package ui

import (
	"testing"

	"github.com/gdamore/tcell/v2"
)

func TestPainterDrawsText(t *testing.T) {
	screen, p := newTestScreen(t, 20, 3)

	p.Text(2, 1, "hello", tcell.StyleDefault)
	screen.Show()

	if got := screenLines(t, screen)[1]; got != "  hello             " {
		t.Errorf("row 1 = %q", got)
	}
}

func TestPainterClipsToItsRegion(t *testing.T) {
	screen, root := newTestScreen(t, 20, 5)

	// A painter for a 5-wide box: the text must be cut off at its edge rather
	// than spilling across the rest of the row.
	box := root.Sub(Rect{X: 2, Y: 1, W: 5, H: 1})
	box.Text(0, 0, "abcdefghij", tcell.StyleDefault)
	screen.Show()

	if got := screenLines(t, screen)[1]; got != "  abcde             " {
		t.Errorf("row 1 = %q, want the text clipped at column 7", got)
	}
}

func TestPainterClipsNegativeCoordinates(t *testing.T) {
	screen, root := newTestScreen(t, 10, 3)
	box := root.Sub(Rect{X: 2, Y: 1, W: 4, H: 1})

	box.SetCell(-5, 0, 'X', tcell.StyleDefault)
	box.SetCell(0, -1, 'Y', tcell.StyleDefault)
	screen.Show()

	lines := screenLines(t, screen)
	for _, line := range lines {
		for _, r := range line {
			if r == 'X' || r == 'Y' {
				t.Errorf("a character escaped the painter's region: %v", lines)
			}
		}
	}
}

func TestSubPainterInheritsItsParentsClip(t *testing.T) {
	screen, root := newTestScreen(t, 20, 5)

	outer := root.Sub(Rect{X: 0, Y: 0, W: 6, H: 5})
	// The child asks for a region reaching past the parent, so its drawing
	// must still stop at the parent's edge.
	inner := outer.Sub(Rect{X: 3, Y: 2, W: 15, H: 1})
	inner.Text(0, 0, "XXXXXXXXXX", tcell.StyleDefault)
	screen.Show()

	if got := screenLines(t, screen)[2]; got != "   XXX              " {
		t.Errorf("row 2 = %q, want the child clipped by its parent", got)
	}
}

func TestPainterSizeIsItsOwnRegion(t *testing.T) {
	_, root := newTestScreen(t, 40, 12)

	if got := root.Size(); got != (Rect{W: 40, H: 12}) {
		t.Errorf("root Size() = %+v", got)
	}
	if got := root.Sub(Rect{X: 5, Y: 5, W: 7, H: 3}).Size(); got != (Rect{W: 7, H: 3}) {
		t.Errorf("sub Size() = %+v, want the region's own size at the origin", got)
	}
}

func TestPainterFillAndClear(t *testing.T) {
	screen, root := newTestScreen(t, 8, 3)

	root.Clear(tcell.StyleDefault)
	root.Fill(Rect{X: 1, Y: 1, W: 3, H: 1}, '#', tcell.StyleDefault)
	screen.Show()

	if got := screenLines(t, screen)[1]; got != " ###    " {
		t.Errorf("row 1 = %q", got)
	}
}

func TestPainterLines(t *testing.T) {
	screen, root := newTestScreen(t, 6, 4)

	root.HLine(1, 0, 4, '-', tcell.StyleDefault)
	root.VLine(0, 1, 3, '|', tcell.StyleDefault)
	screen.Show()

	lines := screenLines(t, screen)
	if lines[0] != " ---- " {
		t.Errorf("row 0 = %q", lines[0])
	}
	for y := 1; y < 4; y++ {
		if lines[y][0] != '|' {
			t.Errorf("row %d = %q, want a vertical line at column 0", y, lines[y])
		}
	}
}

func TestTextLimitedAddsAnEllipsis(t *testing.T) {
	screen, root := newTestScreen(t, 20, 2)

	root.TextLimited(0, 0, 6, "a-very-long-name.go", tcell.StyleDefault)
	root.TextLimited(0, 1, 10, "short.go", tcell.StyleDefault)
	screen.Show()

	lines := screenLines(t, screen)
	if got := string([]rune(lines[0])[:6]); got != "a-ver…" {
		t.Errorf("row 0 = %q, want it cut to six cells with an ellipsis", got)
	}
	if lines[1][:8] != "short.go" {
		t.Errorf("row 1 = %q, want it drawn whole", lines[1])
	}
}

func TestTextLimitedWithNoRoomDrawsNothing(t *testing.T) {
	screen, root := newTestScreen(t, 5, 1)

	if got := root.TextLimited(2, 0, 0, "hello", tcell.StyleDefault); got != 2 {
		t.Errorf("TextLimited returned %d, want the column it was given back", got)
	}
	screen.Show()
	if got := screenLines(t, screen)[0]; got != "     " {
		t.Errorf("row 0 = %q, want nothing drawn", got)
	}
}

func TestShadeKeepsTheCharactersAndChangesTheStyle(t *testing.T) {
	screen, root := newTestScreen(t, 6, 2)
	shadow := tcell.StyleDefault.Foreground(tcell.ColorGray)

	root.Text(0, 0, "abcdef", tcell.StyleDefault)
	root.Shade(Rect{X: 2, Y: 0, W: 2, H: 1}, shadow)
	screen.Show()

	if got := screenLines(t, screen)[0]; got != "abcdef" {
		t.Errorf("row 0 = %q, want the characters untouched", got)
	}
	if got := styleAt(t, screen, 2, 0); got != shadow {
		t.Error("the shaded cell kept its old style")
	}
	if got := styleAt(t, screen, 1, 0); got == shadow {
		t.Error("a cell outside the shaded rectangle was restyled")
	}
}

func TestCellAtOutsideTheClipIsBlank(t *testing.T) {
	_, root := newTestScreen(t, 10, 3)
	box := root.Sub(Rect{X: 1, Y: 1, W: 2, H: 1})

	if r, _ := box.CellAt(9, 9); r != ' ' {
		t.Errorf("CellAt outside the clip returned %q, want a space", r)
	}
}

func TestShowCursorHidesItWhenItFallsOutsideTheClip(t *testing.T) {
	screen, root := newTestScreen(t, 10, 3)
	box := root.Sub(Rect{X: 1, Y: 1, W: 3, H: 1})

	box.ShowCursor(1, 0)
	screen.Show()
	if x, y, visible := screen.GetCursor(); !visible || x != 2 || y != 1 {
		t.Errorf("cursor at (%d, %d) visible=%v, want (2, 1) visible", x, y, visible)
	}

	box.ShowCursor(9, 0)
	screen.Show()
	if _, _, visible := screen.GetCursor(); visible {
		t.Error("the cursor stayed visible although it left the painter's region")
	}
}