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/mna/redisc"
	"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)
}

// Redis连接池适配器
type Hub struct {
	LOG     func() *logger.Logger
	pool    *redis.Pool
	cluster *redisc.Cluster
	once    sync.Once
}

// 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", time.Duration(60000))
	return &Hub{
		LOG: func() *logger.Logger {
			return logger.New()
		},
	}
}

// 创建连接池
func (h *Hub) createPool(addr string, opts ...redis.DialOption) (*redis.Pool, error) {
	maxIdle := viper.GetInt("redis.max_idle")
	maxActive := viper.GetInt("redis.max_active")
	idleTimeout := viper.GetDuration("redis.timeout")

	return &redis.Pool{
		MaxIdle:     maxIdle,
		MaxActive:   maxActive,
		IdleTimeout: idleTimeout,
		Dial: func() (redis.Conn, error) {
			if conn, err := redis.Dial("tcp", addr, opts...); err != nil {
				h.LOG().Warnf("Get Redis connection failed: %s", err.Error())
				return nil, err
			} else {
				return conn, nil
			}
		},
		TestOnBorrow: func(c redis.Conn, t time.Time) error {
			_, err := c.Do("PING")
			return err
		},
	}, nil
}

// 建立与Redis的连接
func (h *Hub) conn() error {
	dialOpts := []redis.DialOption{
		redis.DialConnectTimeout(5 * time.Second),
		//redis.DialReadTimeout(5 * time.Second),
		//redis.DialWriteTimeout(5 * time.Second),
	}

	nodes := viper.GetStringSlice("redis.nodes")
	if nil != nodes && len(nodes) > 0 { // 集群
		cluster := &redisc.Cluster{
			StartupNodes: nodes,
			DialOptions:  dialOpts,
			CreatePool:   h.createPool,
		}
		h.cluster = cluster
	} else { // 单点
		var pool *redis.Pool
		host := viper.GetString("redis.host")
		password := viper.GetString("redis.password")
		if len(strings.TrimSpace(password)) > 0 {
			dialOpts = append(dialOpts, redis.DialPassword(strings.TrimSpace(password)))
		}
		pool, _ = h.createPool(host, dialOpts...)
		h.pool = pool
	}
	return h.ping()
}

// 连接测试
func (h *Hub) ping() error {
	// 连接测试
	conn, err := h.Get()
	if nil != err {
		return err
	}
	defer func(conn redis.Conn) {
		_ = conn.Close()
	}(conn)

	if reply, err := redis.String(conn.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
func (h *Hub) Close() error {
	var err error
	if nil != h.cluster {
		err = h.cluster.Close()
	} else if nil != h.pool {
		err = h.pool.Close()
	}
	return err
}

// 执行Redis命令
func (h *Hub) Do(cmd string, args ...interface{}) (interface{}, error) {
	conn, err := h.Get()
	if nil != err {
		return nil, err
	}
	defer func(conn redis.Conn) {
		_ = conn.Close()
	}(conn)

	if nil == conn {
		return nil, ErrRedisConnNil
	} else {
		reply, err := conn.Do(cmd, args...)
		if nil != err {
			return nil, err
		}
		return reply, nil
	}
}

// 从连接池中获取一个连接
func (h *Hub) Get() (redis.Conn, error) {
	var err error
	// 延迟一次性初始化Redis连接池
	h.once.Do(func() {
		e := h.conn()
		if nil != e {
			err = e
		} else {
			h.closeWait()
		}
	})
	if nil != err {
		return nil, err
	}

	if nil != h.pool {
		return h.pool.Get(), nil
	} else if nil != h.cluster {
		return h.cluster.Get(), nil
	} else {
		return nil, ErrRedisConnNil
	}
}