app.py

"""
Book Translator Application
===========================
Flask application factory and main entry point.
"""

import os

from flask import Flask, send_from_directory
from flask_cors import CORS

from book_translator.api.middleware import add_rate_limit_headers
from book_translator.api.routes import (
    create_files_blueprint,
    create_health_blueprint,
    create_logs_blueprint,
    create_models_blueprint,
    create_translation_blueprint,
)
from book_translator.config import config
from book_translator.database.connection import get_database
from book_translator.utils.logging import debug_print, get_logger


def create_app(testing: bool = False) -> Flask:
    """
    Application factory for Flask app.

    Args:
        testing: If True, configure for testing

    Returns:
        Configured Flask application
    """
    app = Flask(
        __name__, static_folder=config.paths.static_folder, static_url_path="/static"
    )

    # Configuration
    app.config.update(
        SECRET_KEY=config.server.secret_key,
        MAX_CONTENT_LENGTH=config.file.max_file_size_bytes,
        JSON_SORT_KEYS=False,
        TESTING=testing,
    )

    # CORS configuration
    cors_origins = config.server.cors_origins
    if testing:
        cors_origins = ["*"]

    CORS(
        app, resources={r"/api/*": {"origins": cors_origins}}, supports_credentials=True
    )

    # Initialize database
    if not testing:
        get_database()

    # Register blueprints
    app.register_blueprint(create_translation_blueprint())
    app.register_blueprint(create_models_blueprint())
    app.register_blueprint(create_health_blueprint())
    app.register_blueprint(create_files_blueprint())
    app.register_blueprint(create_logs_blueprint())

    # Add middleware
    app.after_request(add_rate_limit_headers)

    # Error handlers
    @app.errorhandler(400)
    def bad_request(e):
        return {"error": "Bad request", "details": str(e)}, 400

    @app.errorhandler(404)
    def not_found(e):
        return {"error": "Resource not found"}, 404

    @app.errorhandler(413)
    def file_too_large(e):
        max_mb = config.file.max_file_size_mb
        return {"error": f"File too large. Maximum size is {max_mb}MB"}, 413

    @app.errorhandler(429)
    def rate_limited(e):
        return {"error": "Rate limit exceeded"}, 429

    @app.errorhandler(500)
    def internal_error(e):
        logger = get_logger().api_logger
        logger.error(f"Internal error: {e}")
        return {"error": "Internal server error"}, 500

    # Serve frontend
    @app.route("/")
    def index():
        return send_from_directory(config.paths.static_folder, "index.html")

    # Log startup
    logger = get_logger()
    logger.api_logger.info(
        f"Book Translator started on {config.server.host}:{config.server.port}"
    )

    if config.logging.verbose_debug:
        debug_print("🚀 Application initialized", "INFO", "APP")

    return app


def run_server():
    """Run the Flask development server."""
    app = create_app()

    print(
        f"""
╔══════════════════════════════════════════════════════════════╗
║                    📚 Book Translator v2.0                   ║
╠══════════════════════════════════════════════════════════════╣
║  Server: http://{config.server.host}:{config.server.port:<5}                              ║
║  Model:  {config.ollama.default_model:<50} ║
║  Debug:  {'Enabled' if config.server.debug else 'Disabled':<50} ║
╚══════════════════════════════════════════════════════════════╝
    """
    )

    app.run(
        host=config.server.host,
        port=config.server.port,
        debug=config.server.debug,
        threaded=True,
    )


if __name__ == "__main__":
    run_server()