// Copyright 2015 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.

#include <array>
#include <cstdlib>
#include <fcntl.h>
#include <iostream>
#include <locale>
#include <map>
#include <sstream>
#include <string>
#include <unistd.h>
#include <vector>
#include <sys/stat.h>

#include "Common/FileUtil.h"
#include "Common/MathUtil.h"
#include "Common/StringUtil.h"
#include "InputCommon/ControllerInterface/Pipes/Pipes.h"

namespace ciface
{
namespace Pipes
{

static const std::array<std::string, 12> s_button_tokens
{{
	"A",
	"B",
	"X",
	"Y",
	"Z",
	"START",
	"L",
	"R",
	"D_UP",
	"D_DOWN",
	"D_LEFT",
	"D_RIGHT"
}};

static const std::array<std::string, 2> s_shoulder_tokens
{{
	"L",
	"R"
}};

static const std::array<std::string, 2> s_axis_tokens
{{
	"MAIN",
	"C"
}};

static double StringToDouble(const std::string& text)
{
	std::istringstream is(text);
	// ignore current locale
	is.imbue(std::locale::classic());
	double result;
	is >> result;
	return result;
}

void Init(std::vector<Core::Device*>& devices)
{
	// Search the Pipes directory for files that we can open in read-only,
	// non-blocking mode. The device name is the virtual name of the file.
	File::FSTEntry fst;
	int found = 0;
	std::string dir_path = File::GetUserPath(D_PIPES_IDX);
	if (!File::Exists(dir_path))
		return;
	fst = File::ScanDirectoryTree(dir_path, false);
	if (!fst.isDirectory)
		return;
	for (unsigned int i = 0; i < fst.size; ++i)
	{
		const File::FSTEntry& child = fst.children[i];
		if (child.isDirectory)
			continue;
		int fd = open(child.physicalName.c_str(), O_RDONLY | O_NONBLOCK);
		if (fd < 0)
			continue;
		devices.push_back(new PipeDevice(fd, child.virtualName, found++));
	}
}

PipeDevice::PipeDevice(int fd, const std::string& name, int id)
	: m_fd(fd), m_name(name), m_id(id)
{
	for (const auto& tok : s_button_tokens)
	{
		PipeInput* btn = new PipeInput("Button " + tok);
		AddInput(btn);
		m_buttons[tok] = btn;
	}
	for (const auto& tok : s_shoulder_tokens)
	{
		AddAxis(tok, 0.0);
	}
	for (const auto& tok : s_axis_tokens)
	{
		AddAxis(tok + " X", 0.5);
		AddAxis(tok + " Y", 0.5);
	}
}

PipeDevice::~PipeDevice()
{
	close(m_fd);
}

void PipeDevice::UpdateInput()
{
	// Read any pending characters off the pipe. If we hit a newline,
	// then dequeue a command off the front of m_buf and parse it.
	char buf[32];
	ssize_t bytes_read = read(m_fd, buf, sizeof buf);
	while (bytes_read > 0)
	{
		m_buf.append(buf, bytes_read);
		bytes_read = read(m_fd, buf, sizeof buf);
	}
	std::size_t newline = m_buf.find("\n");
	while (newline != std::string::npos)
	{
		std::string command = m_buf.substr(0, newline);
		ParseCommand(command);
		m_buf.erase(0, newline + 1);
		newline = m_buf.find("\n");
	}
}

void PipeDevice::AddAxis(const std::string& name, double value)
{
	// Dolphin uses separate axes for left/right, which complicates things.
	PipeInput* ax_hi = new PipeInput("Axis " + name + " +");
	ax_hi->SetState(value);
	PipeInput* ax_lo = new PipeInput("Axis " + name + " -");
	ax_lo->SetState(value);
	m_axes[name + " +"] = ax_hi;
	m_axes[name + " -"] = ax_lo;
	AddAnalogInputs(ax_lo, ax_hi);
}

void PipeDevice::SetAxis(const std::string& entry, double value)
{
	value = MathUtil::Clamp(value, 0.0, 1.0);
	double hi = std::max(0.0, value - 0.5) * 2.0;
	double lo = (0.5 - std::min(0.5, value)) * 2.0;
	auto search_hi = m_axes.find(entry + " +");
	if (search_hi != m_axes.end())
		search_hi->second->SetState(hi);
	auto search_lo = m_axes.find(entry + " -");
	if (search_lo != m_axes.end())
		search_lo->second->SetState(lo);
}

void PipeDevice::ParseCommand(const std::string& command)
{
	std::vector<std::string> tokens;
	SplitString(command, ' ', tokens);
	if (tokens.size() < 2 || tokens.size() > 4)
		return;
	if (tokens[0] == "PRESS" || tokens[0] == "RELEASE")
	{
		auto search = m_buttons.find(tokens[1]);
		if (search != m_buttons.end())
			search->second->SetState(tokens[0] == "PRESS" ? 1.0 : 0.0);
	}
	else if (tokens[0] == "SET")
	{
		if (tokens.size() == 3)
		{
			double value = StringToDouble(tokens[2]);
			SetAxis(tokens[1], (value / 2.0) + 0.5);
		}
		else if (tokens.size() == 4)
		{
			double x = StringToDouble(tokens[2]);
			double y = StringToDouble(tokens[3]);
			SetAxis(tokens[1] + " X", x);
			SetAxis(tokens[1] + " Y", y);
		}
	}
}

}
}