// Copyright 2014 beego Author. All Rights Reserved.
//
// 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 couchbase for session provider
//
// depend on github.com/couchbaselabs/go-couchbasee
//
// go install github.com/couchbaselabs/go-couchbase
//
// Usage:
// import(
//   _ "github.com/henrylee2cn/lessgo/session/couchbase"
//   "github.com/henrylee2cn/lessgo/session"
// )
//
//	func init() {
//		globalSessions, _ = session.NewManager("couchbase", ``{"cookieName":"gosessionid","gclifetime":3600,"ProviderConfig":"http://host:port/, Pool, Bucket"}``)
//		go globalSessions.GC()
//	}
//
// more docs: http://beego.me/docs/module/session.md
package couchbase

import (
	"net/http"
	"strings"
	"sync"

	couchbase "github.com/couchbase/go-couchbase"

	"github.com/henrylee2cn/lessgo/session"
)

var couchbpder = &Provider{}

// SessionStore store each session
type SessionStore struct {
	b           *couchbase.Bucket
	sid         string
	lock        sync.RWMutex
	values      map[interface{}]interface{}
	maxlifetime int64
}

// Provider couchabse provided
type Provider struct {
	maxlifetime int64
	savePath    string
	pool        string
	bucket      string
	b           *couchbase.Bucket
}

// Set value to couchabse session
func (cs *SessionStore) Set(key, value interface{}) {
	cs.lock.Lock()
	defer cs.lock.Unlock()
	cs.values[key] = value
}

// Get value from couchabse session
func (cs *SessionStore) Get(key interface{}) interface{} {
	cs.lock.RLock()
	defer cs.lock.RUnlock()
	if v, ok := cs.values[key]; ok {
		return v
	}
	return nil
}

// Delete value in couchbase session by given key
func (cs *SessionStore) Delete(key interface{}) {
	cs.lock.Lock()
	defer cs.lock.Unlock()
	delete(cs.values, key)
}

// Flush Clean all values in couchbase session
func (cs *SessionStore) Flush() {
	cs.lock.Lock()
	defer cs.lock.Unlock()
	cs.values = make(map[interface{}]interface{})
}

// SessionID Get couchbase session store id
func (cs *SessionStore) SessionID() string {
	return cs.sid
}

// SessionRelease Write couchbase session with Gob string
func (cs *SessionStore) SessionRelease(w http.ResponseWriter) {
	defer cs.b.Close()

	bo, err := session.EncodeGob(cs.values)
	if err != nil {
		return
	}

	cs.b.Set(cs.sid, int(cs.maxlifetime), bo)
}

func (cp *Provider) getBucket() *couchbase.Bucket {
	c, err := couchbase.Connect(cp.savePath)
	if err != nil {
		return nil
	}

	pool, err := c.GetPool(cp.pool)
	if err != nil {
		return nil
	}

	bucket, err := pool.GetBucket(cp.bucket)
	if err != nil {
		return nil
	}

	return bucket
}

// SessionInit init couchbase session
// savepath like couchbase server REST/JSON URL
// e.g. http://host:port/, Pool, Bucket
func (cp *Provider) SessionInit(maxlifetime int64, savePath string) error {
	cp.maxlifetime = maxlifetime
	configs := strings.Split(savePath, ",")
	if len(configs) > 0 {
		cp.savePath = configs[0]
	}
	if len(configs) > 1 {
		cp.pool = configs[1]
	}
	if len(configs) > 2 {
		cp.bucket = configs[2]
	}

	return nil
}

// SessionRead read couchbase session by sid
func (cp *Provider) SessionRead(sid string) (session.Store, error) {
	cp.b = cp.getBucket()

	var doc []byte

	err := cp.b.Get(sid, &doc)
	var kv map[interface{}]interface{}
	if doc == nil {
		kv = make(map[interface{}]interface{})
	} else {
		kv, err = session.DecodeGob(doc)
		if err != nil {
			return nil, err
		}
	}

	cs := &SessionStore{b: cp.b, sid: sid, values: kv, maxlifetime: cp.maxlifetime}
	return cs, nil
}

// SessionExist Check couchbase session exist.
// it checkes sid exist or not.
func (cp *Provider) SessionExist(sid string) bool {
	cp.b = cp.getBucket()
	defer cp.b.Close()

	var doc []byte

	if err := cp.b.Get(sid, &doc); err != nil || doc == nil {
		return false
	}
	return true
}

// SessionRegenerate remove oldsid and use sid to generate new session
func (cp *Provider) SessionRegenerate(oldsid, sid string) (session.Store, error) {
	cp.b = cp.getBucket()

	var doc []byte
	if err := cp.b.Get(oldsid, &doc); err != nil || doc == nil {
		cp.b.Set(sid, int(cp.maxlifetime), "")
	} else {
		err := cp.b.Delete(oldsid)
		if err != nil {
			return nil, err
		}
		_, _ = cp.b.Add(sid, int(cp.maxlifetime), doc)
	}

	err := cp.b.Get(sid, &doc)
	if err != nil {
		return nil, err
	}
	var kv map[interface{}]interface{}
	if doc == nil {
		kv = make(map[interface{}]interface{})
	} else {
		kv, err = session.DecodeGob(doc)
		if err != nil {
			return nil, err
		}
	}

	cs := &SessionStore{b: cp.b, sid: sid, values: kv, maxlifetime: cp.maxlifetime}
	return cs, nil
}

// SessionDestroy Remove bucket in this couchbase
func (cp *Provider) SessionDestroy(sid string) error {
	cp.b = cp.getBucket()
	defer cp.b.Close()

	cp.b.Delete(sid)
	return nil
}

// SessionGC Recycle
func (cp *Provider) SessionGC() {
	return
}

// SessionAll return all active session
func (cp *Provider) SessionAll() int {
	return 0
}

func init() {
	session.Register("couchbase", couchbpder)
}
