/*
 * Copyright 2000-2011 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 org.jetbrains.plugins.github;

import com.intellij.ide.BrowserUtil;
import com.intellij.openapi.actionSystem.AnActionEvent;
import com.intellij.openapi.actionSystem.CommonDataKeys;
import com.intellij.openapi.application.ApplicationManager;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.editor.Document;
import com.intellij.openapi.editor.Editor;
import com.intellij.openapi.fileEditor.FileDocumentManager;
import com.intellij.openapi.fileTypes.FileTypeManager;
import com.intellij.openapi.progress.ProgressIndicator;
import com.intellij.openapi.progress.Task;
import com.intellij.openapi.project.DumbAwareAction;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.util.Computable;
import com.intellij.openapi.util.Ref;
import com.intellij.openapi.util.text.StringUtil;
import com.intellij.openapi.vcs.changes.ChangeListManager;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.util.ThrowableConvertor;
import icons.GithubIcons;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.plugins.github.api.GithubApiUtil;
import org.jetbrains.plugins.github.api.GithubConnection;
import org.jetbrains.plugins.github.api.GithubGist;
import org.jetbrains.plugins.github.exceptions.GithubOperationCanceledException;
import org.jetbrains.plugins.github.ui.GithubCreateGistDialog;
import org.jetbrains.plugins.github.util.GithubAuthData;
import org.jetbrains.plugins.github.util.GithubAuthDataHolder;
import org.jetbrains.plugins.github.util.GithubNotifications;
import org.jetbrains.plugins.github.util.GithubUtil;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import static org.jetbrains.plugins.github.api.GithubGist.FileContent;

/**
 * @author oleg
 * @date 9/27/11
 */
public class GithubCreateGistAction extends DumbAwareAction {
  private static final Logger LOG = GithubUtil.LOG;
  private static final String FAILED_TO_CREATE_GIST = "Can't create Gist";

  protected GithubCreateGistAction() {
    super("Create Gist...", "Create GitHub Gist", GithubIcons.Github_icon);
  }

  @Override
  public void update(final AnActionEvent e) {
    Project project = e.getData(CommonDataKeys.PROJECT);
    if (project == null || project.isDefault()) {
      e.getPresentation().setVisible(false);
      e.getPresentation().setEnabled(false);
      return;
    }
    Editor editor = e.getData(CommonDataKeys.EDITOR);
    VirtualFile file = e.getData(CommonDataKeys.VIRTUAL_FILE);
    VirtualFile[] files = e.getData(CommonDataKeys.VIRTUAL_FILE_ARRAY);

    if ((editor == null && file == null && files == null) || (editor != null && editor.getDocument().getTextLength() == 0)) {
      GithubUtil.setVisibleEnabled(e, false, false);
      return;
    }
    GithubUtil.setVisibleEnabled(e, true, true);
  }

  @Override
  public void actionPerformed(final AnActionEvent e) {
    final Project project = e.getData(CommonDataKeys.PROJECT);
    if (project == null || project.isDefault()) {
      return;
    }

    final Editor editor = e.getData(CommonDataKeys.EDITOR);
    final VirtualFile file = e.getData(CommonDataKeys.VIRTUAL_FILE);
    final VirtualFile[] files = e.getData(CommonDataKeys.VIRTUAL_FILE_ARRAY);
    if (editor == null && file == null && files == null) {
      return;
    }

    createGistAction(project, editor, file, files);
  }

  static void createGistAction(@NotNull final Project project,
                               @Nullable final Editor editor,
                               @Nullable final VirtualFile file,
                               @Nullable final VirtualFile[] files) {

    // Ask for description and other params
    final GithubCreateGistDialog dialog = new GithubCreateGistDialog(project, editor, files, file);
    dialog.show();
    if (!dialog.isOK()) {
      return;
    }

    final GithubAuthDataHolder authHolder = getValidAuthData(project, dialog.isAnonymous());
    if (authHolder == null) {
      return;
    }

    final Ref<String> url = new Ref<String>();
    new Task.Backgroundable(project, "Creating Gist...") {
      @Override
      public void run(@NotNull ProgressIndicator indicator) {
        List<FileContent> contents = collectContents(project, editor, file, files);
        String gistUrl =
          createGist(project, authHolder, indicator, contents, dialog.isPrivate(), dialog.getDescription(), dialog.getFileName());
        url.set(gistUrl);
      }

      @Override
      public void onSuccess() {
        if (url.isNull()) {
          return;
        }
        if (dialog.isOpenInBrowser()) {
          BrowserUtil.browse(url.get());
        }
        else {
          GithubNotifications.showInfoURL(project, "Gist Created Successfully", "Your gist url", url.get());
        }
      }
    }.queue();
  }

  @Nullable
  private static GithubAuthDataHolder getValidAuthData(@NotNull final Project project, boolean isAnonymous) {
    if (isAnonymous) {
      return new GithubAuthDataHolder(GithubAuthData.createAnonymous());
    }
    else {
      try {
        return GithubUtil
          .computeValueInModal(project, "Access to GitHub", new ThrowableConvertor<ProgressIndicator, GithubAuthDataHolder, IOException>() {
                                 @NotNull
                                 @Override
                                 public GithubAuthDataHolder convert(ProgressIndicator indicator) throws IOException {
                                   return GithubUtil.getValidAuthDataHolderFromConfig(project, indicator);
                                 }
                               }
          );
      }
      catch (IOException e) {
        GithubNotifications.showError(project, "Can't create gist", e);
        return null;
      }

    }
  }

  @NotNull
  static List<FileContent> collectContents(@NotNull Project project,
                                           @Nullable Editor editor,
                                           @Nullable VirtualFile file,
                                           @Nullable VirtualFile[] files) {
    if (editor != null) {
      String content = getContentFromEditor(editor);
      if (content == null) {
        return Collections.emptyList();
      }
      if (file != null) {
        return Collections.singletonList(new FileContent(file.getName(), content));
      }
      else {
        return Collections.singletonList(new FileContent("", content));
      }
    }
    if (files != null) {
      List<FileContent> contents = new ArrayList<FileContent>();
      for (VirtualFile vf : files) {
        contents.addAll(getContentFromFile(vf, project, null));
      }
      return contents;
    }

    if (file != null) {
      return getContentFromFile(file, project, null);
    }

    LOG.error("File, files and editor can't be null all at once!");
    throw new IllegalStateException("File, files and editor can't be null all at once!");
  }

  @Nullable
  static String createGist(@NotNull Project project,
                           @NotNull GithubAuthDataHolder auth,
                           @NotNull ProgressIndicator indicator,
                           @NotNull List<FileContent> contents,
                           final boolean isPrivate,
                           @NotNull final String description,
                           @Nullable String filename) {
    if (contents.isEmpty()) {
      GithubNotifications.showWarning(project, FAILED_TO_CREATE_GIST, "Can't create empty gist");
      return null;
    }
    if (contents.size() == 1 && filename != null) {
      FileContent entry = contents.iterator().next();
      contents = Collections.singletonList(new FileContent(filename, entry.getContent()));
    }
    try {
      final List<FileContent> finalContents = contents;
      return GithubUtil.runTask(project, auth, indicator, new ThrowableConvertor<GithubConnection, GithubGist, IOException>() {
        @NotNull
        @Override
        public GithubGist convert(@NotNull GithubConnection connection) throws IOException {
          return GithubApiUtil.createGist(connection, finalContents, description, isPrivate);
        }
      }).getHtmlUrl();
    }
    catch (IOException e) {
      GithubNotifications.showError(project, FAILED_TO_CREATE_GIST, e);
      return null;
    }
  }

  @Nullable
  private static String getContentFromEditor(@NotNull final Editor editor) {
    String text = ApplicationManager.getApplication().runReadAction(new Computable<String>() {
      @Nullable
      @Override
      public String compute() {
        return editor.getSelectionModel().getSelectedText();
      }
    });

    if (text == null) {
      text = editor.getDocument().getText();
    }

    if (StringUtil.isEmptyOrSpaces(text)) {
      return null;
    }
    return text;
  }

  @NotNull
  private static List<FileContent> getContentFromFile(@NotNull final VirtualFile file, @NotNull Project project, @Nullable String prefix) {
    if (file.isDirectory()) {
      return getContentFromDirectory(file, project, prefix);
    }
    String content = ApplicationManager.getApplication().runReadAction(new Computable<String>() {
      @Nullable
      @Override
      public String compute() {
        try {
          Document document = FileDocumentManager.getInstance().getDocument(file);
          if (document != null) {
            return document.getText();
          }
          else {
            return new String(file.contentsToByteArray(), file.getCharset());
          }
        }
        catch (IOException e) {
          LOG.info("Couldn't read contents of the file " + file, e);
          return null;
        }
      }
    });
    if (content == null) {
      GithubNotifications.showWarning(project, FAILED_TO_CREATE_GIST, "Couldn't read the contents of the file " + file);
      return Collections.emptyList();
    }
    if (StringUtil.isEmptyOrSpaces(content)) {
      return Collections.emptyList();
    }
    String filename = addPrefix(file.getName(), prefix, false);
    return Collections.singletonList(new FileContent(filename, content));
  }

  @NotNull
  private static List<FileContent> getContentFromDirectory(@NotNull VirtualFile dir, @NotNull Project project, @Nullable String prefix) {
    List<FileContent> contents = new ArrayList<FileContent>();
    for (VirtualFile file : dir.getChildren()) {
      if (!isFileIgnored(file, project)) {
        String pref = addPrefix(dir.getName(), prefix, true);
        contents.addAll(getContentFromFile(file, project, pref));
      }
    }
    return contents;
  }

  private static String addPrefix(@NotNull String name, @Nullable String prefix, boolean addTrailingSlash) {
    String pref = prefix == null ? "" : prefix;
    pref += name;
    if (addTrailingSlash) {
      pref += "_";
    }
    return pref;
  }

  private static boolean isFileIgnored(@NotNull VirtualFile file, @NotNull Project project) {
    ChangeListManager manager = ChangeListManager.getInstance(project);
    return manager.isIgnoredFile(file) || FileTypeManager.getInstance().isFileIgnored(file);
  }
}