implement conditional redirects

This commit is contained in:
Akbar Rahman 2022-09-21 20:52:40 +01:00
parent 3fcc46c4f9
commit b5fdfcb49c
Signed by: alvierahman90
GPG Key ID: 20609519444A1269

93
main.go
View File

@ -24,6 +24,9 @@ import (
"log"
"net/http"
"os"
"strconv"
"strings"
"time"
"github.com/go-redis/redis/v8"
"github.com/gorilla/mux"
@ -83,7 +86,7 @@ func indexHandler(w http.ResponseWriter, r *http.Request) {
alt_condition,
)
formstring := command+":"+shortlink+":"+redirect+":"+alt_condition+":"+alt_redirect
formstring := command + ":" + shortlink + ":" + redirect + ":" + alt_condition + ":" + alt_redirect
fmt.Println("formstring: " + formstring)
@ -110,7 +113,21 @@ func indexHandler(w http.ResponseWriter, r *http.Request) {
ctx := context.Background()
_, err := client.Get(ctx, shortlink).Result()
if err == redis.Nil {
err = client.Set(ctx, shortlink, shortlink, 0).Err()
err = client.Set(ctx, shortlink+":redirect", shortlink, 0).Err()
if err != nil {
fmt.Println(err)
w.WriteHeader(500)
w.Write([]byte("500 Internal Server Error"))
return
}
err = client.Set(ctx, shortlink+":altcondition", alt_condition, 0).Err()
if err != nil {
fmt.Println(err)
w.WriteHeader(500)
w.Write([]byte("500 Internal Server Error"))
return
}
err = client.Set(ctx, shortlink+":altredirect", alt_redirect, 0).Err()
if err != nil {
fmt.Println(err)
@ -139,7 +156,15 @@ func indexHandler(w http.ResponseWriter, r *http.Request) {
if command == "delete" {
ctx := context.Background()
if err := client.Del(ctx, shortlink).Err(); err != nil {
if err := client.Del(ctx, shortlink+":redirect").Err(); err != nil {
w.WriteHeader(500)
w.Write([]byte("500 Internal Server Error"))
}
if err := client.Del(ctx, shortlink+":altredirect").Err(); err != nil {
w.WriteHeader(500)
w.Write([]byte("500 Internal Server Error"))
}
if err := client.Del(ctx, shortlink+":altcondition").Err(); err != nil {
w.WriteHeader(500)
w.Write([]byte("500 Internal Server Error"))
}
@ -176,7 +201,9 @@ func shortlinkHandler(w http.ResponseWriter, r *http.Request) {
fmt.Println("shortlinkHandler called")
shortlink := string(mux.Vars(r)["shortlink"])
ctx := context.Background()
redirect, err := client.Get(ctx, shortlink).Result()
client.Incr(ctx, shortlink + ":hits")
redirect, err := client.Get(ctx, shortlink+":redirect").Result()
fmt.Printf("shortlink: %v, redirect: %v\n", shortlink, redirect)
if err == redis.Nil {
w.WriteHeader(404)
@ -184,13 +211,67 @@ func shortlinkHandler(w http.ResponseWriter, r *http.Request) {
return
} else if err != nil {
fmt.Println(err)
fmt.Println(0)
w.WriteHeader(500)
w.Write([]byte("500 Internal Server Error"))
return
}
http.Redirect(w, r, redirect, 302)
return
altcondition, err := client.Get(ctx, shortlink+":altcondition").Result()
if err == redis.Nil {
http.Redirect(w, r, redirect, 302)
return
} else if err != nil {
fmt.Println(err)
fmt.Println(1)
w.WriteHeader(500)
w.Write([]byte("500 Internal Server Error"))
return
}
altredirect, err := client.Get(ctx, shortlink+":altredirect").Result()
if err == redis.Nil {
http.Redirect(w, r, redirect, 302)
return
} else if err != nil {
fmt.Println(err)
fmt.Println(2)
w.WriteHeader(500)
w.Write([]byte("500 Internal Server Error"))
return
}
altcondition_split := strings.Split(altcondition, ",")
ac_varname := altcondition_split[0]
ac_operator := altcondition_split[1]
ac_required_value, _ := strconv.Atoi(altcondition_split[2])
var ac_varval int
if ac_varname != "timestamp" {
ac_varvalstr, err := client.Get(ctx, shortlink+":"+ac_varname).Result()
if err == redis.Nil {
ac_varval = 0
} else if err != nil {
fmt.Println(err)
fmt.Println(3)
w.WriteHeader(500)
w.Write([]byte("500 Internal Server Error"))
return
} else {
ac_varval, _ = strconv.Atoi(ac_varvalstr)
}
} else {
ac_varval = int(time.Now().Unix())
}
if (ac_operator == "eq" && ac_varval == ac_required_value) ||
(ac_operator == "gt" && ac_varval > ac_required_value) ||
(ac_operator == "lt" && ac_varval < ac_required_value) {
http.Redirect(w, r, altredirect, 307)
} else {
http.Redirect(w, r, redirect, 307)
}
}
func getSha256HMACSignature(secret []byte, data string) string {