// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
// See LICENSE.txt for license information.

package platform

import (
	"fmt"

	"github.com/pkg/errors"

	"github.com/mattermost/mattermost/server/public/model"
	"github.com/mattermost/mattermost/server/public/shared/mlog"
	"github.com/mattermost/mattermost/server/v8/channels/store"
	"github.com/mattermost/mattermost/server/v8/channels/store/localcachelayer"
	"github.com/mattermost/mattermost/server/v8/channels/store/sqlstore"
	"github.com/mattermost/mattermost/server/v8/config"
	"github.com/mattermost/mattermost/server/v8/einterfaces"
	"github.com/mattermost/mattermost/server/v8/platform/shared/filestore"
)

type Option func(ps *PlatformService) error

// By default, the app will use the store specified by the configuration. This allows you to
// construct an app with a different store.
//
// The override parameter must be either a store.Store or func(App) store.Store().
func StoreOverride(override any) Option {
	return func(ps *PlatformService) error {
		switch o := override.(type) {
		case store.Store:
			ps.newStore = func() (store.Store, error) {
				return o, nil
			}
			return nil

		case func(*PlatformService) store.Store:
			ps.newStore = func() (store.Store, error) {
				return o(ps), nil
			}
			return nil

		default:
			return errors.New("invalid StoreOverride")
		}
	}
}

// StoreOverrideWithCache is a test option to construct the app with the store layer
// wrapped on top of the store that is passed.
func StoreOverrideWithCache(override store.Store) Option {
	return func(ps *PlatformService) error {
		ps.newStore = func() (store.Store, error) {
			lcl, err := localcachelayer.NewLocalCacheLayer(override, ps.metricsIFace, ps.clusterIFace, ps.cacheProvider, ps.Log())
			if err != nil {
				return nil, err
			}
			// Clearing all the caches because the in-mem data
			// is persisted in case of Redis.
			lcl.Invalidate()
			return lcl, nil
		}

		return nil
	}
}

// StoreOption allows passing options when constructing the store.
//
// This option has no effect if StoreOverride or StoreOverrideWithCache is also set.
func StoreOption(option sqlstore.Option) Option {
	return func(ps *PlatformService) error {
		ps.storeOptions = append(ps.storeOptions, option)
		return nil
	}
}

// Config applies the given config dsn, whether a path to config.json
// or a database connection string. It receives as well a set of
// custom defaults that will be applied for any unset property of the
// config loaded from the dsn on top of the normal defaults
func Config(dsn string, readOnly bool, configDefaults *model.Config) Option {
	return func(ps *PlatformService) error {
		configStore, err := config.NewStoreFromDSN(dsn, readOnly, configDefaults, true)
		if err != nil {
			return fmt.Errorf("failed to apply Config option: %w", err)
		}

		ps.configStore = configStore

		return nil
	}
}

func SetFileStore(filestore filestore.FileBackend) Option {
	return func(ps *PlatformService) error {
		ps.filestore = filestore
		return nil
	}
}

func SetExportFileStore(filestore filestore.FileBackend) Option {
	return func(ps *PlatformService) error {
		ps.exportFilestore = filestore
		return nil
	}
}

// ConfigStore applies the given config store, typically to replace the traditional sources with a memory store for testing.
func ConfigStore(configStore *config.Store) Option {
	return func(ps *PlatformService) error {
		ps.configStore = configStore

		return nil
	}
}

func StartMetrics() Option {
	return func(ps *PlatformService) error {
		ps.startMetrics = true
		return nil
	}
}

func SetLogger(logger *mlog.Logger) Option {
	return func(ps *PlatformService) error {
		ps.SetLogger(logger)

		return nil
	}
}

func SetCluster(cluster einterfaces.ClusterInterface) Option {
	return func(ps *PlatformService) error {
		ps.clusterIFace = cluster
		return nil
	}
}

func ForceEnableRedis() Option {
	return func(ps *PlatformService) error {
		ps.forceEnableRedis = true
		return nil
	}
}