package parser

import (
	"net/url"
	"strconv"
	"strings"
	"sub2clash/constant"
	"sub2clash/model"
)

func ParseHysteria(proxy string) (model.Proxy, error) {
	if !strings.HasPrefix(proxy, constant.HysteriaPrefix) {
		return model.Proxy{}, &ParseError{Type: ErrInvalidPrefix, Raw: proxy}
	}

	proxy = strings.TrimPrefix(proxy, constant.HysteriaPrefix)
	urlParts := strings.SplitN(proxy, "?", 2)
	if len(urlParts) != 2 {
		return model.Proxy{}, &ParseError{
			Type:    ErrInvalidStruct,
			Message: "missing character '?' in url",
			Raw:     proxy,
		}
	}

	serverInfo := strings.SplitN(urlParts[0], ":", 2)
	if len(serverInfo) != 2 {
		return model.Proxy{}, &ParseError{
			Type:    ErrInvalidStruct,
			Message: "missing server host or port",
			Raw:     proxy,
		}
	}
	server, portStr := serverInfo[0], serverInfo[1]

	port, err := ParsePort(portStr)
	if err != nil {
		return model.Proxy{}, &ParseError{
			Type:    ErrInvalidPort,
			Message: err.Error(),
			Raw:     proxy,
		}
	}

	params, err := url.ParseQuery(urlParts[1])
	if err != nil {
		return model.Proxy{}, &ParseError{
			Type:    ErrCannotParseParams,
			Raw:     proxy,
			Message: err.Error(),
		}
	}

	protocol, auth, insecure, upmbps, downmbps, obfs, alpnStr := params.Get("protocol"), params.Get("auth"), params.Get("insecure"), params.Get("upmbps"), params.Get("downmbps"), params.Get("obfs"), params.Get("alpn")
	insecureBool, err := strconv.ParseBool(insecure)
	if err != nil {
		insecureBool = false
	}

	var alpn []string
	alpnStr = strings.TrimSpace(alpnStr)
	if alpnStr != "" {
		alpn = strings.Split(alpnStr, ",")
	}

	remarks := server + ":" + portStr
	if params.Get("remarks") != "" {
		remarks = params.Get("remarks")
	}

	result := model.Proxy{
		Type:           "hysteria",
		Name:           remarks,
		Server:         server,
		Port:           port,
		Up:             upmbps,
		Down:           downmbps,
		Auth:           auth,
		Obfs:           obfs,
		SkipCertVerify: insecure == "1",
		Alpn:           alpn,
		Protocol:       protocol,
		AllowInsecure:  insecureBool,
	}
	return result, nil
}