package container

import (
	"image"
	"testing"

	"github.com/mum4k/termdash/canvas/testcanvas"
	"github.com/mum4k/termdash/cell"
	"github.com/mum4k/termdash/draw"
	"github.com/mum4k/termdash/draw/testdraw"
	"github.com/mum4k/termdash/terminal/faketerm"
	"github.com/mum4k/termdash/widgetapi"
	"github.com/mum4k/termdash/widgets/fakewidget"
)

// Example demonstrates how to use the Container API.
func Example() {
	New(
		/* terminal = */ nil,
		SplitVertical(
			Left(
				SplitHorizontal(
					Top(
						Border(draw.LineStyleLight),
					),
					Bottom(
						SplitHorizontal(
							Top(
								Border(draw.LineStyleLight),
							),
							Bottom(
								Border(draw.LineStyleLight),
							),
						),
					),
				),
			),
			Right(
				Border(draw.LineStyleLight),
			),
		),
	)

	// TODO(mum4k): Allow splits on different ratios.
	// TODO(mum4k): Include an example with a widget.
}

func TestNew(t *testing.T) {
	tests := []struct {
		desc      string
		termSize  image.Point
		container func(ft *faketerm.Terminal) *Container
		want      func(size image.Point) *faketerm.Terminal
	}{
		{
			desc:     "empty container",
			termSize: image.Point{10, 10},
			container: func(ft *faketerm.Terminal) *Container {
				return New(ft)
			},
			want: func(size image.Point) *faketerm.Terminal {
				return faketerm.MustNew(size)
			},
		},
		{
			desc:     "container with a border",
			termSize: image.Point{10, 10},
			container: func(ft *faketerm.Terminal) *Container {
				return New(
					ft,
					Border(draw.LineStyleLight),
				)
			},
			want: func(size image.Point) *faketerm.Terminal {
				ft := faketerm.MustNew(size)
				cvs := testcanvas.MustNew(ft.Area())
				testdraw.MustBox(
					cvs,
					image.Rect(0, 0, 10, 10),
					draw.LineStyleLight,
					cell.FgColor(cell.ColorYellow),
				)
				testcanvas.MustApply(cvs, ft)
				return ft
			},
		},
		{
			desc:     "horizontal split, children have borders",
			termSize: image.Point{10, 10},
			container: func(ft *faketerm.Terminal) *Container {
				return New(
					ft,
					SplitHorizontal(
						Top(
							Border(draw.LineStyleLight),
						),
						Bottom(
							Border(draw.LineStyleLight),
						),
					),
				)
			},
			want: func(size image.Point) *faketerm.Terminal {
				ft := faketerm.MustNew(size)
				cvs := testcanvas.MustNew(ft.Area())
				testdraw.MustBox(cvs, image.Rect(0, 0, 10, 5), draw.LineStyleLight)
				testdraw.MustBox(cvs, image.Rect(0, 5, 10, 10), draw.LineStyleLight)
				testcanvas.MustApply(cvs, ft)
				return ft
			},
		},
		{
			desc:     "horizontal split, parent and children have borders",
			termSize: image.Point{10, 10},
			container: func(ft *faketerm.Terminal) *Container {
				return New(
					ft,
					Border(draw.LineStyleLight),
					SplitHorizontal(
						Top(
							Border(draw.LineStyleLight),
						),
						Bottom(
							Border(draw.LineStyleLight),
						),
					),
				)
			},
			want: func(size image.Point) *faketerm.Terminal {
				ft := faketerm.MustNew(size)
				cvs := testcanvas.MustNew(ft.Area())
				testdraw.MustBox(
					cvs,
					image.Rect(0, 0, 10, 10),
					draw.LineStyleLight,
					cell.FgColor(cell.ColorYellow),
				)
				testdraw.MustBox(cvs, image.Rect(1, 1, 9, 5), draw.LineStyleLight)
				testdraw.MustBox(cvs, image.Rect(1, 5, 9, 9), draw.LineStyleLight)
				testcanvas.MustApply(cvs, ft)
				return ft
			},
		},
		{
			desc:     "vertical split, children have borders",
			termSize: image.Point{10, 10},
			container: func(ft *faketerm.Terminal) *Container {
				return New(
					ft,
					SplitVertical(
						Left(
							Border(draw.LineStyleLight),
						),
						Right(
							Border(draw.LineStyleLight),
						),
					),
				)
			},
			want: func(size image.Point) *faketerm.Terminal {
				ft := faketerm.MustNew(size)
				cvs := testcanvas.MustNew(ft.Area())
				testdraw.MustBox(cvs, image.Rect(0, 0, 5, 10), draw.LineStyleLight)
				testdraw.MustBox(cvs, image.Rect(5, 0, 10, 10), draw.LineStyleLight)
				testcanvas.MustApply(cvs, ft)
				return ft
			},
		},
		{
			desc:     "vertical split, parent and children have borders",
			termSize: image.Point{10, 10},
			container: func(ft *faketerm.Terminal) *Container {
				return New(
					ft,
					Border(draw.LineStyleLight),
					SplitVertical(
						Left(
							Border(draw.LineStyleLight),
						),
						Right(
							Border(draw.LineStyleLight),
						),
					),
				)
			},
			want: func(size image.Point) *faketerm.Terminal {
				ft := faketerm.MustNew(size)
				cvs := testcanvas.MustNew(ft.Area())
				testdraw.MustBox(
					cvs,
					image.Rect(0, 0, 10, 10),
					draw.LineStyleLight,
					cell.FgColor(cell.ColorYellow),
				)
				testdraw.MustBox(cvs, image.Rect(1, 1, 5, 9), draw.LineStyleLight)
				testdraw.MustBox(cvs, image.Rect(5, 1, 9, 9), draw.LineStyleLight)
				testcanvas.MustApply(cvs, ft)
				return ft
			},
		},
		{
			desc:     "multi level split",
			termSize: image.Point{10, 16},
			container: func(ft *faketerm.Terminal) *Container {
				return New(
					ft,
					SplitVertical(
						Left(
							SplitHorizontal(
								Top(
									Border(draw.LineStyleLight),
								),
								Bottom(
									SplitHorizontal(
										Top(
											Border(draw.LineStyleLight),
										),
										Bottom(
											Border(draw.LineStyleLight),
										),
									),
								),
							),
						),
						Right(
							Border(draw.LineStyleLight),
						),
					),
				)
			},
			want: func(size image.Point) *faketerm.Terminal {
				ft := faketerm.MustNew(size)
				cvs := testcanvas.MustNew(ft.Area())
				testdraw.MustBox(cvs, image.Rect(0, 0, 5, 8), draw.LineStyleLight)
				testdraw.MustBox(cvs, image.Rect(0, 8, 5, 12), draw.LineStyleLight)
				testdraw.MustBox(cvs, image.Rect(0, 12, 5, 16), draw.LineStyleLight)
				testdraw.MustBox(cvs, image.Rect(5, 0, 10, 16), draw.LineStyleLight)
				testcanvas.MustApply(cvs, ft)
				return ft
			},
		},
		{
			desc:     "inherits border and focused color",
			termSize: image.Point{10, 10},
			container: func(ft *faketerm.Terminal) *Container {
				return New(
					ft,
					Border(draw.LineStyleLight),
					BorderColor(cell.ColorRed),
					FocusedColor(cell.ColorBlue),
					SplitVertical(
						Left(
							Border(draw.LineStyleLight),
						),
						Right(
							Border(draw.LineStyleLight),
						),
					),
				)
			},
			want: func(size image.Point) *faketerm.Terminal {
				ft := faketerm.MustNew(size)
				cvs := testcanvas.MustNew(ft.Area())
				testdraw.MustBox(
					cvs,
					image.Rect(0, 0, 10, 10),
					draw.LineStyleLight,
					cell.FgColor(cell.ColorBlue),
				)
				testdraw.MustBox(
					cvs,
					image.Rect(1, 1, 5, 9),
					draw.LineStyleLight,
					cell.FgColor(cell.ColorRed),
				)
				testdraw.MustBox(
					cvs,
					image.Rect(5, 1, 9, 9),
					draw.LineStyleLight,
					cell.FgColor(cell.ColorRed),
				)
				testcanvas.MustApply(cvs, ft)
				return ft
			},
		},
		{
			desc:     "splitting a container removes the widget",
			termSize: image.Point{10, 10},
			container: func(ft *faketerm.Terminal) *Container {
				return New(
					ft,
					Border(draw.LineStyleLight),
					PlaceWidget(fakewidget.New(widgetapi.Options{})),
					SplitVertical(
						Left(
							Border(draw.LineStyleLight),
						),
						Right(
							Border(draw.LineStyleLight),
						),
					),
				)
			},
			want: func(size image.Point) *faketerm.Terminal {
				ft := faketerm.MustNew(size)
				cvs := testcanvas.MustNew(ft.Area())
				testdraw.MustBox(
					cvs,
					ft.Area(),
					draw.LineStyleLight,
					cell.FgColor(cell.ColorYellow),
				)
				testdraw.MustBox(cvs, image.Rect(1, 1, 5, 9), draw.LineStyleLight)
				testdraw.MustBox(cvs, image.Rect(5, 1, 9, 9), draw.LineStyleLight)
				testcanvas.MustApply(cvs, ft)
				return ft
			},
		},
		{
			desc:     "placing a widget removes container split",
			termSize: image.Point{10, 10},
			container: func(ft *faketerm.Terminal) *Container {
				return New(
					ft,
					SplitVertical(
						Left(
							Border(draw.LineStyleLight),
						),
						Right(
							Border(draw.LineStyleLight),
						),
					),
					PlaceWidget(fakewidget.New(widgetapi.Options{})),
				)
			},
			want: func(size image.Point) *faketerm.Terminal {
				ft := faketerm.MustNew(size)
				cvs := testcanvas.MustNew(ft.Area())
				testdraw.MustBox(cvs, image.Rect(0, 0, 10, 10), draw.LineStyleLight)
				testdraw.MustText(cvs, "(10,10)", draw.TextBounds{Start: image.Point{1, 1}})
				testcanvas.MustApply(cvs, ft)
				return ft
			},
		},
	}

	for _, tc := range tests {
		t.Run(tc.desc, func(t *testing.T) {
			got, err := faketerm.New(tc.termSize)
			if err != nil {
				t.Fatalf("faketerm.New => unexpected error: %v", err)
			}

			if err := tc.container(got).Draw(); err != nil {
				t.Fatalf("Draw => unexpected error: %v", err)
			}

			if diff := faketerm.Diff(tc.want(tc.termSize), got); diff != "" {
				t.Errorf("Draw => %v", diff)
			}
		})
	}

}

// TODO(mum4k) Add missing tests (Keyboard):
// Keyboard event isn't forwarded if container has no widget.
// Keyboard event gets forwarded to focused widget.
// Keyboard event isn't forwarded if widget didn't request it.
// Widget returns an error when receiving the keyboard event.

// TODO(mum4k) Add missing tests (Mouse):
// Mouse event isn't forwarded if container has no widget.
// Mouse event is forwarded to container at that point.
// Mouse event isn't forwarded if widget didn't request it.
// Mouse event isn't forwarded if it falls outside of widget's usable area.
// Mouse coordinates are relative to widget's canvas.
// Widget returns an error when receiving the mouse event.