/*
OneLoneCoder.com - Code-It-Yourself! Racing Game at the command prompt (quick and simple c++)
"Let's go, go, go!!!" - @Javidx9

Disclaimer
~~~~~~~~~~
I don't care what you use this for. It's intended to be educational, and perhaps
to the oddly minded - a little bit of fun. Please hack this, change it and use it
in any way you see fit. BUT, you acknowledge that I am not responsible for anything
bad that happens as a result of your actions. However, if good stuff happens, I
would appreciate a shout out, or at least give the blog some publicity for me.
Cheers!

Background
~~~~~~~~~~
I'm a sim-racer when I'm not coding. Racing games are far more sophisticated than
they used to be. Frankly, retro racing games are a bit naff. But when done in the
command prompt they have a new level of craziness.

Controls
~~~~~~~~
Left Arrow/Right Arrow Steer, Up Arrow accelerates. There are no brakes!
Set the fastest lap times you can!

Author
~~~~~~
Twitter: @javidx9
Blog: www.onelonecoder.com

Video:
~~~~~~
https://youtu.be/KkMZI5Jbf18

Last Updated: 10/07/2017
*/

#include <iostream>
#include <string>
using namespace std;

#include "olcConsoleGameEngine.h"


class OneLoneCoder_FormulaOLC : public olcConsoleGameEngine
{
public:
	OneLoneCoder_FormulaOLC()
	{
		m_sAppName = L"Formula OLC";
	}

private:

	float fDistance = 0.0f;			// Distance car has travelled around track
	float fCurvature = 0.0f;		// Current track curvature, lerped between track sections
	float fTrackCurvature = 0.0f;	// Accumulation of track curvature
	float fTrackDistance = 0.0f;	// Total distance of track

	float fCarPos = 0.0f;			// Current car position
	float fPlayerCurvature = 0.0f;			// Accumulation of player curvature
	float fSpeed = 0.0f;			// Current player speed

	vector<pair<float, float>> vecTrack; // Track sections, sharpness of bend, length of section

	list<float> listLapTimes;		// List of previous lap times
	float fCurrentLapTime;			// Current lap time

protected:
	// Called by olcConsoleGameEngine
	virtual bool OnUserCreate()
	{
		// Define track
		vecTrack.push_back(make_pair(0.0f, 10.0f));		// Short section for start/finish line
		vecTrack.push_back(make_pair(0.0f, 200.0f));
		vecTrack.push_back(make_pair(1.0f, 200.0f));
		vecTrack.push_back(make_pair(0.0f, 400.0f));
		vecTrack.push_back(make_pair(-1.0f, 100.0f));
		vecTrack.push_back(make_pair(0.0f, 200.0f));
		vecTrack.push_back(make_pair(-1.0f, 200.0f));
		vecTrack.push_back(make_pair(1.0f, 200.0f));
		vecTrack.push_back(make_pair(0.0f, 200.0f));
		vecTrack.push_back(make_pair(0.2f, 500.0f));
		vecTrack.push_back(make_pair(0.0f, 200.0f));

		// Calculate total track distance, so we can set lap times
		for (auto t : vecTrack)
			fTrackDistance += t.second;

		listLapTimes = { 0,0,0,0,0 };
		fCurrentLapTime = 0.0f;

		return true;
	}




	// Called by olcConsoleGameEngine
	virtual bool OnUserUpdate(float fElapsedTime)
	{
		// Handle control input
		int nCarDirection = 0;

		if (m_keys[VK_UP].bHeld)
			fSpeed += 2.0f * fElapsedTime;
		else
			fSpeed -= 1.0f * fElapsedTime;

		// Car Curvature is accumulated left/right input, but inversely proportional to speed
		// i.e. it is harder to turn at high speed
		if (m_keys[VK_LEFT].bHeld)
		{
			fPlayerCurvature -= 0.7f * fElapsedTime * (1.0f - fSpeed / 2.0f);
			nCarDirection = -1;
		}

		if (m_keys[VK_RIGHT].bHeld)
		{
			fPlayerCurvature += 0.7f * fElapsedTime * (1.0f - fSpeed / 2.0f);
			nCarDirection = +1;
		}

		// If car curvature is too different to track curvature, slow down
		// as car has gone off track
		if (fabs(fPlayerCurvature - fTrackCurvature) >= 0.8f)
			fSpeed -= 5.0f * fElapsedTime;

		// Clamp Speed
		if (fSpeed < 0.0f)	fSpeed = 0.0f;
		if (fSpeed > 1.0f)	fSpeed = 1.0f;
		
		// Move car along track according to car speed
		fDistance += (70.0f * fSpeed) * fElapsedTime;
		
		// Get Point on track
		float fOffset = 0;
		int nTrackSection = 0;

		// Lap Timing and counting
		fCurrentLapTime += fElapsedTime;
		if (fDistance >= fTrackDistance)
		{
			fDistance -= fTrackDistance;
			listLapTimes.push_front(fCurrentLapTime);
			listLapTimes.pop_back();
			fCurrentLapTime = 0.0f;
		}
		
		// Find position on track (could optimise)
		while (nTrackSection < vecTrack.size() && fOffset <= fDistance)
		{			
			fOffset += vecTrack[nTrackSection].second;
			nTrackSection++;
		}
		
		// Interpolate towards target track curvature
		float fTargetCurvature = vecTrack[nTrackSection - 1].first;
		float fTrackCurveDiff = (fTargetCurvature - fCurvature) * fElapsedTime * fSpeed;

		// Accumulate player curvature
		fCurvature += fTrackCurveDiff;

		// Accumulate track curvature
		fTrackCurvature += (fCurvature) * fElapsedTime * fSpeed;

		// Draw Sky - light blue and dark blue
		for (int y = 0; y < ScreenHeight() / 2; y++)
			for (int x = 0; x < ScreenWidth(); x++)
				Draw(x, y, y< ScreenHeight() / 4 ? PIXEL_HALF : PIXEL_SOLID, FG_DARK_BLUE);

		// Draw Scenery - our hills are a rectified sine wave, where the phase is adjusted by the
		// accumulated track curvature
		for (int x = 0; x < ScreenWidth(); x++)
		{
			int nHillHeight = (int)(fabs(sinf(x * 0.01f + fTrackCurvature) * 16.0f));
			for (int y = (ScreenHeight() / 2) - nHillHeight; y < ScreenHeight() / 2; y++)
				Draw(x, y, PIXEL_SOLID, FG_DARK_YELLOW);
		}


		// Draw Track - Each row is split into grass, clip-board and track
		for (int y = 0; y < ScreenHeight() / 2; y++)
			for (int x = 0; x < ScreenWidth(); x++)
			{
				// Perspective is used to modify the width of the track row segments
				float fPerspective = (float)y / (ScreenHeight()/2.0f);
				float fRoadWidth = 0.1f + fPerspective * 0.8f; // Min 10% Max 90%
				float fClipWidth = fRoadWidth * 0.15f;
				fRoadWidth *= 0.5f;	// Halve it as track is symmetrical around center of track, but offset...

				// ...depending on where the middle point is, which is defined by the current
				// track curvature.
				float fMiddlePoint = 0.5f + fCurvature * powf((1.0f - fPerspective), 3);

				// Work out segment boundaries
				int nLeftGrass = (fMiddlePoint - fRoadWidth - fClipWidth) * ScreenWidth();
				int nLeftClip = (fMiddlePoint - fRoadWidth) * ScreenWidth();
				int nRightClip = (fMiddlePoint + fRoadWidth) * ScreenWidth();
				int nRightGrass = (fMiddlePoint + fRoadWidth + fClipWidth) * ScreenWidth();
				
				int nRow = ScreenHeight() / 2 + y;

				// Using periodic oscillatory functions to give lines, where the phase is controlled
				// by the distance around the track. These take some fine tuning to give the right "feel"
				int nGrassColour = sinf(20.0f *  powf(1.0f - fPerspective,3) + fDistance * 0.1f) > 0.0f ? FG_GREEN : FG_DARK_GREEN;
				int nClipColour = sinf(80.0f *  powf(1.0f - fPerspective, 2) + fDistance) > 0.0f ? FG_RED : FG_WHITE;
				
				// Start finish straight changes the road colour to inform the player lap is reset
				int nRoadColour = (nTrackSection-1) == 0 ? FG_WHITE : FG_GREY;

				// Draw the row segments
				if (x >= 0 && x < nLeftGrass)
					Draw(x, nRow, PIXEL_SOLID, nGrassColour);
				if (x >= nLeftGrass && x < nLeftClip)
					Draw(x, nRow, PIXEL_SOLID, nClipColour);
				if (x >= nLeftClip && x < nRightClip)
					Draw(x, nRow, PIXEL_SOLID, nRoadColour);
				if (x >= nRightClip && x < nRightGrass)
					Draw(x, nRow, PIXEL_SOLID, nClipColour);
				if (x >= nRightGrass && x < ScreenWidth())
					Draw(x, nRow, PIXEL_SOLID, nGrassColour);

			}

		// Draw Car - car position on road is proportional to difference between
		// current accumulated track curvature, and current accumulated player curvature
		// i.e. if they are similar, the car will be in the middle of the track
		fCarPos = fPlayerCurvature - fTrackCurvature;
		int nCarPos = ScreenWidth() / 2 + ((int)(ScreenWidth() * fCarPos) / 2.0) - 7; // Offset for sprite

		// Draw a car that represents what the player is doing. Apologies for the quality
		// of the sprite... :-(
		switch (nCarDirection)
		{
		case 0:
			DrawStringAlpha(nCarPos, 80, L"   ||####||   ");
			DrawStringAlpha(nCarPos, 81, L"      ##      ");
			DrawStringAlpha(nCarPos, 82, L"     ####     ");
			DrawStringAlpha(nCarPos, 83, L"     ####     ");
			DrawStringAlpha(nCarPos, 84, L"|||  ####  |||");
			DrawStringAlpha(nCarPos, 85, L"|||########|||");
			DrawStringAlpha(nCarPos, 86, L"|||  ####  |||");
			break;

		case +1:
			DrawStringAlpha(nCarPos, 80, L"      //####//");
			DrawStringAlpha(nCarPos, 81, L"         ##   ");
			DrawStringAlpha(nCarPos, 82, L"       ####   ");
			DrawStringAlpha(nCarPos, 83, L"      ####    ");
			DrawStringAlpha(nCarPos, 84, L"///  ####//// ");
			DrawStringAlpha(nCarPos, 85, L"//#######///O ");
			DrawStringAlpha(nCarPos, 86, L"/// #### //// ");
			break;

		case -1:
			DrawStringAlpha(nCarPos, 80, L"\\\\####\\\\      ");
			DrawStringAlpha(nCarPos, 81, L"   ##         ");
			DrawStringAlpha(nCarPos, 82, L"   ####       ");
			DrawStringAlpha(nCarPos, 83, L"    ####      ");
			DrawStringAlpha(nCarPos, 84, L" \\\\\\\\####  \\\\\\");
			DrawStringAlpha(nCarPos, 85, L" O\\\\\\#######\\\\");
			DrawStringAlpha(nCarPos, 86, L" \\\\\\\\ #### \\\\\\");
			break;
		}
		
		// Draw Stats
		DrawString(0, 0, L"Distance: " + to_wstring(fDistance));
		DrawString(0, 1, L"Target Curvature: " + to_wstring(fCurvature));
		DrawString(0, 2, L"Player Curvature: " + to_wstring(fPlayerCurvature));
		DrawString(0, 3, L"Player Speed    : " + to_wstring(fSpeed));
		DrawString(0, 4, L"Track Curvature : " + to_wstring(fTrackCurvature));

		auto disp_time = [](float t) // Little lambda to turn floating point seconds into minutes:seconds:millis string
		{
			int nMinutes = t / 60.0f;
			int nSeconds = t - (nMinutes * 60.0f);
			int nMilliSeconds = (t - (float)nSeconds) * 1000.0f;
			return to_wstring(nMinutes) + L"." + to_wstring(nSeconds) + L":" + to_wstring(nMilliSeconds);
		};

		// Display current laptime
		DrawString(10, 8, disp_time(fCurrentLapTime));

		// Display last 5 lap times
		int j = 10;
		for (auto l : listLapTimes)
		{
			DrawString(10, j, disp_time(l));
			j++;
		}

		return true;
	}
};


int main()
{
	// Use olcConsoleGameEngine derived app
	OneLoneCoder_FormulaOLC game;
	game.ConstructConsole(160, 100, 8, 8);
	game.Start();

	return 0;
}