/*
 *
 * VISEQ - Visual Sequencer
 * 2024 Sebastian Kujas
 *
*/

#include "graph-manager.h"
#include "node.h"
#include "vmath.h"
#include <filesystem>
#include <fstream>
#define RAYGUI_IMPLEMENTATION
#include <raylib.h>
#include <raymath.h>

#include "state-manager.h"
#include "datatypes.h"
#include "midi-node.h"

#include "nlohmann/json.hpp"

#include <cstdlib>
#include <stdio.h>
#include <cmath>
#include <ranges>
#include <algorithm>
#include <iterator>
#include <memory>

#include "state-io.h"

using json = nlohmann::json;

VISEQ::APP::AppState app;

Vec2Df mouse_pos;
Vec2Df drag_start;

Camera2D camera = { {0} };

bool mouse_clicked = false;
bool mouse_touched = false;
bool mouse_dragging = false;

int main(){

	srand(time(NULL));

	InitWindow(1920, 1080, "VISEQ - The Visual Sequencer");

	int current_monitor = GetCurrentMonitor();
	int monitor_width = GetMonitorWidth(current_monitor);
	int monitor_height = GetMonitorHeight(current_monitor);
	
	SetWindowMonitor(current_monitor);
	SetWindowState(FLAG_WINDOW_RESIZABLE);
	
	SetWindowSize(monitor_width - 300, monitor_height - 300);

	//ToggleFullscreen();

	app.ui.init();

	app.settings.fps = 60.0f;
	app.settings.bpm = 120.0f;
	app.settings.grid = 60.0f; // 120px for a 16th note

	app.settings.speed = (app.settings.grid * 16.0f) * (app.settings.bpm / 120.f);

	app.settings.width = monitor_width - 300;
	app.settings.height = monitor_height - 300;
	
	SetTargetFPS(app.settings.fps);

    camera.target = (Vector2){ app.settings.width/2.0f, app.settings.height/2.0f };
    camera.offset = (Vector2){ app.settings.width/2.0f, app.settings.height/2.0f };
    camera.rotation = 0.0f;
    camera.zoom = 1.0f;	

	if(std::filesystem::exists("state.json")){
		std::ifstream f("state.json");
		json graph = json::parse(f);

		app.settings = graph.at("settings");

//		app.gm = graph["graphmanager"].get<VISEQ::GRAPH::GraphManager>();
		int highest_id = 0;
		std::shared_ptr<Node> hid;
		for(auto n : graph.at("graphmanager").at("nodes")){
			std::shared_ptr<MidiNode> mn = n;
			app.gm.nodes.push_back(mn);
			if(mn->id > highest_id) {
				highest_id = mn->id;
				hid = mn;
			}
			std::cout << std::format("adding node {}", mn->id) << std::endl;
		}

		for(auto e : graph.at("graphmanager").at("edges")){
			int start_id = e.at("start").get<int>();
			int end_id = e.at("end").get<int>();

			VEC_SPTR_Node start = app.gm.nodes | RANGE_FILTER([start_id](SPTR_Node n){return n->id == start_id;}) | std::ranges::to<VEC_SPTR_Node>();			
			VEC_SPTR_Node end = app.gm.nodes | RANGE_FILTER([end_id](SPTR_Node n){return n->id == end_id;}) | std::ranges::to<VEC_SPTR_Node>();

			if(!start.empty() && !end.empty()) {
				std::cout << std::format("connection {} to {}", start_id, end_id) << std::endl;
				app.gm.addConnection(start.front(), end.front());
			}

		}
		
		for(auto s : graph.at("signalmanager").at("signals")){
			int start_id = s.at("start").get<int>();
			int next_id = s.at("next").get<int>();
			int last_id = s.at("last").get<int>();
			std::shared_ptr<VISEQ::SIGNAL::Signal> ms = s;
			
			VEC_SPTR_Node start = app.gm.nodes | RANGE_FILTER([start_id](SPTR_Node n){return n->id == start_id;}) | std::ranges::to<VEC_SPTR_Node>();
			VEC_SPTR_Node last = app.gm.nodes | RANGE_FILTER([last_id](SPTR_Node n){return n->id == last_id;}) | std::ranges::to<VEC_SPTR_Node>();
			VEC_SPTR_Node next = app.gm.nodes | RANGE_FILTER([next_id](SPTR_Node n){return n->id == next_id;}) | std::ranges::to<VEC_SPTR_Node>();
			ms->start = start.front();
			ms->next = next.front();
			ms->last = last.front();
			app.sm.signals.push_back(ms);

			std::cout << std::format("adding signal with start node {}", start_id) << std::endl;
		}
		
	} else {
		for(int i = 0; i < 4; ++i){
			app.gm.addMidiNode(Vec2Df{(float)i * app.settings.grid*4 + 7 * app.settings.grid, 2 * app.settings.grid*4});
		}
		for(int i = 3; i >= 0; --i){
			app.gm.addMidiNode(Vec2Df{(float)i * app.settings.grid*4 + 7 * app.settings.grid, 3 * app.settings.grid*4});
		}

		for(int i = 0; i < 8; ++i){
			app.gm.addConnection(app.gm.nodes[i], app.gm.nodes[(i+1) % 8]);
		}
		app.sm.addSignalAtNode(app.gm.nodes.front());
	}

	app.sm.startSignalThread();

	enum InteractionState {HOVER_CANVAS, HOVER_NODE, HOVER_CONNECTOR, DRAG_NODE, CONNECT_NODE, DRAW_SELECTION, DELETE_SELECTED_NODES, COPY_SELECTED_NODES, PASTE_SELECTED_NODES};
	InteractionState istate = HOVER_CANVAS;

	Vec2Df select_start;
	Rectangle selection;

	VEC_SPTR_Node copied_nodes;
	
	
	while(!WindowShouldClose()){

        BeginDrawing();
        ClearBackground((Color){46,46,46});
        BeginMode2D(camera);

		app.settings.speed = (app.settings.grid * 16.0f) * (app.settings.bpm / 120.f);
				
		Vector2 mp = GetScreenToWorld2D(GetMousePosition(), camera);
		Vec2Df mouse_pos = {(float)mp.x, (float)mp.y};
		Vec2Df cam_pos = {camera.offset.x, camera.offset.y};

		bool mouse_down = IsMouseButtonDown(MOUSE_BUTTON_LEFT);
		bool mouse_clicked = IsMouseButtonPressed(MOUSE_BUTTON_LEFT);
		bool mouse_released = IsMouseButtonReleased(MOUSE_BUTTON_LEFT);
		
		bool mouse_right_down = IsMouseButtonDown(MOUSE_BUTTON_RIGHT);
		bool mouse_right_clicked = IsMouseButtonPressed(MOUSE_BUTTON_RIGHT);
		bool mouse_right_released = IsMouseButtonReleased(MOUSE_BUTTON_RIGHT);

		Vec2Df mouse_delta = {GetMouseDelta().x, GetMouseDelta().y};
        Vec2Df delta = mouse_delta * (-1.0f/camera.zoom);
		
		auto dragging_nodes = app.gm.nodes | RANGE_FILTER([](SPTR_Node n) { return n->dragging;});
		auto connecting_nodes = app.gm.nodes | RANGE_FILTER([](SPTR_Node n) { return n->connecting;});
		auto selected_nodes = app.gm.nodes | RANGE_FILTER([](SPTR_Node n) { return n->selected && !n->dragging;}) | std::ranges::to<VEC_SPTR_Node>();
		auto hovering_nodes = app.gm.nodes | RANGE_FILTER([&mouse_pos](SPTR_Node n) { return CheckCollisionPointCircle(mouse_pos, n->position, n->radius);});
		auto hovering_connectors = app.gm.nodes | RANGE_FILTER([&mouse_pos](SPTR_Node n) { return CheckCollisionPointCircle(mouse_pos, (n->position - ((n->position - mouse_pos)).norm() * (n->radius + 14.0f)), 8.0f);});

		for(auto &n : app.gm.nodes ){
			if(hovering_nodes.empty()) n->hovering = false;
			if(hovering_connectors.empty()) n->hover_connect = false;
		}

		if(!mouse_down && !mouse_right_down && dragging_nodes.empty() && connecting_nodes.empty() && hovering_nodes.empty() && hovering_connectors.empty()) istate = InteractionState::HOVER_CANVAS;
		if((mouse_clicked || mouse_down || mouse_released) && !mouse_right_down && dragging_nodes.empty() && connecting_nodes.empty() && hovering_nodes.empty() && hovering_connectors.empty()) istate = InteractionState::DRAW_SELECTION;

		if(!hovering_nodes.empty() && !mouse_down && !mouse_right_down) istate = InteractionState::HOVER_NODE;
		if(!dragging_nodes.empty()) istate = InteractionState::DRAG_NODE; 
		if(!hovering_connectors.empty() && !mouse_right_down && istate == InteractionState::HOVER_CANVAS) istate = InteractionState::HOVER_CONNECTOR;
		if(!connecting_nodes.empty()) istate = InteractionState::CONNECT_NODE;

		if(!selected_nodes.empty() && IsKeyPressed(KEY_DELETE)) istate = InteractionState::DELETE_SELECTED_NODES;
		if(!selected_nodes.empty() && IsKeyDown(KEY_LEFT_CONTROL) && IsKeyPressed(KEY_C)) istate = InteractionState::COPY_SELECTED_NODES;
		
		if(!copied_nodes.empty() && IsKeyDown(KEY_LEFT_CONTROL) && IsKeyPressed(KEY_V)) istate = InteractionState::PASTE_SELECTED_NODES;

		if(IsKeyPressed(KEY_TAB)) {
			app.settings.mode = (app.settings.mode + 1) % 3;
			app.gm.setNodeMode(app.settings.mode);
		}

		switch(istate){
			case InteractionState::HOVER_CANVAS:
			{
				for(auto &n : app.gm.nodes){	
					n->hover_connect = false;
				}
				if(mouse_right_down) {
		            camera.target = Vector2Add(camera.target, delta);
				}
				break;
			}
			case InteractionState::DRAW_SELECTION:
			{
				if(mouse_clicked){
					select_start = mouse_pos;
				}
				if(mouse_down){
					Vec2Df select1 = {mouse_pos.x > select_start.x ? select_start.x : mouse_pos.x, mouse_pos.y > select_start.y ? select_start.y : mouse_pos.y};
					Vec2Df select2 = {mouse_pos.x > select_start.x ? mouse_pos.x - select_start.x : select_start.x - mouse_pos.x, mouse_pos.y > select_start.y ? mouse_pos.y - select_start.y : select_start.y - mouse_pos.y};
					DrawRectangleLines(select1.x, select1.y, select2.x, select2.y, (Color){150,150,150,150});
					selection = (Rectangle){select1.x, select1.y, select2.x, select2.y};

					for(auto& n : app.gm.nodes){
						if(CheckCollisionPointRec(n->position, selection)) {
							n->in_rect = true;
						} else {
							n->in_rect = false;
						}
					}
				}

				if(mouse_released){	
					int n_selected = 0;
					for(auto& n : app.gm.nodes){
						if(CheckCollisionPointRec(n->position, selection)) {
							n->selected = true;
							n->in_rect = false;
							n_selected++;
						} else {
							if(!IsKeyDown(KEY_LEFT_SHIFT)) n->selected = false;
						}
					}
					if(n_selected > 0) copied_nodes.clear();
					selection = (Rectangle){0,0,0,0};
				}
				break;
			}
			case InteractionState::HOVER_NODE:
			{
				if(mouse_clicked) {
					if(IsKeyDown(KEY_LEFT_SHIFT)) {
						hovering_nodes.front()->selected = true;
					} else {
						hovering_nodes.front()->dragging = true;
						hovering_nodes.front()->drag_offset = hovering_nodes.front()->position - mouse_pos;
					}
				}
				if(mouse_right_clicked) hovering_nodes.front()->config = true;
				break;
			}
			case InteractionState::DRAG_NODE:
			{
				if(!dragging_nodes.empty()){
					SPTR_Node dragNode = dragging_nodes.front();
					
					for(auto &n : selected_nodes){
						if(!n->picked_up) n->drag_offset = n->position - dragNode->position;
						n->picked_up = true;
					}
					
					if(IsKeyDown(KEY_LEFT_CONTROL)) {
						dragNode->position.x = round((mouse_pos.x + dragNode->drag_offset.x) / app.settings.grid) * app.settings.grid;
						dragNode->position.y = round((mouse_pos.y + dragNode->drag_offset.y) / app.settings.grid) * app.settings.grid;
					} else if(IsKeyDown(KEY_LEFT_SHIFT)){
						float steps = round((dragNode->neighbor->position.dist(mouse_pos)) / app.settings.grid) * app.settings.grid;
						float pol_r = steps;
						float pol_theta = Vector2Angle(Vec2Df{1,0},(mouse_pos - dragNode->neighbor->position));

						Vec2Df polar = VISEQ::VMATH::polarToCartesian(pol_r, pol_theta); 
						dragNode->position = dragNode->neighbor->position + polar;
					} else {
						dragNode->position = mouse_pos + dragNode->drag_offset;
					}
					
					for(auto &n : selected_nodes){
						n->position = dragNode->position + n->drag_offset;
					}
				
					if(mouse_released) {
						for(auto &n : dragging_nodes){
							n->dragging = false;
							n->picked_up = false;
						}
						for(auto &n : selected_nodes){
							n->picked_up = false;
							n->dragging = false;
						}
					}
				}
				break;
			}
			case InteractionState::HOVER_CONNECTOR:
			{
				if(!hovering_connectors.empty()){
					hovering_connectors.front()->hover_connect = true;
					if(mouse_clicked) hovering_connectors.front()->connecting = true;
				}
				break;
			}
			case InteractionState::CONNECT_NODE:
			{
				Vec2Df connector_position = connecting_nodes.front()->position - ((connecting_nodes.front()->position - mouse_pos)).norm() * (connecting_nodes.front()->radius + 14.0f);
				Vec2Df target_position = mouse_pos;

				if(IsKeyDown(KEY_LEFT_CONTROL)) {
					target_position.x = round((mouse_pos.x) / app.settings.grid) * app.settings.grid;
					target_position.y = round((mouse_pos.y) / app.settings.grid) * app.settings.grid;
				} else if(IsKeyDown(KEY_LEFT_SHIFT)){
					std::shared_ptr<Node> closest = app.gm.getClosestNode(mouse_pos);
					float steps = round((closest->position.dist(mouse_pos)) / app.settings.grid) * app.settings.grid;
					float pol_r = steps;
					float pol_theta = Vector2Angle(Vec2Df{1,0},(mouse_pos - closest->position));

					Vec2Df polar = VISEQ::VMATH::polarToCartesian(pol_r, pol_theta); 
					target_position = closest->position + polar;
				} else {
					target_position = mouse_pos;
				}
			
				if(connecting_nodes.front()->connecting && mouse_down){
					DrawLine(connector_position.x, connector_position.y, target_position.x, target_position.y, (Color){229, 181, 103, 255});
					connecting_nodes.front()->hovering = true;
					connecting_nodes.front()->hover_connect = true;
				}

				if(!hovering_connectors.empty()) {
					hovering_connectors.front()->hovering = true;
					hovering_connectors.front()->hover_connect = true;
				}
				if(!hovering_nodes.empty()) hovering_nodes.front()->hovering = true;

				if(mouse_released) {
					if(&hovering_nodes.front() != &connecting_nodes.front() && &connecting_nodes.front() != &hovering_connectors.front()){
						if(!hovering_nodes.empty()){
							app.gm.addConnection(connecting_nodes.front(), hovering_nodes.front());
						} else if(!hovering_connectors.empty()){
							app.gm.addConnection(connecting_nodes.front(), hovering_connectors.front());
						} else {
							SPTR_Node new_node = app.gm.copyNode(std::dynamic_pointer_cast<MidiNode>(connecting_nodes.front()), target_position);
							new_node->connecting = false;
							app.gm.addConnection(connecting_nodes.front(), new_node);
						}
					}
					connecting_nodes.front()->connecting = false;
					istate = InteractionState::HOVER_CANVAS;
				}
				break;
			}
			case InteractionState::DELETE_SELECTED_NODES:
			{
				app.removeNodes(selected_nodes | std::ranges::to<VEC_SPTR_Node>());
				break;
			}
			case InteractionState::COPY_SELECTED_NODES:
			{
				std::ranges::copy(selected_nodes.begin(), selected_nodes.end(), std::back_inserter(copied_nodes));
				std::ranges::for_each(selected_nodes.begin(), selected_nodes.end(), [](SPTR_Node n){n->selected = false;});
				selected_nodes.clear();
				break;
			}
			case InteractionState::PASTE_SELECTED_NODES:
			{
				for(auto n: copied_nodes){
					n->drag_offset = (n->position - copied_nodes.front()->position);
				}
				app.copyNodesAndConnections(copied_nodes, mouse_pos);
				//copied_nodes.clear();
				break;
			}
		};

		float wheel = GetMouseWheelMove();
		if(wheel != 0){
			if(!hovering_nodes.empty() && hovering_nodes.front()->getNodeType() == NodeType::MIDINODE) {
				VEC_SPTR_Node modify_nodes;
				std::copy_if(selected_nodes.begin(), selected_nodes.end(), std::back_inserter(modify_nodes), [](SPTR_Node n){ return n->getNodeType() == NodeType::MIDINODE;});
				if(selected_nodes.empty()) std::copy_if(hovering_nodes.begin(), hovering_nodes.end(), std::back_inserter(modify_nodes), [modify_nodes](SPTR_Node n){ return n->getNodeType() == NodeType::MIDINODE && !std::ranges::contains(modify_nodes, n);});

				for(auto n : modify_nodes){
					std::shared_ptr<MidiNode> midiNode = std::dynamic_pointer_cast<MidiNode>(n);
					if(IsKeyDown(KEY_LEFT_CONTROL) && !IsKeyDown(KEY_LEFT_ALT)){
						switch(app.settings.mode){
							case 0:{
								midiNode->midi_note += wheel;
							break;}
							case 1:{
								midiNode->midi_cc += wheel;
							break;}
							case 2:{
								midiNode->midi_pitch_bend += wheel;
							break;}
						};
						if(midiNode->midi_note < 0 ) midiNode->midi_note = VISEQ::MIDI::Notes.size()-1;
						if(midiNode->midi_note >= VISEQ::MIDI::Notes.size() ) midiNode->midi_note = 0;
						
						if(midiNode->midi_cc < 0 ) midiNode->midi_cc = 127;
						if(midiNode->midi_cc > 127 ) midiNode->midi_cc = 0;
					
						if(midiNode->midi_pitch_bend < 0 ) midiNode->midi_pitch_bend = 0;
						if(midiNode->midi_pitch_bend > 16383 ) midiNode->midi_pitch_bend = 16383;

					} else if(IsKeyDown(KEY_LEFT_SHIFT) && !IsKeyDown(KEY_LEFT_ALT)) {
						midiNode->midi_velocity += wheel;
						if(midiNode->midi_velocity < 0 ) midiNode->midi_velocity = 127;
						if(midiNode->midi_velocity > 127 ) midiNode->midi_velocity = 0; 
					} else if(IsKeyDown(KEY_LEFT_ALT)) {
						switch(app.settings.mode){
							case 0:{
								float incr = (float)wheel * (IsKeyDown(KEY_LEFT_SHIFT) ? 100.0f : IsKeyDown(KEY_LEFT_CONTROL) ? 1000.0f : 10.0f);
								midiNode->midi_gate += incr;
								if(midiNode->midi_gate < 0 ) midiNode->midi_gate = 0;
							break;}
							case 1:{
								midiNode->midi_cc_value += wheel;
								if(midiNode->midi_cc_value < 0 ) midiNode->midi_cc_value = 0;
								if(midiNode->midi_cc_value > 127 ) midiNode->midi_cc_value = 127;
							break;}
							case 2:{
								float incr = (float)wheel * (IsKeyDown(KEY_LEFT_SHIFT) ? 100.0f : IsKeyDown(KEY_LEFT_CONTROL) ? 1000.0f : 10.0f);
								midiNode->midi_pitch_bend += incr;
								if(midiNode->midi_pitch_bend < 0 ) midiNode->midi_pitch_bend = 0;
								if(midiNode->midi_pitch_bend > 16383 ) midiNode->midi_pitch_bend = 16383;
							break;}
						};
					}
				}
			}
			if(!IsKeyDown(KEY_LEFT_SHIFT) && !IsKeyDown(KEY_LEFT_CONTROL) && !IsKeyDown(KEY_LEFT_ALT)){
				Vector2 mouseWorldPos = GetScreenToWorld2D(GetMousePosition(), camera);
				camera.offset = GetMousePosition();
				camera.target = mouseWorldPos;
				float scaleFactor = 1.0f + (0.25f*fabsf(wheel));
				if (wheel < 0) scaleFactor = 1.0f/scaleFactor;
				camera.zoom = Clamp(camera.zoom*scaleFactor, 0.125f, 64.0f);
			}
		}

		for(int x = -app.settings.grid*100; x < app.settings.grid*100; x+=app.settings.grid){
			for(int y = -app.settings.grid*100; y < app.settings.grid*100; y+=app.settings.grid){
				DrawPixel(x, y, (Color){130,130,130,200});
			}
		}
	
		app.draw(mouse_pos, camera);

		EndMode2D();

		app.drawUI(&mouse_pos, &camera);

		EndDrawing();
	}

	std::ofstream file("state.json");
	file << json(app);

 	std::cout << std::setw(4) << json(app) << std::endl;
	
	CloseWindow();

	return 0;
}