package matrix

import (
	"testing"
)

// extractThreadID is the pure logic extracted from the listener for testability.
// It mirrors the extraction in listener.go's EventMessage handler.
func extractThreadID(rawContent map[string]any) string {
	relatesTo, ok := rawContent["m.relates_to"].(map[string]any)
	if !ok {
		return ""
	}
	relType, _ := relatesTo["rel_type"].(string)
	if relType != "m.thread" {
		return ""
	}
	threadRoot, _ := relatesTo["event_id"].(string)
	return threadRoot
}

func TestExtractThreadID_ThreadMessage(t *testing.T) {
	raw := map[string]any{
		"body": "hello",
		"m.relates_to": map[string]any{
			"rel_type": "m.thread",
			"event_id": "$root123",
			"is_falling_back": true,
			"m.in_reply_to": map[string]any{
				"event_id": "$last456",
			},
		},
	}

	got := extractThreadID(raw)
	if got != "$root123" {
		t.Errorf("expected $root123, got %q", got)
	}
}

func TestExtractThreadID_ReplyNotThread(t *testing.T) {
	raw := map[string]any{
		"body": "hello",
		"m.relates_to": map[string]any{
			"m.in_reply_to": map[string]any{
				"event_id": "$evt789",
			},
		},
	}

	got := extractThreadID(raw)
	if got != "" {
		t.Errorf("expected empty string for non-thread reply, got %q", got)
	}
}

func TestExtractThreadID_NoRelatesTo(t *testing.T) {
	raw := map[string]any{
		"body": "plain message",
	}

	got := extractThreadID(raw)
	if got != "" {
		t.Errorf("expected empty string for plain message, got %q", got)
	}
}

func TestExtractThreadID_ReplaceRelation(t *testing.T) {
	raw := map[string]any{
		"body": "edited",
		"m.relates_to": map[string]any{
			"rel_type": "m.replace",
			"event_id": "$original",
		},
	}

	got := extractThreadID(raw)
	if got != "" {
		t.Errorf("expected empty string for m.replace, got %q", got)
	}
}

func TestExtractThreadID_ThreadWithoutEventID(t *testing.T) {
	raw := map[string]any{
		"m.relates_to": map[string]any{
			"rel_type": "m.thread",
			// missing event_id
		},
	}

	got := extractThreadID(raw)
	if got != "" {
		t.Errorf("expected empty string for thread without event_id, got %q", got)
	}
}