package widget

import (
	"fmt"
	"image"
	"testing"

	"gioui.org/font"
	"gioui.org/font/gofont"
	"gioui.org/io/key"
	"gioui.org/layout"
	"gioui.org/op"
	"gioui.org/text"
	"gioui.org/unit"
)

func TestSelectableZeroValue(t *testing.T) {
	var s Selectable
	if s.Text() != "" {
		t.Errorf("expected zero value to have no text, got %q", s.Text())
	}
	if start, end := s.Selection(); start != 0 || end != 0 {
		t.Errorf("expected start=0, end=0, got start=%d, end=%d", start, end)
	}
	if selected := s.SelectedText(); selected != "" {
		t.Errorf("expected selected text to be \"\", got %q", selected)
	}
	s.SetCaret(5, 5)
	if start, end := s.Selection(); start != 0 || end != 0 {
		t.Errorf("expected start=0, end=0, got start=%d, end=%d", start, end)
	}
}

// Verify that an existing selection is dismissed when you press arrow keys.
func TestSelectableMove(t *testing.T) {
	gtx := layout.Context{
		Ops:    new(op.Ops),
		Locale: english,
	}
	cache := text.NewShaper(gofont.Collection())
	fnt := font.Font{}
	fontSize := unit.Sp(10)

	str := `0123456789`

	// Layout once to populate e.lines and get focus.
	gtx.Queue = newQueue(key.FocusEvent{Focus: true})
	s := new(Selectable)

	s.SetText(str)
	s.Layout(gtx, cache, font.Font{}, fontSize, op.CallOp{}, op.CallOp{})

	testKey := func(keyName string) {
		// Select 345
		s.SetCaret(3, 6)
		if start, end := s.Selection(); start != 3 || end != 6 {
			t.Errorf("expected start=%d, end=%d, got start=%d, end=%d", 3, 6, start, end)
		}
		if expected, got := "345", s.SelectedText(); expected != got {
			t.Errorf("KeyName %s, expected %q, got %q", keyName, expected, got)
		}

		// Press the key
		gtx.Queue = newQueue(key.Event{State: key.Press, Name: keyName})
		s.SetText(str)
		s.Layout(gtx, cache, fnt, fontSize, op.CallOp{}, op.CallOp{})

		if expected, got := "", s.SelectedText(); expected != got {
			t.Errorf("KeyName %s, expected %q, got %q", keyName, expected, got)
		}
	}

	testKey(key.NameLeftArrow)
	testKey(key.NameRightArrow)
	testKey(key.NameUpArrow)
	testKey(key.NameDownArrow)
}

func TestSelectableConfigurations(t *testing.T) {
	gtx := layout.Context{
		Ops:         new(op.Ops),
		Constraints: layout.Exact(image.Pt(300, 300)),
		Locale:      english,
	}
	cache := text.NewShaper(gofont.Collection())
	fontSize := unit.Sp(10)
	font := font.Font{}
	sentence := "\n\n\n\n\n\n\n\n\n\n\n\nthe quick brown fox jumps over the lazy dog"

	for _, alignment := range []text.Alignment{text.Start, text.Middle, text.End} {
		for _, zeroMin := range []bool{true, false} {
			t.Run(fmt.Sprintf("Alignment: %v ZeroMinConstraint: %v", alignment, zeroMin), func(t *testing.T) {
				defer func() {
					if err := recover(); err != nil {
						t.Error(err)
					}
				}()
				if zeroMin {
					gtx.Constraints.Min = image.Point{}
				} else {
					gtx.Constraints.Min = gtx.Constraints.Max
				}
				s := new(Selectable)
				s.Alignment = alignment
				s.SetText(sentence)
				interactiveDims := s.Layout(gtx, cache, font, fontSize, op.CallOp{}, op.CallOp{})
				staticDims := Label{Alignment: alignment}.Layout(gtx, cache, font, fontSize, sentence, op.CallOp{})

				if interactiveDims != staticDims {
					t.Errorf("expected consistent dimensions, static returned %#+v, interactive returned %#+v", staticDims, interactiveDims)
				}
			})
		}
	}
}