From 8014a0d6ddf6c7f623be5e1e30a967b8d6e847cf Mon Sep 17 00:00:00 2001
From: Logan Cox <mail@logan-cox.com>
Date: Wed, 12 Jun 2024 08:24:50 +0100
Subject: [PATCH] feat: add authenticated URL delete endpoint

---
 collision.go                  | 28 +++++++++++++++++++++
 handlers.go                   | 46 +++++++++++++++++------------------
 internal/database/urls.sql.go | 16 ++++++++++++
 main.go                       |  2 ++
 sql/queries/urls.sql          |  5 ++++
 5 files changed, 74 insertions(+), 23 deletions(-)
 create mode 100644 collision.go

diff --git a/collision.go b/collision.go
new file mode 100644
index 0000000..cd584e0
--- /dev/null
+++ b/collision.go
@@ -0,0 +1,28 @@
+package main
+
+import (
+	"context"
+	"database/sql"
+
+	"url-short/internal/database"
+	"url-short/internal/shortener"
+)
+
+func hashCollisionDetection(DB *database.Queries, url string, count int, requestContext context.Context) (string, error) {
+	hashURL := shortener.Hash(url, count)
+	shortURLHash := shortener.Shorten(hashURL)
+
+	_, err := DB.SelectURL(requestContext, shortURLHash)
+
+	if err == sql.ErrNoRows {
+		return shortURLHash, nil
+	}
+
+	if err != nil && err != sql.ErrNoRows {
+		return "", err
+	}
+
+	count++
+
+	return hashCollisionDetection(DB, url, count, requestContext)
+}
diff --git a/handlers.go b/handlers.go
index faafd85..25f6484 100644
--- a/handlers.go
+++ b/handlers.go
@@ -1,7 +1,6 @@
 package main
 
 import (
-	"context"
 	"crypto/rand"
 	"database/sql"
 	"encoding/hex"
@@ -15,11 +14,10 @@ import (
 	"strings"
 	"time"
 
-	"url-short/internal/database"
-	"url-short/internal/shortener"
-
 	"github.com/golang-jwt/jwt/v5"
 	"golang.org/x/crypto/bcrypt"
+
+	"url-short/internal/database"
 )
 
 type apiConfig struct {
@@ -114,25 +112,6 @@ func (apiCfg *apiConfig) postLongURL(w http.ResponseWriter, r *http.Request, use
 	})
 }
 
-func hashCollisionDetection(DB *database.Queries, url string, count int, requestContext context.Context) (string, error) {
-	hashURL := shortener.Hash(url, count)
-	shortURLHash := shortener.Shorten(hashURL)
-
-	_, err := DB.SelectURL(requestContext, shortURLHash)
-
-	if err == sql.ErrNoRows {
-		return shortURLHash, nil
-	}
-
-	if err != nil && err != sql.ErrNoRows {
-		return "", err
-	}
-
-	count++
-
-	return hashCollisionDetection(DB, url, count, requestContext)
-}
-
 func (apiCfg *apiConfig) getShortURL(w http.ResponseWriter, r *http.Request) {
 	query := r.PathValue("shortUrl")
 
@@ -147,6 +126,27 @@ func (apiCfg *apiConfig) getShortURL(w http.ResponseWriter, r *http.Request) {
 	http.Redirect(w, r, row.LongUrl, http.StatusMovedPermanently)
 }
 
+func (apiCfg *apiConfig) deleteShortURL(w http.ResponseWriter, r * http.Request, user database.User) {
+	query := r.PathValue("shortUrl")
+
+	if query == "" {
+		respondWithError(w, http.StatusBadRequest, "no short url supplied")
+		return
+	}
+
+	err := apiCfg.DB.DeleteURL(r.Context(), database.DeleteURLParams{
+		UserID: user.ID,
+		ShortUrl: query,
+	})
+
+	if err != nil {
+		respondWithError(w, http.StatusBadRequest,  "could not delete short url")
+		return 
+	}
+
+	w.WriteHeader(http.StatusOK)
+}
+
 func (apiCfg *apiConfig) postAPIUsers(w http.ResponseWriter, r *http.Request) {
 	payload := APIUserRequest{}
 
diff --git a/internal/database/urls.sql.go b/internal/database/urls.sql.go
index af18260..10a0f9b 100644
--- a/internal/database/urls.sql.go
+++ b/internal/database/urls.sql.go
@@ -44,6 +44,22 @@ func (q *Queries) CreateURL(ctx context.Context, arg CreateURLParams) (Url, erro
 	return i, err
 }
 
+const deleteURL = `-- name: DeleteURL :exec
+DELETE FROM urls
+WHERE user_id = $1 AND 
+short_url = $2
+`
+
+type DeleteURLParams struct {
+	UserID   int32
+	ShortUrl string
+}
+
+func (q *Queries) DeleteURL(ctx context.Context, arg DeleteURLParams) error {
+	_, err := q.db.ExecContext(ctx, deleteURL, arg.UserID, arg.ShortUrl)
+	return err
+}
+
 const selectURL = `-- name: SelectURL :one
 SELECT id, short_url, long_url, created_at, updated_at, user_id 
 FROM urls
diff --git a/main.go b/main.go
index 653ff0f..9a9e947 100644
--- a/main.go
+++ b/main.go
@@ -41,6 +41,8 @@ func main() {
 	// url management endpoints
 	mux.HandleFunc("POST /api/v1/data/shorten", apiCfg.authenticationMiddlewear(apiCfg.postLongURL))
 	mux.HandleFunc("GET /api/v1/{shortUrl}", apiCfg.getShortURL)
+	mux.HandleFunc("DELETE /api/v1/{shortUrl}", apiCfg.authenticationMiddlewear(apiCfg.deleteShortURL))
+
 
 	// user management endpoints
 	mux.HandleFunc("POST /api/v1/users", apiCfg.postAPIUsers)
diff --git a/sql/queries/urls.sql b/sql/queries/urls.sql
index 04d90c6..76c634b 100644
--- a/sql/queries/urls.sql
+++ b/sql/queries/urls.sql
@@ -7,3 +7,8 @@ RETURNING *;
 SELECT * 
 FROM urls
 WHERE short_url = $1;
+
+-- name: DeleteURL :exec
+DELETE FROM urls
+WHERE user_id = $1 AND 
+short_url = $2;