package tmux

import (
	"os/exec"
	"strings"
	"testing"
)

func hasTmux() bool {
	_, err := exec.LookPath("tmux")
	return err == nil
}

func TestListSessionsNoServer(t *testing.T) {
	if !hasTmux() {
		t.Skip("tmux not installed")
	}

	tm := NewTmux()
	sessions, err := tm.ListSessions()
	// Should not error even if no server running
	if err != nil {
		t.Fatalf("ListSessions: %v", err)
	}
	// Result may be nil or empty slice
	_ = sessions
}

func TestHasSessionNoServer(t *testing.T) {
	if !hasTmux() {
		t.Skip("tmux not installed")
	}

	tm := NewTmux()
	has, err := tm.HasSession("nonexistent-session-xyz")
	if err != nil {
		t.Fatalf("HasSession: %v", err)
	}
	if has {
		t.Error("expected session to not exist")
	}
}

func TestSessionLifecycle(t *testing.T) {
	if !hasTmux() {
		t.Skip("tmux not installed")
	}

	tm := NewTmux()
	sessionName := "gt-test-session-" + t.Name()

	// Clean up any existing session
	_ = tm.KillSession(sessionName)

	// Create session
	if err := tm.NewSession(sessionName, ""); err != nil {
		t.Fatalf("NewSession: %v", err)
	}
	defer func() { _ = tm.KillSession(sessionName) }()

	// Verify exists
	has, err := tm.HasSession(sessionName)
	if err != nil {
		t.Fatalf("HasSession: %v", err)
	}
	if !has {
		t.Error("expected session to exist after creation")
	}

	// List should include it
	sessions, err := tm.ListSessions()
	if err != nil {
		t.Fatalf("ListSessions: %v", err)
	}
	found := false
	for _, s := range sessions {
		if s == sessionName {
			found = true
			break
		}
	}
	if !found {
		t.Error("session not found in list")
	}

	// Kill session
	if err := tm.KillSession(sessionName); err != nil {
		t.Fatalf("KillSession: %v", err)
	}

	// Verify gone
	has, err = tm.HasSession(sessionName)
	if err != nil {
		t.Fatalf("HasSession after kill: %v", err)
	}
	if has {
		t.Error("expected session to not exist after kill")
	}
}

func TestDuplicateSession(t *testing.T) {
	if !hasTmux() {
		t.Skip("tmux not installed")
	}

	tm := NewTmux()
	sessionName := "gt-test-dup-" + t.Name()

	// Clean up any existing session
	_ = tm.KillSession(sessionName)

	// Create session
	if err := tm.NewSession(sessionName, ""); err != nil {
		t.Fatalf("NewSession: %v", err)
	}
	defer func() { _ = tm.KillSession(sessionName) }()

	// Try to create duplicate
	err := tm.NewSession(sessionName, "")
	if err != ErrSessionExists {
		t.Errorf("expected ErrSessionExists, got %v", err)
	}
}

func TestSendKeysAndCapture(t *testing.T) {
	if !hasTmux() {
		t.Skip("tmux not installed")
	}

	tm := NewTmux()
	sessionName := "gt-test-keys-" + t.Name()

	// Clean up any existing session
	_ = tm.KillSession(sessionName)

	// Create session
	if err := tm.NewSession(sessionName, ""); err != nil {
		t.Fatalf("NewSession: %v", err)
	}
	defer func() { _ = tm.KillSession(sessionName) }()

	// Send echo command
	if err := tm.SendKeys(sessionName, "echo HELLO_TEST_MARKER"); err != nil {
		t.Fatalf("SendKeys: %v", err)
	}

	// Give it a moment to execute
	// In real tests you'd wait for output, but for basic test we just capture
	output, err := tm.CapturePane(sessionName, 50)
	if err != nil {
		t.Fatalf("CapturePane: %v", err)
	}

	// Should contain our marker (might not if shell is slow, but usually works)
	if !strings.Contains(output, "echo HELLO_TEST_MARKER") {
		t.Logf("captured output: %s", output)
		// Don't fail, just note - timing issues possible
	}
}

func TestGetSessionInfo(t *testing.T) {
	if !hasTmux() {
		t.Skip("tmux not installed")
	}

	tm := NewTmux()
	sessionName := "gt-test-info-" + t.Name()

	// Clean up any existing session
	_ = tm.KillSession(sessionName)

	// Create session
	if err := tm.NewSession(sessionName, ""); err != nil {
		t.Fatalf("NewSession: %v", err)
	}
	defer func() { _ = tm.KillSession(sessionName) }()

	info, err := tm.GetSessionInfo(sessionName)
	if err != nil {
		t.Fatalf("GetSessionInfo: %v", err)
	}

	if info.Name != sessionName {
		t.Errorf("Name = %q, want %q", info.Name, sessionName)
	}
	if info.Windows < 1 {
		t.Errorf("Windows = %d, want >= 1", info.Windows)
	}
}

func TestWrapError(t *testing.T) {
	tm := NewTmux()

	tests := []struct {
		stderr string
		want   error
	}{
		{"no server running on /tmp/tmux-...", ErrNoServer},
		{"error connecting to /tmp/tmux-...", ErrNoServer},
		{"duplicate session: test", ErrSessionExists},
		{"session not found: test", ErrSessionNotFound},
		{"can't find session: test", ErrSessionNotFound},
	}

	for _, tt := range tests {
		err := tm.wrapError(nil, tt.stderr, []string{"test"})
		if err != tt.want {
			t.Errorf("wrapError(%q) = %v, want %v", tt.stderr, err, tt.want)
		}
	}
}

func TestEnsureSessionFresh_NoExistingSession(t *testing.T) {
	if !hasTmux() {
		t.Skip("tmux not installed")
	}

	tm := NewTmux()
	sessionName := "gt-test-fresh-" + t.Name()

	// Clean up any existing session
	_ = tm.KillSession(sessionName)

	// EnsureSessionFresh should create a new session
	if err := tm.EnsureSessionFresh(sessionName, ""); err != nil {
		t.Fatalf("EnsureSessionFresh: %v", err)
	}
	defer func() { _ = tm.KillSession(sessionName) }()

	// Verify session exists
	has, err := tm.HasSession(sessionName)
	if err != nil {
		t.Fatalf("HasSession: %v", err)
	}
	if !has {
		t.Error("expected session to exist after EnsureSessionFresh")
	}
}

func TestEnsureSessionFresh_ZombieSession(t *testing.T) {
	if !hasTmux() {
		t.Skip("tmux not installed")
	}

	tm := NewTmux()
	sessionName := "gt-test-zombie-" + t.Name()

	// Clean up any existing session
	_ = tm.KillSession(sessionName)

	// Create a zombie session (session exists but no Claude/node running)
	// A normal tmux session with bash/zsh is a "zombie" for our purposes
	if err := tm.NewSession(sessionName, ""); err != nil {
		t.Fatalf("NewSession: %v", err)
	}
	defer func() { _ = tm.KillSession(sessionName) }()

	// Verify it's a zombie (not running Claude/node)
	if tm.IsClaudeRunning(sessionName) {
		t.Skip("session unexpectedly has Claude running - can't test zombie case")
	}

	// EnsureSessionFresh should kill the zombie and create fresh session
	// This should NOT error with "session already exists"
	if err := tm.EnsureSessionFresh(sessionName, ""); err != nil {
		t.Fatalf("EnsureSessionFresh on zombie: %v", err)
	}

	// Session should still exist
	has, err := tm.HasSession(sessionName)
	if err != nil {
		t.Fatalf("HasSession: %v", err)
	}
	if !has {
		t.Error("expected session to exist after EnsureSessionFresh on zombie")
	}
}

func TestEnsureSessionFresh_IdempotentOnZombie(t *testing.T) {
	if !hasTmux() {
		t.Skip("tmux not installed")
	}

	tm := NewTmux()
	sessionName := "gt-test-idem-" + t.Name()

	// Clean up any existing session
	_ = tm.KillSession(sessionName)

	// Call EnsureSessionFresh multiple times - should work each time
	for i := 0; i < 3; i++ {
		if err := tm.EnsureSessionFresh(sessionName, ""); err != nil {
			t.Fatalf("EnsureSessionFresh attempt %d: %v", i+1, err)
		}
	}
	defer func() { _ = tm.KillSession(sessionName) }()

	// Session should exist
	has, err := tm.HasSession(sessionName)
	if err != nil {
		t.Fatalf("HasSession: %v", err)
	}
	if !has {
		t.Error("expected session to exist after multiple EnsureSessionFresh calls")
	}
}