#!/usr/bin/env python3
"""
GasFlux Web API Server using Waitress WSGI server.

This is the production server entry point for the GasFlux Web API.
Includes full GasFlux processing capabilities with task pool management.

Features:
- File upload and processing (.xlsx, .xls)
- Asynchronous task processing with background workers
- Task pool management with pagination and filtering
- Real-time task status monitoring
- Report generation and file download
- Health monitoring and statistics

API Endpoints:
- /upload - File upload and processing initiation
- /task/<task_id> - Task status management
- /tasks - Task pool management (NEW)
- /download/<filename> - File download
- /reports - Report listing
- /health - Health monitoring
- /stats - System statistics
- /config - Configuration info
- / - Web interface

Usage:
    python server_waitress.py

Or package with PyInstaller:
    pyinstaller --onefile --name GasFluxAPI server_waitress.py
"""

import os
import sys
from pathlib import Path

# Add the project root and src directory to PYTHONPATH
project_root = Path(__file__).parent.absolute()
src_dir = project_root / "src"

sys.path.insert(0, str(project_root))
sys.path.insert(0, str(src_dir))

# Set environment variables for production
os.environ['FLASK_APP'] = 'src/gasflux/app.py'
os.environ['FLASK_ENV'] = 'production'

def main():
    """Main entry point for the GasFlux Web API server."""
    print("Starting GasFlux Web API with Waitress...")

    try:
        # Import the Flask app
        import gasflux.app as gasflux_app
        from src.gasflux.app import Config

        app = gasflux_app.app
        print("✓ GasFlux app imported successfully")
        print("✓ Task pool management enabled")
        print("✓ All blueprints loaded: upload, tasks, task_pool, download, reports, health, stats, config, web")

        # Import waitress
        from waitress import serve
        print("✓ Waitress WSGI server imported")

        # Server configuration from environment variables
        host = Config.HOST
        port = Config.PORT
        threads = Config.THREADS
        connection_limit = Config.CONNECTION_LIMIT
        channel_timeout = Config.CHANNEL_TIMEOUT

        print(f"Starting Waitress server on {host}:{port}")
        print(f"- Threads: {threads}")
        print(f"- Connection limit: {connection_limit}")
        print(f"- Channel timeout: {channel_timeout}s")
        print("Press Ctrl+C to stop the server")
        print("=" * 50)
        print("Available API endpoints:")
        print("  POST /upload           - Upload files for processing")
        print("  GET  /task/<id>        - Get task status")
        print("  PUT  /task/<id>        - Update task status")
        print("  DEL  /task/<id>        - Delete task")
        print("  GET  /tasks            - List tasks (paginated)")
        print("  GET  /tasks/stats      - Task pool statistics")
        print("  GET  /tasks/active     - Active tasks")
        print("  GET  /tasks/queue      - Queued tasks")
        print("  GET  /download/<file>  - Download files")
        print("  GET  /reports          - List reports")
        print("  GET  /health           - Health check")
        print("  GET  /stats            - System stats")
        print("  GET  /config           - Configuration")
        print("  GET  /                 - Web interface")
        print("=" * 50)
        print(f"Configuration: {Config.to_dict()}")

        # Start the server with valid Waitress parameters
        serve(
            app,
            host=host,
            port=port,
            threads=threads,
            connection_limit=connection_limit,
            channel_timeout=channel_timeout,
        )

    except KeyboardInterrupt:
        print("\nServer stopped by user")
    except Exception as e:
        print(f"✗ Error starting GasFlux app: {e}")
        import traceback
        traceback.print_exc()
        sys.exit(1)

if __name__ == "__main__":
    main()