Added oauth for gitea

internal/web/handlers/oauth.go

@@ -0,0 +1,59 @@
+package handlers
+
+import (
+	"CatsOfMastodonBotGo/internal/auth"
+	"CatsOfMastodonBotGo/internal/config"
+	"CatsOfMastodonBotGo/internal/web/dto"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+type OauthLoginHandler struct {
+	Jwt               auth.JwtTokenGenerator
+	OauthLoginHandler auth.GiteaOAuth2Handler
+}
+
+var OauthLoginHandlerInstance *OauthLoginHandler
+
+func InitOauthLoginHandler() {
+	OauthLoginHandlerInstance = &OauthLoginHandler{
+		Jwt: *auth.JwtTokenGeneratorInstance,
+	}
+}
+
+func (_ *OauthLoginHandler) GoToGiteaLogin(c *gin.Context) {
+	c.Redirect(http.StatusFound, auth.GiteaOauth2HandlerInstance.GetGiteaLoginURL(c.Request.Host))
+}
+
+func (olh *OauthLoginHandler) LoginWithGitea(c *gin.Context) {
+	var input dto.GiteaLoginInput
+	if err := c.ShouldBindJSON(&input); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	userEmail, err := olh.OauthLoginHandler.GetGiteaUserEmailByCode(input.Code)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	for _, email := range config.Config.GiteaOauthAllowedEmails {
+		if email == userEmail {
+			token, err := olh.Jwt.GenerateToken(map[string]interface{}{"role": "admin"})
+			if err != nil {
+				c.JSON(http.StatusInternalServerError, gin.H{"error": "Token generation failed"})
+				return
+			}
+
+			c.JSON(http.StatusOK, gin.H{"message": "Login successful", "token": token})
+		} else {
+			c.JSON(401, gin.H{
+				"error": "oath login faied or yyour email does not have access",
+			})
+			return
+		}
+	}
+
+}