package gziphandler

import (
	"compress/gzip"
	"io"
	"net"
	"net/http"
	"strings"
	"testing"
)

type d struct {
	data string
	gzip bool
}

func TestHandler(t *testing.T) {
	data := []d{
		{"abc", true},
		{"qweqweqwe", false},
		{"lkajwdlajwdlkajwdlkjawl", true},
	}
	http.HandleFunc("/test", func(w http.ResponseWriter, r *http.Request) {
		_, err := io.Copy(w, r.Body)
		if err != nil {
			t.Fatal(err)
		}

	})
	handler := Handler(http.DefaultServeMux)
	l, err := net.Listen("tcp", "127.0.0.1:8080")
	if err != nil {
		t.Fatal(err)
	}
	defer l.Close()
	go http.Serve(l, handler)
	for _, d := range data {
		doReq(t, d)
	}
}

func doReq(t *testing.T, d d) {
	req, err := http.NewRequest(http.MethodPost, "http://127.0.0.1:8080/test", strings.NewReader(d.data))
	if err != nil {
		t.Fatal(err)
	}
	if d.gzip {
		req.Header.Set("Accept-Encoding", "gzip")
	}
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	var sb strings.Builder
	r := resp.Body
	if d.gzip {
		ce := resp.Header.Get("Content-Encoding")
		if ce != "gzip" {
			t.Errorf("expected content encoding %s, got %s", "gzip", ce)
		}
		r, err = gzip.NewReader(resp.Body)
		if err != nil {
			t.Fatal(err)
		}
	}
	_, err = io.Copy(&sb, r)
	if err != nil {
		t.Fatal(err)
	}
	s := sb.String()
	if d.data != s {
		t.Errorf("expected response %s, got %s", d.data, s)
	}
}