// Copyright (c) 2015 Spinpunch, Inc. All Rights Reserved.
// See License.txt for license information.

package store

import (
	l4g "code.google.com/p/log4go"
	"github.com/mattermost/platform/model"
)

type SqlSessionStore struct {
	*SqlStore
}

func NewSqlSessionStore(sqlStore *SqlStore) SessionStore {
	us := &SqlSessionStore{sqlStore}

	for _, db := range sqlStore.GetAllConns() {
		table := db.AddTableWithName(model.Session{}, "Sessions").SetKeys(false, "Id")
		table.ColMap("Id").SetMaxSize(26)
		table.ColMap("AltId").SetMaxSize(26)
		table.ColMap("UserId").SetMaxSize(26)
		table.ColMap("TeamId").SetMaxSize(26)
		table.ColMap("DeviceId").SetMaxSize(128)
		table.ColMap("Roles").SetMaxSize(64)
		table.ColMap("Props").SetMaxSize(1000)
	}

	return us
}

func (me SqlSessionStore) UpgradeSchemaIfNeeded() {
}

func (me SqlSessionStore) CreateIndexesIfNotExists() {
	me.CreateIndexIfNotExists("idx_user_id", "Sessions", "UserId")
}

func (me SqlSessionStore) Save(session *model.Session) StoreChannel {

	storeChannel := make(StoreChannel)

	go func() {
		result := StoreResult{}

		if len(session.Id) > 0 {
			result.Err = model.NewAppError("SqlSessionStore.Save", "Cannot update existing session", "id="+session.Id)
			storeChannel <- result
			close(storeChannel)
			return
		}

		session.PreSave()

		if cur := <-me.CleanUpExpiredSessions(session.UserId); cur.Err != nil {
			l4g.Error("Failed to cleanup sessions in Save err=%v", cur.Err)
		}

		if err := me.GetMaster().Insert(session); err != nil {
			result.Err = model.NewAppError("SqlSessionStore.Save", "We couldn't save the session", "id="+session.Id+", "+err.Error())
		} else {
			result.Data = session
		}

		storeChannel <- result
		close(storeChannel)
	}()

	return storeChannel
}

func (me SqlSessionStore) Get(id string) StoreChannel {

	storeChannel := make(StoreChannel)

	go func() {
		result := StoreResult{}

		if obj, err := me.GetReplica().Get(model.Session{}, id); err != nil {
			result.Err = model.NewAppError("SqlSessionStore.Get", "We encounted an error finding the session", "id="+id+", "+err.Error())
		} else if obj == nil {
			result.Err = model.NewAppError("SqlSessionStore.Get", "We couldn't find the existing session", "id="+id)
		} else {
			result.Data = obj.(*model.Session)
		}

		storeChannel <- result
		close(storeChannel)

	}()

	return storeChannel
}

func (me SqlSessionStore) GetSessions(userId string) StoreChannel {
	storeChannel := make(StoreChannel)

	go func() {

		if cur := <-me.CleanUpExpiredSessions(userId); cur.Err != nil {
			l4g.Error("Failed to cleanup sessions in getSessions err=%v", cur.Err)
		}

		result := StoreResult{}

		var sessions []*model.Session

		if _, err := me.GetReplica().Select(&sessions, "SELECT * FROM Sessions WHERE UserId = ? ORDER BY LastActivityAt DESC", userId); err != nil {
			result.Err = model.NewAppError("SqlSessionStore.GetSessions", "We encounted an error while finding user sessions", err.Error())
		} else {

			result.Data = sessions
		}

		storeChannel <- result
		close(storeChannel)
	}()

	return storeChannel
}

func (me SqlSessionStore) Remove(sessionIdOrAlt string) StoreChannel {
	storeChannel := make(StoreChannel)

	go func() {
		result := StoreResult{}

		_, err := me.GetMaster().Exec("DELETE FROM Sessions WHERE Id = ? Or AltId = ?", sessionIdOrAlt, sessionIdOrAlt)
		if err != nil {
			result.Err = model.NewAppError("SqlSessionStore.RemoveSession", "We couldn't remove the session", "id="+sessionIdOrAlt+", err="+err.Error())
		}

		storeChannel <- result
		close(storeChannel)
	}()

	return storeChannel
}

func (me SqlSessionStore) CleanUpExpiredSessions(userId string) StoreChannel {
	storeChannel := make(StoreChannel)

	go func() {
		result := StoreResult{}

		if _, err := me.GetMaster().Exec("DELETE FROM Sessions WHERE UserId = ? AND ExpiresAt != 0 AND ? > ExpiresAt", userId, model.GetMillis()); err != nil {
			result.Err = model.NewAppError("SqlSessionStore.CleanUpExpiredSessions", "We encounted an error while deleting expired user sessions", err.Error())
		} else {
			result.Data = userId
		}

		storeChannel <- result
		close(storeChannel)
	}()

	return storeChannel
}

func (me SqlSessionStore) UpdateLastActivityAt(sessionId string, time int64) StoreChannel {
	storeChannel := make(StoreChannel)

	go func() {
		result := StoreResult{}

		if _, err := me.GetMaster().Exec("UPDATE Sessions SET LastActivityAt = ? WHERE Id = ?", time, sessionId); err != nil {
			result.Err = model.NewAppError("SqlSessionStore.UpdateLastActivityAt", "We couldn't update the last_activity_at", "sessionId="+sessionId)
		} else {
			result.Data = sessionId
		}

		storeChannel <- result
		close(storeChannel)
	}()

	return storeChannel
}