package main

import (
	"github.com/gen2brain/raylib-go/raylib"
)

type Sketch struct {
	layerTools map[string]LayerTools
}

func NewSketch() Sketch {
	return Sketch {
		layerTools: make(map[string]LayerTools),
	}
}

func (s *Sketch) CreateLayer(name string, layer Layer, sourceWidth int32, sourceHeight int32) {
	texture := rl.LoadRenderTexture(sourceWidth, sourceHeight)
	s.layerTools[name] = LayerTools {
		name: name,
		texture: &texture,
		layer: layer,
	}
}

func (s *Sketch) Draw(ctx *RenderCtx) {
	// render onto all layer textures
	for _, instance := range s.layerTools {
		layer := instance.layer
		rl.BeginTextureMode(*instance.texture)
		layer.Draw(ctx)
		rl.EndTextureMode()
	}
	// composite all layers to screen

	src := rl.Rectangle {
		X: 0, Y: 0,
		Width: float32(ctx.SourceWidth),
		Height: -float32(ctx.SourceHeight),
	}
	dst := rl.Rectangle {
		X: 0, Y: 0,
		Width: float32(ctx.TargetWidth),
		Height: float32(ctx.TargetHeight),
	}

	for _, instance := range s.layerTools {
		rl.DrawTexturePro(instance.texture.Texture, src, dst, rl.Vector2{}, 0, rl.White)
	}
	
}

type LayerTools struct {
	name string
	layer Layer
	texture *rl.RenderTexture2D
}


/** Layer **/

type Layer interface {
	Draw(ctx *RenderCtx)
}

type TestPattern struct { }

func (tp *TestPattern) Draw(ctx *RenderCtx) {
	rl.DrawRectangle(0, 0, int32(ctx.SourceWidth), int32(ctx.SourceHeight), rl.Magenta)
	rl.PushMatrix()
	rl.Translatef(float32(ctx.SourceWidth)/2.0, float32(ctx.SourceHeight)/2.0, 0.0)
	rl.DrawRectangle(-100, -100, 200, 200, rl.Green)
	rl.PopMatrix()
}


/** Ports **/

type Ports map[string]Signal

func MakePorts() Ports {
	return make(Ports)
}

/**
 * materialize current value for all ports
 **/
func (p Ports) Eval(t float64) map[string]float64 {
	out := make(map[string]float64, len(p))
	for name, sig := range p {
		out[name] = sig.Eval(t)
	}
	return out
}

/** RenderCtx **/

type RenderCtx struct {
	TargetWidth  int32
	TargetHeight int32
	SourceWidth int32
	SourceHeight int32
	Time   float64
	Ports  map[string]float64
	Cam    rl.Camera2D
}