From 0339f10a64b4ed92a3c6532e9e9be33b83688c14 Mon Sep 17 00:00:00 2001
From: SnO2WMaN <me@sno2wman.net>
Date: Fri, 8 Dec 2023 18:36:50 +0900
Subject: [PATCH] proxy

---
 main.go  |  2 ++
 proxy.go | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)
 create mode 100644 proxy.go

diff --git a/main.go b/main.go
index 11d647b..2614a05 100644
--- a/main.go
+++ b/main.go
@@ -20,6 +20,8 @@ func main() {
 
 	e.GET("/mads/:serial/primary", MADPrimaryThumbnail)
 
+	e.GET("/proxy", Proxy)
+
 	e.GET("/original/youtube/:vid", OriginalYoutubeThumbnail)
 	e.GET("/original/nicovideo/:vid", OriginalNicovideoThumbnail)
 	e.GET("/original/bilibili/:vid", OriginalBilibiliThumbnail)
diff --git a/proxy.go b/proxy.go
new file mode 100644
index 0000000..180dc20
--- /dev/null
+++ b/proxy.go
@@ -0,0 +1,52 @@
+package main
+
+import (
+	"encoding/base64"
+	"fmt"
+	"net/http"
+	"os"
+	"time"
+
+	"github.com/labstack/echo/v4"
+	"github.com/redis/go-redis/v9"
+)
+
+func Proxy(c echo.Context) error {
+	url := c.FormValue("url")
+	if url == "" {
+		return c.String(http.StatusBadRequest, "Bad request at url")
+	}
+
+	scale := c.FormValue("scale")
+	if scale == "" {
+		return c.String(http.StatusBadRequest, "Bad request at scale")
+	}
+	width, height, err := ParseScale(scale)
+	if err != nil {
+		return c.String(http.StatusBadRequest, err.Error())
+	}
+
+	rdb := redis.NewClient(&redis.Options{Addr: os.Getenv("REDIS_ADDRESS")})
+	defer rdb.Close()
+
+	redisKey := fmt.Sprintf("proxy_%s_%d_%d", url, width, height)
+	cachedUrl, err := rdb.Get(ctx, redisKey).Result()
+	if err != nil && err != redis.Nil {
+		c.Logger().Error(err)
+		return c.String(http.StatusInternalServerError, "Internal Server Error")
+	}
+	if cachedUrl != "" {
+		return c.Redirect(http.StatusTemporaryRedirect, cachedUrl)
+	}
+
+	proxiedUrl := SignURL(
+		fmt.Sprintf("/rs:fit:%d:%d:1:1/background:000000/%s", width, height, base64.URLEncoding.EncodeToString([]byte(url))))
+	c.Logger().Debug(proxiedUrl)
+
+	err = rdb.Set(ctx, redisKey, proxiedUrl, time.Duration(600*time.Second)).Err()
+	if err != nil {
+		c.Logger().Error(err)
+	}
+
+	return c.Redirect(http.StatusTemporaryRedirect, proxiedUrl)
+}