package tui

import "testing"

func TestIsInputStep(t *testing.T) {
	input := []step{
		StepDockerLogin, StepIPQuestion, StepWireguardConfig,
		StepAppConfig, StepServerConfig, StepDatabaseConfig,
		StepCertConfig, StepReview,
	}
	for _, s := range input {
		if !isInputStep(s) {
			t.Errorf("isInputStep(%d) = false, want true", s)
		}
	}

	action := []step{
		StepCheckDocker, StepDockerInstall, StepDownloadImage,
		StepGenerateWireguardFile, StepDownloadWireguard, StepRunWireguard,
		StepGenerateFile, StepRunDocker, StepDone,
	}
	for _, s := range action {
		if isInputStep(s) {
			t.Errorf("isInputStep(%d) = true, want false", s)
		}
	}
}

func TestAdvancePushesInputSteps(t *testing.T) {
	m := Model{currentStep: StepAppConfig}

	m.advance(StepServerConfig)
	if m.currentStep != StepServerConfig {
		t.Fatalf("currentStep = %d, want StepServerConfig", m.currentStep)
	}
	if len(m.history) != 1 || m.history[0] != StepAppConfig {
		t.Fatalf("history = %v, want [StepAppConfig]", m.history)
	}
}

func TestAdvanceSkipsActionSteps(t *testing.T) {
	// Advancing away from an action step must not record it on the stack.
	m := Model{currentStep: StepDownloadImage}

	m.advance(StepIPQuestion)
	if len(m.history) != 0 {
		t.Fatalf("history = %v, want empty (action step not recorded)", m.history)
	}
}

func TestAdvanceDedupesConsecutive(t *testing.T) {
	m := Model{currentStep: StepIPQuestion}

	m.advance(StepIPQuestion) // self-advance (e.g. re-entering) must not duplicate
	m.currentStep = StepIPQuestion
	m.advance(StepIPQuestion)

	if len(m.history) > 1 {
		t.Fatalf("history = %v, want at most one entry", m.history)
	}
}

func TestGoBack(t *testing.T) {
	m := Model{currentStep: StepCertConfig, history: []step{StepAppConfig, StepServerConfig, StepDatabaseConfig}}

	if !m.goBack() {
		t.Fatal("goBack() = false, want true")
	}
	if m.currentStep != StepDatabaseConfig {
		t.Errorf("currentStep = %d, want StepDatabaseConfig", m.currentStep)
	}
	if len(m.history) != 2 {
		t.Errorf("history len = %d, want 2", len(m.history))
	}
}

func TestGoBackEmptyHistory(t *testing.T) {
	m := Model{currentStep: StepDockerLogin}
	if m.goBack() {
		t.Error("goBack() = true on empty history, want false")
	}
	if m.currentStep != StepDockerLogin {
		t.Error("currentStep changed on empty goBack")
	}
}

func TestCanGoBack(t *testing.T) {
	// Input step with history -> can go back.
	m := Model{currentStep: StepServerConfig, history: []step{StepAppConfig}}
	if !m.canGoBack() {
		t.Error("canGoBack() = false, want true for input step with history")
	}

	// Input step, empty history -> cannot.
	m = Model{currentStep: StepDockerLogin}
	if m.canGoBack() {
		t.Error("canGoBack() = true, want false with empty history")
	}

	// Action step with history -> cannot (esc handled by the step, not global back).
	m = Model{currentStep: StepDownloadImage, history: []step{StepDockerLogin}}
	if m.canGoBack() {
		t.Error("canGoBack() = true on action step, want false")
	}
}