package redis

import (
	"git.aionnect.com/aionnect/go-common/utils"
	"git.aionnect.com/aionnect/go-common/utils/logger"
	"github.com/gomodule/redigo/redis"
	"github.com/spf13/viper"
	"os"
	"os/signal"
	"strings"
	"sync"
	"syscall"
	"time"
)

// 自定义错误
const (
	ErrRedisConnNil = ErrRedis("redis conn nil")
)

type ErrRedis string

func (err ErrRedis) Error() string {
	return string(err)
}

// 抽象的Redis操作适配器接口定义
type IRedisAdapter interface {
	Close() error
	Do(commandName string, args ...interface{}) (interface{}, error)
	Pipeline() IRedisPipeline
}

type IRedisPipeline interface {
	Send(commandName string, args ...interface{}) IRedisPipeline
	Execute() ([]interface{}, error)
}

type redisCmd struct {
	commandName string
	args        []interface{}
}

// Redis连接池适配器
type Hub struct {
	LOG     func() *logger.Logger
	once    sync.Once
	adapter IRedisAdapter
}

// 获取Redis连接池适配器的新实例
func NewHub() *Hub {
	viper.SetDefault("redis.max_idle", 300)
	viper.SetDefault("redis.max_active", 1000)
	viper.SetDefault("redis.timeout", 5*time.Second)
	return &Hub{
		LOG: func() *logger.Logger {
			return logger.New()
		},
	}
}

// 建立与Redis的连接
func (h *Hub) conn() error {
	var err error
	nodes := viper.GetStringSlice("redis.nodes")
	if nil != nodes && len(nodes) > 0 { // 集群
		masterName := viper.GetString("redis.master")
		if len(strings.TrimSpace(masterName)) > 0 { // redis sentinel集群
			h.adapter, err = NewSentinelAdapter(nodes, masterName) // 采用sentinel适配器
		} else { // redis cluster集群
			//h.adapter, err = NewGoRedisClusterAdapter(nodes) // 采用redis-go-cluster适配器
			h.adapter, err = NewRediscAdapter(nodes) // 采用redisc适配器
		}
	} else { // 单点
		host := viper.GetString("redis.host") // 采用redigo适配器
		h.adapter, err = NewRedigoAdapter(host)
	}
	if nil != err {
		h.LOG().Errorf("Get Redis connection pool failed: %s", err.Error())
		return err
	}
	return h.ping()
}

// 连接测试
func (h *Hub) ping() error {
	if reply, err := redis.String(h.adapter.Do("PING")); err != nil || reply != "PONG" {
		if err != nil {
			h.LOG().Warnf("Can not connect to redis: %s", err.Error())
		} else {
			h.LOG().Warnf("Can not connect to redis: %s", reply)
		}
		return err
	}
	h.LOG().Info("Redis connected")
	return nil
}

// 监听系统退出信号量，自动关闭Redis连接
func (h *Hub) closeWait() {
	go func(h *Hub) {
		defer utils.DefaultGoroutineRecover(nil, `Redis连接池关闭`)
		var c chan os.Signal
		var s os.Signal
		c = make(chan os.Signal, 1)
		signal.Notify(c, syscall.SIGHUP, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT, syscall.SIGKILL)
		for {
			s = <-c
			switch s {
			case syscall.SIGHUP, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT, syscall.SIGKILL:
				if err := h.Close(); nil != err {
					h.LOG().Error("Close redis connection failed:", err.Error())
				}
				h.LOG().Info("Redis connection closed")
				return
			default:
				return
			}
		}
	}(h)
}

// 关闭Redis连接池适配器
func (h *Hub) Close() error {
	return h.adapter.Close()
}

// 执行Redis命令
func (h *Hub) Do(commandName string, args ...interface{}) (interface{}, error) {
	var err error
	h.once.Do(func() {
		e := h.conn()
		if nil != e {
			err = e
		} else {
			h.closeWait()
		}
	})
	if nil != err {
		return nil, err
	}

	return h.adapter.Do(commandName, args...)
}

// 返回命令管道操作对象
func (h *Hub) Pipeline() IRedisPipeline {
	return h.adapter.Pipeline()
}