/*
 *     Copyright 2020 The Dragonfly Authors
 *
 * 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 database

import (
	"errors"
	"fmt"

	"github.com/go-redis/redis/v8"
	"gorm.io/gorm"

	logger "d7y.io/dragonfly/v2/internal/dflog"
	"d7y.io/dragonfly/v2/manager/config"
	"d7y.io/dragonfly/v2/manager/models"
	"d7y.io/dragonfly/v2/manager/types"
	pkgredis "d7y.io/dragonfly/v2/pkg/redis"
	schedulerconfig "d7y.io/dragonfly/v2/scheduler/config"
)

const (
	// Default name for scheduler cluster.
	DefaultSchedulerClusterName = "scheduler-cluster-1"

	// Default name for seed peer cluster.
	DefaultSeedPeerClusterName = "seed-peer-cluster-1"
)

type Database struct {
	DB  *gorm.DB
	RDB redis.UniversalClient
}

func New(cfg *config.Config) (*Database, error) {
	var (
		db  *gorm.DB
		err error
	)
	switch cfg.Database.Type {
	case config.DatabaseTypeMysql, config.DatabaseTypeMariaDB:
		db, err = newMyqsl(cfg)
		if err != nil {
			logger.Errorf("mysql: %s", err.Error())
			return nil, err
		}
	case config.DatabaseTypePostgres:
		db, err = newPostgres(cfg)
		if err != nil {
			logger.Errorf("postgres: %s", err.Error())
			return nil, err
		}
	default:
		return nil, fmt.Errorf("invalid database type %s", cfg.Database.Type)
	}

	rdb, err := pkgredis.NewRedis(&redis.UniversalOptions{
		Addrs:      cfg.Database.Redis.Addrs,
		MasterName: cfg.Database.Redis.MasterName,
		DB:         cfg.Database.Redis.DB,
		Username:   cfg.Database.Redis.Username,
		Password:   cfg.Database.Redis.Password,
	})
	if err != nil {
		logger.Errorf("redis: %s", err.Error())
		return nil, err
	}

	return &Database{
		DB:  db,
		RDB: rdb,
	}, nil
}

func migrate(db *gorm.DB) error {
	return db.AutoMigrate(
		&models.Job{},
		&models.SeedPeerCluster{},
		&models.SeedPeer{},
		&models.SchedulerCluster{},
		&models.Scheduler{},
		&models.User{},
		&models.Oauth{},
		&models.Config{},
		&models.Application{},
		&models.Model{},
	)
}

func seed(cfg *config.Config, db *gorm.DB) error {
	// Create default scheduler cluster.
	var schedulerClusterCount int64
	if err := db.Model(models.SchedulerCluster{}).Count(&schedulerClusterCount).Error; err != nil {
		return err
	}

	if schedulerClusterCount <= 0 {
		if err := db.Create(&models.SchedulerCluster{
			BaseModel: models.BaseModel{
				ID: uint(1),
			},
			Name: DefaultSchedulerClusterName,
			Config: map[string]any{
				"candidate_parent_limit": schedulerconfig.DefaultSchedulerCandidateParentLimit,
				"filter_parent_limit":    schedulerconfig.DefaultSchedulerFilterParentLimit,
			},
			ClientConfig: map[string]any{
				"load_limit":             schedulerconfig.DefaultPeerConcurrentUploadLimit,
				"concurrent_piece_count": schedulerconfig.DefaultPeerConcurrentPieceCount,
			},
			Scopes:    map[string]any{},
			IsDefault: true,
		}).Error; err != nil {
			return err
		}
	}

	// Create default seed peer cluster.
	var seedPeerClusterCount int64
	if err := db.Model(models.SeedPeerCluster{}).Count(&seedPeerClusterCount).Error; err != nil {
		return err
	}

	if seedPeerClusterCount <= 0 {
		if err := db.Create(&models.SeedPeerCluster{
			BaseModel: models.BaseModel{
				ID: uint(1),
			},
			Name: DefaultSeedPeerClusterName,
			Config: map[string]any{
				"load_limit": schedulerconfig.DefaultSeedPeerConcurrentUploadLimit,
			},
		}).Error; err != nil {
			return err
		}

		seedPeerCluster := models.SeedPeerCluster{}
		if err := db.First(&seedPeerCluster).Error; err != nil {
			return err
		}

		schedulerCluster := models.SchedulerCluster{}
		if err := db.First(&schedulerCluster).Error; err != nil {
			return err
		}

		if err := db.Model(&seedPeerCluster).Association("SchedulerClusters").Append(&schedulerCluster); err != nil {
			return err
		}
	}

	// TODO Compatible with old version.
	// Update scheduler features when features is NULL.
	var schedulers []models.Scheduler
	if err := db.Model(models.Scheduler{}).Find(&schedulers).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil
		}

		return err
	}

	for _, scheduler := range schedulers {
		if scheduler.Features == nil {
			if err := db.Model(&scheduler).Update("features", models.Array(types.DefaultSchedulerFeatures)).Error; err != nil {
				logger.Errorf("update scheduler %d features: %s", scheduler.ID, err.Error())
				continue
			}

			logger.Infof("update scheduler %d default features", scheduler.ID)
		}
	}

	return nil
}