hermes/backend/api/controllers/v1/backends/create.go

package backends

import (
	"encoding/base64"
	"encoding/json"
	"fmt"
	"net/http"

	"git.terah.dev/imterah/hermes/backend/api/backendruntime"
	"git.terah.dev/imterah/hermes/backend/api/db"
	"git.terah.dev/imterah/hermes/backend/api/permissions"
	"git.terah.dev/imterah/hermes/backend/api/state"
	"git.terah.dev/imterah/hermes/backend/commonbackend"
	"github.com/charmbracelet/log"
	"github.com/gin-gonic/gin"
)

type BackendCreationRequest struct {
	Token             string `validate:"required"`
	Name              string `validate:"required"`
	Description       *string
	Backend           string      `validate:"required"`
	BackendParameters interface{} `json:"connectionDetails" validate:"required"`
}

func SetupCreateBackend(state *state.State) {
	state.Engine.POST("/api/v1/backends/create", func(c *gin.Context) {
		var req BackendCreationRequest

		if err := c.BindJSON(&req); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{
				"error": fmt.Sprintf("Failed to parse body: %s", err.Error()),
			})

			return
		}

		if err := state.Validator.Struct(&req); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{
				"error": fmt.Sprintf("Failed to validate body: %s", err.Error()),
			})

			return
		}

		user, err := state.JWT.GetUserFromJWT(req.Token)

		if err != nil {
			if err.Error() == "token is expired" || err.Error() == "user does not exist" {
				c.JSON(http.StatusForbidden, gin.H{
					"error": err.Error(),
				})

				return
			} else {
				log.Warnf("Failed to get user from the provided JWT token: %s", err.Error())

				c.JSON(http.StatusInternalServerError, gin.H{
					"error": "Failed to parse token",
				})

				return
			}
		}

		if !permissions.UserHasPermission(user, "backends.add") {
			c.JSON(http.StatusForbidden, gin.H{
				"error": "Missing permissions",
			})

			return
		}

		var backendParameters []byte

		switch parameters := req.BackendParameters.(type) {
		case string:
			backendParameters = []byte(parameters)
		case map[string]interface{}:
			backendParameters, err = json.Marshal(parameters)

			if err != nil {
				log.Warnf("Failed to marshal JSON recieved as BackendParameters: %s", err.Error())

				c.JSON(http.StatusInternalServerError, gin.H{
					"error": "Failed to prepare parameters",
				})

				return
			}
		default:
			c.JSON(http.StatusBadRequest, gin.H{
				"error": fmt.Sprintf("Invalid type for connectionDetails (recieved %T)", parameters),
			})

			return
		}

		var backendRuntimeFilePath string

		for _, runtime := range backendruntime.AvailableBackends {
			if runtime.Name == req.Backend {
				backendRuntimeFilePath = runtime.Path
			}
		}

		if backendRuntimeFilePath == "" {
			c.JSON(http.StatusBadRequest, gin.H{
				"error": "Unsupported backend recieved",
			})

			return
		}

		backend := backendruntime.NewBackend(backendRuntimeFilePath)
		err = backend.Start()

		if err != nil {
			log.Warnf("Failed to start backend: %s", err.Error())

			c.JSON(http.StatusInternalServerError, gin.H{
				"error": "Failed to start backend",
			})

			return
		}

		backendParamCheckResponse, err := backend.ProcessCommand(&commonbackend.CheckServerParameters{
			Arguments: backendParameters,
		})

		if err != nil {
			log.Warnf("Failed to get response for backend: %s", err.Error())

			err = backend.Stop()

			if err != nil {
				log.Warnf("Failed to stop backend: %s", err.Error())
			}

			c.JSON(http.StatusInternalServerError, gin.H{
				"error": "Failed to get status response from backend",
			})

			return
		}

		switch responseMessage := backendParamCheckResponse.(type) {
		case *commonbackend.CheckParametersResponse:
			if responseMessage.InResponseTo != "checkServerParameters" {
				log.Errorf("Got illegal response to CheckServerParameters: %s", responseMessage.InResponseTo)

				err = backend.Stop()

				if err != nil {
					log.Warnf("Failed to stop backend: %s", err.Error())
				}

				c.JSON(http.StatusInternalServerError, gin.H{
					"error": "Failed to get status response from backend",
				})

				return
			}

			if !responseMessage.IsValid {
				err = backend.Stop()

				if err != nil {
					log.Warnf("Failed to stop backend: %s", err.Error())
				}

				var errorMessage string

				if responseMessage.Message == "" {
					errorMessage = "Unkown error while trying to parse connectionDetails"
				} else {
					errorMessage = fmt.Sprintf("Invalid backend parameters: %s", responseMessage.Message)
				}

				c.JSON(http.StatusBadRequest, gin.H{
					"error": errorMessage,
				})

				return
			}
		default:
			log.Warnf("Got illegal response type for backend: %T", responseMessage)
		}

		log.Info("Passed backend checks successfully")

		backendInDatabase := &db.Backend{
			UserID:            user.ID,
			Name:              req.Name,
			Description:       req.Description,
			Backend:           req.Backend,
			BackendParameters: base64.StdEncoding.EncodeToString(backendParameters),
		}

		if result := state.DB.DB.Create(&backendInDatabase); result.Error != nil {
			log.Warnf("Failed to create backend: %s", result.Error.Error())

			err = backend.Stop()

			if err != nil {
				log.Warnf("Failed to stop backend: %s", err.Error())
			}

			c.JSON(http.StatusInternalServerError, gin.H{
				"error": "Failed to add backend into database",
			})

			return
		}

		backendStartResponse, err := backend.ProcessCommand(&commonbackend.Start{
			Arguments: backendParameters,
		})

		if err != nil {
			log.Warnf("Failed to get response for backend: %s", err.Error())

			err = backend.Stop()

			if err != nil {
				log.Warnf("Failed to stop backend: %s", err.Error())
			}

			c.JSON(http.StatusInternalServerError, gin.H{
				"error": "Failed to get status response from backend",
			})

			return
		}

		switch responseMessage := backendStartResponse.(type) {
		case *commonbackend.BackendStatusResponse:
			if !responseMessage.IsRunning {
				err = backend.Stop()

				if err != nil {
					log.Warnf("Failed to start backend: %s", err.Error())
				}

				var errorMessage string

				if responseMessage.Message == "" {
					errorMessage = "Unkown error while trying to start the backend"
				} else {
					errorMessage = fmt.Sprintf("Failed to start backend: %s", responseMessage.Message)
				}

				c.JSON(http.StatusBadRequest, gin.H{
					"error": errorMessage,
				})

				return
			}
		default:
			log.Warnf("Got illegal response type for backend: %T", responseMessage)
		}

		backendruntime.RunningBackends[backendInDatabase.ID] = backend

		c.JSON(http.StatusOK, gin.H{
			"success": true,
		})
	})
}