add a command to the database through the api

cmd/api/command.go

@@ -1,8 +1,8 @@
 package main
 
 import (
-	"encoding/json"
 	"errors"
+	"fmt"
 	"net/http"
 
 	"github.com/lyx0/nourybot/internal/data"
@@ -37,30 +37,40 @@ func (app *application) showCommandHandler(w http.ResponseWriter, r *http.Reques
 	}
 }
 
-type envelope map[string]interface{}
+func (app *application) createCommandHandler(w http.ResponseWriter, r *http.Request) {
+	var input struct {
+		Name     string `json:"name"`
+		Text     string `json:"text"`
+		Category string `json:"category"`
+		Level    int    `json:"level"`
+	}
 
-func (app *application) writeJSON(w http.ResponseWriter, status int, data envelope, headers http.Header) error {
+	err := app.readJSON(w, r, &input)
-	// Encode the data into JSON and return any errors if there were any.
-	// Use MarshalIndent instead of normal Marshal so it looks prettier on terminals.
-	js, err := json.MarshalIndent(data, "", "\t")
 	if err != nil {
-		return err
+		app.badRequestResponse(w, r, err)
+		return
 	}
 
-	// Append a newline to make it prettier on terminals.
+	command := &data.Command{
-	js = append(js, '\n')
+		Name:     input.Name,
-
+		Text:     input.Text,
-	// Iterate over the header map and add each header to the
+		Category: input.Category,
-	// http.ResponseWriter header map.
+		Level:    input.Level,
-	for key, value := range headers {
-		w.Header()[key] = value
 	}
 
-	// Set `Content-Type` to `application/json` because go
+	err = app.Models.Commands.Insert(command)
-	// defaults to `text-plain; charset=utf8`.
+	if err != nil {
-	w.Header().Set("Content-Type", "application/json")
+		app.serverErrorResponse(w, r, err)
-	w.WriteHeader(status)
+		return
-	w.Write(js)
+	}
 
-	return nil
+	headers := make(http.Header)
+	headers.Set("Location", fmt.Sprintf("/v1/commands/%s", command.Name))
+
+	err = app.writeJSON(w, http.StatusCreated, envelope{"command": command}, headers)
+	if err != nil {
+		app.serverErrorResponse(w, r, err)
+	}
 }
+
+type envelope map[string]interface{}

cmd/api/errors.go

@@ -29,3 +29,7 @@ func (app *application) errorResponse(w http.ResponseWriter, r *http.Request, st
 	// 500 Internal Server Error status code.
 	fmt.Fprintf(w, "Error: %d", status)
 }
+
+func (app *application) badRequestResponse(w http.ResponseWriter, r *http.Request, err error) {
+	app.errorResponse(w, r, http.StatusBadRequest, err.Error())
+}

cmd/api/helpers.go

@@ -1,7 +1,12 @@
 package main
 
 import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
 	"net/http"
+	"strings"
 
 	"github.com/julienschmidt/httprouter"
 )
@@ -20,6 +25,57 @@ import (
 // 	return id, nil
 // }
 
+func (app *application) readJSON(w http.ResponseWriter, r *http.Request, dst interface{}) error {
+	// Limit the size of the requst body to 1MB.
+	maxBytes := 1_048_576
+	r.Body = http.MaxBytesReader(w, r.Body, int64(maxBytes))
+
+	dec := json.NewDecoder(r.Body)
+	dec.DisallowUnknownFields()
+
+	err := dec.Decode(dst)
+	if err != nil {
+		var syntaxError *json.SyntaxError
+		var unmarshalTypeError *json.UnmarshalTypeError
+		var invalidUnmarshalError *json.InvalidUnmarshalError
+
+		switch {
+		case errors.As(err, &syntaxError):
+			return fmt.Errorf("body contains malformed JSON (at character %d)", syntaxError.Offset)
+
+		case errors.Is(err, io.ErrUnexpectedEOF):
+			return errors.New("body contains invalid JSON")
+
+		case errors.As(err, &unmarshalTypeError):
+			if unmarshalTypeError.Field != "" {
+				return fmt.Errorf("body contains invalid JSON type for field %q", unmarshalTypeError.Field)
+			}
+			return fmt.Errorf("body contains invalid JSON type (at character %d)", unmarshalTypeError.Offset)
+
+		case errors.Is(err, io.EOF):
+			return errors.New("body contains no data")
+
+		case strings.HasPrefix(err.Error(), "json: unknown field "):
+			fieldName := strings.TrimPrefix(err.Error(), "json: unknown field ")
+			return fmt.Errorf("body contains unknown key %s", fieldName)
+
+		case err.Error() == "htto: request body too large":
+			return fmt.Errorf("body must not be larger than %d bytes", maxBytes)
+
+		case errors.As(err, &invalidUnmarshalError):
+			app.Logger.Panic(err)
+		default:
+			return err
+		}
+	}
+
+	err = dec.Decode(&struct{}{})
+	if err != io.EOF {
+		return errors.New("body must only contain a single JSON value")
+	}
+	return nil
+}
+
 func (app *application) readCommandNameParam(r *http.Request) (string, error) {
 	params := httprouter.ParamsFromContext(r.Context())
 
@@ -30,3 +86,29 @@ func (app *application) readCommandNameParam(r *http.Request) (string, error) {
 
 	return name, nil
 }
+
+func (app *application) writeJSON(w http.ResponseWriter, status int, data envelope, headers http.Header) error {
+	// Encode the data into JSON and return any errors if there were any.
+	// Use MarshalIndent instead of normal Marshal so it looks prettier on terminals.
+	js, err := json.MarshalIndent(data, "", "\t")
+	if err != nil {
+		return err
+	}
+
+	// Append a newline to make it prettier on terminals.
+	js = append(js, '\n')
+
+	// Iterate over the header map and add each header to the
+	// http.ResponseWriter header map.
+	for key, value := range headers {
+		w.Header()[key] = value
+	}
+
+	// Set `Content-Type` to `application/json` because go
+	// defaults to `text-plain; charset=utf8`.
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	w.Write(js)
+
+	return nil
+}

cmd/api/routes.go

@@ -10,5 +10,6 @@ func (app *application) routes() *httprouter.Router {
 	router := httprouter.New()
 
 	router.HandlerFunc(http.MethodGet, "/v1/commands/:name", app.showCommandHandler)
+	router.HandlerFunc(http.MethodPost, "/v1/commands", app.createCommandHandler)
 	return router
 }