server/api/api.go

package api

import (
	"fmt"
	"log"
	"net/http"

	"github.com/gin-gonic/gin"
	"github.com/iomodo/staff/app"
)

const APIURLSuffix = "/api/v1"
const HealthCheckPath = "/healthcheck"

type API struct {
	Logger  *log.Logger
	Root    *gin.Engine
	APIRoot *gin.RouterGroup // 'api/v1'
	Auth    *gin.RouterGroup // 'api/v1/auth'
}

// Init initializes api
func Init(router *gin.Engine, application *app.App) error {
	apiObj := API{}
	apiObj.Root = router
	apiObj.Root.Use(func(c *gin.Context) {
		c.Set("app", application)
		c.Next()
	})
	apiObj.APIRoot = router.Group(APIURLSuffix)
	apiObj.initHealthCheck()

	apiObj.Root.NoRoute(func(c *gin.Context) {
		c.JSON(http.StatusNotFound, "Page not found")
	})

	return nil
}

func (apiObj *API) initHealthCheck() {
	apiObj.Root.GET(HealthCheckPath, healthCheck)
}

func healthCheck(c *gin.Context) {
	_, err := getApp(c)
	if err != nil {
		responseFormat(c, http.StatusInternalServerError, err.Error())
		return
	}
	responseFormat(c, http.StatusOK, "OK")
}

func responseFormat(c *gin.Context, respStatus int, data interface{}) {
	c.JSON(respStatus, data)
}

func getApp(c *gin.Context) (*app.App, error) {
	appInt, ok := c.Get("app")
	if !ok {
		return nil, fmt.Errorf("missing application in the context")
	}
	a, ok := appInt.(*app.App)
	if !ok {
		return nil, fmt.Errorf("wrong data type of the application in the context")
	}
	return a, nil
}