package chart

import (
	"bytes"
	"image"
	_ "image/png"
	"testing"

	"ukrrs.com/mopac/pdf/internal/markdown"
)

func TestBarPNG(t *testing.T) {
	c := &markdown.Chart{
		Type:   "bar",
		Title:  "Revenue",
		Unit:   "$K",
		Labels: []string{"Q1", "Q2", "Q3"},
		Values: []float64{10, 20, 15},
	}
	png, err := Bar(c)
	if err != nil {
		t.Fatalf("render: %v", err)
	}
	if !bytes.HasPrefix(png, []byte{0x89, 'P', 'N', 'G'}) {
		t.Fatalf("not a PNG: % x", png[:4])
	}
	img, _, err := image.Decode(bytes.NewReader(png))
	if err != nil {
		t.Fatalf("decode: %v", err)
	}
	b := img.Bounds()
	if b.Dx() < 300 || b.Dy() < 200 {
		t.Fatalf("unexpected dimensions %dx%d", b.Dx(), b.Dy())
	}
}

func TestBarRejectsUnknownType(t *testing.T) {
	c := &markdown.Chart{Type: "pie", Labels: []string{"a"}, Values: []float64{1}}
	if _, err := Bar(c); err == nil {
		t.Fatal("pie must be rejected in v0")
	}
}

func TestBarRejectsEmpty(t *testing.T) {
	if _, err := Bar(nil); err == nil {
		t.Fatal("nil chart must be rejected")
	}
	c := &markdown.Chart{Type: "bar"}
	if _, err := Bar(c); err == nil {
		t.Fatal("chart without data must be rejected")
	}
}