package curl2info

import (
	"errors"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/http/cookiejar"
	"net/url"
	"os"
	"regexp"
	"strings"

	"github.com/474420502/requests"
)

// CURL 信息结构
type CURL struct {
	ParsedURL *url.URL
	Method    string
	Header    http.Header
	CookieJar http.CookieJar
	Cookies   []*http.Cookie
	Body      *requests.Body
}

// NewCURL new 一个 curl 出来
func NewCURL(scurl ...string) *CURL {

	if len(scurl) != 0 {
		if len(scurl) > 1 {
			panic(errors.New("NewCURL only accept one curl info"))
		}

		curl, err := ParseRawCURL(scurl[0])
		if err != nil {
			panic(err)
		}
		return curl

	}

	u := &CURL{}
	u.Header = make(http.Header)
	u.CookieJar, _ = cookiejar.New(nil)
	u.Body = requests.NewBody()

	return u
}

func (curl *CURL) String() string {
	return fmt.Sprintf("Method: %s\nParsedURL: %s\nHeader: %s\nCookie: %s",
		curl.Method, curl.ParsedURL.String(), curl.Header, curl.Cookies)
}

// CreateSession 创建Session
func (curl *CURL) CreateSession() *requests.Session {
	ses := requests.NewSession()
	ses.SetHeader(curl.Header)
	ses.SetCookies(curl.ParsedURL, curl.Cookies)
	return ses
}

// CreateWorkflow 根据Session 创建Workflow
func (curl *CURL) CreateWorkflow(ses *requests.Session) *requests.Workflow {
	var wf *requests.Workflow
	switch curl.Method {
	case "HEAD":
		wf = ses.Head(curl.ParsedURL.String())
	case "GET":
		wf = ses.Get(curl.ParsedURL.String())
	case "POST":
		wf = ses.Post(curl.ParsedURL.String())
	case "PUT":
		wf = ses.Put(curl.ParsedURL.String())
	case "PATCH":
		wf = ses.Patch(curl.ParsedURL.String())
	case "OPTIONS":
		wf = ses.Options(curl.ParsedURL.String())
	case "DELETE":
		wf = ses.Delete(curl.ParsedURL.String())
	}

	wf.SetBody(curl.Body)
	return wf
}

// ParseRawCURL curl_bash
func ParseRawCURL(scurl string) (cURL *CURL, err error) {

	defer func() {
		if _err := recover(); _err != nil {
			cURL = nil
			err = _err.(error)
		}
	}()

	curl := NewCURL()
	scurl = strings.TrimSpace(scurl)
	scurl = strings.TrimLeft(scurl, "curl")
	mathches := regexp.MustCompile(`--[^ ]+ +'[^']+'|--[^ ]+ +[^ ]+|-[A-Za-z] +'[^']+'|-[A-Za-z] +[^ ]+| '[^']+'|--[a-z]+ {0,}`).FindAllString(scurl, -1)
	for _, m := range mathches {
		m = strings.TrimSpace(m)
		switch v := m[0]; v {
		case '\'':
			purl, err := url.Parse(strings.Trim(m, "'"))
			if err != nil {
				panic(err)
			}
			curl.ParsedURL = purl
		case '-':
			judgeAndParseOptions(curl, m)
		}
	}

	if curl.Method == "" {
		curl.Method = "GET"
	}

	return curl, nil
}

func judgeAndParseOptions(u *CURL, soption string) {
	switch prefix := soption[0:2]; prefix {
	case "-H":
		parseHeader(u, soption)
	case "-X":
		matches := regexp.MustCompile("-X +(.+)").FindStringSubmatch(soption)
		method := strings.Trim(matches[1], "'")
		u.Method = method
	case "-A": // User-Agent 先后顺序的问题
		parseHeader(u, soption)
	case "-I":
		u.Method = "HEAD"
	case "--":
		parseLongOption(u, soption)
	}
}

func parseLongOption(u *CURL, soption string) {
	// -d, --data <data>   HTTP POST data
	// --data-ascii <data> HTTP POST ASCII data
	// --data-binary <data> HTTP POST binary data
	// --data-raw <data> HTTP POST data, '@' allowed
	// --data-urlencode <data> HTTP POST data url encoded

	switch {
	case regexp.MustCompile("^--data |^--data-urlencode|^--data-binary|^--data-ascii|^--data-raw").MatchString(soption):
		datas := regexp.MustCompile("^--data-(binary) +(.+)|^--data-(ascii) +(.+)|^--data-(raw) +(.+)|^--data-(urlencode) +(.+)|^--(data) +(.+)").FindStringSubmatch(soption)

		dtype := datas[1]
		data := strings.Trim(datas[2], "'")

		if u.Method != "" {
			u.Method = "POST"
		}

		switch dtype {
		case "binary":
			parseBodyBinary(u, data)
		case "ascii":
			parseBodyASCII(u, data)
		case "raw":
			parseBodyRaw(u, data)
		case "urlencode":
			parseBodyURLEncode(u, data)
		case "data":
			parseBodyASCII(u, data)
		}
	case regexp.MustCompile("^--header").MatchString(soption):
		parseHeader(u, soption)
	}

}

func parseBodyURLEncode(u *CURL, data string) {
	u.Body.SetPrefix(requests.TypeURLENCODED)
	u.Body.SetIOBody(data)
}

func parseBodyRaw(u *CURL, data string) {
	u.Body.SetPrefix(requests.TypeURLENCODED)
	u.Body.SetIOBody(data)
}

func parseBodyASCII(u *CURL, data string) {
	u.Body.SetPrefix(requests.TypeURLENCODED)

	if data[0] != '@' {
		u.Body.SetIOBody(data)
	} else {
		f, err := os.Open(data[1:])
		if err != nil {
			panic(err)
		}
		defer f.Close()

		bdata, err := ioutil.ReadAll(f)
		if err != nil {
			panic(err)
		}
		u.Body.SetIOBody(bdata)
	}
}

// 处理@ 并且替/r/n符号
func parseBodyBinary(u *CURL, data string) {
	u.Body.SetPrefix(requests.TypeURLENCODED)

	if data[0] != '@' {
		u.Body.SetIOBody(data)
	} else {
		f, err := os.Open(data[1:])
		if err != nil {
			panic(err)
		}
		defer f.Close()
		bdata, err := ioutil.ReadAll(f)
		if err != nil {
			panic(err)
		}
		bdata = regexp.MustCompile("\n|\r").ReplaceAll(bdata, []byte(""))
		u.Body.SetIOBody(bdata)
	}
}

func parseHeader(u *CURL, soption string) {
	matches := regexp.MustCompile(`'([^:]+): ([^']+)'`).FindAllStringSubmatch(soption, 1)[0]
	key := matches[1]
	value := matches[2]

	switch key {
	case "Cookie":
		u.Cookies = ReadRawCookies(value, "")
		u.CookieJar.SetCookies(u.ParsedURL, u.Cookies)
	case "Content-Type":
		u.Body.SetPrefix(value)
	default:
		u.Header.Add(key, value)
	}

}