package middleware

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

	"github.com/labstack/echo/v5"
	"github.com/stretchr/testify/assert"
)

func TestBodyLimitConfig_ToMiddleware(t *testing.T) {
	e := echo.New()
	hw := []byte("Hello, World!")
	req := httptest.NewRequest(http.MethodPost, "/", bytes.NewReader(hw))
	rec := httptest.NewRecorder()
	c := e.NewContext(req, rec)
	h := func(c echo.Context) error {
		body, err := io.ReadAll(c.Request().Body)
		if err != nil {
			return err
		}
		return c.String(http.StatusOK, string(body))
	}

	// Based on content length (within limit)
	mw, err := BodyLimitConfig{LimitBytes: 2 * MB}.ToMiddleware()
	assert.NoError(t, err)

	err = mw(h)(c)
	if assert.NoError(t, err) {
		assert.Equal(t, http.StatusOK, rec.Code)
		assert.Equal(t, hw, rec.Body.Bytes())
	}

	// Based on content read (overlimit)
	mw, err = BodyLimitConfig{LimitBytes: 2}.ToMiddleware()
	assert.NoError(t, err)
	he := mw(h)(c).(*echo.HTTPError)
	assert.Equal(t, http.StatusRequestEntityTooLarge, he.Code)

	// Based on content read (within limit)
	req = httptest.NewRequest(http.MethodPost, "/", bytes.NewReader(hw))
	req.ContentLength = -1
	rec = httptest.NewRecorder()
	c = e.NewContext(req, rec)

	mw, err = BodyLimitConfig{LimitBytes: 2 * MB}.ToMiddleware()
	assert.NoError(t, err)
	err = mw(h)(c)
	assert.NoError(t, err)
	assert.Equal(t, http.StatusOK, rec.Code)
	assert.Equal(t, "Hello, World!", rec.Body.String())

	// Based on content read (overlimit)
	req = httptest.NewRequest(http.MethodPost, "/", bytes.NewReader(hw))
	req.ContentLength = -1
	rec = httptest.NewRecorder()
	c = e.NewContext(req, rec)
	mw, err = BodyLimitConfig{LimitBytes: 2}.ToMiddleware()
	assert.NoError(t, err)
	he = mw(h)(c).(*echo.HTTPError)
	assert.Equal(t, http.StatusRequestEntityTooLarge, he.Code)
}

func TestBodyLimitReader(t *testing.T) {
	hw := []byte("Hello, World!")

	config := BodyLimitConfig{
		Skipper:    DefaultSkipper,
		LimitBytes: 2,
	}
	reader := &limitedReader{
		BodyLimitConfig: config,
		reader:          io.NopCloser(bytes.NewReader(hw)),
	}

	// read all should return ErrStatusRequestEntityTooLarge
	_, err := io.ReadAll(reader)
	he := err.(*echo.HTTPError)
	assert.Equal(t, http.StatusRequestEntityTooLarge, he.Code)

	// reset reader and read two bytes must succeed
	bt := make([]byte, 2)
	reader.Reset(io.NopCloser(bytes.NewReader(hw)))
	n, err := reader.Read(bt)
	assert.Equal(t, 2, n)
	assert.Equal(t, nil, err)
}

func TestBodyLimit_skipper(t *testing.T) {
	e := echo.New()
	h := func(c echo.Context) error {
		body, err := io.ReadAll(c.Request().Body)
		if err != nil {
			return err
		}
		return c.String(http.StatusOK, string(body))
	}
	mw, err := BodyLimitConfig{
		Skipper: func(c echo.Context) bool {
			return true
		},
		LimitBytes: 2,
	}.ToMiddleware()
	assert.NoError(t, err)

	hw := []byte("Hello, World!")
	req := httptest.NewRequest(http.MethodPost, "/", bytes.NewReader(hw))
	rec := httptest.NewRecorder()
	c := e.NewContext(req, rec)

	err = mw(h)(c)
	assert.NoError(t, err)
	assert.Equal(t, http.StatusOK, rec.Code)
	assert.Equal(t, hw, rec.Body.Bytes())
}

func TestBodyLimitWithConfig(t *testing.T) {
	e := echo.New()
	hw := []byte("Hello, World!")
	req := httptest.NewRequest(http.MethodPost, "/", bytes.NewReader(hw))
	rec := httptest.NewRecorder()
	c := e.NewContext(req, rec)
	h := func(c echo.Context) error {
		body, err := io.ReadAll(c.Request().Body)
		if err != nil {
			return err
		}
		return c.String(http.StatusOK, string(body))
	}

	mw := BodyLimitWithConfig(BodyLimitConfig{LimitBytes: 2 * MB})

	err := mw(h)(c)
	assert.NoError(t, err)
	assert.Equal(t, http.StatusOK, rec.Code)
	assert.Equal(t, hw, rec.Body.Bytes())
}

func TestBodyLimit(t *testing.T) {
	e := echo.New()
	hw := []byte("Hello, World!")
	req := httptest.NewRequest(http.MethodPost, "/", bytes.NewReader(hw))
	rec := httptest.NewRecorder()
	c := e.NewContext(req, rec)
	h := func(c echo.Context) error {
		body, err := io.ReadAll(c.Request().Body)
		if err != nil {
			return err
		}
		return c.String(http.StatusOK, string(body))
	}

	mw := BodyLimit(2 * MB)

	err := mw(h)(c)
	assert.NoError(t, err)
	assert.Equal(t, http.StatusOK, rec.Code)
	assert.Equal(t, hw, rec.Body.Bytes())
}