Sync updates with elichika

As of https://github.com/YumeMichi/elichika/commit/81a78e964dcdb8bb2d123237f966f95e7fba190e

Signed-off-by: Yuan Si <do4suki@gmail.com>

config/json.go

@@ -0,0 +1,53 @@
+package config
+
+import (
+	"encoding/json"
+	"honoka-chan/utils"
+	"os"
+	"strconv"
+	"time"
+)
+
+type AppConfigs struct {
+	AppName  string   `json:"app_name"`
+	Settings Settings `json:"settings"`
+}
+
+type Settings struct {
+	SifCdnServer string `json:"sif_cdn_server"`
+	AsCdnServer  string `json:"as_cdn_server"`
+}
+
+func DefaultConfigs() *AppConfigs {
+	return &AppConfigs{
+		AppName: "honoka-chan",
+		Settings: Settings{
+			SifCdnServer: "http://192.168.1.123/static",
+			AsCdnServer:  "http://192.168.1.123/static",
+		},
+	}
+}
+
+func Load(p string) *AppConfigs {
+	if !utils.PathExists(p) {
+		_ = DefaultConfigs().Save(p)
+	}
+	c := AppConfigs{}
+	err := json.Unmarshal([]byte(utils.ReadAllText(p)), &c)
+	if err != nil {
+		_ = os.Rename(p, p+".backup"+strconv.FormatInt(time.Now().Unix(), 10))
+		_ = DefaultConfigs().Save(p)
+	}
+	c = AppConfigs{}
+	_ = json.Unmarshal([]byte(utils.ReadAllText(p)), &c)
+	return &c
+}
+
+func (c *AppConfigs) Save(p string) error {
+	data, err := json.Marshal(c)
+	if err != nil {
+		return err
+	}
+	utils.WriteAllText(p, string(data))
+	return nil
+}