package template

import (
	"fmt"
	"html/template"
	"regexp"
	"strings"
	"time"

	"wego/util"
)

// funcMap 模板函数
var funcMap = make(template.FuncMap, 15)

// AddFuncMap 添加模板函数，需要在Init模板初始化之前添加才能生效
func AddFuncMap(name string, f interface{}) error {
	funcMap[name] = f
	return nil
}

// ****************************************************************************

func init() {
	funcMap["UnHTML"] = UnHTML           // func(x string) interface{}
	funcMap["Split"] = strings.Split     // func(s, sep string) []string
	funcMap["SubStr"] = util.SubStr      // func(str string, start int, length ...int) string
	funcMap["HTML2str"] = HTML2str       // func(html string) string
	funcMap["DateFormat"] = DateFormat   // func(t time.Time, layout string) (datestring string)
	funcMap["DateParse"] = DateParse     // func(dateString, format string) (time.Time, error)
	funcMap["Date"] = Date               // func(t time.Time, format string) string
	funcMap["Compare"] = Compare         // func(a, b interface{}) (equal bool)
	funcMap["CompareNot"] = CompareNot   // func(a, b interface{}) (equal bool)
	funcMap["Empty"] = Empty             // func(a interface{}) bool
	funcMap["Htmlquote"] = Htmlquote     // func(text string) string
	funcMap["Htmlunquote"] = Htmlunquote // func(text string) string
}

// UnHTML template.HTML
func UnHTML(x string) interface{} {
	return template.HTML(x)
}

// HTML2str html转化为字符串，剔除一些 script、css 之类的元素，返回纯文本信息，使用方法 {{html2str .Htmlinfo}}
func HTML2str(html string) string {

	re, _ := regexp.Compile(`\<[\S\s]+?\>`)
	html = re.ReplaceAllStringFunc(html, strings.ToLower)

	//remove STYLE
	re, _ = regexp.Compile(`\<style[\S\s]+?\</style\>`)
	html = re.ReplaceAllString(html, "")

	//remove SCRIPT
	re, _ = regexp.Compile(`\<script[\S\s]+?\</script\>`)
	html = re.ReplaceAllString(html, "")

	re, _ = regexp.Compile(`\<[\S\s]+?\>`)
	html = re.ReplaceAllString(html, "\n")

	re, _ = regexp.Compile(`\s{2,}`)
	html = re.ReplaceAllString(html, "\n")

	return strings.TrimSpace(html)
}

// DateFormat 时间的格式化，返回字符串，使用方法 {{dateformat .Time “2006-01-02T15:04:05Z07:00”}}
func DateFormat(t time.Time, layout string) (datestring string) {
	datestring = t.Format(layout)
	return
}

// datePatterns pattern rules.
var datePatterns = []string{
	// year
	"Y", "2006", // A full numeric representation of a year, 4 digits   Examples: 1999 or 2003
	"y", "06", //A two digit representation of a year   Examples: 99 or 03

	// month
	"m", "01", // Numeric representation of a month, with leading zeros 01 through 12
	"n", "1", // Numeric representation of a month, without leading zeros   1 through 12
	"M", "Jan", // A short textual representation of a month, three letters Jan through Dec
	"F", "January", // A full textual representation of a month, such as January or March   January through December

	// day
	"d", "02", // Day of the month, 2 digits with leading zeros 01 to 31
	"j", "2", // Day of the month without leading zeros 1 to 31

	// week
	"D", "Mon", // A textual representation of a day, three letters Mon through Sun
	"l", "Monday", // A full textual representation of the day of the week  Sunday through Saturday

	// time
	"g", "3", // 12-hour format of an hour without leading zeros    1 through 12
	"G", "15", // 24-hour format of an hour without leading zeros   0 through 23
	"h", "03", // 12-hour format of an hour with leading zeros  01 through 12
	"H", "15", // 24-hour format of an hour with leading zeros  00 through 23

	"a", "pm", // Lowercase Ante meridiem and Post meridiem am or pm
	"A", "PM", // Uppercase Ante meridiem and Post meridiem AM or PM

	"i", "04", // Minutes with leading zeros    00 to 59
	"s", "05", // Seconds, with leading zeros   00 through 59

	// time zone
	"T", "MST",
	"P", "-07:00",
	"O", "-0700",

	// RFC 2822
	"r", time.RFC1123Z,
}

// DateParse 兼容php语言风格的时间字符串解析
func DateParse(dateString, format string) (time.Time, error) {
	replacer := strings.NewReplacer(datePatterns...)
	format = replacer.Replace(format)
	return time.ParseInLocation(format, dateString, time.Local)
}

// Date 兼容php语言风格的时间的格式化
func Date(t time.Time, format string) string {
	replacer := strings.NewReplacer(datePatterns...)
	format = replacer.Replace(format)
	return t.Format(format)
}

// Compare 比较两个对象，如果相同返回 true，否者 false，使用方法 {{compare .A .B}}
func Compare(a, b interface{}) (equal bool) {
	equal = false
	if strings.TrimSpace(fmt.Sprintf("%v", a)) == strings.TrimSpace(fmt.Sprintf("%v", b)) {
		equal = true
	}
	return
}

// CompareNot !Compare
func CompareNot(a, b interface{}) (equal bool) {
	return !Compare(a, b)
}

// Empty 对象为空时返回true
func Empty(a interface{}) bool {
	return Compare(a, nil)
}

// Htmlquote html字符转义，使用方法 {{htmlquote .quote}}
func Htmlquote(text string) string {
	//HTML编码为实体符号
	/*
	   Encodes `text` for raw use in HTML.
	       >>> htmlquote("<'&\\">")
	       '&lt;&#39;&amp;&quot;&gt;'
	*/

	text = strings.Replace(text, "&", "&amp;", -1) // Must be done first!
	text = strings.Replace(text, "<", "&lt;", -1)
	text = strings.Replace(text, ">", "&gt;", -1)
	text = strings.Replace(text, "'", "&#39;", -1)
	text = strings.Replace(text, "\"", "&quot;", -1)
	text = strings.Replace(text, "“", "&ldquo;", -1)
	text = strings.Replace(text, "”", "&rdquo;", -1)
	text = strings.Replace(text, " ", "&nbsp;", -1)

	return strings.TrimSpace(text)
}

// Htmlunquote html字符反转义，使用方法 {{htmlunquote .unquote}}
func Htmlunquote(text string) string {
	//实体符号解释为HTML
	/*
	   Decodes `text` that's HTML quoted.
	       >>> htmlunquote('&lt;&#39;&amp;&quot;&gt;')
	       '<\\'&">'
	*/

	// strings.Replace(s, old, new, n)
	// 在s字符串中，把old字符串替换为new字符串，n表示替换的次数，小于0表示全部替换

	text = strings.Replace(text, "&nbsp;", " ", -1)
	text = strings.Replace(text, "&rdquo;", "”", -1)
	text = strings.Replace(text, "&ldquo;", "“", -1)
	text = strings.Replace(text, "&quot;", "\"", -1)
	text = strings.Replace(text, "&#39;", "'", -1)
	text = strings.Replace(text, "&gt;", ">", -1)
	text = strings.Replace(text, "&lt;", "<", -1)
	text = strings.Replace(text, "&amp;", "&", -1) // Must be done last!

	return strings.TrimSpace(text)
}