping.items():
        stations.append(StationResponse(
            station_id=int(station_id),
            station_code=station_info["code"],
            thai_name=station_info["thai_name"],
            english_name=station_info["english_name"],
            latitude=station_info.get("latitude"),
            longitude=station_info.get("longitude"),
            status="active"
        ))
    
    return stations

@app.post("/stations", response_model=StationResponse)
async def create_station(station: StationCreateModel):
    """Create a new monitoring station"""
    increment_counter("api_requests", labels={"endpoint": "create_station"})
    
    scraper = app_state["scraper"]
    if not scraper:
        raise HTTPException(status_code=503, detail="Scraper not initialized")
    
    try:
        # Find next available station ID
        existing_ids = [int(sid) for sid in scraper.station_mapping.keys()]
        new_station_id = max(existing_ids) + 1 if existing_ids else 1
        
        # Add to station mapping
        scraper.station_mapping[str(new_station_id)] = {
            'code': station.station_code,
            'thai_name': station.thai_name,
            'english_name': station.english_name,
            'latitude': station.latitude,
            'longitude': station.longitude,
            'geohash': station.geohash
        }
        
        logger.info(f"Created new station: {station.station_code} ({station.english_name})")
        
        return StationResponse(
            station_id=new_station_id,
            station_code=station.station_code,
            thai_name=station.thai_name,
            english_name=station.english_name,
            latitude=station.latitude,
            longitude=station.longitude,
            geohash=station.geohash,
            status=station.status
        )
        
    except Exception as e:
        logger.error(f"Error creating station: {e}")
        raise HTTPException(status_code=500, detail=str(e))

@app.put("/stations/{station_id}", response_model=StationResponse)
async def update_station(station_id: int, updates: StationUpdateModel):
    """Update an existing monitoring station"""
    increment_counter("api_requests", labels={"endpoint": "update_station"})
    
    scraper = app_state["scraper"]
    if not scraper:
        raise HTTPException(status_code=503, detail="Scraper not initialized")
    
    station_key = str(station_id)
    if station_key not in scraper.station_mapping:
        raise HTTPException(status_code=404, detail="Station not found")
    
    try:
        station_info = scraper.station_mapping[station_key]
        
        # Update fields if provided
        if updates.thai_name is not None:
            station_info['thai_name'] = updates.thai_name
        if updates.english_name is not None:
            station_info['english_name'] = updates.english_name
        if updates.latitude is not None:
            station_info['latitude'] = updates.latitude
        if updates.longitude is not None:
            station_info['longitude'] = updates.longitude
        if updates.geohash is not None:
            station_info['geohash'] = updates.geohash
        
        logger.info(f"Updated station {station_id}: {station_info['code']}")
        
        return StationResponse(
            station_id=station_id,
            station_code=station_info['code'],
            thai_name=station_info['thai_name'],
            english_name=station_info['english_name'],
            latitude=station_info.get('latitude'),
            longitude=station_info.get('longitude'),
            geohash=station_info.get('geohash'),
            status=updates.status or "active"
        )
        
    except Exception as e:
        logger.error(f"Error updating station {station_id}: {e}")
        raise HTTPException(status_code=500, detail=str(e))

@app.delete("/stations/{station_id}")
async def delete_station(station_id: int):
    """Delete a monitoring station"""
    increment_counter("api_requests", labels={"endpoint": "delete_station"})
    
    scraper = app_state["scraper"]
    if not scraper:
        raise HTTPException(status_code=503, detail="Scraper not initialized")
    
    station_key = str(station_id)
    if station_key not in scraper.station_mapping:
        raise HTTPException(status_code=404, detail="Station not found")
    
    try:
        station_info = scraper.station_mapping.pop(station_key)
        logger.info(f"Deleted station {station_id}: {station_info['code']}")
        
        return {"message": f"Station {station_info['code']} deleted successfully"}
        
    except Exception as e:
        logger.error(f"Error deleting station {station_id}: {e}")
        raise HTTPException(status_code=500, detail=str(e))

@app.get("/stations/{station_id}", response_model=StationResponse)
async def get_station(station_id: int):
    """Get details of a specific monitoring station"""
    increment_counter("api_requests", labels={"endpoint": "get_station"})
    
    scraper = app_state["scraper"]
    if not scraper:
        raise HTTPException(status_code=503, detail="Scraper not initialized")
    
    station_key = str(station_id)
    if station_key not in scraper.station_mapping:
        raise HTTPException(status_code=404, detail="Station not found")
    
    station_info = scraper.station_mapping[station_key]
    
    return StationResponse(
        station_id=station_id,
        station_code=station_info['code'],
        thai_name=station_info['thai_name'],
        english_name=station_info['english_name'],
        latitude=station_info.get('latitude'),
        longitude=station_info.get('longitude'),
        geohash=station_info.get('geohash'),
        status="active"
    )

@app.get("/measurements/latest", response_model=List[MeasurementResponse])
async def get_latest_measurements(limit: int = 100):
    """Get latest measurements from all stations"""
    increment_counter("api_requests", labels={"endpoint": "measurements_latest"})
    
    scraper = app_state["scraper"]
    if not scraper or not scraper.db_adapter:
        raise HTTPException(status_code=503, detail="Database not available")
    
    try:
        measurements = scraper.get_latest_data(limit=limit)
        
        response = []
        for measurement in measurements:
            response.append(MeasurementResponse(
                timestamp=measurement["timestamp"],
                station_code=measurement["station_code"],
                station_name_en=measurement["station_name_en"],
                station_name_th=measurement["station_name_th"],
                water_level=measurement["water_level"],
                discharge=measurement["discharge"],
                discharge_percent=measurement.get("discharge_percent"),
                status=measurement.get("status", "active")
            ))
        
        return response
        
    except Exception as e:
        logger.error(f"Error fetching latest measurements: {e}")
        raise HTTPException(status_code=500, detail=str(e))

@app.get("/measurements/station/{station_code}", response_model=List[MeasurementResponse])
async def get_station_measurements(
    station_code: str, 
    hours: int = 24,
    limit: int = 1000
):
    """Get measurements for a specific station"""
    increment_counter("api_requests", labels={"endpoint": "measurements_station"})
    
    scraper = app_state["scraper"]
    if not scraper or not scraper.db_adapter:
        raise HTTPException(status_code=503, detail="Database not available")
    
    try:
        # Get measurements for the specified time range
        end_time = datetime.now()
        start_time = end_time - timedelta(hours=hours)
        
        measurements = scraper.db_adapter.get_measurements_by_timerange(
            start_time, end_time, station_codes=[station_code]
        )
        
        # Limit results
        measurements = measurements[:limit]
        
        response = []
        for measurement in measurements:
            response.append(MeasurementResponse(
                timestamp=measurement["timestamp"],
                station_code=measurement["station_code"],
                station_name_en=measurement["station_name_en"],
                station_name_th=measurement["station_name_th"],
                water_level=measurement["water_level"],
                discharge=measurement["discharge"],
                discharge_percent=measurement.get("discharge_percent"),
                status=measurement.get("status", "active")
            ))
        
        return response
        
    except Exception as e:
        logger.error(f"Error fetching station measurements: {e}")
        raise HTTPException(status_code=500, detail=str(e))

@app.post("/scrape/trigger")
async def trigger_scraping(background_tasks: BackgroundTasks):
    """Trigger manual data scraping"""
    increment_counter("api_requests", labels={"endpoint": "scrape_trigger"})
    
    if app_state["is_scraping"]:
        raise HTTPException(status_code=409, detail="Scraping already in progress")
    
    scraper = app_state["scraper"]
    if not scraper:
        raise HTTPException(status_code=503, detail="Scraper not initialized")
    
    def run_scraping():
        """Background task to run scraping"""
        try:
            app_state["is_scraping"] = True
            logger.info("Manual scraping triggered via API")
            
            result = scraper.run_scraping_cycle()
            
            # Update stats
            app_state["scraping_stats"]["total_runs"] += 1
            app_state["scraping_stats"]["last_run"] = datetime.now()
            
            if result:
                app_state["scraping_stats"]["successful_runs"] += 1
                increment_counter("manual_scraping_successful")
            else:
                app_state["scraping_stats"]["failed_runs"] += 1
                increment_counter("manual_scraping_failed")
                
        except Exception as e:
            app_state["scraping_stats"]["failed_runs"] += 1
            increment_counter("manual_scraping_failed")
            logger.error(f"Manual scraping failed: {e}")
        finally:
            app_state["is_scraping"] = False
    
    background_tasks.add_task(run_scraping)
    
    return {"message": "Scraping triggered", "status": "started"}

@app.get("/scraping/status", response_model=ScrapingStatusResponse)
async def get_scraping_status():
    """Get current scraping status"""
    increment_counter("api_requests", labels={"endpoint": "scraping_status"})
    
    stats = app_state["scraping_stats"]
    
    return ScrapingStatusResponse(
        is_running=app_state["is_scraping"],
        last_run=stats["last_run"],
        next_run=stats["next_run"],
        total_runs=stats["total_runs"],
        successful_runs=stats["successful_runs"],
        failed_runs=stats["failed_runs"]
    )

@app.get("/config")
async def get_config():
    """Get current configuration (sensitive data masked)"""
    increment_counter("api_requests", labels={"endpoint": "config"})
    
    config = Config.get_all_settings()
    
    # Mask sensitive information
    for key in config:
        if 'password' in key.lower() or 'secret' in key.lower():
            if config[key]:
                config[key] = '*' * 8
    
    return config

if __name__ == "__main__":
    import uvicorn
    
    # Setup logging
    setup_logging(
        log_level=Config.LOG_LEVEL,
        log_file=Config.LOG_FILE,
        enable_console=True,
        enable_colors=True
    )
    
    # Run the API server
    uvicorn.run(
        "web_api:app",
        host="0.0.0.0",
        port=8000,
        reload=False,
        log_config=None  # Use our custom logging
    )