/*
 * Copyright 2000-2014 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 com.intellij.openapi.fileEditor;

import com.intellij.ide.*;
import com.intellij.ide.FileEditorProvider;
import com.intellij.openapi.actionSystem.DataContext;
import com.intellij.openapi.actionSystem.DataKey;
import com.intellij.openapi.editor.*;
import com.intellij.openapi.fileTypes.FileType;
import com.intellij.openapi.fileTypes.FileTypeManager;
import com.intellij.openapi.fileTypes.INativeFileType;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.util.Comparing;
import com.intellij.openapi.util.TextRange;
import com.intellij.openapi.vfs.VirtualFile;
import com.intellij.openapi.wm.IdeFocusManager;
import com.intellij.pom.Navigatable;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.util.List;

public class OpenFileDescriptor implements Navigatable {
  /**
   * Tells descriptor to navigate in specific editor rather than file editor
   * in main IDEA window.
   * For example if you want to navigate in editor embedded into modal dialog,
   * you should provide this data.
   */
  public static final DataKey<Editor> NAVIGATE_IN_EDITOR = DataKey.create("NAVIGATE_IN_EDITOR");

  @NotNull
  private final VirtualFile myFile;
  private final int myOffset;
  private final int myLogicalLine;
  private final int myLogicalColumn;
  private final RangeMarker myRangeMarker;
  @NotNull
  private final Project myProject;

  private boolean myUseCurrentWindow = false;

  public OpenFileDescriptor(@NotNull Project project, @NotNull VirtualFile file, int offset) {
    this(project, file, -1, -1, offset, null, false);
  }

  public OpenFileDescriptor(@NotNull Project project, @NotNull VirtualFile file, int logicalLine, int logicalColumn) {
    this(project, file, logicalLine, logicalColumn, -1, null, false);
  }

  public OpenFileDescriptor(@NotNull Project project, @NotNull VirtualFile file,
                            int logicalLine, int logicalColumn, boolean persistent) {
    this(project, file, logicalLine, logicalColumn, -1, null, persistent);
  }

  public OpenFileDescriptor(@NotNull Project project, @NotNull VirtualFile file) {
    this(project, file, -1, -1, -1, null, false);
  }

  private OpenFileDescriptor(@NotNull Project project, @NotNull VirtualFile file,
                             int logicalLine, int logicalColumn, int offset, @Nullable RangeMarker rangeMarker, boolean persistent) {
    myProject = project;

    myFile = file;
    myLogicalLine = logicalLine;
    myLogicalColumn = logicalColumn;
    myOffset = offset;
    if (rangeMarker != null) {
      myRangeMarker = rangeMarker;
    }
    else if (offset >= 0) {
      myRangeMarker = LazyRangeMarkerFactory.getInstance(project).createRangeMarker(file, offset);
    }
    else if (logicalLine >= 0 ){
      myRangeMarker = LazyRangeMarkerFactory.getInstance(project).createRangeMarker(file, logicalLine, Math.max(0, logicalColumn), persistent);
    }
    else {
      myRangeMarker = null;
    }
  }

  @NotNull
  public VirtualFile getFile() {
    return myFile;
  }

  @Nullable
  public RangeMarker getRangeMarker() {
    return myRangeMarker;
  }

  public int getOffset() {
    return myRangeMarker != null && myRangeMarker.isValid() ? myRangeMarker.getStartOffset() : myOffset;
  }

  public int getLine() {
    return myLogicalLine;
  }

  public int getColumn() {
    return myLogicalColumn;
  }

  @Override
  public void navigate(boolean requestFocus) {
    if (!canNavigate()) {
      throw new IllegalStateException("Navigation is not possible with null project");
    }

    if (!myFile.isDirectory() && navigateInEditorOrNativeApp(myProject, requestFocus)) return;

    navigateInProjectView(requestFocus);
  }

  private boolean navigateInEditorOrNativeApp(@NotNull Project project, boolean requestFocus) {
    FileType type = FileTypeManager.getInstance().getKnownFileTypeOrAssociate(myFile,project);
    if (type == null || !myFile.isValid()) return false;

    if (type instanceof INativeFileType) {
      return ((INativeFileType) type).openFileInAssociatedApplication(project, myFile);
    }

    return navigateInEditor(project, requestFocus);
  }

  public boolean navigateInEditor(@NotNull Project project, boolean requestFocus) {
    return navigateInRequestedEditor() || navigateInAnyFileEditor(project, requestFocus);
  }

  private boolean navigateInRequestedEditor() {
    DataContext ctx = DataManager.getInstance().getDataContext();
    Editor e = NAVIGATE_IN_EDITOR.getData(ctx);
    if (e == null) return false;
    if (!Comparing.equal(FileDocumentManager.getInstance().getFile(e.getDocument()), myFile)) return false;
    
    navigateIn(e);
    return true;
  }

  private boolean navigateInAnyFileEditor(Project project, boolean focusEditor) {
    List<FileEditor> editors = FileEditorManager.getInstance(project).openEditor(this, focusEditor);
    for (FileEditor editor : editors) {
      if (editor instanceof TextEditor) {
        Editor e = ((TextEditor)editor).getEditor();
        unfoldCurrentLine(e);
        if (focusEditor) {
          IdeFocusManager.getInstance(myProject).requestFocus(e.getContentComponent(), true);
        }
      }
    }
    return !editors.isEmpty();
  }

  private void navigateInProjectView(boolean requestFocus) {
    SelectInContext context = new SelectInContext() {
      @Override
      @NotNull
      public Project getProject() {
        return myProject;
      }

      @Override
      @NotNull
      public VirtualFile getVirtualFile() {
        return myFile;
      }

      @Override
      @Nullable
      public Object getSelectorInFile() {
        return null;
      }

      @Override
      @Nullable
      public FileEditorProvider getFileEditorProvider() {
        return null;
      }
    };

    for (SelectInTarget target : SelectInManager.getInstance(myProject).getTargets()) {
      if (target.canSelect(context)) {
        target.selectIn(context, requestFocus);
        return;
      }
    }
  }

  public void navigateIn(@NotNull Editor e) {
    final int offset = getOffset();
    CaretModel caretModel = e.getCaretModel();
    boolean caretMoved = false;
    if (myLogicalLine >= 0) {
      LogicalPosition pos = new LogicalPosition(myLogicalLine, Math.max(myLogicalColumn, 0));
      if (offset < 0 || offset == e.logicalPositionToOffset(pos)) {
        caretModel.removeSecondaryCarets();
        caretModel.moveToLogicalPosition(pos);
        caretMoved = true;
      }
    }
    if (!caretMoved && offset >= 0) {
      caretModel.removeSecondaryCarets();
      caretModel.moveToOffset(Math.min(offset, e.getDocument().getTextLength()));
      caretMoved = true;
    }

    if (caretMoved) {
      e.getSelectionModel().removeSelection();
      scrollToCaret(e);
      unfoldCurrentLine(e);
    }
  }

  private static void unfoldCurrentLine(@NotNull final Editor editor) {
    final FoldRegion[] allRegions = editor.getFoldingModel().getAllFoldRegions();
    final int offset = editor.getCaretModel().getOffset();
    int line = editor.getDocument().getLineNumber(offset);
    int start = editor.getDocument().getLineStartOffset(line);
    int end = editor.getDocument().getLineEndOffset(line);
    final TextRange range = new TextRange(start, end);
    editor.getFoldingModel().runBatchFoldingOperation(new Runnable() {
      @Override
      public void run() {
        for (FoldRegion region : allRegions) {
          if (!region.isExpanded() && range.intersects(TextRange.create(region))) {
            region.setExpanded(true);
          }
        }
      }
    });
  }

  private static void scrollToCaret(@NotNull Editor e) {
    e.getScrollingModel().scrollToCaret(ScrollType.CENTER);
  }

  @Override
  public boolean canNavigate() {
    return myFile.isValid();
  }

  @Override
  public boolean canNavigateToSource() {
    return canNavigate();
  }

  @NotNull
  public Project getProject() {
    return myProject;
  }

  public OpenFileDescriptor setUseCurrentWindow(boolean search) {
    myUseCurrentWindow = search;
    return this;
  }

  public boolean isUseCurrentWindow() {
    return myUseCurrentWindow;
  }

  public void dispose() {
    if (myRangeMarker != null) {
      myRangeMarker.dispose();
    }
  }
}