// Copyright 2023 Harness, Inc.
//
// 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 cleanup

import (
	"context"
	"fmt"
	"math"
	"time"

	"github.com/harness/gitness/app/api/controller/repo"
	"github.com/harness/gitness/app/bootstrap"
	"github.com/harness/gitness/app/store"
	"github.com/harness/gitness/job"
	"github.com/harness/gitness/types"
	"github.com/harness/gitness/types/enum"

	"github.com/rs/zerolog/log"
)

const (
	jobTypeDeletedRepos        = "gitness:cleanup:deleted-repos"
	jobCronDeletedRepos        = "50 0 * * *" // At minute 50 past midnight every day.
	jobMaxDurationDeletedRepos = 10 * time.Minute
)

type deletedReposCleanupJob struct {
	retentionTime time.Duration

	repoStore store.RepoStore
	repoCtrl  *repo.Controller
}

func newDeletedReposCleanupJob(
	retentionTime time.Duration,
	repoStore store.RepoStore,
	repoCtrl *repo.Controller,
) *deletedReposCleanupJob {
	return &deletedReposCleanupJob{
		retentionTime: retentionTime,

		repoStore: repoStore,
		repoCtrl:  repoCtrl,
	}
}

// Handle purges old deleted repositories that are past the retention time.
func (j *deletedReposCleanupJob) Handle(ctx context.Context, _ string, _ job.ProgressReporter) (string, error) {
	olderThan := time.Now().Add(-j.retentionTime)

	log.Ctx(ctx).Info().Msgf(
		"start purging deleted repositories older than %s (aka created before %s)",
		j.retentionTime,
		olderThan.Format(time.RFC3339Nano))

	deletedBeforeOrAt := olderThan.UnixMilli()
	filter := &types.RepoFilter{
		Page:              1,
		Size:              int(math.MaxInt),
		Query:             "",
		Order:             enum.OrderAsc,
		Sort:              enum.RepoAttrDeleted,
		DeletedBeforeOrAt: &deletedBeforeOrAt,
	}
	toBePurgedRepos, err := j.repoStore.List(ctx, 0, filter)
	if err != nil {
		return "", fmt.Errorf("failed to list ready-to-delete repositories: %w", err)
	}

	session := bootstrap.NewSystemServiceSession()
	purgedRepos := 0
	for _, r := range toBePurgedRepos {
		err := j.repoCtrl.PurgeNoAuth(ctx, session, r)
		if err != nil {
			log.Warn().Err(err).Msgf("failed to purge repo uid: %s, path: %s, deleted at %d",
				r.Identifier, r.Path, *r.Deleted)
			continue
		}
		purgedRepos++
	}

	result := "no old deleted repositories found"
	if purgedRepos > 0 {
		result = fmt.Sprintf("purged %d deleted repositories", purgedRepos)
	}

	log.Ctx(ctx).Info().Msg(result)

	return result, nil
}