package middleware

import (
	"bytes"
	"compress/gzip"
	"io"
	"net/http"
	"net/http/httptest"
	"testing"

	"github.com/andybalholm/brotli"
	"github.com/gin-gonic/gin"
	"github.com/stretchr/testify/require"
)

func TestDecompressRequestMiddlewareExposesGzipAndBrotliPayload(t *testing.T) {
	gin.SetMode(gin.TestMode)
	for _, encoding := range []string{"gzip", "br"} {
		t.Run(encoding, func(t *testing.T) {
			var compressed bytes.Buffer
			var writer io.WriteCloser
			if encoding == "gzip" {
				writer = gzip.NewWriter(&compressed)
			} else {
				writer = brotli.NewWriter(&compressed)
			}
			_, err := writer.Write([]byte(`{"message":"hello"}`))
			require.NoError(t, err)
			require.NoError(t, writer.Close())

			router := gin.New()
			router.Use(DecompressRequestMiddleware())
			router.POST("/", func(c *gin.Context) {
				body, err := io.ReadAll(c.Request.Body)
				require.NoError(t, err)
				require.Equal(t, `{"message":"hello"}`, string(body))
				require.Empty(t, c.GetHeader("Content-Encoding"))
				c.Status(http.StatusNoContent)
			})

			request := httptest.NewRequest(http.MethodPost, "/", &compressed)
			request.Header.Set("Content-Encoding", encoding)
			response := httptest.NewRecorder()
			router.ServeHTTP(response, request)
			require.Equal(t, http.StatusNoContent, response.Code)
		})
	}
}

func TestDecompressRequestMiddlewareRejectsMalformedGzip(t *testing.T) {
	gin.SetMode(gin.TestMode)
	reachedHandler := false
	router := gin.New()
	router.Use(DecompressRequestMiddleware())
	router.POST("/", func(c *gin.Context) { reachedHandler = true })

	request := httptest.NewRequest(http.MethodPost, "/", bytes.NewBufferString("not-gzip"))
	request.Header.Set("Content-Encoding", "gzip")
	response := httptest.NewRecorder()
	router.ServeHTTP(response, request)

	require.Equal(t, http.StatusBadRequest, response.Code)
	require.False(t, reachedHandler)
}