package edge

import (
	"bufio"
	"bytes"
	"context"
	"io"
	"net"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
	"time"
)

func TestStartupGateFailsWhenHandlerSetupFails(t *testing.T) {
	if os.Getenv("CARLOS_TEST_SETUP_FAILURE") == "1" {
		RunWithActivatorReady([]string{"-dev", "-registry", filepath.Join(os.Getenv("CARLOS_DATA_DIR"), "registry.db"), "-http", os.Getenv("CARLOS_TEST_HTTP_ADDR")}, nil, nil, nil, func(*Edge) {
			_, _ = os.Stdout.WriteString("configuring\n")
			_, _ = io.CopyN(io.Discard, os.Stdin, 1)
		})
		os.Exit(0)
	}
	listener, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatal(err)
	}
	addr := listener.Addr().String()
	listener.Close()
	exe, err := os.Executable()
	if err != nil {
		t.Fatal(err)
	}
	ctx, cancel := context.WithTimeout(t.Context(), 10*time.Second)
	defer cancel()
	cmd := exec.CommandContext(ctx, exe, "-test.run=^TestStartupGateFailsWhenHandlerSetupFails$")
	dd := t.TempDir()
	cmd.Dir = dd
	cmd.Env = []string{
		"HOME=" + dd, "TMPDIR=" + os.TempDir(),
		"CARLOS_DATA_DIR=" + dd, "CARLOS_TEST_SETUP_FAILURE=1", "CARLOS_TEST_HTTP_ADDR=" + addr,
		"CARLOS_TUNNEL_HOST=tunnel.example.com", "CARLOS_TUNNEL_CLIENTS=invalid",
	}
	var stderr bytes.Buffer
	cmd.Stderr = &stderr
	stdout, err := cmd.StdoutPipe()
	if err != nil {
		t.Fatal(err)
	}
	stdin, err := cmd.StdinPipe()
	if err != nil {
		t.Fatal(err)
	}
	if err := cmd.Start(); err != nil {
		t.Fatal(err)
	}
	defer func() { cancel(); _ = cmd.Wait() }()
	line, err := bufio.NewReader(stdout).ReadString('\n')
	if err != nil || line != "configuring\n" {
		t.Fatalf("setup barrier: %q, %v", line, err)
	}
	client := &http.Client{Transport: &http.Transport{Proxy: nil}, Timeout: 100 * time.Millisecond}
	defer client.CloseIdleConnections()
	probeMustFail := func() {
		t.Helper()
		resp, err := client.Get("http://" + addr + "/")
		if err == nil {
			resp.Body.Close()
			t.Fatalf("update probe succeeded before handler setup: %d", resp.StatusCode)
		}
	}
	probeMustFail()
	if _, err := stdin.Write([]byte("x")); err != nil {
		t.Fatal(err)
	}
	stdin.Close()
	if err := cmd.Wait(); err == nil {
		t.Fatal("invalid tunnel configuration did not fail setup")
	}
	if !strings.Contains(stderr.String(), "edge: tunnels:") {
		t.Fatalf("did not reach handler setup failure: %s", stderr.String())
	}
	probeMustFail()
}