//  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 maven

import (
	"context"
	"io"

	"github.com/harness/gitness/app/auth/authz"
	corestore "github.com/harness/gitness/app/store"
	"github.com/harness/gitness/registry/app/api/openapi/contracts/artifact"
	"github.com/harness/gitness/registry/app/dist_temp/errcode"
	"github.com/harness/gitness/registry/app/pkg"
	"github.com/harness/gitness/registry/app/store"
	registrytypes "github.com/harness/gitness/registry/types"
	"github.com/harness/gitness/store/database/dbtx"
	"github.com/harness/gitness/types/enum"

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

var _ Artifact = (*LocalRegistry)(nil)
var _ Artifact = (*RemoteRegistry)(nil)

type ArtifactType int

const (
	LocalRegistryType ArtifactType = 1 << iota
	RemoteRegistryType
)

var TypeRegistry = map[ArtifactType]Artifact{}

type Controller struct {
	local      *LocalRegistry
	remote     *RemoteRegistry
	authorizer authz.Authorizer
	DBStore    *DBStore
	_          dbtx.Transactor
}

type DBStore struct {
	RegistryDao      store.RegistryRepository
	ImageDao         store.ImageRepository
	ArtifactDao      store.ArtifactRepository
	SpaceStore       corestore.SpaceStore
	BandwidthStatDao store.BandwidthStatRepository
	DownloadStatDao  store.DownloadStatRepository
	NodeDao          store.NodesRepository
	UpstreamProxyDao store.UpstreamProxyConfigRepository
}

func NewController(
	local *LocalRegistry,
	remote *RemoteRegistry,
	authorizer authz.Authorizer,
	dBStore *DBStore,
) *Controller {
	c := &Controller{
		local:      local,
		remote:     remote,
		authorizer: authorizer,
		DBStore:    dBStore,
	}

	TypeRegistry[LocalRegistryType] = local
	TypeRegistry[RemoteRegistryType] = remote
	return c
}

func NewDBStore(
	registryDao store.RegistryRepository,
	imageDao store.ImageRepository,
	artifactDao store.ArtifactRepository,
	spaceStore corestore.SpaceStore,
	bandwidthStatDao store.BandwidthStatRepository,
	downloadStatDao store.DownloadStatRepository,
	nodeDao store.NodesRepository,
	upstreamProxyDao store.UpstreamProxyConfigRepository,
) *DBStore {
	return &DBStore{
		RegistryDao:      registryDao,
		SpaceStore:       spaceStore,
		ImageDao:         imageDao,
		ArtifactDao:      artifactDao,
		BandwidthStatDao: bandwidthStatDao,
		DownloadStatDao:  downloadStatDao,
		NodeDao:          nodeDao,
		UpstreamProxyDao: upstreamProxyDao,
	}
}

func (c *Controller) factory(t ArtifactType) Artifact {
	switch t {
	case LocalRegistryType:
		return TypeRegistry[t]
	case RemoteRegistryType:
		return TypeRegistry[t]
	default:
		log.Error().Stack().Msgf("Invalid artifact type %v", t)
		return nil
	}
}

func (c *Controller) GetArtifactRegistry(registry registrytypes.Registry) Artifact {
	if string(registry.Type) == string(artifact.RegistryTypeVIRTUAL) {
		return c.factory(LocalRegistryType)
	}
	return c.factory(RemoteRegistryType)
}

func (c *Controller) GetArtifact(ctx context.Context, info pkg.MavenArtifactInfo) Response {
	err := pkg.GetRegistryCheckAccess(
		ctx, c.DBStore.RegistryDao, c.authorizer, c.DBStore.SpaceStore, info.RegIdentifier, info.ParentID,
		enum.PermissionArtifactsDownload,
	)
	if err != nil {
		return &GetArtifactResponse{
			Errors: []error{errcode.ErrCodeDenied},
		}
	}

	f := func(registry registrytypes.Registry, a Artifact) Response {
		info.SetMavenRepoKey(registry.Name)
		info.RegistryID = registry.ID
		headers, body, fileReader, e := a.(Registry).GetArtifact(ctx, info)
		return &GetArtifactResponse{e, headers, "", body, fileReader}
	}
	return c.ProxyWrapper(ctx, f, info)
}

func (c *Controller) HeadArtifact(ctx context.Context, info pkg.MavenArtifactInfo) Response {
	err := pkg.GetRegistryCheckAccess(
		ctx, c.DBStore.RegistryDao, c.authorizer, c.DBStore.SpaceStore, info.RegIdentifier, info.ParentID,
		enum.PermissionArtifactsDownload,
	)
	if err != nil {
		return &HeadArtifactResponse{
			Errors: []error{errcode.ErrCodeDenied},
		}
	}

	f := func(registry registrytypes.Registry, a Artifact) Response {
		info.SetMavenRepoKey(registry.Name)
		info.RegistryID = registry.ID
		headers, e := a.(Registry).HeadArtifact(ctx, info)
		return &HeadArtifactResponse{e, headers}
	}
	return c.ProxyWrapper(ctx, f, info)
}

func (c *Controller) PutArtifact(ctx context.Context, info pkg.MavenArtifactInfo, fileReader io.Reader) Response {
	err := pkg.GetRegistryCheckAccess(
		ctx, c.DBStore.RegistryDao, c.authorizer, c.DBStore.SpaceStore, info.RegIdentifier, info.ParentID,
		enum.PermissionArtifactsUpload,
	)
	if err != nil {
		return &PutArtifactResponse{
			Errors: []error{errcode.ErrCodeDenied},
		}
	}

	responseHeaders, errs := c.local.PutArtifact(ctx, info, fileReader)
	return &PutArtifactResponse{
		ResponseHeaders: responseHeaders,
		Errors:          errs,
	}
}

func (c *Controller) ProxyWrapper(
	ctx context.Context,
	f func(registry registrytypes.Registry, a Artifact) Response,
	info pkg.MavenArtifactInfo,
) Response {
	none := pkg.MavenArtifactInfo{}
	if info == none {
		log.Ctx(ctx).Error().Stack().Msg("artifactinfo is not found")
		return nil
	}

	var response Response
	requestRepoKey := info.RegIdentifier
	if repos, err := c.GetOrderedRepos(ctx, requestRepoKey, *info.BaseInfo); err == nil {
		for _, registry := range repos {
			log.Ctx(ctx).Info().Msgf("Using Repository: %s, Type: %s", registry.Name, registry.Type)
			artifact, ok := c.GetArtifactRegistry(registry).(Registry)
			if !ok {
				log.Ctx(ctx).Warn().Msgf("artifact %s is not a registry", registry.Name)
				continue
			}
			if artifact != nil {
				response = f(registry, artifact)
				if pkg.IsEmpty(response.GetErrors()) {
					return response
				}
				log.Ctx(ctx).Warn().Msgf("Repository: %s, Type: %s, errors: %v", registry.Name, registry.Type,
					response.GetErrors())
			}
		}
	}
	return response
}

func (c *Controller) GetOrderedRepos(
	ctx context.Context,
	repoKey string,
	artInfo pkg.BaseInfo,
) ([]registrytypes.Registry, error) {
	var result []registrytypes.Registry
	if registry, err := c.DBStore.RegistryDao.GetByParentIDAndName(ctx, artInfo.ParentID, repoKey); err == nil {
		result = append(result, *registry)
		proxies := registry.UpstreamProxies
		if len(proxies) > 0 {
			upstreamRepos, _ := c.DBStore.RegistryDao.GetByIDIn(ctx, proxies)
			result = append(result, *upstreamRepos...)
		}
	} else {
		return result, err
	}

	return result, nil
}