/*
 * Copyright 2016-2024 DiffPlug
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.diffplug.spotless.markdown;

import static com.diffplug.spotless.markdown.LibMarkdownPreconditions.requireKeysAndValuesNonNull;

import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.NavigableMap;
import java.util.Objects;
import java.util.TreeMap;
import java.util.function.Consumer;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.diffplug.spotless.FormatterFunc;
import com.diffplug.spotless.FormatterStep;
import com.diffplug.spotless.JarState;
import com.diffplug.spotless.Jvm;
import com.diffplug.spotless.Provisioner;

/** A step for <a href="https://github.com/diffplug/freshmark">FreshMark</a>. */
public class FreshMarkStep implements java.io.Serializable {
	private static final long serialVersionUID = 1L;

	private static final String DEFAULT_VERSION = "1.3.1";
	private static final String NAME = "freshmark";
	private static final String MAVEN_COORDINATE = "com.diffplug.freshmark:freshmark:";

	private static final String NASHORN_MAVEN_COORDINATE = "org.openjdk.nashorn:nashorn-core:";

	private static final String NASHORN_VERSION = "15.4";
	private static final String FORMATTER_CLASS = "com.diffplug.freshmark.FreshMark";
	private static final String FORMATTER_METHOD = "compile";

	private final JarState.Promised jarState;
	private final Map<String, ?> properties;

	private FreshMarkStep(JarState.Promised jarState, Map<String, ?> properties) {
		this.jarState = jarState;
		this.properties = properties;
	}

	/** Creates a formatter step for the given version and settings file. */
	public static FormatterStep create(Map<String, ?> properties, Provisioner provisioner) {
		return create(defaultVersion(), properties, provisioner);
	}

	/** Creates a formatter step for the given version and settings file. */
	public static FormatterStep create(String version, Map<String, ?> properties, Provisioner provisioner) {
		Objects.requireNonNull(version, "version");
		Objects.requireNonNull(properties, "properties");
		Objects.requireNonNull(provisioner, "provisioner");

		List<String> mavenCoordinates = new ArrayList<>();
		mavenCoordinates.add(MAVEN_COORDINATE + version);
		if (Jvm.version() >= 15) {
			mavenCoordinates.add("com.diffplug.jscriptbox:jscriptbox:3.0.1");
			mavenCoordinates.add(NASHORN_MAVEN_COORDINATE + NASHORN_VERSION);
		}

		return FormatterStep.create(NAME,
				new FreshMarkStep(JarState.promise(() -> JarState.from(mavenCoordinates, provisioner)), properties),
				FreshMarkStep::equalityState,
				State::createFormat);
	}

	public static String defaultVersion() {
		return DEFAULT_VERSION;
	}

	private State equalityState() throws Exception {
		return new State(jarState.get(), properties);
	}

	private static class State implements Serializable {
		private static final long serialVersionUID = 1L;

		private final JarState jarState;
		private final NavigableMap<String, ?> properties;

		State(JarState jarState, Map<String, ?> properties) {
			this.jarState = jarState;
			// because equality is computed based on serialization, it's important to order the properties
			// before writing them
			this.properties = new TreeMap<>(properties);
			requireKeysAndValuesNonNull(this.properties);
		}

		FormatterFunc createFormat() throws Exception {
			Logger logger = LoggerFactory.getLogger(FreshMarkStep.class);
			Consumer<String> loggingStream = logger::warn;

			ClassLoader classLoader = jarState.getClassLoader();

			// instantiate the formatter and get its format method
			Class<?> formatterClazz = classLoader.loadClass(FORMATTER_CLASS);
			Object formatter = formatterClazz.getConstructor(Map.class, Consumer.class).newInstance(properties, loggingStream);
			Method method = formatterClazz.getMethod(FORMATTER_METHOD, String.class);
			return input -> (String) method.invoke(formatter, input);
		}
	}
}