refactor(api): restructured API for type safety, maintainability and docs generation

- These changes makes the API incombatible with previous versions
- Added new types for error handling, success responses, and health checks.
- Updated health check logic to utilize the new types for better clarity and structure.
- Refactored existing handlers to improve response consistency and error handling.
- Updated Makefile to include a new target for generating API types from Swagger.
- Updated "new agent" API to respond an encrypted cert pair

internal/api/v1/cert/info.go

@@ -0,0 +1,53 @@
+package certapi
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	apitypes "github.com/yusing/go-proxy/internal/api/types"
+	config "github.com/yusing/go-proxy/internal/config/types"
+)
+
+type CertInfo struct {
+	Subject        string   `json:"subject"`
+	Issuer         string   `json:"issuer"`
+	NotBefore      int64    `json:"not_before"`
+	NotAfter       int64    `json:"not_after"`
+	DNSNames       []string `json:"dns_names"`
+	EmailAddresses []string `json:"email_addresses"`
+} // @name CertInfo
+
+// @BasePath		/api/v1
+// @Summary		Get cert info
+// @Description	Get cert info
+// @Tags			cert
+// @Accept			json
+// @Produce		json
+// @Success		200	{object}	CertInfo
+// @Failure		403	{object}	apitypes.ErrorResponse
+// @Failure		404	{object}	apitypes.ErrorResponse
+// @Failure		500	{object}	apitypes.ErrorResponse
+// @Router			/cert/info [get]
+func Info(c *gin.Context) {
+	autocert := config.GetInstance().AutoCertProvider()
+	if autocert == nil {
+		c.JSON(http.StatusNotFound, apitypes.Error("autocert is not enabled"))
+		return
+	}
+
+	cert, err := autocert.GetCert(nil)
+	if err != nil {
+		c.Error(apitypes.InternalServerError(err, "failed to get cert info"))
+		return
+	}
+
+	certInfo := CertInfo{
+		Subject:        cert.Leaf.Subject.CommonName,
+		Issuer:         cert.Leaf.Issuer.CommonName,
+		NotBefore:      cert.Leaf.NotBefore.Unix(),
+		NotAfter:       cert.Leaf.NotAfter.Unix(),
+		DNSNames:       cert.Leaf.DNSNames,
+		EmailAddresses: cert.Leaf.EmailAddresses,
+	}
+	c.JSON(http.StatusOK, certInfo)
+}

internal/api/v1/cert/renew.go

@@ -0,0 +1,72 @@
+package certapi
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/rs/zerolog/log"
+	apitypes "github.com/yusing/go-proxy/internal/api/types"
+	config "github.com/yusing/go-proxy/internal/config/types"
+	"github.com/yusing/go-proxy/internal/gperr"
+	"github.com/yusing/go-proxy/internal/logging/memlogger"
+	"github.com/yusing/go-proxy/internal/net/gphttp/websocket"
+)
+
+// @BasePath		/api/v1
+// @Summary		Renew cert
+// @Description	Renew cert
+// @Tags			cert
+// @Accept			json
+// @Produce		json
+// @Success		200	{object}	apitypes.SuccessResponse
+// @Failure		403	{object}	apitypes.ErrorResponse
+// @Failure		500	{object}	apitypes.ErrorResponse
+// @Router			/cert/renew [post]
+func Renew(c *gin.Context) {
+	autocert := config.GetInstance().AutoCertProvider()
+	if autocert == nil {
+		c.JSON(http.StatusNotFound, apitypes.Error("autocert is not enabled"))
+		return
+	}
+
+	manager, err := websocket.NewManagerWithUpgrade(c)
+	if err != nil {
+		c.Error(apitypes.InternalServerError(err, "failed to create websocket manager"))
+		return
+	}
+	defer manager.Close()
+
+	logs, cancel := memlogger.Events()
+	defer cancel()
+
+	done := make(chan struct{})
+
+	go func() {
+		defer close(done)
+
+		err = autocert.ObtainCert()
+		if err != nil {
+			gperr.LogError("failed to obtain cert", err)
+			_ = manager.WriteData(websocket.TextMessage, []byte(err.Error()), 10*time.Second)
+		} else {
+			log.Info().Msg("cert obtained successfully")
+		}
+	}()
+
+	for {
+		select {
+		case l := <-logs:
+			if err != nil {
+				return
+			}
+
+			err = manager.WriteData(websocket.TextMessage, l, 10*time.Second)
+			if err != nil {
+				return
+			}
+		case <-done:
+			return
+		}
+	}
+}