package bjc.utils.components;

import java.io.InputStream;

import bjc.utils.parserutils.RuleBasedConfigReader;

import static bjc.utils.parserutils.RuleBasedReaderPragmas.*;

/**
 * Read a component description from a file
 * 
 * @author ben
 *
 */
public class ComponentDescriptionFileParser {
	// The reader used to read in component descriptions
	private static RuleBasedConfigReader<ComponentDescriptionState> reader;

	// Initialize the reader and its pragmas
	static {
		// This reader works entirely off of pragmas, so no need to handle
		// rules
		reader = new RuleBasedConfigReader<>((tokenizer, statePair) -> {
			// Don't need to do anything on rule start
		}, (tokenizer, state) -> {
			// Don't need to do anything on rule continuation
		}, (state) -> {
			// Don't need to do anything on rule end
		});

		setupReaderPragmas();
	}

	/**
	 * Parse a component description from a stream
	 * 
	 * @param inputSource
	 *            The stream to parse from
	 * @return The description parsed from the stream
	 */
	public static ComponentDescription
			fromStream(InputStream inputSource) {
		ComponentDescriptionState readState = reader
				.fromStream(inputSource, new ComponentDescriptionState());

		return readState.toDescription();
	}

	/*
	 * Create all the pragmas the reader needs to function
	 */
	private static void setupReaderPragmas() {
		reader.addPragma("name", buildStringCollapser("name",
				(name, state) -> state.setName(name)));

		reader.addPragma("author", buildStringCollapser("author",
				(author, state) -> state.setAuthor(author)));

		reader.addPragma("description",
				buildStringCollapser("description", (description,
						state) -> state.setDescription(description)));

		reader.addPragma("version", buildInteger("version",
				(version, state) -> state.setVersion(version)));
	}
}