/** @module config */
import { Descriptor } from 'pip-services3-commons-node';
import { TypeDescriptor } from 'pip-services3-commons-node';
import { ConfigParams } from 'pip-services3-commons-node';
import { ConfigException } from 'pip-services3-commons-node';

/**
 * Configuration of a component inside a container.
 * 
 * The configuration includes type information or descriptor,
 * and component configuration parameters.
 */
export class ComponentConfig {

    /**
     * Creates a new instance of the component configuration.
     * 
     * @param descriptor    (optional) a components descriptor (locator).
     * @param type          (optional) a components type descriptor.
     * @param config        (optional) component configuration parameters.
     */
    public constructor(descriptor?: Descriptor, type?: TypeDescriptor, config?: ConfigParams) {
        this.descriptor = descriptor;
        this.type = type;
        this.config = config;
    }

	public descriptor: Descriptor = null;
	public type: TypeDescriptor = null;
	public config: ConfigParams = null;

    /**
     * Creates a new instance of ComponentConfig based on
     * section from container configuration.
     * 
     * @param config    component parameters from container configuration
     * @returns a newly created ComponentConfig
     * 
     * @throws ConfigException when neither component descriptor or type is found.
     */
    public static fromConfig(config: ConfigParams): ComponentConfig {
        var descriptor = Descriptor.fromString(config.getAsNullableString("descriptor"));
        var type = TypeDescriptor.fromString(config.getAsNullableString("type"));

        if (descriptor == null && type == null)
            throw new ConfigException(null, "BAD_CONFIG", "Component configuration must have descriptor or type");

        return new ComponentConfig(descriptor, type, config);
    }
		
}