/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with this
 * work for additional information regarding copyright ownership. The ASF
 * licenses this file to You 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 org.apache.sling.tooling.lc;

import java.io.BufferedReader;
import java.io.File;
import java.nio.file.Files;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.function.Function;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;

import org.apache.sling.maven.projectsupport.BundleListUtils;
import org.apache.sling.maven.projectsupport.bundlelist.v1_0_0.Bundle;
import org.apache.sling.maven.projectsupport.bundlelist.v1_0_0.BundleList;
import org.apache.sling.provisioning.model.Artifact;
import org.apache.sling.provisioning.model.Model;
import org.apache.sling.provisioning.model.ModelUtility;
import org.apache.sling.provisioning.model.io.ModelReader;

import com.google.common.collect.Sets;

public class Main {

    public static void main(String[] args) throws Exception {
        
        // 0. read CLI arguments
        String firstVersion = "7";
        String secondVersion = "8";
        if ( args.length == 2) {
            firstVersion = args[0];
            secondVersion = args[1];
        }
        
        System.out.format("Computing differences between Launchpad versions %s and %s...%n", 
                firstVersion, secondVersion);
        
        // 1. download artifacts
        AetherSetup aether = new AetherSetup();

        File fromFile = aether.download(Artifacts.launchpadCoordinates(firstVersion));
        File toFile = aether.download(Artifacts.launchpadCoordinates(secondVersion));

        // 2. parse artifact definitions
        Model model;
        try (BufferedReader reader = Files.newBufferedReader(toFile.toPath())) {
            model = ModelUtility.getEffectiveModel(ModelReader.read(reader, null));
        }
        
        // TODO - versions are not interpolated
        Map<ArtifactKey, Artifact> to = model.getFeatures().stream()
            .flatMap( f -> f.getRunModes().stream())
            .flatMap( r -> r.getArtifactGroups().stream())
            .flatMap( g -> StreamSupport.stream(g.spliterator(), false))
            .collect(Collectors.toMap( a -> new ArtifactKey(a), Function.identity()));
        
        BundleList readBundleList = BundleListUtils.readBundleList(fromFile);
        
        // 3. generate added / removed / changed
        Map<ArtifactKey, Artifact> from = readBundleList.getStartLevels().stream()
            .flatMap( sl -> sl.getBundles().stream() )
            .collect(Collectors.toMap( b -> new ArtifactKey(b), Main::newArtifact));
        
        Set<Artifact> removed = Sets.difference(from.keySet(), to.keySet()).stream()
            .map( k -> from.get(k))
            .collect(Collectors.toSet());

        Set<Artifact> added = Sets.difference(to.keySet(), from.keySet()).stream()
                .map( k -> to.get(k))
                .collect(Collectors.toSet());

        Map<ArtifactKey, VersionChange> changed = to.values().stream()
                .filter( k -> !added.contains(k) && !removed.contains(k))
                .map( k -> new ArtifactKey(k))
                .filter( k -> !Objects.equals(to.get(k).getVersion(), from.get(k).getVersion()))
                .collect(Collectors.toMap( Function.identity(), k -> new VersionChange(from.get(k).getVersion(), to.get(k).getVersion())));

        // 4. output changes
        
        System.out.println("Added ");
        added.stream().sorted().forEach(Main::outputFormatted);
        
        System.out.println("Removed ");
        removed.stream().sorted().forEach(Main::outputFormatted);
        
        System.out.println("Changed");
        changed.entrySet().stream()
            .sorted( (a, b) -> a.getKey().compareTo(b.getKey()) )
            .forEach(Main::outputFormatted);
    }

    private static Artifact newArtifact(Bundle bundle) {
        
        return new Artifact(bundle.getGroupId(), bundle.getArtifactId(), bundle.getVersion(), bundle.getClassifier(), bundle.getType());
    }
    
    private static void outputFormatted(Artifact a) {
        
        System.out.format("    %-30s : %-55s : %s%n", a.getGroupId(), a.getArtifactId(), a.getVersion());
        
    }

    private static void outputFormatted(Map.Entry<ArtifactKey, VersionChange> e) {
        
        System.out.format("    %-30s : %-55s : %s -> %s%n", e.getKey().getGroupId(), e.getKey().getArtifactId(), e.getValue().getFrom(), e.getValue().getTo());
        
    }
}