pomme/internal/api/helpers.go

package api

import (
	"context"
	"fmt"
	"net/http"
	"time"

	"dns.froth.zone/pomme/internal"
	"dns.froth.zone/pomme/internal/db"
	"github.com/go-chi/httplog"
	"github.com/go-chi/render"
	"gorm.io/gorm"
)

// setDBMiddleware is the http Handler func for the GORM middleware with context.
func setDBMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		var (
			pommeDB *gorm.DB
			ok      bool
		)
		c, err := internal.ReadConfig()
		if err != nil {
			logger := newResponder(Response[any]{
				Message: "No config file defined",
				Err:     err.Error(),
			})
			logger.writeLogEntry()
		}

		switch r.Header.Get("User-Agent") {
		case "pomme-api-test-slave":
			pommeDB, err, ok = db.InitDb(c.TestDB)
		default:
			pommeDB, err, ok = db.InitDb(c.DB)
		}

		if err != nil && !ok {
			logger := newResponder(Response[any]{
				Message: "Error initializing DB",
				Err:     err.Error(),
			})
			logger.writeLogEntry()
			err = internal.SysKill()
			if err != nil {
				panic("this should not happen.")
			}
		}

		timeoutContext, cancelContext := context.WithTimeout(context.Background(), time.Second)
		ctx := context.WithValue(r.Context(), keyPrincipalContextID, pommeDB.WithContext(timeoutContext))
		defer cancelContext()
		next.ServeHTTP(w, r.WithContext(ctx))
	})
}

// apiError sends unsuccessful API requests back to the user with the appropriate information.
func (e *Response[T]) apiError(w http.ResponseWriter, r *http.Request) {
	v := map[string]any{
		"message": e.Message,
		"status":  e.Status,
		"realm":   e.Realm,
		"error":   e.Err,
	}

	w.Header().Set("X-Content-Type-Options", "nosniff")
	w.Header().Set("Content-Type", "application/json; charset=utf-8")

	switch v["realm"] {
	default:
		w.Header().Add("WWW-Authenticate", fmt.Sprintf(`realm="%v"`, e.Realm))
		delete(v, "realm")

		fallthrough
	case nil:
		w.Header().Add("API Error", v["message"].(string))
	}

	w.WriteHeader(v["status"].(int))

	delete(v, "error")
	delete(v, "status")
	delete(v, "realm")

	render.JSON(w, r, v)
}

// writeLogEntry takes a response struct and writes info and error level logs
// todo: make it write to file maybe
func (e *Response[T]) writeLogEntry() {
	v := map[string]any{
		"message": e.Message,
		"error":   e.Err,
	}

	logger := httplog.NewLogger("Pomme", httplog.Options{
		JSON: true,
	})

	switch v["error"] {
	default:
		logger.Error().Msg(v["error"].(string))

		fallthrough
	case nil:
		logger.Info().Msg(v["message"].(string))
	}
}