package foo.zaaarf.routecartographer;

import org.springframework.web.bind.annotation.RequestMethod;

import java.util.Arrays;

/**
 * Representation of a REST route.
 */
public class Route {
	/**
	 * The paths of the endpoint.
	 */
	public final String[] paths;

	/**
	 * The supported {@link RequestMethod}s, as strings.
	 */
	public final String[] methods;

	/**
	 * The media types produced by the endpoint.
	 * May be null if not specified.
	 */
	public final String[] produces;

	/**
	 * The media types consumed by the endpoint.
	 * May be null if not specified.
	 */
	public final String[] consumes;

	/**
	 * Whether the endpoint is deprecated.
	 */
	public final boolean deprecated;

	/**
	 * A {@link DTO} representing the response body.
	 */
	public final DTO returnType;

	/**
	 * A {@link DTO} representing the request body.
	 */
	public final DTO inputType;

	/**
	 * An array of {@link Param}s, representing parameters accepted by the endpoint.
	 */
	public final Param[] params;

	/**
	 * The one and only constructor.
	 * @param paths the paths of the endpoint
	 * @param methods the {@link RequestMethod}s accepted by the endpoint
	 * @param consumes the media types consumed by the endpoint, may be null
	 * @param produces the media types produced by the endpoint, may be null
	 * @param deprecated whether the endpoint is deprecated
	 * @param returnType the DTO for the response type, may be null
	 * @param inputType the DTO for the request type, may be null
	 * @param params {@link Param}s of the endpoint, may be null
	 */
	public Route(String[] paths, RequestMethod[] methods, String[] consumes, String[] produces,
	             boolean deprecated, DTO returnType, DTO inputType, Param... params) {
		this.paths = paths;
		this.methods = Arrays.stream(methods).map(Enum::name).toArray(String[]::new);

		if(produces != null) this.produces = produces;
		else this.produces = new String[0];

		if(consumes != null) this.consumes = consumes;
		else this.consumes = new String[0];

		this.deprecated = deprecated;

		this.returnType = returnType;
		this.inputType = inputType;

		if(params != null) this.params = params;
		else this.params = new Param[0]; //just in case
	}

	/**
	 * Representation of a parameter of a REST route.
	 */
	public static class Param {
		/**
		 * The fully-qualified name of the expected type of the parameter.
		 */
		public final String typeFQN;

		/**
		 * The name of the parameter.
		 */
		public final String name;

		/**
		 * The default value of the parameter.
		 * May be null, in which case the parameter is required.
		 */
		public final String defaultValue;

		/**
		 * The one and only constructor.
		 * @param typeFQN the FQN of the expected type of the parameter
		 * @param name the name of the parameter
		 * @param defaultValue the default value of the parameter, may be null if the parameter is required
		 */
		public Param(String typeFQN, String name, String defaultValue) {
			this.typeFQN = typeFQN;
			this.name = name;
			this.defaultValue = defaultValue;
		}
	}

	/**
	 * Representation of a DTO type.
	 */
	public static class DTO {

		/**
		 * Fully-qualified name of the type.
		 */
		public final String FQN;

		/**
		 * An array of {@link Param} representing the type's fields.
		 */
		public final Route.Param[] fields;

		/**
		 * The one and only constructor.
		 * @param FQN the fully-qualified name
		 * @param fields the {@link Param}s representing the fields
		 */
		public DTO(String FQN, Route.Param ... fields) {
			this.FQN = FQN;
			if(fields == null) this.fields = new Route.Param[0];
			else this.fields = fields;
		}
	}
}