package main_test

import (
	"encoding/json"
	"fmt"
	"io"
	"net"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"syscall"
	"testing"
	"time"
)

// Binary path shared across tests — built once in TestMain to keep the
// integration suite fast.
var binPath string

func TestMain(m *testing.M) {
	dir, err := os.MkdirTemp("", "fjmcp-broker-bin-*")
	if err != nil {
		fmt.Fprintln(os.Stderr, "integration: mkdir:", err)
		os.Exit(1)
	}
	defer os.RemoveAll(dir)

	binPath = filepath.Join(dir, "fjmcp-broker")
	build := exec.Command("go", "build", "-o", binPath, ".")
	build.Stderr = os.Stderr
	if err := build.Run(); err != nil {
		fmt.Fprintln(os.Stderr, "integration: build:", err)
		os.Exit(1)
	}
	os.Exit(m.Run())
}

func TestBinary_Version(t *testing.T) {
	out, err := exec.Command(binPath, "--version").CombinedOutput()
	if err != nil {
		t.Fatalf("--version should exit 0: %v (output: %s)", err, out)
	}
	if !strings.Contains(string(out), "fjmcp-broker") {
		t.Errorf("version output missing binary name: %s", out)
	}
}

func TestBinary_MissingConfig_FailsWithClearError(t *testing.T) {
	cmd := exec.Command(binPath)
	// Reset env so the binary sees no ambient config.
	cmd.Env = []string{"PATH=" + os.Getenv("PATH")}
	out, err := cmd.CombinedOutput()
	if err == nil {
		t.Fatal("binary should exit nonzero with no config")
	}
	// Every required field should be mentioned, not just the first.
	for _, want := range []string{
		"public-url", "forgejo-url",
		"forgejo-oauth-client-id", "forgejo-oauth-client-secret",
	} {
		if !strings.Contains(string(out), want) {
			t.Errorf("config error should mention %q, got:\n%s", want, out)
		}
	}
}

func TestBinary_Health_And_SigtermShutsDownCleanly(t *testing.T) {
	addr := freePort(t)
	storePath := filepath.Join(t.TempDir(), "broker.db")

	cmd := exec.Command(binPath,
		"--public-url", "http://localhost:1234",
		"--forgejo-url", "https://forgejo.example.com",
		"--forgejo-oauth-client-id", "test-id",
		"--forgejo-oauth-client-secret", "test-secret",
		"--store-path", storePath,
		"--listen", addr,
	)
	cmd.Env = []string{"PATH=" + os.Getenv("PATH")}
	// Capture stderr so test failures surface the broker's logs.
	stderrR, stderrW := io.Pipe()
	cmd.Stderr = stderrW
	var capturedStderr strings.Builder
	go func() {
		_, _ = io.Copy(&capturedStderr, stderrR)
	}()

	if err := cmd.Start(); err != nil {
		t.Fatalf("start broker: %v", err)
	}
	// Ensure we always try to reap the process.
	defer func() {
		if cmd.ProcessState == nil && cmd.Process != nil {
			_ = cmd.Process.Kill()
			_, _ = cmd.Process.Wait()
		}
		_ = stderrW.Close()
	}()

	waitListening(t, addr, 5*time.Second)

	resp, err := http.Get("http://" + addr + "/healthz")
	if err != nil {
		t.Fatalf("GET /healthz: %v", err)
	}
	body, _ := io.ReadAll(resp.Body)
	_ = resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		t.Errorf("/healthz status = %d, want 200\nbody: %s", resp.StatusCode, body)
	}

	var h map[string]string
	if err := json.Unmarshal(body, &h); err != nil {
		t.Fatalf("/healthz body not JSON: %v\nbody: %s", err, body)
	}
	for _, k := range []string{"status", "version", "git_revision", "build_date", "store"} {
		if h[k] == "" {
			t.Errorf("/healthz missing field %q: %v", k, h)
		}
	}
	if h["status"] != "ok" {
		t.Errorf("/healthz status = %q, want ok (body: %s)", h["status"], body)
	}
	if h["store"] != "ok" {
		t.Errorf("/healthz store = %q, want ok (body: %s)", h["store"], body)
	}

	// Send SIGTERM and verify clean exit.
	start := time.Now()
	if err := cmd.Process.Signal(syscall.SIGTERM); err != nil {
		t.Fatalf("signal SIGTERM: %v", err)
	}

	done := make(chan error, 1)
	go func() { done <- cmd.Wait() }()

	select {
	case err := <-done:
		if err != nil {
			t.Errorf("broker exit with error: %v\nstderr:\n%s", err, capturedStderr.String())
		}
		if elapsed := time.Since(start); elapsed > 2*time.Second {
			t.Errorf("shutdown took %s, want < 2s", elapsed)
		}
	case <-time.After(3 * time.Second):
		_ = cmd.Process.Kill()
		t.Fatal("broker did not exit within 3s of SIGTERM")
	}
}

// freePort returns a 127.0.0.1:<port> the kernel assigned. The listener is
// closed immediately, so there's a tiny race window before the broker
// rebinds — acceptable on loopback.
func freePort(t *testing.T) string {
	t.Helper()
	l, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("pick free port: %v", err)
	}
	addr := l.Addr().String()
	_ = l.Close()
	return addr
}

// waitListening polls the target until a TCP dial succeeds or the deadline
// expires. Serves as a sync barrier for "the binary is up".
func waitListening(t *testing.T, addr string, within time.Duration) {
	t.Helper()
	deadline := time.Now().Add(within)
	for time.Now().Before(deadline) {
		c, err := net.DialTimeout("tcp", addr, 100*time.Millisecond)
		if err == nil {
			_ = c.Close()
			return
		}
		time.Sleep(25 * time.Millisecond)
	}
	t.Fatalf("broker did not start listening on %s within %s", addr, within)
}