package parser

import (
	"bytes"
	"testing"
)

func TestSplitSlideBreaks_NoMarkerReturnsBodyUnchanged(t *testing.T) {
	body := []byte("# A\n\nsome text\n")
	got := splitSlideBreaks(body)
	if len(got) != 1 || !bytes.Equal(got[0], body) {
		t.Errorf("splitSlideBreaks() = %q, want [%q]", got, body)
	}
}

func TestSplitSlideBreaks_SplitsOnMarkerLine(t *testing.T) {
	body := []byte("# A\n\n<!-- new slide -->\n\n# B\n")
	got := splitSlideBreaks(body)
	want := [][]byte{[]byte("# A"), []byte("# B")}
	if len(got) != len(want) {
		t.Fatalf("splitSlideBreaks() = %q, want %q", got, want)
	}
	for i := range want {
		if !bytes.Equal(got[i], want[i]) {
			t.Errorf("part %d = %q, want %q", i, got[i], want[i])
		}
	}
}

func TestSplitSlideBreaks_HandlesMultipleMarkersAndSurroundingWhitespace(t *testing.T) {
	body := []byte("<!-- new slide -->\n# A\n<!-- new slide -->\n# B\n<!-- new slide -->\n")
	got := splitSlideBreaks(body)
	want := [][]byte{[]byte("# A"), []byte("# B")}
	if len(got) != len(want) {
		t.Fatalf("splitSlideBreaks() = %q, want %q", got, want)
	}
	for i := range want {
		if !bytes.Equal(got[i], want[i]) {
			t.Errorf("part %d = %q, want %q", i, got[i], want[i])
		}
	}
}

func TestSplitSlideBreaks_IgnoresMarkerInsideBacktickFence(t *testing.T) {
	body := []byte("# A\n\n```\n<!-- new slide -->\n```\n\n# B\n")
	got := splitSlideBreaks(body)
	if len(got) != 1 {
		t.Fatalf("splitSlideBreaks() = %q, want a single part (marker is inside a fence)", got)
	}
	if !bytes.Equal(got[0], body) {
		t.Errorf("splitSlideBreaks()[0] = %q, want unchanged body %q", got[0], body)
	}
}

func TestSplitSlideBreaks_IgnoresMarkerInsideTildeFence(t *testing.T) {
	body := []byte("# A\n\n~~~\n<!-- new slide -->\n~~~\n\n# B\n")
	got := splitSlideBreaks(body)
	if len(got) != 1 {
		t.Fatalf("splitSlideBreaks() = %q, want a single part (marker is inside a fence)", got)
	}
}

func TestSplitSlideBreaks_SplitsAfterFenceCloses(t *testing.T) {
	body := []byte("```\ncode\n```\n\n<!-- new slide -->\n\n# B\n")
	got := splitSlideBreaks(body)
	want := [][]byte{[]byte("```\ncode\n```"), []byte("# B")}
	if len(got) != len(want) {
		t.Fatalf("splitSlideBreaks() = %q, want %q", got, want)
	}
	for i := range want {
		if !bytes.Equal(got[i], want[i]) {
			t.Errorf("part %d = %q, want %q", i, got[i], want[i])
		}
	}
}