package app

import (
	"fmt"
	"strings"
	"testing"

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

func TestRenderScreenSnapshotClipsRowsToViewport(t *testing.T) {
	// hostRows=8 leaves three rows of viewport once the 3-row tab bar
	// and 1-row status line are reserved.
	layout := newTerminalLayout(20, 8)
	mainTop := int(layout.mainTop)
	got := string(renderScreenSnapshot("abcdefghijklmnopqrstuvwxy\nsecond", vt.CursorState{}, layout))
	if strings.Contains(got, "uvwxy") {
		t.Fatalf("line leaked past viewport width: %q", got)
	}
	first := fmt.Sprintf("\x1b[%d;1Habcdefghijklmnopqrst", mainTop)
	if !strings.Contains(got, first) {
		t.Fatalf("first row not drawn at viewport top: %q", got)
	}
	second := fmt.Sprintf("\x1b[%d;1Hsecond              ", mainTop+1)
	if !strings.Contains(got, second) {
		t.Fatalf("second row not padded in viewport: %q", got)
	}
	blank := fmt.Sprintf("\x1b[%d;1H                    ", mainTop+2)
	if !strings.Contains(got, blank) {
		t.Fatalf("blank viewport row not cleared: %q", got)
	}
}

func TestRenderScreenSnapshotPlacesCursorInsideViewport(t *testing.T) {
	layout := newTerminalLayout(20, 8)
	got := string(renderScreenSnapshot("abc", vt.CursorState{Col: 2, Row: 1, Visible: true}, layout))
	want := fmt.Sprintf("\x1b[?25h\x1b[%d;3H", int(layout.mainTop)+1)
	if !strings.HasSuffix(got, want) {
		t.Fatalf("cursor not placed inside viewport: %q (want suffix %q)", got, want)
	}
}