// Copyright (C) 2009 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.server.patch;

import com.google.gerrit.common.ChangeHookRunner;
import com.google.gerrit.common.data.ApprovalType;
import com.google.gerrit.common.data.ApprovalTypes;
import com.google.gerrit.reviewdb.ApprovalCategory;
import com.google.gerrit.reviewdb.ApprovalCategoryValue;
import com.google.gerrit.reviewdb.Change;
import com.google.gerrit.reviewdb.ChangeMessage;
import com.google.gerrit.reviewdb.PatchLineComment;
import com.google.gerrit.reviewdb.PatchSet;
import com.google.gerrit.reviewdb.PatchSetApproval;
import com.google.gerrit.reviewdb.ReviewDb;
import com.google.gerrit.server.ChangeUtil;
import com.google.gerrit.server.IdentifiedUser;
import com.google.gerrit.server.git.GitRepositoryManager;
import com.google.gerrit.server.git.MergeOp;
import com.google.gerrit.server.git.MergeQueue;
import com.google.gerrit.server.mail.CommentSender;
import com.google.gerrit.server.mail.EmailException;
import com.google.gerrit.server.project.ChangeControl;
import com.google.gerrit.server.project.InvalidChangeOperationException;
import com.google.gerrit.server.project.NoSuchChangeException;
import com.google.gerrit.server.project.NoSuchRefException;
import com.google.gerrit.server.workflow.FunctionState;
import com.google.gwtjsonrpc.client.VoidResult;
import com.google.gwtorm.client.OrmException;
import com.google.inject.Inject;
import com.google.inject.assistedinject.Assisted;

import org.eclipse.jgit.lib.Repository;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.Callable;

public class PublishComments implements Callable<VoidResult> {
  private static final Logger log =
      LoggerFactory.getLogger(PublishComments.class);

  public interface Factory {
    PublishComments create(PatchSet.Id patchSetId, String messageText,
        Set<ApprovalCategoryValue.Id> approvals);
  }

  private final ReviewDb db;
  private final IdentifiedUser user;
  private final ApprovalTypes types;
  private final CommentSender.Factory commentSenderFactory;
  private final PatchSetInfoFactory patchSetInfoFactory;
  private final ChangeControl.Factory changeControlFactory;
  private final FunctionState.Factory functionStateFactory;
  private final ChangeHookRunner hooks;
  private final GitRepositoryManager gitManager;
  private final MergeOp.Factory mergeFactory;
  private final MergeQueue merger;

  private final PatchSet.Id patchSetId;
  private final String messageText;
  private final Set<ApprovalCategoryValue.Id> approvals;

  private Change change;
  private PatchSet patchSet;
  private ChangeMessage message;
  private List<PatchLineComment> drafts;

  @Inject
  PublishComments(final ReviewDb db, final IdentifiedUser user,
      final ApprovalTypes approvalTypes,
      final CommentSender.Factory commentSenderFactory,
      final PatchSetInfoFactory patchSetInfoFactory,
      final ChangeControl.Factory changeControlFactory,
      final FunctionState.Factory functionStateFactory,
      final ChangeHookRunner hooks,
      final GitRepositoryManager gitManager,
      final MergeOp.Factory mergeFactory,
      final MergeQueue merger,

      @Assisted final PatchSet.Id patchSetId,
      @Assisted final String messageText,
      @Assisted final Set<ApprovalCategoryValue.Id> approvals) {
    this.db = db;
    this.user = user;
    this.types = approvalTypes;
    this.patchSetInfoFactory = patchSetInfoFactory;
    this.commentSenderFactory = commentSenderFactory;
    this.changeControlFactory = changeControlFactory;
    this.functionStateFactory = functionStateFactory;
    this.hooks = hooks;
    this.gitManager = gitManager;
    this.mergeFactory = mergeFactory;
    this.merger = merger;

    this.patchSetId = patchSetId;
    this.messageText = messageText;
    this.approvals = approvals;
  }

  @Override
  public VoidResult call() throws NoSuchChangeException, OrmException,
      InvalidChangeOperationException, NoSuchRefException, IOException {
    final Change.Id changeId = patchSetId.getParentKey();
    final ChangeControl ctl = changeControlFactory.validateFor(changeId);
    change = ctl.getChange();
    patchSet = db.patchSets().get(patchSetId);
    if (patchSet == null) {
      throw new NoSuchChangeException(changeId);
    }
    drafts = drafts();

    publishDrafts();

    final boolean isCurrent = patchSetId.equals(change.currentPatchSetId());
    // Only message will be published for changes with status INTEGRATING.
    if (isCurrent && change.getStatus().isOpen()
        && !change.getStatus().isIntegrating()) {
      publishApprovals();
       // Update staging, if score required for staging was removed.
      // E.g. Existing +2 code review changed to +1 or -2 score was added.
      if (change.getStatus() == Change.Status.STAGED && !canRemainInStaging()) {
        removeChangeFromStaging();
      }
    } else if (!change.getStatus().isOpen() && !approvals.isEmpty()) {
      throw new InvalidChangeOperationException("Change is closed");
    } else {
      publishMessageOnly();
    }

    touchChange();
    email();
    fireHook();
    return VoidResult.INSTANCE;
  }

  private void publishDrafts() throws OrmException {
    for (final PatchLineComment c : drafts) {
      c.setStatus(PatchLineComment.Status.PUBLISHED);
      c.updated();
    }
    db.patchComments().update(drafts);
  }

  private void publishApprovals() throws OrmException {
    ChangeUtil.updated(change);

    final Set<ApprovalCategory.Id> dirty = new HashSet<ApprovalCategory.Id>();
    final List<PatchSetApproval> ins = new ArrayList<PatchSetApproval>();
    final List<PatchSetApproval> upd = new ArrayList<PatchSetApproval>();
    final Collection<PatchSetApproval> all =
        db.patchSetApprovals().byPatchSet(patchSetId).toList();
    final Map<ApprovalCategory.Id, PatchSetApproval> mine = mine(all);

    // Ensure any new approvals are stored properly.
    //
    for (final ApprovalCategoryValue.Id want : approvals) {
      PatchSetApproval a = mine.get(want.getParentKey());
      if (a == null) {
        a = new PatchSetApproval(new PatchSetApproval.Key(//
            patchSetId, user.getAccountId(), want.getParentKey()), want.get());
        a.cache(change);
        ins.add(a);
        all.add(a);
        mine.put(a.getCategoryId(), a);
        dirty.add(a.getCategoryId());
      }
    }

    // Normalize all of the items the user is changing.
    //
    final FunctionState functionState =
        functionStateFactory.create(change, patchSetId, all);
    for (final ApprovalCategoryValue.Id want : approvals) {
      final PatchSetApproval a = mine.get(want.getParentKey());
      final short o = a.getValue();
      a.setValue(want.get());
      a.cache(change);
      if (!ApprovalCategory.SUBMIT.equals(a.getCategoryId())) {
        functionState.normalize(types.byId(a.getCategoryId()), a);
      }
      if (o != a.getValue()) {
        // Value changed, ensure we update the database.
        //
        a.setGranted();
        dirty.add(a.getCategoryId());
      }
      if (!ins.contains(a)) {
        upd.add(a);
      }
    }

    // Format a message explaining the actions taken.
    //
    final StringBuilder msgbuf = new StringBuilder();
    for (final ApprovalType at : types.getApprovalTypes()) {
      if (dirty.contains(at.getCategory().getId())) {
        final PatchSetApproval a = mine.get(at.getCategory().getId());
        if (a.getValue() == 0 && ins.contains(a)) {
          // Don't say "no score" for an initial entry.
          continue;
        }

        final ApprovalCategoryValue val = at.getValue(a);
        if (msgbuf.length() > 0) {
          msgbuf.append("; ");
        }
        if (val != null && val.getName() != null && !val.getName().isEmpty()) {
          msgbuf.append(val.getName());
        } else {
          msgbuf.append(at.getCategory().getName());
          msgbuf.append(" ");
          if (a.getValue() > 0) msgbuf.append('+');
          msgbuf.append(a.getValue());
        }
      }
    }

    // Update dashboards for everyone else.
    //
    for (PatchSetApproval a : all) {
      if (!user.getAccountId().equals(a.getAccountId())) {
        a.cache(change);
        upd.add(a);
      }
    }

    db.patchSetApprovals().update(upd);
    db.patchSetApprovals().insert(ins);

    summarizeInlineComments(msgbuf);
    message(msgbuf.toString());
  }

  private void publishMessageOnly() throws OrmException {
    StringBuilder msgbuf = new StringBuilder();
    summarizeInlineComments(msgbuf);
    message(msgbuf.toString());
  }

  private void message(String actions) throws OrmException {
    if ((actions == null || actions.isEmpty())
        && (messageText == null || messageText.isEmpty())) {
      // They had nothing to say?
      //
      return;
    }

    final StringBuilder msgbuf = new StringBuilder();
    msgbuf.append("Patch Set " + patchSetId.get() + ":");
    if (actions != null && !actions.isEmpty()) {
      msgbuf.append(" ");
      msgbuf.append(actions);
    }
    msgbuf.append("\n\n");
    msgbuf.append(messageText != null ? messageText : "");

    message = new ChangeMessage(new ChangeMessage.Key(change.getId(),//
        ChangeUtil.messageUUID(db)), user.getAccountId());
    message.setMessage(msgbuf.toString());
    db.changeMessages().insert(Collections.singleton(message));
  }

  private Map<ApprovalCategory.Id, PatchSetApproval> mine(
      Collection<PatchSetApproval> all) {
    Map<ApprovalCategory.Id, PatchSetApproval> r =
        new HashMap<ApprovalCategory.Id, PatchSetApproval>();
    for (PatchSetApproval a : all) {
      if (user.getAccountId().equals(a.getAccountId())) {
        r.put(a.getCategoryId(), a);
      }
    }
    return r;
  }

  private void touchChange() {
    try {
      ChangeUtil.touch(change, db);
    } catch (OrmException e) {
    }
  }

  private List<PatchLineComment> drafts() throws OrmException {
    return db.patchComments().draft(patchSetId, user.getAccountId()).toList();
  }

  private void email() {
    try {
      final CommentSender cm = commentSenderFactory.create(change);
      cm.setFrom(user.getAccountId());
      cm.setPatchSet(patchSet, patchSetInfoFactory.get(patchSetId));
      cm.setChangeMessage(message);
      cm.setPatchLineComments(drafts);
      cm.send();
    } catch (EmailException e) {
      log.error("Cannot send comments by email for patch set " + patchSetId, e);
    } catch (PatchSetInfoNotAvailableException e) {
      log.error("Failed to obtain PatchSetInfo for patch set " + patchSetId, e);
    }
  }

  private void fireHook() {
    final Map<ApprovalCategory.Id, ApprovalCategoryValue.Id> changed =
        new HashMap<ApprovalCategory.Id, ApprovalCategoryValue.Id>();
    for (ApprovalCategoryValue.Id v : approvals) {
      changed.put(v.getParentKey(), v);
    }

    hooks.doCommentAddedHook(change, user.getAccount(), patchSet, messageText, changed);
  }

  private void summarizeInlineComments(StringBuilder in) {
    if (!drafts.isEmpty()) {
      if (in.length() != 0) {
        in.append("\n\n");
      }
      if (drafts.size() == 1) {
        in.append("(1 inline comment)");
      } else {
        in.append("(" + drafts.size() + " inline comments)");
      }
    }
  }

  private void removeChangeFromStaging() throws NoSuchChangeException,
      OrmException, IOException, NoSuchRefException {
    ChangeUtil.rejectStagedChange(patchSetId, user, db);
    Repository git = gitManager.openRepository(change.getProject());
    try {
      ChangeUtil.rebuildStaging(change.getDest(), user, db, git,
          mergeFactory, merger, hooks);
    } finally {
      if (git != null) {
        git.close();
      }
    }
  }

  private boolean canRemainInStaging() throws OrmException,
      NoSuchChangeException {
    final ChangeControl control = changeControlFactory.controlFor(change);
    return control.hasValidCategoryFunctions(patchSet.getId(), db, types,
          functionStateFactory);
  }
}