// Fill out your copyright notice in the Description page of Project Settings.


#include "ChannelRack.h"

#include "ChannelRackItem.h"
#include "SlateOptMacros.h"
#include "SScrollBox.h"
#include "Singleton/PluginHostList.h"
#include "Pattern/MidiPattern.h"
#include "Singleton/MidiSequencer.h"

BEGIN_SLATE_FUNCTION_BUILD_OPTIMIZATION

void SChannelRack::Construct(const FArguments& InArgs)
{
	FPluginHostList::Get().OnInstrumentHostCreated.AddRaw(this, &SChannelRack::OnInstrumentHostCreated);
	FPluginHostList::Get().OnPluginHostRemoved.AddRaw(this, &SChannelRack::OnInstrumentHostRemoved);
	FPatternSelector::Get().OnPatternSelected.AddRaw(this, &SChannelRack::OnSelectPattern);
	
	for (FPluginHost* PluginHost : FPluginHostList::Get().Instruments)
	{
		OnInstrumentHostCreated(PluginHost);
	}

	ChildSlot
	[
		SAssignNew(ListView, SScrollBox)
		.AnimateWheelScrolling(true)
		.ScrollBarThickness(FVector2D(2, 2))
	];
	
	OnSelectPattern(FPatternSelector::Get().GetSelectedPattern());
}

void SChannelRack::SelectPattern(FMidiPattern* Pattern)
{
	TSharedPtr<SScrollPanel> ScrollPanel = ListView->GetScrollPanel();
	auto& Children = ScrollPanel->Children;
	for (int i = 0; i < Children.Num(); ++i)
	{
		TSharedRef<SChannelRackItem, ESPMode::ThreadSafe> Item = StaticCastSharedRef<SChannelRackItem>(Children.GetChildAt(i));
		Item->SetPattern(Pattern);
	}
}

void SChannelRack::OnSelectPattern(FPattern* Pattern)
{
	if (!Pattern)
		return;
	if (Pattern->Type != EPatternType::Midi)
		return;
	SelectPattern((FMidiPattern*)Pattern);
}

void SChannelRack::UpdateSplitterAPosition(float A)
{
	TSharedPtr<SScrollPanel> ScrollPanel = ListView->GetScrollPanel();
	auto& Children = ScrollPanel->Children;
	for (int i = 0; i < Children.Num(); ++i)
	{
		TSharedPtr<SChannelRackItem, ESPMode::ThreadSafe> Item = StaticCastSharedRef<SChannelRackItem>(Children.GetChildAt(i));
		Item->SetSplliterASize(A);
	}
}

void SChannelRack::UpdateSplitterBPosition(float B)
{
	TSharedPtr<SScrollPanel> ScrollPanel = ListView->GetScrollPanel();
	auto& Children = ScrollPanel->Children;
	for (int i = 0; i < Children.Num(); ++i)
	{
		TSharedPtr<SChannelRackItem, ESPMode::ThreadSafe> Item = StaticCastSharedRef<SChannelRackItem>(Children.GetChildAt(i));
		Item->SetSplliterBSize(B);
	}
}

void SChannelRack::OnInstrumentHostCreated(FPluginHost* PluginHost)
{
	ListView->AddSlot()
	.AutoSize()
	.Padding(0, 0, 0, 10)
	[
		SNew(SChannelRackItem, PluginHost)
		.OnSplliterAPositionChanged(this, &SChannelRack::UpdateSplitterAPosition)
		.OnSplliterBPositionChanged(this, &SChannelRack::UpdateSplitterBPosition)
	];
}

void SChannelRack::OnInstrumentHostRemoved(FPluginHost* PluginHost)
{
	TSharedPtr<SScrollPanel> ScrollPanel = ListView->GetScrollPanel();
	FChildren* Children = ScrollPanel->GetChildren();
	for (int i = 0; i < Children->Num(); ++i)
	{
		const TSharedRef<SChannelRackItem> ChannelRackItem = StaticCastSharedRef<SChannelRackItem>(Children->GetChildAt(i));
		if (ChannelRackItem->GetPluginHost() == PluginHost)
		{
			ListView->RemoveSlot(ChannelRackItem);
			break;
		}
	}
}

END_SLATE_FUNCTION_BUILD_OPTIMIZATION