http-wokou/pkg/controller.go

package httpserver

import (
	"fmt"
	"io"
	"log"
	"net/http"
	"net/http/cookiejar"
	"net/url"
	"strings"

	"github.com/gin-gonic/gin"
	"golang.org/x/net/publicsuffix"
)

// Implementing a 'set'
var NonmutableHeaders = map[string]struct{}{
	"Cookie":          struct{}{},
	"User-Agent":      struct{}{},
	"Accept-Encoding": struct{}{},
	"Referer":         struct{}{},
	"X-Proxy-Url":     struct{}{},
	"Host":            struct{}{},
}

type Controller struct {
	Config  *HttpServerConfig
	Client  *http.Client
	SiteUrl *url.URL
}

type ProxyCookies struct {
	ck map[*url.URL][]*http.Cookie
}

/*
Returns a new Controller struct to register routes to the gin router

	:param cfg: A pointer to an HttpServerConfig struct
*/
func NewController(cfg *HttpServerConfig) *Controller {
	jar, err := cookiejar.New(&cookiejar.Options{PublicSuffixList: publicsuffix.List})
	if err != nil {
		log.Fatal(err)
	}

	sessCookies := cfg.CookieJar
	domain, err := url.Parse("https://www.semrush.com")
	if err != nil {
		log.Fatal(err)
	}
	jar.SetCookies(domain, sessCookies)

	return &Controller{Config: cfg, Client: &http.Client{Jar: jar}, SiteUrl: domain}
}

/*
This handler will be responsible for proxying out the GET requests that the server recieves
*/
func (c *Controller) Get(ctx *gin.Context) {
	var allowedDomain string
	if ctx.Param("ProxiedPath") == "/siteaudit/i18n/messages_en.fd3cadbc.json" {
		data, ctype, err := c.RetrieveStaticResource(ctx.Param("ProxiedPath"))
		if err != nil {
			log.Fatal(err, "failed to get site config")
		}
		ctx.Data(200, ctype, data)
		return
	}
	if strings.Contains(ctx.Param("ProxiedPath"), "/siteaudit/index/") {
		data, ctype, err := c.RetrieveStaticResource(ctx.Param("ProxiedPath"))
		if err != nil {
			log.Fatal(err, "failed to get site config")
		}
		ctx.Data(200, ctype, data)
		return
	}
	if strings.Contains(ctx.Param("ProxiedPath"), "/siteaudit/review/") {
		data, ctype, err := c.RetrieveStaticResource(ctx.Param("ProxiedPath"))
		if err != nil {
			log.Fatal(err, "failed to get site config")
		}
		ctx.Data(200, ctype, data)
		return
	}
	if strings.Contains(ctx.Param("ProxiedPath"), "/projects/api/") {
		data, ctype, err := c.SiteauditApiCall(ctx.Request.Method, ctx.Param("ProxiedPath"), ctx.Request.URL.RawQuery, ctx.Request.Body)
		if err != nil {
			log.Fatal(err, "failed to get site config")
		}
		ctx.Data(200, ctype, data)
		return
	}
	if strings.Contains(ctx.Param("ProxiedPath"), "/siteaudit/api/") {
		data, ctype, err := c.SiteauditApiCall(ctx.Request.Method, ctx.Param("ProxiedPath"), ctx.Request.URL.RawQuery, ctx.Request.Body)
		if err != nil {
			log.Fatal(err, "failed to get site config")
		}
		ctx.Data(200, ctype, data)
		return
	}

	allowedDomain = c.Config.AllowedDomain
	reqUrl := fmt.Sprintf("https://%s%s", allowedDomain, ctx.Param("ProxiedPath"))
	req, err := http.NewRequest(ctx.Request.Method, reqUrl, ctx.Request.Body)
	if err != nil {
		ctx.JSON(500, map[string]string{
			"Error": "Error creating the request.",
			"Msg:":  err.Error(),
		})
		return
	}
	req.URL.Path = ctx.Param("ProxiedPath")
	cookie, err := ctx.Cookie("csrftoken")
	req.Header.Add("User-Agent", c.Config.UserAgent)
	req.AddCookie(&http.Cookie{Name: "csrftoken", Value: cookie, Path: "/siteaudit", MaxAge: 3600, HttpOnly: true, Secure: true, SameSite: http.SameSiteNoneMode})
	req.Header.Set("Referer", c.Config.AllowedDomain)
	if ctx.Param("ProxiedPath") == "/" {
		ctx.Header("Location", "https://sem.bunnytools.shop/analytics/overview/")
	}
	if ctx.Param("ProxiedPath") == "/_compatibility/traffic/overview/" {
		ctx.Header("Location", "https://sem.bunnytools.shop/analytics/traffic/overview/ebay.com")
	}
	for k, v := range ctx.Request.Header {
		_, ok := NonmutableHeaders[k]
		if !ok {
			req.Header.Add(k, v[0])
		}
	}
	resp, err := c.Client.Do(req)
	if err != nil {
		ctx.JSON(500, map[string]string{
			"Error": "Error creating the request.",
			"Msg:":  err.Error(),
		})
		return
	}
	defer resp.Body.Close()
	b, err := io.ReadAll(resp.Body)
	if err != nil {
		ctx.JSON(500, map[string]string{
			"Error": "Error creating the request.",
			"Msg:":  err.Error(),
		})
		return
	}
	for k, v := range resp.Header {
		_, ok := NonmutableHeaders[k]
		if !ok {
			ctx.Header(k, v[0])
		}
	}

	newBody := strings.ReplaceAll(string(b), "\"srf-browser-unhappy\"", "\"srf-browser-unhappy\" style=\"display:none;\"")
	newBody = strings.ReplaceAll(newBody, "\"srf-navbar__right\"", "\"srf-navbar__right\" style=\"display:none;\"")
	newBody = strings.ReplaceAll(newBody, "<footer", "<footer style=\"display:none;\"")
	newBody = strings.ReplaceAll(newBody, "\"srf-report-sidebar-extras\"", "\"srf-report-sidebar-extra\" style=\"display:none;\"")
	newBody = strings.ReplaceAll(newBody, "www.semrush.com", "sem.bunnytools.shop")
	newBody = strings.ReplaceAll(newBody, "static.semrush.com", "sem.bunnytools.shop")
	ctx.Data(resp.StatusCode, resp.Header.Get("Content-Type"), []byte(newBody))
}