// Package redis ...
//
// Description : redis 客户端
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 2021-02-27 4:49 下午
package redis

import (
	"encoding/json"
	"fmt"
	"strings"
	"sync"
	"time"

	"git.zhangdeman.cn/zhangdeman/util"

	"git.zhangdeman.cn/zhangdeman/logger"
	redisInstance "github.com/go-redis/redis/v8"
	"go.uber.org/zap"
)

var (
	// Client 连接实例
	Client ClientInterface
)

func init() {
	Client = &OwnClient{
		lock:           &sync.RWMutex{},
		instanceTable:  make(map[string]*RealClient),
		confTable:      make(map[string]Options),
		parseErrorFunc: defaultParseError,
	}
}

// defaultParseError ...
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 10:59 下午 2021/2/27
func defaultParseError(err error) error {
	if nil == err {
		return nil
	}
	errMsg := err.Error()
	if errMsg == "nil" || errMsg == "<nil>" {
		return nil
	}
	strArr := strings.Split(errMsg, ":")
	if len(strArr) != 2 {
		return err
	}
	msg := strings.ToLower(strings.TrimSpace(strArr[1]))
	if msg == "nil" || msg == "<nil>" {
		return nil
	}
	return err
}

// Options 连接选项,百分之百兼容第三方包的选项
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 4:57 下午 2021/2/27
type Options struct {
	Conf              *redisInstance.Options // 第三方包的选项
	Logger            *LoggerConfig          // 日志的配置
	LoggerFieldConfig *LogFieldConfig        // 日志字段的配置
}

// RealClient 包装好的 redis client
type RealClient struct {
	Flag              string                // redis 标识
	Instance          *redisInstance.Client // redis 实例
	Logger            *zap.Logger           // 日志实例
	LoggerFieldConfig *LogFieldConfig       // 日志字段的配置
}

// NewClient 获取redis client实例
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 5:05 下午 2021/2/27
func NewClient(config map[string]Options, parseErrorFunc func(err error) error) (ClientInterface, error) {
	c := &OwnClient{
		instanceTable:  make(map[string]*RealClient),
		loggerTable:    make(map[string]*zap.Logger),
		confTable:      config,
		parseErrorFunc: parseErrorFunc,
	}
	if nil == c.parseErrorFunc {
		c.parseErrorFunc = defaultParseError
	}
	return c, c.init()
}

// OwnClient 包装的redis client
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 4:52 下午 2021/2/27
type OwnClient struct {
	lock           *sync.RWMutex          // 锁
	loggerTable    map[string]*zap.Logger // 日志实例
	instanceTable  map[string]*RealClient // redis 实例
	confTable      map[string]Options     // redis 配置
	parseErrorFunc func(err error) error  // 解析err的function,解析执行结果是否为失败,有的场景,执行成功,返回 redis:nil / redis:<nil>
}

// loadConfig 载入配置文件
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 14:31 2022/6/15
func (c *OwnClient) loadConfig(cfgPath string) (*FullConfig, error) {
	var (
		err error
		cfg FullConfig
	)

	if err = util.File.ReadJSONContent(cfgPath, &cfg); nil != err {
		return nil, err
	}
	return &cfg, nil
}

// init 初始化redis连接
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 5:31 下午 2021/2/27
func (c *OwnClient) init() error {

	for flag, conf := range c.confTable {
		c.instanceTable[flag] = &RealClient{
			Flag:              flag,
			Instance:          redisInstance.NewClient(conf.Conf),
			Logger:            nil,
			LoggerFieldConfig: conf.LoggerFieldConfig,
		}
		if nil == c.instanceTable[flag].LoggerFieldConfig {
			c.instanceTable[flag].LoggerFieldConfig = &LogFieldConfig{
				Message:       "",
				UsedTimeField: "",
				CommandField:  "",
				FlagField:     "",
			}
		}
		if len(c.instanceTable[flag].LoggerFieldConfig.Message) == 0 {
			c.instanceTable[flag].LoggerFieldConfig.Message = defaultMessage
		}
		if len(c.instanceTable[flag].LoggerFieldConfig.CommandField) == 0 {
			c.instanceTable[flag].LoggerFieldConfig.CommandField = defaultCommandField
		}
		if len(c.instanceTable[flag].LoggerFieldConfig.UsedTimeField) == 0 {
			c.instanceTable[flag].LoggerFieldConfig.UsedTimeField = defaultUsedTimeField
		}
		if len(c.instanceTable[flag].LoggerFieldConfig.FlagField) == 0 {
			c.instanceTable[flag].LoggerFieldConfig.FlagField = defaultFlagField
		}
	}
	return nil
}

// initLogger 初始化日志
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 7:07 下午 2021/2/27
func (c *OwnClient) initLogger(flag string, conf *logger.InputLogConfig) error {
	var err error
	c.loggerTable[flag], err = logger.GetLogInstanceFromInputConfig(conf)
	return LoggerInitFail(flag, err)
}

// GetRedisClient 获取redis实例
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 5:16 下午 2021/2/27
func (c *OwnClient) GetRedisClient(flag string) (*RealClient, error) {
	redisClient, exist := c.instanceTable[flag]
	if !exist {
		return nil, FlagNotFound(flag)
	}
	return redisClient, nil
}

// log 记录redis请求日志
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 8:52 下午 2021/2/27
func (c *OwnClient) log(ctx *Context, realClient *RealClient, cmdResult redisInstance.Cmder, startTime int64, finishTime int64) {
	if nil == realClient || nil == realClient.Logger {
		return
	}
	realClient.Logger.Info(
		"执行redis命令日志记录",
		zap.Any(ctx.RequestIDField, ctx.RequestID),                                                 // 上下文串联的requestID
		zap.String(realClient.LoggerFieldConfig.CommandField, cmdResult.String()),                  // 执行的命令
		zap.Float64(realClient.LoggerFieldConfig.UsedTimeField, float64(finishTime-startTime)/1e6), // 耗时,单位: ms
		zap.Error(cmdResult.Err()),                                                                 // 异常信息
	)
}

// CommandProxy 执行命令的代理
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 9:41 下午 2021/2/27
func (c *OwnClient) CommandProxy(ctx *Context, flag string, cmd string, param ...interface{}) (string, error) {
	var (
		realClient *RealClient
		err        error
	)
	if len(cmd) == 0 {
		return "", EmptyCmd()
	}

	if nil == ctx {
		ctx = NewContext(flag)
	}
	if realClient, err = c.GetRedisClient(ctx.Flag); nil != err {
		return "", err
	}
	redisCmd := append([]interface{}{cmd}, param...)
	startTime := time.Now().Unix()
	cmdResult := realClient.Instance.Do(ctx.Ctx, redisCmd...)
	go c.log(ctx, realClient, cmdResult, startTime, time.Now().UnixNano())
	return fmt.Sprintf("%v", cmdResult.Val()), c.parseErrorFunc(cmdResult.Err())
}

// CommandProxyWithReceiver 执行命令,并解析结果
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 10:00 下午 2021/2/27
func (c *OwnClient) CommandProxyWithReceiver(ctx *Context, flag string, receiver interface{}, cmd string, param ...interface{}) error {
	if nil == receiver {
		return ReceiverISNIL()
	}
	var (
		err    error
		result string
	)

	if result, err = c.CommandProxy(ctx, flag, cmd, param...); nil != err {
		return err
	}

	return ResultConvertFail(json.Unmarshal([]byte(result), receiver))
}

// ClientInterface 定义redis client的接口实现,方便单元测试数据mock
//
// Author : go_developer@163.com<白茶清欢>
//
// Date : 10:49 下午 2021/2/27
type ClientInterface interface {
	GetRedisClient(flag string) (*RealClient, error)
	CommandProxy(ctx *Context, flag string, cmd string, param ...interface{}) (string, error)
	CommandProxyWithReceiver(ctx *Context, flag string, receiver interface{}, cmd string, param ...interface{}) error
}