/*
 * Copyright 2000-2020 JetBrains s.r.o.
 *
 * 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 jetbrains.teamcity.ui.actions;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashSet;
import java.util.regex.Pattern;

import jetbrains.buildServer.util.FileUtil;
import jetbrains.teamcity.Activator;
import jetbrains.teamcity.core.Debug;
import jetbrains.teamcity.core.Util;

import org.eclipse.compare.CompareConfiguration;
import org.eclipse.compare.patch.ApplyPatchOperation;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IStorage;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.jface.action.Action;

public class ApplyPatchAction extends Action {

    private final IStorage myPatch;

    public ApplyPatchAction(IStorage patch) {
        super("Apply patch...");
        myPatch = patch;
    }

    private class PatchParser {

        private String[] indexes;

        PatchParser parse(InputStream source) throws CoreException {
            try {
                final Pattern indexPattern = Pattern.compile("Index: ");
                final HashSet<String> out = new HashSet<String>();
                BufferedReader reader = new BufferedReader(new InputStreamReader(myPatch.getContents()));
                String str;
                while ((str = reader.readLine()) != null) {
                    if (indexPattern.matcher(str).matches()) {
                        out.add(str.substring(indexPattern.pattern().length(), str.length()).trim());
                    }
                }
                indexes = out.toArray(new String[out.size()]);
            } catch (Exception e) {
                throw new CoreException(Util.createStatus(e));
            } finally {
                FileUtil.close(source);
            }
            return this;
        }

        String[] indexes() {
            return indexes;
        }
    }

    @Override
    public void run() {
        try {
            // prepare for safe patching
            HashSet<IResource> resourceToPatch = new HashSet<IResource>();
            for (String index : new PatchParser().parse(myPatch.getContents()).indexes()) {
                final IPath target = Path.fromPortableString(index);
                IResource member = ResourcesPlugin.getWorkspace().getRoot().findMember(target);
                if (member == null) {
                    member = findInProjects(target);
                    if (member != null) {
                        resourceToPatch.add(member);
                    } else {
                        Debug.getInstance().log(Debug.DEBUG_PLATFORM, String.format("%s: Could not find member for %s", getClass().getSimpleName(), target));
                    }
                }
            }
            // TODO: check modification states of files and ask for shelving
            final CompareConfiguration configuration = new CompareConfiguration();
            configuration.setLeftEditable(true);
            configuration.setProperty(CompareConfiguration.SHOW_PSEUDO_CONFLICTS, true);
            configuration.setProperty(CompareConfiguration.USE_OUTLINE_VIEW, true);
            final ApplyPatchOperation op = new ApplyPatchOperation(null, myPatch, null, configuration) {

            };
            op.openWizard();

        } catch (Exception e) {
            Activator.getDefault().getLog().log(Util.createStatus(e));
        }
        super.run();
    }

    private static IResource findInProjects(IPath target) {
        for (IProject prj : ResourcesPlugin.getWorkspace().getRoot().getProjects()) {
            final IResource member = prj.findMember(target);
            if (member != null) {
                return member;
            }
        }
        return null;
    }

}