// Copyright (C) 2015 The Android Open Source Project
//
// 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 net.codemirror.lib;

import static com.google.gwt.dom.client.Style.Display.INLINE_BLOCK;
import static com.google.gwt.dom.client.Style.Unit.PX;
import static net.codemirror.lib.CodeMirror.style;
import static net.codemirror.lib.CodeMirror.LineClassWhere.WRAP;

import com.google.gerrit.client.FormatUtil;
import com.google.gerrit.client.RangeInfo;
import com.google.gerrit.client.blame.BlameInfo;
import com.google.gerrit.client.diff.DisplaySide;
import com.google.gerrit.client.rpc.Natives;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.core.client.JsArray;
import com.google.gwt.core.client.JsArrayString;
import com.google.gwt.dom.client.Element;
import com.google.gwt.i18n.client.DateTimeFormat;
import com.google.gwt.user.client.DOM;

import net.codemirror.lib.CodeMirror.LineHandle;

import java.util.Date;
import java.util.Objects;

/** Additional features added to CodeMirror by Gerrit Code Review. */
public class Extras {
  private static final String ANNOTATION_GUTTER_ID = "CodeMirror-lint-markers";
  private static final BlameConfig C = GWT.create(BlameConfig.class);

  static final native Extras get(CodeMirror c) /*-{ return c.gerritExtras }-*/;
  private static native void set(CodeMirror c, Extras e)
  /*-{ c.gerritExtras = e }-*/;

  static void attach(CodeMirror c) {
    set(c, new Extras(c));
  }

  private final CodeMirror cm;
  private Element margin;
  private DisplaySide side;
  private double charWidthPx;
  private double lineHeightPx;
  private LineHandle activeLine;
  private boolean annotated;

  private Extras(CodeMirror cm) {
    this.cm = cm;
  }

  public DisplaySide side() {
    return side;
  }

  public void side(DisplaySide s) {
    side = s;
  }

  public double charWidthPx() {
    if (charWidthPx <= 1) {
      int len = 100;
      StringBuilder s = new StringBuilder();
      for (int i = 0; i < len; i++) {
        s.append('m');
      }

      Element e = DOM.createSpan();
      e.getStyle().setDisplay(INLINE_BLOCK);
      e.setInnerText(s.toString());

      cm.measure().appendChild(e);
      charWidthPx = ((double) e.getOffsetWidth()) / len;
      e.removeFromParent();
    }
    return charWidthPx;
  }

  public double lineHeightPx() {
    if (lineHeightPx <= 1) {
      Element p = DOM.createDiv();
      int lines = 1;
      for (int i = 0; i < lines; i++) {
        Element e = DOM.createDiv();
        p.appendChild(e);

        Element pre = DOM.createElement("pre");
        pre.setInnerText("gqyŚŻŹŃ");
        e.appendChild(pre);
      }

      cm.measure().appendChild(p);
      lineHeightPx = ((double) p.getOffsetHeight()) / lines;
      p.removeFromParent();
    }
    return lineHeightPx;
  }

  public void lineLength(int columns) {
    if (margin == null) {
      margin = DOM.createDiv();
      margin.setClassName(style().margin());
      cm.mover().appendChild(margin);
    }
    margin.getStyle().setMarginLeft(columns * charWidthPx(), PX);
  }

  public void showTabs(boolean show) {
    Element e = cm.getWrapperElement();
    if (show) {
      e.addClassName(style().showTabs());
    } else {
      e.removeClassName(style().showTabs());
    }
  }

  public final boolean hasActiveLine() {
    return activeLine != null;
  }

  public final LineHandle activeLine() {
    return activeLine;
  }

  public final boolean activeLine(LineHandle line) {
    if (Objects.equals(activeLine, line)) {
      return false;
    }

    if (activeLine != null) {
      cm.removeLineClass(activeLine, WRAP, style().activeLine());
    }
    activeLine = line;
    cm.addLineClass(activeLine, WRAP, style().activeLine());
    return true;
  }

  public final void clearActiveLine() {
    if (activeLine != null) {
      cm.removeLineClass(activeLine, WRAP, style().activeLine());
      activeLine = null;
    }
  }

  public boolean isAnnotated() {
    return annotated;
  }

  public final void clearAnnotations() {
    JsArrayString gutters = ((JsArrayString) JsArrayString.createArray());
    cm.setOption("gutters", gutters);
    annotated = false;
  }

  public final void setAnnotations(JsArray<BlameInfo> blameInfos) {
    if (blameInfos.length() > 0) {
      setBlameInfo(blameInfos);
      JsArrayString gutters = ((JsArrayString) JsArrayString.createArray());
      gutters.push(ANNOTATION_GUTTER_ID);
      cm.setOption("gutters", gutters);
      annotated = true;
      DateTimeFormat format = DateTimeFormat.getFormat(
          DateTimeFormat.PredefinedFormat.DATE_SHORT);
      JsArray<LintLine> annotations = JsArray.createArray().cast();
      for (BlameInfo blameInfo : Natives.asList(blameInfos)) {
        for (RangeInfo range : Natives.asList(blameInfo.ranges())) {
          Date commitTime = new Date(blameInfo.time() * 1000L);
          String shortId = blameInfo.id().substring(0, 8);
          String shortBlame = C.shortBlameMsg(
              shortId, format.format(commitTime), blameInfo.author());
          String detailedBlame = C.detailedBlameMsg(blameInfo.id(),
              blameInfo.author(), FormatUtil.mediumFormat(commitTime),
              blameInfo.commitMsg());

          annotations.push(LintLine.create(shortBlame, detailedBlame, shortId,
              Pos.create(range.start() - 1)));
        }
      }
      cm.setOption("lint", getAnnotation(annotations));
    }
  }

  private native JavaScriptObject getAnnotation(JsArray<LintLine> annotations) /*-{
     return {
        getAnnotations: function(text, options, cm) { return annotations; }
     };
  }-*/;

  public final native JsArray<BlameInfo> getBlameInfo() /*-{
    return this.blameInfos;
  }-*/;

  public final native void setBlameInfo(JsArray<BlameInfo> blameInfos) /*-{
    this['blameInfos'] = blameInfos;
  }-*/;

  public final void toggleAnnotation() {
    toggleAnnotation(getBlameInfo());
  }

  public final void toggleAnnotation(JsArray<BlameInfo> blameInfos) {
    if (isAnnotated()) {
      clearAnnotations();
    } else {
      setAnnotations(blameInfos);
    }
  }
}