feat: save & get auth code cache

internal/cache/mod.go

@@ -1,6 +1,8 @@
 package cache
 
 import (
+	"encoding/json"
+	"fmt"
 	"log"
 	"time"
 
@@ -27,10 +29,56 @@ func NewClient(cfg *config.AppConfig) *Client {
 	}
 }
 
+type OAuthCode struct {
+	ClientID string `json:"client_id"`
+	UserID   string `json:"user_id"`
+	Nonce    string `json:"nonce"`
+}
+
+type SaveAuthCodeParams struct {
+	AuthCode string
+	UserID   string
+	ClientID string
+	Nonce    string
+}
+
 func (c *Client) Set(ctx context.Context, key string, value any, expiration time.Duration) *redis.StatusCmd {
 	return c.rClient.Set(ctx, key, value, expiration)
 }
 
+func (c *Client) SaveAuthCode(ctx context.Context, params *SaveAuthCodeParams) error {
+	code := OAuthCode{
+		ClientID: params.ClientID,
+		UserID:   params.UserID,
+		Nonce:    params.Nonce,
+	}
+	row, err := json.Marshal(&code)
+	if err != nil {
+		return err
+	}
+
+	return c.Set(ctx, fmt.Sprintf("oauth.%s", params.AuthCode), string(row), 5*time.Minute).Err()
+}
+
+func (c *Client) GetAuthCode(ctx context.Context, authCode string) (*OAuthCode, error) {
+	row, err := c.Get(ctx, fmt.Sprintf("oauth.%s", authCode)).Result()
+	if err != nil {
+		return nil, err
+	}
+
+	if len(row) == 0 {
+		return nil, fmt.Errorf("no auth params found under %s", authCode)
+	}
+
+	var parsed OAuthCode
+
+	if err := json.Unmarshal([]byte(row), &parsed); err != nil {
+		return nil, err
+	}
+
+	return &parsed, nil
+}
+
 func (c *Client) Get(ctx context.Context, key string) *redis.StringCmd {
 	return c.rClient.Get(ctx, key)
 }