package surfer

import (
	"net/http"
	"strings"
	"sync"
	"time"
)

type Request interface {
	// url
	GetUrl() string
	// GET POST POST-M HEAD
	GetMethod() string
	// POST values
	GetPostData() string
	// http header
	GetHeader() http.Header
	// enable http cookies
	GetEnableCookie() bool
	// dial tcp: i/o timeout
	GetDialTimeout() time.Duration
	// WSARecv tcp: i/o timeout
	GetConnTimeout() time.Duration
	// the max times of download
	GetTryTimes() int
	// the pause time of retry
	GetRetryPause() time.Duration
	// the download ProxyHost
	GetProxy() string
	// max redirect times
	GetRedirectTimes() int
	// select Surf ro PhomtomJS
	GetDownloaderID() int
}

const (
	SurfID             = 0               // Surf下载器标识符
	PhomtomJsID        = 1               // PhomtomJs下载器标识符
	DefaultMethod      = "GET"           // 默认请求方法
	DefaultDialTimeout = 2 * time.Minute // 默认请求服务器超时
	DefaultConnTimeout = 2 * time.Minute // 默认下载超时
	DefaultTryTimes    = 3               // 默认最大下载次数
	DefaultRetryPause  = 2 * time.Second // 默认重新下载前停顿时长
)

// 默认实现的Request
type DefaultRequest struct {
	// url (必须填写)
	Url string
	// GET POST POST-M HEAD (默认为GET)
	Method string
	// http header
	Header http.Header
	// 是否使用cookies，在Spider的EnableCookie设置
	EnableCookie bool
	// POST values
	PostData string
	// dial tcp: i/o timeout
	DialTimeout time.Duration
	// WSARecv tcp: i/o timeout
	ConnTimeout time.Duration
	// the max times of download
	TryTimes int
	// how long pause when retry
	RetryPause time.Duration
	// max redirect times
	// when RedirectTimes equal 0, redirect times is ∞
	// when RedirectTimes less than 0, redirect times is 0
	RedirectTimes int
	// the download ProxyHost
	Proxy string

	// 指定下载器ID
	// 0为Surf高并发下载器，各种控制功能齐全
	// 1为PhantomJS下载器，特点破防力强，速度慢，低并发
	DownloaderID int

	// 保证prepare只调用一次
	once sync.Once
}

func (self *DefaultRequest) prepare() {
	if self.Method == "" {
		self.Method = DefaultMethod
	}
	self.Method = strings.ToUpper(self.Method)

	if self.Header == nil {
		self.Header = make(http.Header)
	}

	if self.DialTimeout < 0 {
		self.DialTimeout = 0
	} else if self.DialTimeout == 0 {
		self.DialTimeout = DefaultDialTimeout
	}

	if self.ConnTimeout < 0 {
		self.ConnTimeout = 0
	} else if self.ConnTimeout == 0 {
		self.ConnTimeout = DefaultConnTimeout
	}

	if self.TryTimes == 0 {
		self.TryTimes = DefaultTryTimes
	}

	if self.RetryPause <= 0 {
		self.RetryPause = DefaultRetryPause
	}

	if self.DownloaderID != PhomtomJsID {
		self.DownloaderID = SurfID
	}
}

// url
func (self *DefaultRequest) GetUrl() string {
	self.once.Do(self.prepare)
	return self.Url
}

// GET POST POST-M HEAD
func (self *DefaultRequest) GetMethod() string {
	self.once.Do(self.prepare)
	return self.Method
}

// POST values
func (self *DefaultRequest) GetPostData() string {
	self.once.Do(self.prepare)
	return self.PostData
}

// http header
func (self *DefaultRequest) GetHeader() http.Header {
	self.once.Do(self.prepare)
	return self.Header
}

// enable http cookies
func (self *DefaultRequest) GetEnableCookie() bool {
	self.once.Do(self.prepare)
	return self.EnableCookie
}

// dial tcp: i/o timeout
func (self *DefaultRequest) GetDialTimeout() time.Duration {
	self.once.Do(self.prepare)
	return self.DialTimeout
}

// WSARecv tcp: i/o timeout
func (self *DefaultRequest) GetConnTimeout() time.Duration {
	self.once.Do(self.prepare)
	return self.ConnTimeout
}

// the max times of download
func (self *DefaultRequest) GetTryTimes() int {
	self.once.Do(self.prepare)
	return self.TryTimes
}

// the pause time of retry
func (self *DefaultRequest) GetRetryPause() time.Duration {
	self.once.Do(self.prepare)
	return self.RetryPause
}

// the download ProxyHost
func (self *DefaultRequest) GetProxy() string {
	self.once.Do(self.prepare)
	return self.Proxy
}

// max redirect times
func (self *DefaultRequest) GetRedirectTimes() int {
	self.once.Do(self.prepare)
	return self.RedirectTimes
}

// select Surf ro PhomtomJS
func (self *DefaultRequest) GetDownloaderID() int {
	self.once.Do(self.prepare)
	return self.DownloaderID
}