package ui

import (
	"image/color"

	rl "github.com/gen2brain/raylib-go/raylib"
)

var defaultGridPadding float32 = 0
var defaultGridRoundness float32 = 0

var defaultGridStyle = &Style {
	BacgroundColor:	&color.RGBA{0, 0, 0, 0},
	FontColor:		&rl.DarkGray,
	Padding:		&defaultGridPadding,
	Roundness:		&defaultGridRoundness,
}

type GridRow struct {
	// A portion of the screen the row will occupy. Works similar to CSS's 'flex-grow'
	HeightWeight float32
	// The objects that lay in this row
	Objects []UIElement
	// Spaces between the columns
	Spacing float32
	// Styling preferences
	Style *Style

	location rl.Rectangle
	cache layoutCache
}

func (base *GridRow) GetElements() []UIElement {
	return base.Objects
}

func (base *GridRow) GetSpacing() float32 {
	return base.Spacing
}

func (base *GridRow) Init(parent *Menu) {
	base.Style = InitStyle(base.Style, defaultGridStyle)
	for _, v := range base.Objects {
		v.Init(parent)
	}
	base.cache = layoutCache {
		ScreenResolution: rl.Vector2{ X:0, Y:0 },
	}
}

func (base *GridRow) Destroy() {
}

// Gets the scale width of the element. Works similar to CSS's 'flex-grow'
func (base *GridRow) GetOccupationWeight() float32 {
	return base.HeightWeight
}

// Draw the element with the given size
func (base *GridRow) Draw(span *rl.Rectangle) {
	if !base.cache.IsValid() {
		base.RecalculateCache(span)
	}
	for i, v := range base.Objects {
		var offset = base.cache.RowLocations[i]
		var elemSpan = rl.Rectangle {
			X: offset.X,
			Y: span.Y + *base.Style.Padding,
			Width: offset.Y,
			Height: span.Height - *base.Style.Padding * 2,
		}
		v.Draw(&elemSpan)
	}
}

func (base *GridRow) RecalculateCache(span *rl.Rectangle) {
	base.cache.SpanResolution = rl.Vector2{ 
		X: span.Width,
		Y: span.Height,
	}
	base.cache.ScreenResolution = rl.Vector2 {
		X: float32(rl.GetScreenWidth()),
		Y: float32(rl.GetScreenHeight()),
	}
	base.cache.CalculateOffsets(span.Width, span.Height, *base.Style.Padding, *base.Style.Padding)
	var weightToScale = getWeightToPixelsRatio(base, base.cache.Width)
	var spacingPx = base.Spacing * span.Width
	rl.TraceLog(rl.LogInfo, "Spacing: %v (%v px)", base.Spacing, spacingPx)
	base.cache.CalculateRowsLocations(base.Objects, weightToScale, spacingPx, span.X)
}