package model

import (
	"testing"

	"github.com/charmbracelet/crush/internal/message"
	"github.com/charmbracelet/crush/internal/ui/chat"
	"github.com/stretchr/testify/require"
)

// TestChatToggleExpandedSelectedItem_AssistantMessage is the regression test
// for §4.8.1: before the fix, AssistantMessageItem.ToggleExpanded returned no
// value so the type did not satisfy chat.Expandable, and the keyboard-driven
// ToggleExpandedSelectedItem path silently skipped thinking blocks. This
// wires a real Chat with an AssistantMessageItem, selects it, invokes
// ToggleExpandedSelectedItem, and asserts the thinking block actually
// flipped.
func TestChatToggleExpandedSelectedItem_AssistantMessage(t *testing.T) {
	t.Parallel()

	u := newTestUI()

	msg := &message.Message{ID: "m-assist", Role: message.Assistant}
	item := chat.NewAssistantMessageItem(u.com.Styles, msg)

	// The keyboard expand path uses the generic Expandable interface;
	// verifying satisfaction at runtime guards the contract.
	exp, ok := item.(chat.Expandable)
	require.True(t, ok, "AssistantMessageItem must satisfy chat.Expandable")

	u.chat.SetMessages(item)
	u.chat.SetSelected(0)

	// First keyboard toggle should expand. Immediately follow with a
	// direct ToggleExpanded: it flips the now-expanded item back to
	// collapsed and returns false. If the keyboard path had silently
	// skipped the item (the bug), the item would still be collapsed and
	// the direct toggle would return true.
	u.chat.ToggleExpandedSelectedItem()
	require.False(t, exp.ToggleExpanded(),
		"keyboard toggle did not expand the assistant thinking block")

	// Second keyboard toggle against the re-collapsed item should expand
	// it again. Direct ToggleExpanded then returns false because it
	// re-collapses.
	u.chat.ToggleExpandedSelectedItem()
	require.False(t, exp.ToggleExpanded(),
		"second keyboard toggle did not re-expand the assistant thinking block")
}