package app

import (
	"context"
	"encoding/json"
	"io"
	"net"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"github.com/hjbdev/patterm/internal/protocol"
)

func TestDaemonDetachReattachPreservesProcess(t *testing.T) {
	root := t.TempDir()
	t.Setenv("XDG_CONFIG_HOME", filepath.Join(root, "config"))
	t.Setenv("XDG_DATA_HOME", filepath.Join(root, "data"))
	t.Setenv("XDG_RUNTIME_DIR", filepath.Join(root, "runtime"))
	projectDir := filepath.Join(root, "project")
	if err := os.MkdirAll(projectDir, 0o700); err != nil {
		t.Fatalf("mkdir project: %v", err)
	}
	socket := filepath.Join(root, "runtime", "patterm", "daemon.sock")
	pid := filepath.Join(root, "runtime", "patterm", "daemon.pid")

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	errCh := make(chan error, 1)
	go func() {
		errCh <- RunDaemon(ctx, DaemonOptions{
			ProjectDir: projectDir,
			SocketPath: socket,
			PidPath:    pid,
			Cols:       80,
			Rows:       24,
		})
	}()
	waitForSocket(t, socket, errCh)

	client1 := dialDaemon(t, socket)
	sendFrame(t, client1, protocol.FrameAttach, protocol.Attach{
		ProjectPath: projectDir,
		TermSize:    protocol.Size{Cols: 80, Rows: 24},
	})
	expectFrame(t, client1, protocol.FrameHello)
	expectFrame(t, client1, protocol.FrameProjectList)
	expectFrame(t, client1, protocol.FrameChrome)

	data, _ := json.Marshal(map[string]any{
		"argv": []string{"sh", "-c", "trap 'exit 0' TERM; while :; do echo STILL-HERE; sleep 1; done"},
		"name": "survivor",
	})
	sendFrame(t, client1, protocol.FramePaletteCommand, protocol.PaletteCommand{
		Kind: "spawn_command",
		Data: data,
	})
	waitForLifecycle(t, client1, protocol.LifecycleSpawned, 3*time.Second)
	sendFrame(t, client1, protocol.FrameDetach, protocol.Detach{})
	_ = client1.Close()

	client2 := dialDaemon(t, socket)
	defer client2.Close()
	sendFrame(t, client2, protocol.FrameAttach, protocol.Attach{
		ProjectPath: projectDir,
		TermSize:    protocol.Size{Cols: 80, Rows: 24},
	})
	expectFrame(t, client2, protocol.FrameHello)
	expectFrame(t, client2, protocol.FrameProjectList)
	chrome := expectChrome(t, client2)
	if !chromeHasProcess(chrome, "survivor") {
		t.Fatalf("reattached chrome did not include surviving process: %s", string(chrome.Model))
	}
	expectFrame(t, client2, protocol.FramePaneSnapshot)

	cancel()
	select {
	case err := <-errCh:
		if err != nil {
			t.Fatalf("daemon returned error: %v", err)
		}
	case <-time.After(3 * time.Second):
		t.Fatalf("daemon did not stop")
	}
}

func TestDaemonTCPTokenAuthAndUnixExemption(t *testing.T) {
	root := t.TempDir()
	t.Setenv("XDG_CONFIG_HOME", filepath.Join(root, "config"))
	t.Setenv("XDG_DATA_HOME", filepath.Join(root, "data"))
	t.Setenv("XDG_RUNTIME_DIR", filepath.Join(root, "runtime"))
	projectDir := filepath.Join(root, "project")
	if err := os.MkdirAll(projectDir, 0o700); err != nil {
		t.Fatalf("mkdir project: %v", err)
	}
	socket := filepath.Join(root, "runtime", "patterm", "daemon.sock")
	pid := filepath.Join(root, "runtime", "patterm", "daemon.pid")

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	errCh := make(chan error, 1)
	ready := make(chan string, 1)
	go func() {
		errCh <- RunDaemon(ctx, DaemonOptions{
			ProjectDir:  projectDir,
			SocketPath:  socket,
			PidPath:     pid,
			ListenAddr:  "127.0.0.1:0",
			Token:       "secret-token",
			TokenOut:    io.Discard,
			ListenReady: ready,
			Cols:        80,
			Rows:        24,
		})
	}()
	waitForSocket(t, socket, errCh)
	tcpAddr := waitForTCPAddr(t, ready, errCh)

	assertTCPAttachDenied(t, tcpAddr, "")
	assertTCPAttachDenied(t, tcpAddr, "wrong-token")

	tcpClient := dialTCPDaemon(t, tcpAddr)
	defer tcpClient.Close()
	sendFrame(t, tcpClient, protocol.FrameAttach, protocol.Attach{
		Token:       "secret-token",
		ProjectPath: projectDir,
		TermSize:    protocol.Size{Cols: 80, Rows: 24},
	})
	expectFrame(t, tcpClient, protocol.FrameHello)
	expectFrame(t, tcpClient, protocol.FrameProjectList)
	expectFrame(t, tcpClient, protocol.FrameChrome)
	data, _ := json.Marshal(map[string]any{
		"argv": []string{"sh", "-c", "trap 'exit 0' TERM; echo TCP-SNAPSHOT; sleep 30"},
		"name": "tcp-survivor",
	})
	sendFrame(t, tcpClient, protocol.FramePaletteCommand, protocol.PaletteCommand{
		Kind: "spawn_command",
		Data: data,
	})
	expectFrame(t, tcpClient, protocol.FramePaneSnapshot)

	unixClient := dialDaemon(t, socket)
	defer unixClient.Close()
	sendFrame(t, unixClient, protocol.FrameAttach, protocol.Attach{
		ProjectPath: projectDir,
		TermSize:    protocol.Size{Cols: 80, Rows: 24},
	})
	expectFrame(t, unixClient, protocol.FrameHello)

	cancel()
	select {
	case err := <-errCh:
		if err != nil {
			t.Fatalf("daemon returned error: %v", err)
		}
	case <-time.After(3 * time.Second):
		t.Fatalf("daemon did not stop")
	}
}

func waitForSocket(t *testing.T, socket string, errCh <-chan error) {
	t.Helper()
	deadline := time.Now().Add(3 * time.Second)
	for time.Now().Before(deadline) {
		if _, err := os.Stat(socket); err == nil {
			return
		}
		select {
		case err := <-errCh:
			if err != nil && strings.Contains(err.Error(), "operation not permitted") {
				t.Skipf("unix sockets unavailable in this sandbox: %v", err)
			}
			t.Fatalf("daemon exited before creating socket: %v", err)
		default:
		}
		time.Sleep(25 * time.Millisecond)
	}
	t.Fatalf("socket %s was not created", socket)
}

func dialDaemon(t *testing.T, socket string) protocol.Transport {
	t.Helper()
	conn, err := net.Dial("unix", socket)
	if err != nil {
		t.Fatalf("dial daemon: %v", err)
	}
	return protocol.NewConnTransport(conn)
}

func dialTCPDaemon(t *testing.T, addr string) protocol.Transport {
	t.Helper()
	conn, err := net.Dial("tcp", addr)
	if err != nil {
		t.Fatalf("dial tcp daemon: %v", err)
	}
	return protocol.NewConnTransport(conn)
}

func waitForTCPAddr(t *testing.T, ready <-chan string, errCh <-chan error) string {
	t.Helper()
	select {
	case addr := <-ready:
		return addr
	case err := <-errCh:
		if err != nil && strings.Contains(err.Error(), "operation not permitted") {
			t.Skipf("tcp sockets unavailable in this sandbox: %v", err)
		}
		t.Fatalf("daemon exited before TCP listener was ready: %v", err)
	case <-time.After(3 * time.Second):
		t.Fatalf("tcp listener was not ready")
	}
	return ""
}

func assertTCPAttachDenied(t *testing.T, addr, token string) {
	t.Helper()
	client := dialTCPDaemon(t, addr)
	defer client.Close()
	sendFrame(t, client, protocol.FrameAttach, protocol.Attach{
		Token:    token,
		TermSize: protocol.Size{Cols: 80, Rows: 24},
	})
	f := expectFrame(t, client, protocol.FrameError)
	msg, err := protocol.Decode[protocol.Error](f)
	if err != nil {
		t.Fatalf("decode error frame: %v", err)
	}
	if !strings.Contains(msg.Message, "auth denied") {
		t.Fatalf("error message = %q, want auth denied", msg.Message)
	}
}

func sendFrame[T any](t *testing.T, tr protocol.Transport, typ protocol.FrameType, payload T) {
	t.Helper()
	f, err := protocol.NewFrame(typ, payload)
	if err != nil {
		t.Fatalf("frame %s: %v", typ, err)
	}
	if err := tr.Send(f); err != nil {
		t.Fatalf("send %s: %v", typ, err)
	}
}

func expectFrame(t *testing.T, tr protocol.Transport, typ protocol.FrameType) protocol.Frame {
	t.Helper()
	deadline := time.Now().Add(3 * time.Second)
	for time.Now().Before(deadline) {
		f, err, ok := recvFrameWithin(tr, time.Until(deadline))
		if !ok {
			break
		}
		if err != nil {
			t.Fatalf("recv %s: %v", typ, err)
		}
		if f.Type == typ {
			return f
		}
	}
	t.Fatalf("frame %s not received", typ)
	return protocol.Frame{}
}

func expectChrome(t *testing.T, tr protocol.Transport) protocol.Chrome {
	t.Helper()
	f := expectFrame(t, tr, protocol.FrameChrome)
	chrome, err := protocol.Decode[protocol.Chrome](f)
	if err != nil {
		t.Fatalf("decode chrome: %v", err)
	}
	return chrome
}

func waitForLifecycle(t *testing.T, tr protocol.Transport, kind protocol.LifecycleKind, timeout time.Duration) {
	t.Helper()
	deadline := time.Now().Add(timeout)
	for time.Now().Before(deadline) {
		f, err, ok := recvFrameWithin(tr, time.Until(deadline))
		if !ok {
			break
		}
		if err != nil {
			t.Fatalf("recv lifecycle: %v", err)
		}
		if f.Type != protocol.FrameLifecycle {
			continue
		}
		msg, err := protocol.Decode[protocol.Lifecycle](f)
		if err != nil {
			t.Fatalf("decode lifecycle: %v", err)
		}
		if msg.Kind == kind {
			return
		}
	}
	t.Fatalf("lifecycle %s not received", kind)
}

func recvFrameWithin(tr protocol.Transport, timeout time.Duration) (protocol.Frame, error, bool) {
	type result struct {
		f   protocol.Frame
		err error
	}
	ch := make(chan result, 1)
	go func() {
		f, err := tr.Recv()
		ch <- result{f: f, err: err}
	}()
	select {
	case r := <-ch:
		return r.f, r.err, true
	case <-time.After(timeout):
		return protocol.Frame{}, nil, false
	}
}

func chromeHasProcess(chrome protocol.Chrome, name string) bool {
	var model struct {
		Processes []childModel `json:"processes"`
	}
	if err := json.Unmarshal(chrome.Model, &model); err != nil {
		return false
	}
	for _, p := range model.Processes {
		if p.Name == name {
			return true
		}
	}
	return false
}