// 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.server.change;

import static com.google.gerrit.server.mail.MailUtil.getRecipientsFromFooters;

import com.google.gerrit.common.ChangeHooks;
import com.google.gerrit.common.Nullable;
import com.google.gerrit.common.TimeUtil;
import com.google.gerrit.common.data.LabelTypes;
import com.google.gerrit.common.errors.EmailException;
import com.google.gerrit.extensions.restapi.AuthException;
import com.google.gerrit.extensions.restapi.ResourceConflictException;
import com.google.gerrit.extensions.restapi.ResourceNotFoundException;
import com.google.gerrit.extensions.restapi.Response;
import com.google.gerrit.extensions.restapi.RestApiException;
import com.google.gerrit.extensions.restapi.RestModifyView;
import com.google.gerrit.extensions.webui.UiAction;
import com.google.gerrit.reviewdb.client.Account;
import com.google.gerrit.reviewdb.client.Change;
import com.google.gerrit.reviewdb.client.ChangeMessage;
import com.google.gerrit.reviewdb.client.PatchSet;
import com.google.gerrit.reviewdb.client.PatchSetInfo;
import com.google.gerrit.reviewdb.server.ReviewDb;
import com.google.gerrit.server.ApprovalsUtil;
import com.google.gerrit.server.ChangeUtil;
import com.google.gerrit.server.CurrentUser;
import com.google.gerrit.server.account.AccountResolver;
import com.google.gerrit.server.change.PublishDraftPatchSet.Input;
import com.google.gerrit.server.git.BatchUpdate;
import com.google.gerrit.server.git.BatchUpdate.ChangeContext;
import com.google.gerrit.server.git.BatchUpdate.Context;
import com.google.gerrit.server.git.BatchUpdate.RepoContext;
import com.google.gerrit.server.git.UpdateException;
import com.google.gerrit.server.mail.CreateChangeSender;
import com.google.gerrit.server.mail.MailUtil.MailRecipients;
import com.google.gerrit.server.mail.ReplacePatchSetSender;
import com.google.gerrit.server.patch.PatchSetInfoFactory;
import com.google.gwtorm.server.OrmException;
import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;

import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.revwalk.FooterLine;
import org.eclipse.jgit.revwalk.RevCommit;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

@Singleton
public class PublishDraftPatchSet implements RestModifyView<RevisionResource, Input>,
    UiAction<RevisionResource> {
  private static final Logger log =
      LoggerFactory.getLogger(PublishDraftPatchSet.class);

  public static class Input {
  }

  private final Provider<ReviewDb> dbProvider;
  private final BatchUpdate.Factory updateFactory;
  private final ChangeHooks hooks;
  private final ApprovalsUtil approvalsUtil;
  private final AccountResolver accountResolver;
  private final PatchSetInfoFactory patchSetInfoFactory;
  private final CreateChangeSender.Factory createChangeSenderFactory;
  private final ReplacePatchSetSender.Factory replacePatchSetFactory;

  @Inject
  public PublishDraftPatchSet(
      Provider<ReviewDb> dbProvider,
      BatchUpdate.Factory updateFactory,
      ChangeHooks hooks,
      ApprovalsUtil approvalsUtil,
      AccountResolver accountResolver,
      PatchSetInfoFactory patchSetInfoFactory,
      CreateChangeSender.Factory createChangeSenderFactory,
      ReplacePatchSetSender.Factory replacePatchSetFactory) {
    this.dbProvider = dbProvider;
    this.updateFactory = updateFactory;
    this.hooks = hooks;
    this.approvalsUtil = approvalsUtil;
    this.accountResolver = accountResolver;
    this.patchSetInfoFactory = patchSetInfoFactory;
    this.createChangeSenderFactory = createChangeSenderFactory;
    this.replacePatchSetFactory = replacePatchSetFactory;
  }

  @Override
  public Response<?> apply(RevisionResource rsrc, Input input)
      throws RestApiException, UpdateException {
    return apply(rsrc.getUser(), rsrc.getChange(), rsrc.getPatchSet().getId(),
        rsrc.getPatchSet());
  }

  private Response<?> apply(CurrentUser u, Change c, PatchSet.Id psId,
      PatchSet ps) throws RestApiException, UpdateException {
    try (BatchUpdate bu = updateFactory.create(
        dbProvider.get(), c.getProject(), u, TimeUtil.nowTs())) {
      bu.addOp(c.getId(), new Op(psId, ps));
      bu.execute();
    }
    return Response.none();
  }

  @Override
  public UiAction.Description getDescription(RevisionResource rsrc) {
    try {
      return new UiAction.Description()
        .setTitle(String.format("Publish revision %d",
            rsrc.getPatchSet().getPatchSetId()))
        .setVisible(rsrc.getPatchSet().isDraft()
            && rsrc.getControl().canPublish(dbProvider.get()));
    } catch (OrmException e) {
      throw new IllegalStateException(e);
    }
  }

  public static class CurrentRevision implements
      RestModifyView<ChangeResource, Input> {
    private final PublishDraftPatchSet publish;

    @Inject
    CurrentRevision(PublishDraftPatchSet publish) {
      this.publish = publish;
    }

    @Override
    public Response<?> apply(ChangeResource rsrc, Input input)
        throws RestApiException, UpdateException {
      return publish.apply(rsrc.getControl().getUser(), rsrc.getChange(),
          rsrc.getChange().currentPatchSetId(), null);
    }
  }

  private class Op extends BatchUpdate.Op {
    private final PatchSet.Id psId;

    private PatchSet patchSet;
    private Change change;
    private boolean wasDraftChange;
    private RevCommit commit;
    private PatchSetInfo patchSetInfo;
    private MailRecipients recipients;

    private Op(PatchSet.Id psId, @Nullable PatchSet patchSet) {
      this.psId = psId;
      this.patchSet = patchSet;
    }

    @Override
    public void updateRepo(RepoContext ctx)
        throws RestApiException, OrmException, IOException {
      PatchSet ps = patchSet;
      if (ps == null) {
        // Don't save in patchSet, since we're not in a transaction. Here we
        // just need the revision, which is immutable.
        ps = ctx.getDb().patchSets().get(psId);
        if (ps == null) {
          throw new ResourceNotFoundException(psId.toString());
        }
      }
      commit = ctx.getRevWalk().parseCommit(
          ObjectId.fromString(ps.getRevision().get()));
      patchSetInfo = patchSetInfoFactory.get(ctx.getRevWalk(), commit, psId);
    }

    @Override
    public void updateChange(ChangeContext ctx)
        throws RestApiException, OrmException {
      if (!ctx.getChangeControl().canPublish(ctx.getDb())) {
        throw new AuthException("Cannot publish this draft patch set");
      }
      saveChange(ctx);
      savePatchSet(ctx);
      addReviewers(ctx);
    }

    private void saveChange(ChangeContext ctx) throws OrmException {
      change = ctx.getChange();
      wasDraftChange = change.getStatus() == Change.Status.DRAFT;
      if (wasDraftChange) {
        change.setStatus(Change.Status.NEW);
        ChangeUtil.updated(change);
        ctx.getDb().changes().update(Collections.singleton(change));
      }
    }

    private void savePatchSet(ChangeContext ctx)
        throws RestApiException, OrmException {
      patchSet = ctx.getDb().patchSets().get(psId);
      if (!patchSet.isDraft()) {
        throw new ResourceConflictException("Patch set is not a draft");
      }
      patchSet.setDraft(false);
      // Force ETag invalidation if not done already
      if (!wasDraftChange) {
        ChangeUtil.updated(change);
        ctx.getDb().changes().update(Collections.singleton(change));
      }
      ctx.getDb().patchSets().update(Collections.singleton(patchSet));
    }

    private void addReviewers(ChangeContext ctx) throws OrmException {
      LabelTypes labelTypes = ctx.getChangeControl().getLabelTypes();
      Collection<Account.Id> oldReviewers = approvalsUtil.getReviewers(
          ctx.getDb(), ctx.getChangeNotes()).values();
      List<FooterLine> footerLines = commit.getFooterLines();
      recipients =
          getRecipientsFromFooters(accountResolver, patchSet, footerLines);
      recipients.remove(ctx.getUser().getAccountId());
      approvalsUtil.addReviewers(ctx.getDb(), ctx.getChangeUpdate(), labelTypes,
          change, patchSet, patchSetInfo, recipients.getReviewers(),
          oldReviewers);
    }

    @Override
    public void postUpdate(Context ctx) throws OrmException {
      hooks.doDraftPublishedHook(change, patchSet, ctx.getDb());
      if (patchSet.isDraft() && change.getStatus() == Change.Status.DRAFT) {
        // Skip emails if the patch set is still a draft.
        return;
      }
      try {
        if (wasDraftChange) {
          sendCreateChange(ctx);
        } else {
          sendReplacePatchSet(ctx);
        }
      } catch (EmailException | OrmException e) {
        log.error("Cannot send email for publishing draft " + psId, e);
      }
    }

    private void sendCreateChange(Context ctx) throws EmailException {
      CreateChangeSender cm =
          createChangeSenderFactory.create(change.getId());
      cm.setFrom(ctx.getUser().getAccountId());
      cm.setPatchSet(patchSet, patchSetInfo);
      cm.addReviewers(recipients.getReviewers());
      cm.addExtraCC(recipients.getCcOnly());
      cm.send();
    }

    private void sendReplacePatchSet(Context ctx)
        throws EmailException, OrmException {
      Account.Id accountId = ctx.getUser().getAccountId();
      ChangeMessage msg =
          new ChangeMessage(new ChangeMessage.Key(change.getId(),
              ChangeUtil.messageUUID(ctx.getDb())), accountId,
              ctx.getWhen(), psId);
      msg.setMessage("Uploaded patch set " + psId.get() + ".");
      ReplacePatchSetSender cm =
          replacePatchSetFactory.create(change.getId());
      cm.setFrom(accountId);
      cm.setPatchSet(patchSet, patchSetInfo);
      cm.setChangeMessage(msg);
      cm.addReviewers(recipients.getReviewers());
      cm.addExtraCC(recipients.getCcOnly());
      cm.send();
    }
  }
}