Adding Delete route implementation

NOTES.md

@@ -5,6 +5,13 @@
   send_interrupt = true
 ```
 
+
+## Get Movie
+
+```bash
+curl -i http://0.0.0.0:5002/v1/movies/1
+```
+
 ## Creating a movie
 
 ```bash
@@ -19,3 +26,9 @@ curl -i -X POST -d '{"title":"The Batman","year":2022,"runtime":"177 mins", "gen
 ```bash
 curl -i -X POST -d '{"title":"Death of a Unicorn","year":2025,"runtime":"126 mins", "genres":["comedy","satire"]}' http://0.0.0.0:5002/v1/movies
 ```
+
+
+```bash
+BODY='{"title":"Black Panther","year":2018,"runtime":"134 mins","genres":["sci-fi","action","adventure"]}'
+curl -X PUT -d "$BODY" http://0.0.0.0:5002/v1/movies/1
+```

cmd/api/handlers.go

@@ -167,7 +167,20 @@ func (app *application) deleteMovieHandler(w http.ResponseWriter, r *http.Reques
 	}
 
 	// Maybe should be passing a timeout context
-	_, err = app.models.Movies.Get(r.Context(), id)
+	// WE DON"T NEED THIS BECAUSE EXEC RETURNS A RESULT OBJECT WITH THE NUMBER
+	// OF ROWS AFFECTED. IF THE RESULT IS 0 THEN WE 404
+	// _, err = app.models.Movies.Get(r.Context(), id)
+	// if err != nil {
+	// 	switch {
+	// 	case errors.Is(err, data.ErrRecordNotFound):
+	// 		app.notFoundResponse(w, r)
+	// 	default:
+	// 		app.serverErrorResponse(w, r, err)
+	// 	}
+	// 	return
+	// }
+
+	err = app.models.Movies.Delete(r.Context(), id)
 	if err != nil {
 		switch {
 		case errors.Is(err, data.ErrRecordNotFound):
@@ -178,13 +191,15 @@ func (app *application) deleteMovieHandler(w http.ResponseWriter, r *http.Reques
 		return
 	}
 
-	err = app.models.Movies.Delete(r.Context(), id)
+	// I personally think this should be a 202 or a 204 but Alex thinks otherwise.
+	// his rule of thumb is if the clients are humans send human readable messages. If they
+	// are machines then status code is alright.
+	//w.WriteHeader(http.StatusAccepted)
+
+	err = app.writeJSON(w, http.StatusOK, envelope{"message": "movie successfully deleted"}, nil)
 	if err != nil {
 		app.serverErrorResponse(w, r, err)
-		return
 	}
-
-	w.WriteHeader(http.StatusAccepted)
 }
 
 func (app *application) healthCheckHandler(w http.ResponseWriter, r *http.Request) {

internal/data/movies.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgconn"
 	"github.com/jackc/pgx/v5/pgxpool"
 )
 
@@ -98,7 +99,18 @@ func (m MovieModel) Update(ctx context.Context, movie *Movie) error {
 	return m.pool.QueryRow(ctx, query, args...).Scan(&movie.Version)
 }
 
-func (m MovieModel) Delete(ctx context.Context, id int64) error {
+// Here I decided to attempt an idiomatic version of the Delete service with
+// a database transaction. Since this is updating just one entry in a single table
+// an explicit db transaction isn't really necessary but I thought I'd practice it
+// none the less. If using sqlc you'd probably not even worry about implementing
+// it this way, but I am here to learn so.
+
+func (m MovieModel) Delete(ctx context.Context, id int64) (err error) {
+
+	if id < 1 {
+		return ErrRecordNotFound
+	}
+
 	query := `DELETE FROM movies WHERE id = $1`
 
 	tx, err := m.pool.BeginTx(ctx, pgx.TxOptions{})
@@ -106,9 +118,24 @@ func (m MovieModel) Delete(ctx context.Context, id int64) error {
 		return err
 	}
 	defer func() {
-		tx.Rollback(ctx)
+		// If it's in error or the context was canceled, rollback
+		if err != nil || ctx.Err() != nil {
+			_ = tx.Rollback(ctx)
+			return
+		}
+		// if the commit fails raises the error.
+		err = tx.Commit(ctx)
 	}()
-	_, err = tx.Exec(ctx, query, id)
 
-	return err
+	var cmd pgconn.CommandTag
+	cmd, err = tx.Exec(ctx, query, id)
+	if err != nil {
+		return err
+	}
+
+	if cmd.RowsAffected() == 0 {
+		return ErrRecordNotFound
+	}
+
+	return nil
 }