// Copyright (C) 2013 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 com.google.gerrit.client.diff;

import com.google.gerrit.client.DiffWebLinkInfo;
import com.google.gerrit.client.info.WebLinkInfo;
import com.google.gerrit.client.rpc.Natives;
import com.google.gerrit.extensions.client.GeneralPreferencesInfo.DiffView;
import com.google.gerrit.reviewdb.client.Patch.ChangeType;
import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.core.client.JsArray;
import com.google.gwt.core.client.JsArrayString;
import java.util.ArrayList;
import java.util.List;

public class DiffInfo extends JavaScriptObject {
  public final native FileMeta metaA() /*-{ return this.meta_a; }-*/;

  public final native FileMeta metaB() /*-{ return this.meta_b; }-*/;

  public final native JsArrayString diffHeader() /*-{ return this.diff_header; }-*/;

  public final native JsArray<Region> content() /*-{ return this.content; }-*/;

  public final native JsArray<DiffWebLinkInfo> webLinks() /*-{ return this.web_links; }-*/;

  public final native boolean binary() /*-{ return this.binary || false; }-*/;

  public final List<WebLinkInfo> sideBySideWebLinks() {
    return filterWebLinks(DiffView.SIDE_BY_SIDE);
  }

  public final List<WebLinkInfo> unifiedWebLinks() {
    return filterWebLinks(DiffView.UNIFIED_DIFF);
  }

  private List<WebLinkInfo> filterWebLinks(DiffView diffView) {
    List<WebLinkInfo> filteredDiffWebLinks = new ArrayList<>();
    List<DiffWebLinkInfo> allDiffWebLinks = Natives.asList(webLinks());
    if (allDiffWebLinks != null) {
      for (DiffWebLinkInfo webLink : allDiffWebLinks) {
        if (diffView == DiffView.SIDE_BY_SIDE && webLink.showOnSideBySideDiffView()) {
          filteredDiffWebLinks.add(webLink);
        }
        if (diffView == DiffView.UNIFIED_DIFF && webLink.showOnUnifiedDiffView()) {
          filteredDiffWebLinks.add(webLink);
        }
      }
    }
    return filteredDiffWebLinks;
  }

  public final ChangeType changeType() {
    return ChangeType.valueOf(changeTypeRaw());
  }

  private native String changeTypeRaw() /*-{ return this.change_type }-*/;

  public final IntraLineStatus intralineStatus() {
    String s = intralineStatusRaw();
    return s != null ? IntraLineStatus.valueOf(s) : IntraLineStatus.OFF;
  }

  private native String intralineStatusRaw() /*-{ return this.intraline_status }-*/;

  public final boolean hasSkip() {
    JsArray<Region> c = content();
    for (int i = 0; i < c.length(); i++) {
      if (c.get(i).skip() != 0) {
        return true;
      }
    }
    return false;
  }

  public final String textA() {
    StringBuilder s = new StringBuilder();
    JsArray<Region> c = content();
    for (int i = 0; i < c.length(); i++) {
      Region r = c.get(i);
      if (r.ab() != null) {
        append(s, r.ab());
      } else if (r.a() != null) {
        append(s, r.a());
      }
      // TODO skip may need to be handled
    }
    return s.toString();
  }

  public final String textB() {
    StringBuilder s = new StringBuilder();
    JsArray<Region> c = content();
    for (int i = 0; i < c.length(); i++) {
      Region r = c.get(i);
      if (r.ab() != null) {
        append(s, r.ab());
      } else if (r.b() != null) {
        append(s, r.b());
      }
      // TODO skip may need to be handled
    }
    return s.toString();
  }

  public final String textUnified() {
    StringBuilder s = new StringBuilder();
    JsArray<Region> c = content();
    for (int i = 0; i < c.length(); i++) {
      Region r = c.get(i);
      if (r.ab() != null) {
        append(s, r.ab());
      } else {
        if (r.a() != null) {
          append(s, r.a());
        }
        if (r.b() != null) {
          append(s, r.b());
        }
      }
      // TODO skip may need to be handled
    }
    return s.toString();
  }

  private static void append(StringBuilder s, JsArrayString lines) {
    for (int i = 0; i < lines.length(); i++) {
      if (s.length() > 0) {
        s.append('\n');
      }
      s.append(lines.get(i));
    }
  }

  protected DiffInfo() {}

  public enum IntraLineStatus {
    OFF,
    OK,
    TIMEOUT,
    FAILURE
  }

  public static class FileMeta extends JavaScriptObject {
    public final native String name() /*-{ return this.name; }-*/;

    public final native String contentType() /*-{ return this.content_type; }-*/;

    public final native int lines() /*-{ return this.lines || 0 }-*/;

    public final native JsArray<WebLinkInfo> webLinks() /*-{ return this.web_links; }-*/;

    protected FileMeta() {}
  }

  public static class Region extends JavaScriptObject {
    public final native JsArrayString ab() /*-{ return this.ab; }-*/;

    public final native JsArrayString a() /*-{ return this.a; }-*/;

    public final native JsArrayString b() /*-{ return this.b; }-*/;

    public final native int skip() /*-{ return this.skip || 0; }-*/;

    public final native boolean common() /*-{ return this.common || false; }-*/;

    public final native JsArray<Span> editA() /*-{ return this.edit_a }-*/;

    public final native JsArray<Span> editB() /*-{ return this.edit_b }-*/;

    protected Region() {}
  }

  public static class Span extends JavaScriptObject {
    public final native int skip() /*-{ return this[0]; }-*/;

    public final native int mark() /*-{ return this[1]; }-*/;

    protected Span() {}
  }
}