package platepdf

import (
	"bytes"
	"fmt"
	"os"
	"strings"
	"testing"

	"printer.backend/internal/layout"
	"printer.backend/internal/model"
	"printer.backend/internal/svgtemplate"
)

const sampleItemSVG = `<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg" width="80mm" height="80mm" viewBox="-13 -13 106 106">
  <defs>
    <clipPath id="item-mask">
      <rect x="0" y="0" width="80" height="80" rx="5" ry="5" />
    </clipPath>
  </defs>
  <rect x="-13" y="-13" width="106" height="106" fill="#f9f9f9" />
  <g clip-path="url(#item-mask)">
    <rect x="-2" y="-2" width="84" height="84" fill="#00ff00" opacity="0.7" />
  </g>
</svg>`

func requireRsvg(t *testing.T) {
	t.Helper()
	if !rsvgAvailable() {
		t.Skip("rsvg-convert not available")
	}
}

func TestBuildCompositeSVG(t *testing.T) {
	requireRsvg(t)

	plate := model.Plate{
		WidthMM: 300, HeightMM: 400,
		MarginTop: 10, MarginRight: 10, MarginBottom: 10, MarginLeft: 10,
	}
	spec := model.ItemSpec{WidthMM: 80, HeightMM: 80, BleedMM: 2, MarginMM: 5, PaddingMM: 3}
	preview := layout.Pack(plate, spec, 2)

	out, err := BuildCompositeSVG(plate, spec, []byte(sampleItemSVG), preview)
	if err != nil {
		t.Fatal(err)
	}
	s := string(out)
	if !strings.Contains(s, `viewBox="0 0 300`) {
		t.Fatalf("expected plate viewBox, got: %s", s[:min(200, len(s))])
	}
	if preview.Count > 0 && !strings.Contains(s, `<image `) {
		t.Fatal("expected embedded item images")
	}
	if preview.Count > 0 && !strings.Contains(s, `x="10.0000"`) {
		t.Fatal("expected items at plate margin (canvas origin)")
	}
	if preview.Count > 0 && !strings.Contains(s, fmt.Sprintf(`width="%.4f"`, preview.CanvasWidthMM)) {
		t.Fatal("expected full canvas width on placed images")
	}
}

func TestBuildCompositeSVGInvalid(t *testing.T) {
	requireRsvg(t)

	_, err := BuildCompositeSVG(model.Plate{}, model.ItemSpec{}, []byte("not svg"), model.LayoutPreview{})
	if err == nil {
		t.Fatal("expected error for invalid svg")
	}
}

func TestGeneratePDF(t *testing.T) {
	requireRsvg(t)

	plate := model.Plate{
		WidthMM: 200, HeightMM: 200,
		MarginLeft: 10, MarginTop: 10, MarginRight: 10, MarginBottom: 10,
	}
	spec := model.ItemSpec{WidthMM: 80, HeightMM: 80, BleedMM: 2, MarginMM: 5, PaddingMM: 3}
	preview := layout.Pack(plate, spec, 2)

	var buf bytes.Buffer
	if err := svgtemplate.Write(&buf, svgtemplate.Build(
		spec.WidthMM, spec.HeightMM,
		spec.BleedMM, spec.MarginMM, spec.PaddingMM,
		spec.CornerRadiusMM,
	)); err != nil {
		t.Fatal(err)
	}

	path := t.TempDir() + "/item.svg"
	if err := os.WriteFile(path, buf.Bytes(), 0o644); err != nil {
		t.Fatal(err)
	}

	pdf, err := Generate(plate, spec, path, preview)
	if err != nil {
		t.Fatal(err)
	}
	if len(pdf) < 4 || string(pdf[:4]) != "%PDF" {
		t.Fatalf("expected PDF header, got %d bytes", len(pdf))
	}
}

func TestGenerateRequiresRsvg(t *testing.T) {
	if rsvgAvailable() {
		t.Skip("rsvg-convert is available")
	}
	_, err := Generate(model.Plate{}, model.ItemSpec{}, "/nonexistent", model.LayoutPreview{})
	if err == nil || !strings.Contains(err.Error(), "rsvg-convert") {
		t.Fatalf("expected rsvg error, got: %v", err)
	}
}