// 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.change;

import com.google.gerrit.client.Gerrit;
import com.google.gerrit.client.changes.ChangeApi;
import com.google.gerrit.client.changes.ChangeInfo.ApprovalInfo;
import com.google.gerrit.client.changes.ChangeInfo.LabelInfo;
import com.google.gerrit.client.changes.ReviewInput;
import com.google.gerrit.client.rpc.GerritCallback;
import com.google.gerrit.client.rpc.NativeMap;
import com.google.gerrit.common.PageLinks;
import com.google.gerrit.common.data.LabelValue;
import com.google.gerrit.reviewdb.client.PatchSet;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.JsArrayString;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.dom.client.Element;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.resources.client.CssResource;
import com.google.gwt.uibinder.client.UiBinder;
import com.google.gwt.uibinder.client.UiField;
import com.google.gwt.uibinder.client.UiHandler;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.CheckBox;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.Grid;
import com.google.gwt.user.client.ui.HTMLPanel;
import com.google.gwt.user.client.ui.PopupPanel;
import com.google.gwt.user.client.ui.RadioButton;
import com.google.gwt.user.client.ui.UIObject;
import com.google.gwt.user.client.ui.Widget;
import com.google.gwtexpui.globalkey.client.NpTextArea;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;

class ReplyBox extends Composite {
  interface Binder extends UiBinder<HTMLPanel, ReplyBox> {}
  private static final Binder uiBinder = GWT.create(Binder.class);

  interface Styles extends CssResource {
    String label_name();
    String label_value();
  }

  private final PatchSet.Id psId;
  private final String revision;
  private ReviewInput in = ReviewInput.create();
  private List<Runnable> lgtm;

  @UiField Styles style;
  @UiField NpTextArea message;
  @UiField Element labelsParent;
  @UiField Grid labelsTable;
  @UiField Button send;
  @UiField CheckBox email;
  @UiField Button cancel;

  ReplyBox(
      PatchSet.Id psId,
      String revision,
      NativeMap<LabelInfo> all,
      NativeMap<JsArrayString> permitted) {
    this.psId = psId;
    this.revision = revision;
    initWidget(uiBinder.createAndBindUi(this));

    List<String> names = new ArrayList<String>(permitted.keySet());
    if (names.isEmpty()) {
      UIObject.setVisible(labelsParent, false);
    } else {
      Collections.sort(names);
      lgtm = new ArrayList<Runnable>(names.size());
      renderLabels(names, all, permitted);
    }
  }

  @Override
  protected void onLoad() {
    Scheduler.get().scheduleDeferred(new ScheduledCommand() {
      @Override
      public void execute() {
        message.setFocus(true);
      }});
  }

  @UiHandler("message")
  void onMessageKey(KeyPressEvent event) {
    if ((event.getCharCode() == '\n' || event.getCharCode() == KeyCodes.KEY_ENTER)
        && event.isControlKeyDown()) {
      event.preventDefault();
      event.stopPropagation();
      onSend(null);
    } else if (lgtm != null
        && event.getCharCode() == 'M'
        && message.getValue().equals("LGT")) {
      Scheduler.get().scheduleDeferred(new ScheduledCommand() {
        @Override
        public void execute() {
          if (message.getValue().startsWith("LGTM")) {
            for (Runnable r : lgtm) {
              r.run();
            }
          }
        }
      });
    }
  }

  @UiHandler("email")
  void onEmail(ValueChangeEvent<Boolean> e) {
    if (e.getValue()) {
      in.notify(ReviewInput.NotifyHandling.ALL);
    } else {
      in.notify(ReviewInput.NotifyHandling.NONE);
    }
  }

  @UiHandler("send")
  void onSend(ClickEvent e) {
    in.message(message.getText().trim());
    ChangeApi.revision(psId.getParentKey().get(), revision)
      .view("review")
      .post(in, new GerritCallback<ReviewInput>() {
        @Override
        public void onSuccess(ReviewInput result) {
          Gerrit.display(PageLinks.toChange(
              psId.getParentKey(),
              String.valueOf(psId.get())));
        }
      });
    hide();
  }

  @UiHandler("cancel")
  void onCancel(ClickEvent e) {
    hide();
  }

  private void hide() {
    for (Widget w = getParent(); w != null; w = w.getParent()) {
      if (w instanceof PopupPanel) {
        ((PopupPanel) w).hide();
        break;
      }
    }
  }

  private void renderLabels(
      List<String> names,
      NativeMap<LabelInfo> all,
      NativeMap<JsArrayString> permitted) {
    TreeSet<Short> values = new TreeSet<Short>();
    for (String id : names) {
      JsArrayString p = permitted.get(id);
      if (p != null) {
        for (int i = 0; i < p.length(); i++) {
          values.add(LabelInfo.parseValue(p.get(i)));
        }
      }
    }
    List<Short> columns = new ArrayList<Short>(values);

    labelsTable.resize(1 + permitted.size(), 1 + values.size());
    for (int c = 0; c < columns.size(); c++) {
      labelsTable.setText(0, 1 + c, LabelValue.formatValue(columns.get(c)));
      labelsTable.getCellFormatter().setStyleName(0, 1 + c, style.label_value());
    }

    List<String> checkboxes = new ArrayList<String>(permitted.size());
    int row = 1;
    for (String id : names) {
      Set<Short> vals = all.get(id).value_set();
      if (isCheckBox(vals)) {
        checkboxes.add(id);
      } else {
        renderRadio(row++, id, columns, vals, all.get(id));
      }
    }
    for (String id : checkboxes) {
      renderCheckBox(row++, id, all.get(id));
    }
  }

  private void renderRadio(int row, final String id,
      List<Short> columns,
      Set<Short> values,
      LabelInfo info) {
    labelsTable.setText(row, 0, id);
    labelsTable.getCellFormatter().setStyleName(row, 0, style.label_name());

    ApprovalInfo self = Gerrit.isSignedIn()
        ? info.for_user(Gerrit.getUserAccount().getId().get())
        : null;

    final List<RadioButton> group = new ArrayList<RadioButton>(values.size());
    for (int i = 0; i < columns.size(); i++) {
      final Short v = columns.get(i);
      if (values.contains(v)) {
        RadioButton b = new RadioButton(id);
        b.setTitle(info.value_text(LabelValue.formatValue(v)));
        if ((self != null && v == self.value()) || (self == null && v == 0)) {
          b.setValue(true);
        }
        b.addValueChangeHandler(new ValueChangeHandler<Boolean>() {
          @Override
          public void onValueChange(ValueChangeEvent<Boolean> event) {
            if (event.getValue()) {
              in.label(id, v);
            }
          }
        });
        group.add(b);
        labelsTable.setWidget(row, 1 + i, b);
      }
    }

    if (!group.isEmpty()) {
      lgtm.add(new Runnable() {
        @Override
        public void run() {
          for (int i = 0; i < group.size() - 1; i++) {
            group.get(i).setValue(false, false);
          }
          group.get(group.size() - 1).setValue(true, true);
        }
      });
    }
  }

  private void renderCheckBox(int row, final String id, LabelInfo info) {
    ApprovalInfo self = Gerrit.isSignedIn()
        ? info.for_user(Gerrit.getUserAccount().getId().get())
        : null;

    final CheckBox b = new CheckBox();
    b.setText(id);
    b.setTitle(info.value_text("+1"));
    if (self != null && self.value() == 1) {
      b.setValue(true);
    }
    b.addValueChangeHandler(new ValueChangeHandler<Boolean>() {
      @Override
      public void onValueChange(ValueChangeEvent<Boolean> event) {
        in.label(id, event.getValue() ? (short) 1 : (short) 0);
      }
    });
    b.setStyleName(style.label_name());
    labelsTable.setWidget(row, 0, b);

    lgtm.add(new Runnable() {
      @Override
      public void run() {
        b.setValue(true, true);
      }
    });
  }

  private static boolean isCheckBox(Set<Short> values) {
    return values.size() == 2
        && values.contains((short) 0)
        && values.contains((short) 1);
  }
}