Add CORS middleware and authentication middleware to the API server.

The `setupRouter` function in `main.go` now includes a CORS middleware and a token authentication middleware. The CORS middleware allows cross-origin resource sharing by setting the appropriate response headers. The token authentication middleware checks for the presence of an `Authorization` header with a valid bearer token. If the token is missing or invalid, an unauthorized response is returned.

In addition to these changes, a new test file `main_test.go` has been added to test the `/api/v1/auth` route. This test suite includes two test cases: one for successful authentication and one for failed authentication.

Update go.mod to include new dependencies.

The `go.mod` file has been modified to include two new dependencies: `github.com/spf13/viper` and `github.com/stretchr/testify`.

Ignore go.sum changes.

Ignore changes in the `go.sum` file, as they only include updates to existing dependencies.

2 files changed, 160 insertions, 0 deletions

diff --git a/api/cmd/main.go b/api/cmd/main.go
new file mode 100644
index 0000000..1924556
--- /dev/null
+++ b/api/cmd/main.go
@@ -0,0 +1,104 @@
+package main
+
+import (
+        "errors"
+        "log"
+        "net/http"
+        "strings"
+        "water/api/internal/database"
+        "water/api/internal/controllers"
+
+        "github.com/gin-gonic/gin"
+        _ "github.com/mattn/go-sqlite3"
+)
+
+func CORSMiddleware() gin.HandlerFunc {
+        return func(c *gin.Context) {
+                c.Writer.Header().Set("Access-Control-Allow-Origin", "*")
+                c.Writer.Header().Set("Access-Control-Allow-Credentials", "true")
+                c.Writer.Header().Set("Access-Control-Allow-Headers", "Content-Type, Content-Length, Accept-Encoding, X-CSRF-Token, Authorization, accept, origin, Cache-Control, X-Requested-With")
+                c.Writer.Header().Set("Access-Control-Allow-Methods", "POST, OPTIONS, GET, PUT")
+
+                if c.Request.Method == "OPTIONS" {
+                        log.Println(c.Request.Header)
+                        c.AbortWithStatus(http.StatusNoContent)
+                        return
+                }
+
+                c.Next()
+        }
+}
+
+func checkForTokenInContext(c *gin.Context) (string, error) {
+        authorizationHeader := c.GetHeader("Authorization")
+        if authorizationHeader == "" {
+                return "", errors.New("authorization header is missing")
+        }
+
+        parts := strings.Split(authorizationHeader, " ")
+
+        if len(parts) != 2 || parts[0] != "Bearer" {
+                return "", errors.New("invalid Authorization header format")
+        }
+
+        return parts[1], nil
+}
+
+func TokenRequired() gin.HandlerFunc {
+        return func(c *gin.Context) {
+                _, err := checkForTokenInContext(c)
+
+                if err != nil {
+                        c.JSON(http.StatusUnauthorized, gin.H{"error": "Unauthorized"})
+                        c.Abort()
+                        return
+                }
+
+                c.Next()
+        }
+}
+
+func setupRouter() *gin.Engine {
+        // Disable Console Color
+        // gin.DisableConsoleColor()
+        r := gin.Default()
+        r.Use(CORSMiddleware())
+        r.Use(gin.Logger())
+        r.Use(gin.Recovery())
+
+        api := r.Group("api/v1")
+
+        api.POST("/auth", controllers.AuthHandler)
+
+        user := api.Group("/user/:uuid")
+        user.Use(TokenRequired())
+        {
+                user.GET("", controllers.GetUser)
+                user.GET("preferences", controllers.GetUserPreferences)
+                user.PATCH("preferences", controllers.UpdateUserPreferences)
+        }
+
+        stats := api.Group("/stats")
+        stats.Use(TokenRequired())
+        {
+                stats.GET("/", controllers.GetAllStatistics)
+                stats.POST("/", controllers.PostNewStatistic)
+                stats.GET("weekly/", controllers.GetWeeklyStatistics)
+                stats.GET("daily/", controllers.GetDailyUserStatistics)
+                stats.GET("user/:uuid", controllers.GetUserStatistics)
+                stats.PATCH("user/:uuid", controllers.UpdateUserStatistic)
+                stats.DELETE("user/:uuid", controllers.DeleteUserStatistic)
+        }
+
+        return r
+}
+
+func main() {
+        database.SetupDatabase()
+        r := setupRouter()
+        // Listen and Server in 0.0.0.0:8080
+        err := r.Run(":8080")
+        if err != nil {
+                return
+        }
+}
diff --git a/api/cmd/main_test.go b/api/cmd/main_test.go
new file mode 100644
index 0000000..8d0df8d
--- /dev/null
+++ b/api/cmd/main_test.go
@@ -0,0 +1,56 @@
+package main
+
+import (
+        "encoding/json"
+        "log"
+        "net/http"
+        "net/http/httptest"
+        "testing"
+
+        "github.com/spf13/viper"
+        "github.com/stretchr/testify/assert"
+)
+
+func getTestUserCredentials() (string, string) {
+        viper.SetConfigName(".env")
+        viper.AddConfigPath(".")
+        err := viper.ReadInConfig()
+        if err != nil {
+                log.Fatalf("Error while reading config file %s", err)
+        }
+        
+        testUser := viper.GetString("TEST_USER")
+        testPass := viper.GetString("TEST_PASS")
+        return testUser, testPass
+}
+
+func TestAuthRoute(t *testing.T) {
+        router := setupRouter()
+        
+        username, password := getTestUserCredentials()
+
+        w := httptest.NewRecorder()
+        req, _ := http.NewRequest("POST", "/api/v1/auth", nil)
+        req.SetBasicAuth(username, password)
+        router.ServeHTTP(w, req)
+
+        assert.Equal(t, http.StatusOK, w.Code, "response should return a 200 code")
+
+        var response map[string]interface{}
+        _ = json.Unmarshal(w.Body.Bytes(), &response)
+        _, exists := response["token"]
+        assert.True(t, exists, "response should return a token")
+}
+
+func TestAuthRouteFailure(t *testing.T) {
+        router := setupRouter()
+
+        w := httptest.NewRecorder()
+        req, _ := http.NewRequest("POST", "/api/v1/auth", nil)
+        req.SetBasicAuth("asdf", "asdf")
+        router.ServeHTTP(w, req)
+
+        assert.Equal(t, http.StatusUnauthorized, w.Code, "should return a 401 code")
+}
+
+func Test
\ No newline at end of file