package app

import (
	"context"
	"syscall"
	"testing"

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

func TestSwitchProjectPreservesProjectProcessTrees(t *testing.T) {
	t.Setenv("XDG_DATA_HOME", t.TempDir())
	t.Setenv("XDG_CONFIG_HOME", t.TempDir())

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	reg := newProjectRegistry(preset.Set{}, defaultSettings(), nil, 80, 24)
	defer reg.Shutdown()

	projectA, err := reg.Open(ctx, t.TempDir())
	if err != nil {
		t.Fatalf("open project A: %v", err)
	}
	projectB, err := reg.Open(ctx, t.TempDir())
	if err != nil {
		t.Fatalf("open project B: %v", err)
	}

	a, err := projectA.Session.Spawn(SpawnSpec{
		Kind: KindCommand,
		Argv: []string{"sh", "-c", "trap 'exit 0' TERM; while :; do sleep 1; done"},
		Name: "a-loop",
	}, 80, 24)
	if err != nil {
		t.Fatalf("spawn project A command: %v", err)
	}
	b, err := projectB.Session.Spawn(SpawnSpec{
		Kind: KindCommand,
		Argv: []string{"sh", "-c", "trap 'exit 0' TERM; while :; do sleep 1; done"},
		Name: "b-loop",
	}, 80, 24)
	if err != nil {
		t.Fatalf("spawn project B command: %v", err)
	}
	t.Cleanup(func() {
		_ = projectA.Session.Kill(a.ID, syscall.SIGTERM)
		_ = projectB.Session.Kill(b.ID, syscall.SIGTERM)
	})
	waitUntilLive(t, a)
	waitUntilLive(t, b)

	st := &uiState{
		registry:   reg,
		project:    projectA,
		sess:       projectA.Session,
		launcher:   projectA.Launcher,
		pads:       projectA.Pads,
		trust:      projectA.Trust,
		timers:     projectA.Host.timers,
		chromeWake: make(chan struct{}, 1),
		view: ClientView{
			ID:          "test",
			ProjectKey:  projectA.Key,
			ProjectName: projectA.Name,
			Cols:        80,
			Rows:        24,
		},
	}
	st.focusChildLocked(a)
	projectA.Session.Subscribe(st)

	st.switchProject(projectB)
	if st.view.ProjectKey != projectB.Key {
		t.Fatalf("view project key = %q, want %q", st.view.ProjectKey, projectB.Key)
	}
	if st.sess != projectB.Session {
		t.Fatalf("ui session did not move to project B")
	}
	if projectA.Session.FindChild(a.ID) == nil {
		t.Fatalf("project A child disappeared after switch")
	}
	if projectB.Session.FindChild(b.ID) == nil {
		t.Fatalf("project B child disappeared after switch")
	}
	if !a.IsLive() {
		t.Fatalf("project A child stopped after switch")
	}
	if !b.IsLive() {
		t.Fatalf("project B child stopped after switch")
	}

	st.switchProject(projectA)
	if st.view.ProjectKey != projectA.Key {
		t.Fatalf("view project key after switching back = %q, want %q", st.view.ProjectKey, projectA.Key)
	}
	if projectA.Session.FindChild(a.ID) == nil || projectB.Session.FindChild(b.ID) == nil {
		t.Fatalf("switching back should preserve both project process trees")
	}
}