package world

import (
	"testing"

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

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

	// World is 10x10 world units => 10000x10000 fixed.
	w := NewWorld(10, 10)
	w.resetGrid(2 * SCALE)

	// Place a point near the origin so that expanded canvas (larger than world)
	// will require torus repetition and the point will appear in multiple tiles.
	id, err := w.AddPoint(1.0, 1.0) // (1000,1000)
	require.NoError(t, err)

	// Index only this object.
	w.indexObject(w.objects[id])

	// Choose viewport such that viewport==world in pixels at zoom=1:
	// - With zoom=1 (zoomFp=SCALE), 1 world unit maps to 1 px.
	// - world width=10 units => 10 px.
	// Use margin=2 px on each side => canvas 14x14 px => expanded world span 14 units > world.
	params := RenderParams{
		ViewportWidthPx:  10,
		ViewportHeightPx: 10,
		MarginXPx:        2,
		MarginYPx:        2,
		CameraXWorldFp:   5 * SCALE,
		CameraYWorldFp:   5 * SCALE,
		CameraZoom:       1.0,
	}

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

	d := &fakePrimitiveDrawer{}
	drawPointsFromPlan(d, plan, true)

	// We expect 4 point copies:
	// (tx=0,ty=0), (tx=0,ty=1), (tx=1,ty=0), (tx=1,ty=1)
	// due to expanded rect spanning beyond world on both axes.
	wantNames := []string{
		"Save", "ClipRect", "AddPoint", "Fill", "Restore",
		"Save", "ClipRect", "AddPoint", "Fill", "Restore",
		"Save", "ClipRect", "AddPoint", "Fill", "Restore",
		"Save", "ClipRect", "AddPoint", "Fill", "Restore",
	}
	require.Equal(t, wantNames, d.CommandNames())

	pointRadiusPx := DefaultRenderStyle().PointRadiusPx

	// Command group 1: tile (offsetX=0, offsetY=0), clip should be (2,2,10,10), point at (3,3).
	{
		clip := requireDrawerCommandAt(t, d, 1)
		require.Equal(t, "ClipRect", clip.Name)
		requireCommandArgs(t, clip, 2, 2, 10, 10)

		pt := requireDrawerCommandAt(t, d, 2)
		require.Equal(t, "AddPoint", pt.Name)
		requireCommandArgs(t, pt, 3, 3, pointRadiusPx)
	}

	// Command group 2: tile (offsetX=0, offsetY=10000), clip (2,12,10,2), point at (3,13).
	{
		clip := requireDrawerCommandAt(t, d, 6)
		require.Equal(t, "ClipRect", clip.Name)
		requireCommandArgs(t, clip, 2, 12, 10, 2)

		pt := requireDrawerCommandAt(t, d, 7)
		require.Equal(t, "AddPoint", pt.Name)
		requireCommandArgs(t, pt, 3, 13, pointRadiusPx)
	}

	// Command group 3: tile (offsetX=10000, offsetY=0), clip (12,2,2,10), point at (13,3).
	{
		clip := requireDrawerCommandAt(t, d, 11)
		require.Equal(t, "ClipRect", clip.Name)
		requireCommandArgs(t, clip, 12, 2, 2, 10)

		pt := requireDrawerCommandAt(t, d, 12)
		require.Equal(t, "AddPoint", pt.Name)
		requireCommandArgs(t, pt, 13, 3, pointRadiusPx)
	}

	// Command group 4: tile (offsetX=10000, offsetY=10000), clip (12,12,2,2), point at (13,13).
	{
		clip := requireDrawerCommandAt(t, d, 16)
		require.Equal(t, "ClipRect", clip.Name)
		requireCommandArgs(t, clip, 12, 12, 2, 2)

		pt := requireDrawerCommandAt(t, d, 17)
		require.Equal(t, "AddPoint", pt.Name)
		requireCommandArgs(t, pt, 13, 13, pointRadiusPx)
	}
}

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

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

	// Add only a line, no points.
	id, err := w.AddLine(2, 2, 8, 2)
	require.NoError(t, err)
	w.indexObject(w.objects[id])

	params := RenderParams{
		ViewportWidthPx:  10,
		ViewportHeightPx: 10,
		MarginXPx:        2,
		MarginYPx:        2,
		CameraXWorldFp:   5 * SCALE,
		CameraYWorldFp:   5 * SCALE,
		CameraZoom:       1.0,
	}

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

	d := &fakePrimitiveDrawer{}
	drawPointsFromPlan(d, plan, true)

	// No points => no drawing commands at all.
	require.Empty(t, d.Commands())
}

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

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

	_, err := w.AddPoint(5, 5)
	require.NoError(t, err)

	// Build index. In real UI it happens via IndexOnViewportChange.
	for _, obj := range w.objects {
		w.indexObject(obj)
	}

	params := RenderParams{
		ViewportWidthPx:  10,
		ViewportHeightPx: 10,
		MarginXPx:        2,
		MarginYPx:        2,
		CameraXWorldFp:   5 * SCALE,
		CameraYWorldFp:   5 * SCALE,
		CameraZoom:       1.0,
	}

	d := &fakePrimitiveDrawer{}
	err = w.Render(d, params)
	require.NoError(t, err)

	// At least one point draw should happen.
	require.Contains(t, d.CommandNames(), "AddPoint")
}