package parse

import (
	"io"
	"strings"
	"testing"
)

func TestExtractImages_NoMarkers(t *testing.T) {
	input := "Hello\nWorld\nNo images here\n"
	r, images := ExtractImages(strings.NewReader(input))
	if len(images) != 0 {
		t.Errorf("got %d images, want 0", len(images))
	}
	out, _ := io.ReadAll(r)
	if string(out) != input {
		t.Errorf("output = %q, want %q", string(out), input)
	}
}

func TestExtractImages_SingleMarker(t *testing.T) {
	input := "Line 1\n\033]9;image:path=/tmp/img.png;alt=photo\007\nLine 2\n"
	r, images := ExtractImages(strings.NewReader(input))
	if len(images) != 1 {
		t.Fatalf("got %d images, want 1", len(images))
	}
	if images[0].Path != "/tmp/img.png" {
		t.Errorf("path = %q", images[0].Path)
	}
	if images[0].Alt != "photo" {
		t.Errorf("alt = %q", images[0].Alt)
	}
	if images[0].Index != 0 {
		t.Errorf("index = %d, want 0", images[0].Index)
	}
	out, _ := io.ReadAll(r)
	expected := "Line 1\n\x00IMG:0\x00\nLine 2\n"
	if string(out) != expected {
		t.Errorf("output = %q, want %q", string(out), expected)
	}
}

func TestExtractImages_MultipleMarkers(t *testing.T) {
	input := "Text\n\033]9;image:path=/tmp/a.png\007\nMiddle\n\033]9;image:path=/tmp/b.jpg;alt=second\007\nEnd\n"
	r, images := ExtractImages(strings.NewReader(input))
	if len(images) != 2 {
		t.Fatalf("got %d images, want 2", len(images))
	}
	if images[0].Index != 0 || images[1].Index != 1 {
		t.Errorf("indices: %d, %d", images[0].Index, images[1].Index)
	}
	if images[1].Path != "/tmp/b.jpg" {
		t.Errorf("second path = %q", images[1].Path)
	}
	out, _ := io.ReadAll(r)
	if !strings.Contains(string(out), "\x00IMG:0\x00") {
		t.Error("missing placeholder 0")
	}
	if !strings.Contains(string(out), "\x00IMG:1\x00") {
		t.Error("missing placeholder 1")
	}
}

func TestExtractImages_EmptyInput(t *testing.T) {
	r, images := ExtractImages(strings.NewReader(""))
	if len(images) != 0 {
		t.Errorf("got %d images, want 0", len(images))
	}
	out, _ := io.ReadAll(r)
	if len(out) != 0 {
		t.Errorf("expected empty output, got %q", string(out))
	}
}

func TestExtractImages_MarkerAtStartAndEnd(t *testing.T) {
	input := "\033]9;image:path=/tmp/first.png\007\nContent\n\033]9;image:path=/tmp/last.png\007\n"
	r, images := ExtractImages(strings.NewReader(input))
	if len(images) != 2 {
		t.Fatalf("got %d images, want 2", len(images))
	}
	out, _ := io.ReadAll(r)
	lines := strings.Split(strings.TrimSuffix(string(out), "\n"), "\n")
	if lines[0] != "\x00IMG:0\x00" {
		t.Errorf("first line = %q, want placeholder", lines[0])
	}
	if lines[2] != "\x00IMG:1\x00" {
		t.Errorf("last line = %q, want placeholder", lines[2])
	}
}

func TestExtractImages_InvalidMarkerPassesThrough(t *testing.T) {
	input := "Text\n\033]9;image:alt=no path\007\nMore text\n"
	r, images := ExtractImages(strings.NewReader(input))
	if len(images) != 0 {
		t.Errorf("got %d images, want 0 (invalid marker)", len(images))
	}
	out, _ := io.ReadAll(r)
	if !strings.Contains(string(out), "Text") {
		t.Error("text content lost")
	}
}