package z1captcha

import (
	"fmt"
	"image/color"
	"strings"
	"time"
	"unicode/utf8"

	"gitee.com/z1gotool/z1crypto"
	"gitee.com/z1gotool/z1err"
	"github.com/mojocn/base64Captcha"
)

type CaptchaOpt struct {
	Length               int    // 验证码长度
	Timeout              int64  // 验证码超时时间
	Source               string // 验证码中可能出现的字符
	Password             string // 验证码密码
	TimeoutPeriodSteps   int64  // 验证码超时时间周期分步
	TimeoutPeriodPreStep int64  // 验证码超时时间周期前面第几部

	// Height png height in pixel.
	Height int
	// Width Captcha png width in pixel.
	Width int
	//NoiseCount text noise count.
	NoiseCount int
	//ShowLineOptions := OptionShowHollowLine | OptionShowSlimeLine | OptionShowSineLine .
	ShowLineOptions int
	//BgColor captcha image background color (optional)
	BgColor *color.RGBA
}

func Generate(opt ...CaptchaOpt) (text, b64s string) {
	optTmp := GetCaptchaOpt(opt...)
	text = GenerateText(optTmp)

	if `DrawCaptcha` != `` {
		driver := base64Captcha.NewDriverString(
			optTmp.Height,
			optTmp.Width,
			optTmp.NoiseCount,
			optTmp.ShowLineOptions,
			optTmp.Length,
			// `0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ`,
			optTmp.Source,
			// &color.RGBA{R: 255, G: 255, B: 255, A: 255},
			optTmp.BgColor,
			[]string{},
		)

		item, err := driver.ConvertFonts().DrawCaptcha(text)
		z1err.Check(err)
		b64s = item.EncodeB64string()

		// log.Println(`--------b64s-------`, b64s)
	}

	return
}

func GenerateText(opt ...CaptchaOpt) (ret string) {
	optTmp := GetCaptchaOpt(opt...)

	length := optTmp.Length
	timeout := optTmp.Timeout / optTmp.TimeoutPeriodSteps
	if timeout == 0 {
		timeout = 1
	}
	password := optTmp.Password
	source := optTmp.Source
	timeoutPeriodPreStep := optTmp.TimeoutPeriodPreStep
	// source := `1a张三李四王五田七`

	// length := int64(4)
	// timeout := int64(3)
	// password := `myzero1`
	// source := `0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ`
	// // source := `1a张三李四王五田七`

	expirationPeriod := time.Now().Unix() / timeout
	expirationPeriod = expirationPeriod - timeoutPeriodPreStep
	sourceLenth := utf8.RuneCountInString(source)
	chars := strings.Split(source, "")
	md51 := z1crypto.MD5Encode(fmt.Sprintf(`%v%v`, expirationPeriod, password))
	md52 := z1crypto.MD5Encode(fmt.Sprintf(`%v%v1`, expirationPeriod, password))
	baseStr := md51 + md52

	captchaChart := ``
	for i := 0; i < length; i++ {
		start := 4 * i
		end := 4 * (i + 1)
		tmp := baseStr[start:end]

		charCount := 0
		for i := 0; i < len(tmp); i++ {
			charCount = charCount + int(tmp[i])
		}

		index := charCount % sourceLenth

		chart := chars[index]
		captchaChart = captchaChart + chart
	}

	// log.Println(`-----expirationPeriod----------`, expirationPeriod)
	// log.Println(`-----captchaChart----1------`, captchaChart, md51)

	ret = captchaChart
	return
}

func Verify(captcha string, opt ...CaptchaOpt) (ret bool) {
	optTmp := GetCaptchaOpt(opt...)

	for i := int64(0); i < optTmp.TimeoutPeriodSteps; i++ {
		optTmp.TimeoutPeriodPreStep = i

		if captcha == GenerateText(optTmp) {
			ret = true
			return
		}
	}

	return
}

func GetCaptchaOpt(opt ...CaptchaOpt) (optRet CaptchaOpt) {
	optTmp := CaptchaOpt{
		Length:  6,
		Timeout: 60,
		Source:  `0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ`,
		// Source: `1a张三李四王五田七`,
		Password:           `567myzero1@#$`,
		TimeoutPeriodSteps: 5,

		Height:          60,
		Width:           180,
		NoiseCount:      0,
		ShowLineOptions: 14,
		BgColor:         &color.RGBA{R: 255, G: 255, B: 255, A: 255},
	}

	if len(opt) > 0 {
		if opt[0].Length == 0 {
			opt[0].Length = optTmp.Length
			if opt[0].Length > 8 {
				opt[0].Length = 8
			}
		}
		if opt[0].Timeout == 0 {
			opt[0].Timeout = optTmp.Timeout
		}
		if opt[0].TimeoutPeriodSteps == 0 {
			opt[0].TimeoutPeriodSteps = optTmp.TimeoutPeriodSteps
		}
		if opt[0].Source == `` {
			opt[0].Source = optTmp.Source
		}
		if opt[0].Password == `` {
			opt[0].Password = optTmp.Password
		}

		if opt[0].Height == 0 {
			opt[0].Height = optTmp.Height
		}
		if opt[0].Width == 0 {
			opt[0].Width = optTmp.Width
		}
		if opt[0].NoiseCount == 0 {
			opt[0].NoiseCount = optTmp.NoiseCount
		}
		if opt[0].ShowLineOptions == 0 {
			opt[0].ShowLineOptions = optTmp.ShowLineOptions
		}
		if opt[0].BgColor == nil {
			opt[0].BgColor = optTmp.BgColor
		}

		optTmp = opt[0]
	}

	optRet = optTmp

	return
}