// Copyright 2023 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
//go:build plus

package oss

import (
	"errors"
	"github.com/TeaOSLab/EdgeCommon/pkg/serverconfigs/ossconfigs"
	teaconst "github.com/TeaOSLab/EdgeNode/internal/const"
	"github.com/TeaOSLab/EdgeNode/internal/utils/fasttime"
	"github.com/TeaOSLab/EdgeNode/internal/utils/goman"
	"net/http"
	"sync"
	"time"
)

var SharedManager = NewManager()

func init() {
	if !teaconst.IsMain {
		return
	}

	var ticker = time.NewTicker(24 * time.Hour)
	goman.New(func() {
		for range ticker.C {
			SharedManager.GC()
		}
	})
}

type Manager struct {
	providerMap map[string]*Provider // unique id => *Provider
	locker      sync.RWMutex
}

func NewManager() *Manager {
	return &Manager{
		providerMap: map[string]*Provider{},
	}
}

func (this *Manager) FindProviderWithConfig(req *http.Request, host string, ossConfig *ossconfigs.OSSConfig) (provider *Provider, objectBucketName string, objectKey string, err error) {
	if ossConfig == nil {
		return nil, "", "", errors.New("provider 'config' should not be nil")
	}
	var originOptions = ossConfig.Options
	if originOptions == nil {
		return nil, "", "", errors.New("provider 'options' should not be nil")
	}

	options, ok := originOptions.(ossconfigs.OSSOptions)
	if !ok {
		return nil, "", "", errors.New("provider 'options' should implement 'OSSOptions' interface")
	}

	bucketName, key, uniqueId := ossConfig.ParseRequest(req, host)
	if len(bucketName) == 0 || len(key) == 0 {
		err = errNotFound
		return
	}

	objectBucketName = bucketName
	objectKey = key

	// 查询已有
	this.locker.RLock()
	provider, ok = this.providerMap[uniqueId]
	if ok {
		this.locker.RUnlock()
		return provider, bucketName, objectKey, nil
	}
	this.locker.RUnlock()

	this.locker.Lock()
	defer this.locker.Unlock()

	// 再次查询
	provider, ok = this.providerMap[uniqueId]
	if ok {
		return provider, bucketName, objectKey, nil
	}

	var rawProvider ProviderInterface
	switch ossConfig.Type {
	case ossconfigs.OSSTypeTencentCOS:
		rawProvider = NewTencentCOSProvider()
	case ossconfigs.OSSTypeAliyunOSS:
		rawProvider = NewAliyunOSSProvider()
	case ossconfigs.OSSTypeHuaweiOBS:
		rawProvider = NewHuaweiOBSProvider()
	case ossconfigs.OSSTypeBaiduBOS:
		rawProvider = NewBaiduBOSProvider()
	case ossconfigs.OSSTypeQiniuKodo:
		rawProvider = NewQiniuKodoProvider()
	case ossconfigs.OSSTypeAmazonS3:
		rawProvider = NewAmazonS3Provider()
	case ossconfigs.OSSTypeB2:
		rawProvider = NewB2Provider()
	default:
		return nil, "", "", errors.New("invalid provider '" + ossConfig.Type + "'")
	}

	if rawProvider == nil {
		return nil, "", "", errors.New("invalid provider '" + ossConfig.Type + "'")
	}

	// 包装
	provider = NewProvider(rawProvider)
	provider.SetUniqueId(uniqueId)

	// 初始化
	err = provider.Init(options, bucketName)
	if err != nil {
		return nil, "", "", err
	}

	// 放入缓存
	this.providerMap[uniqueId] = provider

	return
}

func (this *Manager) Head(req *http.Request, host string, ossConfig *ossconfigs.OSSConfig) (resp *http.Response, nativeErrCode string, nativeBucketName string, err error) {
	if ossConfig == nil {
		return nil, "", "", errors.New("provider config should not be nil")
	}

	provider, bucketName, key, err := this.FindProviderWithConfig(req, host, ossConfig)
	if err != nil {
		return nil, "", "", err
	}

	nativeBucketName = bucketName
	resp, nativeErrCode, err = provider.Head(key)

	if err == errNoBucket {
		this.locker.Lock()
		delete(this.providerMap, provider.UniqueId())
		this.locker.Unlock()
	}
	return
}

func (this *Manager) Get(req *http.Request, host string, ossConfig *ossconfigs.OSSConfig) (resp *http.Response, nativeErrCode string, nativeBucketName string, err error) {
	if ossConfig == nil {
		return nil, "", "", errors.New("provider config should not be nil")
	}

	provider, bucketName, key, err := this.FindProviderWithConfig(req, host, ossConfig)
	if err != nil {
		return nil, "", "", err
	}

	nativeBucketName = bucketName
	resp, nativeErrCode, err = provider.Get(key)

	if err == errNoBucket {
		this.locker.Lock()
		delete(this.providerMap, provider.UniqueId())
		this.locker.Unlock()
	}

	return
}

func (this *Manager) GetRange(req *http.Request, host string, bytesRange string, ossConfig *ossconfigs.OSSConfig) (resp *http.Response, nativeErrCode string, nativeBucketName string, err error) {
	if ossConfig == nil {
		return nil, "", "", errors.New("provider config should not be nil")
	}

	provider, bucketName, key, err := this.FindProviderWithConfig(req, host, ossConfig)
	if err != nil {
		return nil, "", "", err
	}

	nativeBucketName = bucketName
	resp, nativeErrCode, err = provider.GetRange(key, bytesRange)

	if err == errNoBucket {
		this.locker.Lock()
		delete(this.providerMap, provider.UniqueId())
		this.locker.Unlock()
	}

	return
}

func (this *Manager) GC() {
	// 查询
	this.locker.RLock()
	if len(this.providerMap) < 1024 { // 如果数量很小，则不需要清理
		this.locker.RUnlock()
		return
	}

	// 查询"过期"的Provider实例
	var expiredKeys = []string{}
	var currentTime = fasttime.Now().Unix()
	for key, provider := range this.providerMap {
		if provider.UpdatedAt < currentTime-86400 {
			expiredKeys = append(expiredKeys, key)
		}
	}

	this.locker.RUnlock()

	// 删除
	if len(expiredKeys) > 0 {
		this.locker.Lock()
		for _, key := range expiredKeys {
			delete(this.providerMap, key)
		}
		this.locker.Unlock()
	}
}