package redis

import (
	"net"
	"time"

	"gopkg.in/redis.v4/internal/pool"
)

type Options struct {
	// The network type, either tcp or unix.
	// Default is tcp.
	Network string
	// host:port address.
	Addr string

	// Dialer creates new network connection and has priority over
	// Network and Addr options.
	Dialer func() (net.Conn, error)

	// Optional password. Must match the password specified in the
	// requirepass server configuration option.
	Password string
	// Database to be selected after connecting to the server.
	DB int

	// Maximum number of retries before giving up.
	// Default is to not retry failed commands.
	MaxRetries int

	// Dial timeout for establishing new connections.
	// Default is 5 seconds.
	DialTimeout time.Duration
	// Timeout for socket reads. If reached, commands will fail
	// with a timeout instead of blocking.
	// Default is 3 seconds.
	ReadTimeout time.Duration
	// Timeout for socket writes. If reached, commands will fail
	// with a timeout instead of blocking.
	// Default is 3 seconds.
	WriteTimeout time.Duration

	// Maximum number of socket connections.
	// Default is 10 connections.
	PoolSize int
	// Amount of time client waits for connection if all connections
	// are busy before returning an error.
	// Default is ReadTimeout + 1 second.
	PoolTimeout time.Duration
	// Amount of time after which client closes idle connections.
	// Should be less than server's timeout.
	// Default is to not close idle connections.
	IdleTimeout time.Duration
	// Frequency of idle checks.
	// Default is 1 minute.
	// When minus value is set, then idle check is disabled.
	IdleCheckFrequency time.Duration

	// Enables read only queries on slave nodes.
	ReadOnly bool
}

func (opt *Options) init() {
	if opt.Network == "" {
		opt.Network = "tcp"
	}
	if opt.Dialer == nil {
		opt.Dialer = func() (net.Conn, error) {
			return net.DialTimeout(opt.Network, opt.Addr, opt.DialTimeout)
		}
	}
	if opt.PoolSize == 0 {
		opt.PoolSize = 10
	}
	if opt.DialTimeout == 0 {
		opt.DialTimeout = 5 * time.Second
	}
	if opt.ReadTimeout == 0 {
		opt.ReadTimeout = 3 * time.Second
	}
	if opt.WriteTimeout == 0 {
		opt.WriteTimeout = opt.ReadTimeout
	}
	if opt.PoolTimeout == 0 {
		opt.PoolTimeout = opt.ReadTimeout + time.Second
	}
	if opt.IdleTimeout == 0 {
		opt.IdleTimeout = 5 * time.Minute
	}
	if opt.IdleCheckFrequency == 0 {
		opt.IdleCheckFrequency = time.Minute
	}
}

func newConnPool(opt *Options) *pool.ConnPool {
	return pool.NewConnPool(
		opt.Dialer,
		opt.PoolSize,
		opt.PoolTimeout,
		opt.IdleTimeout,
		opt.IdleCheckFrequency,
	)
}

// PoolStats contains pool state information and accumulated stats.
type PoolStats struct {
	Requests uint32 // number of times a connection was requested by the pool
	Hits     uint32 // number of times free connection was found in the pool
	Timeouts uint32 // number of times a wait timeout occurred

	TotalConns uint32 // the number of total connections in the pool
	FreeConns  uint32 // the number of free connections in the pool
}