package world

import (
	"testing"

	"github.com/stretchr/testify/require"
)

func TestPoints_WrapCopies_AppearInsideViewportWhenViewportEqualsWorld(t *testing.T) {
	t.Parallel()

	params := RenderParams{
		ViewportWidthPx:  10,
		ViewportHeightPx: 10,
		MarginXPx:        0,
		MarginYPx:        0,
		CameraXWorldFp:   5 * SCALE,
		CameraYWorldFp:   5 * SCALE,
		CameraZoom:       1.0,
		Options: &RenderOptions{
			Style: func() *RenderStyle {
				s := DefaultRenderStyle()
				s.PointRadiusPx = 2.0 // so that a point at 9 "spills" by 1 and needs a copy at -1
				return &s
			}(),
		},
	}

	type tc struct {
		name        string
		x, y        float64
		wantCenters [][2]float64
	}

	tests := []tc{
		{
			name:        "bottom boundary wraps to top",
			x:           5,
			y:           9,
			wantCenters: [][2]float64{{5, 9}, {5, -1}},
		},
		{
			name:        "right boundary wraps to left",
			x:           9,
			y:           5,
			wantCenters: [][2]float64{{9, 5}, {-1, 5}},
		},
		{
			name:        "corner wraps to three extra copies",
			x:           9,
			y:           9,
			wantCenters: [][2]float64{{9, 9}, {9, -1}, {-1, 9}, {-1, -1}},
		},
		{
			name:        "no wrap inside",
			x:           5,
			y:           5,
			wantCenters: [][2]float64{{5, 5}},
		},
	}

	for _, tt := range tests {
		tt := tt
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			w := NewWorld(10, 10)
			w.resetGrid(2 * SCALE)

			_, err := w.AddPoint(tt.x, tt.y)
			require.NoError(t, err)

			for _, obj := range w.objects {
				w.indexObject(obj)
			}

			plan, err := w.buildRenderPlanStageA(params)
			require.NoError(t, err)

			d := &fakePrimitiveDrawer{}
			style := DefaultRenderStyle()
			style.PointRadiusPx = 2.0

			applyPointStyle(d, style)
			drawPointsFromPlanWithRadius(d, plan, w.W, w.H, style.PointRadiusPx)

			cmds := d.CommandsByName("AddPoint")
			require.Len(t, cmds, len(tt.wantCenters))

			got := make([][2]float64, 0, len(cmds))
			for _, c := range cmds {
				require.Len(t, c.Args, 3)
				got = append(got, [2]float64{c.Args[0], c.Args[1]})
			}

			require.ElementsMatch(t, tt.wantCenters, got)
		})
	}
}