#include "iostream"
#include "fstream"
#include "stdio.h"
#include "stdlib.h"
#include "unistd.h"
#include "sstream"
#include "vector"
#include "string.h"
#include "cmath"
#include "iomanip"
#include "map"

#define WGS84_PoleRadius 6356752.3//WGS84椭球极半径
#define WGS84_EquatorRadius 6378137//WGS84椭球长半径
#define EarthRadius 6371008.8
#define Pi (4.0*atan(1.0))
#define BOLDRED "\033[1m\033[31m"
#define RESET "\033[0m"
#define MAX_DBL 1e+30
#define ZERO 1e-20

using namespace std;

int open_infile(ifstream &infile,char* filename)
{
	infile.open(filename);
	if (!infile)
	{
		cout << BOLDRED << "error ==> " << RESET << "file not found: " << filename << endl;
		return -1;
	}
	return 0;
}

int open_outfile(ofstream &outfile,char* filename)
{
	outfile.open(filename);
	if (!outfile)
	{
		cout << BOLDRED << "error ==> " << RESET << "fail to create the file: " << filename << endl;
		return -1;
	}
	return 0;
}

//计算一个参考椭球或者参考球在纬度位置的半径
double refRadius(double lati,double refr,double refR)
{
	return refr*refR/sqrt(pow(refr,2)*pow(cos((double) lati*Pi/180.0),2)+pow(refR,2)*pow(sin((double) lati*Pi/180.0),2));
}

//直角坐标系下的一个点
struct cpoint
{
	double x,y,z;
	cpoint() //初始化坐标值
	{
		x = y = z = MAX_DBL;
	}
};

//球坐标系下的一个点
struct spoint
{
	double lon,lat,rad;
	spoint() //初始化坐标值
	{
		lon = lat = rad = MAX_DBL;
	}
};

/*直角坐标与球坐标相互转换函数 注意这里使用的球坐标是地理坐标范围 即经度为-180~180 纬度为-90~90*/
cpoint s2c(spoint s)
{
	cpoint c;
	c.x = s.rad*sin((0.5 - s.lat/180.0)*Pi)*cos((2.0 + s.lon/180.0)*Pi);
	c.y = s.rad*sin((0.5 - s.lat/180.0)*Pi)*sin((2.0 + s.lon/180.0)*Pi);
	c.z = s.rad*cos((0.5 - s.lat/180.0)*Pi);
	return c;
}

spoint c2s(cpoint c)
{
	spoint s;
	s.rad = sqrt(pow(c.x,2)+pow(c.y,2)+pow(c.z,2));
	if (fabs(s.rad)<ZERO) //点距离原点极近 将点置于原点
	{
		s.lat = s.lon = 0.0;
	}
	else
	{
		s.lat = 90.0 - acos(c.z/s.rad)*180.0/Pi;
		s.lon = atan2(c.y,c.x)*180.0/Pi;
	}
	return s;
}

struct node
{
	int id;
	cpoint posic; //直角坐标系位置
	spoint posis; //球坐标系位置
	void set(cpoint c) //从直角坐标位置初始化
	{
		posic.x = c.x; posic.y = c.y; posic.z = c.z;
		posis = c2s(posic);
	}
	void set(spoint s) //从球坐标位置初始化
	{
		posis.lon = s.lon; posis.lat = s.lat; posis.rad = s.rad;
		posic = s2c(posis);
	}
};
typedef vector<node> nodeArray;
typedef map<string,int> strMap; //顶点位置映射 用于通过顶点位置寻找相应顶点

struct triangle
{
	int id;
	int index[3];
};
typedef vector<triangle> triArray;

class gmt2msh
{
public:
	gmt2msh(){}
	~gmt2msh(){}
	int getRef(char*);
	int getNode(char*,double,double);
	int getNode(char*,double);
	int outMsh(char*);
private:
	double refr,refR;
	nodeArray Nodes;
	strMap mapStr;
	strMap::iterator ivm;
	triArray Triangles;
};

int gmt2msh::getRef(char* para)
{
	//首先匹配预定义类型
	if (!strcmp(para,"WGS84"))
	{
		refr = WGS84_PoleRadius;
		refR = WGS84_EquatorRadius;
	}
	else if (!strcmp(para,"EarthRadius"))
	{
		refr = EarthRadius;
		refR = EarthRadius;
	}
	//匹配参数格式
	else if (2 == sscanf(para,"%lf/%lf",&refr,&refR))
	{
		if (refr <= 0 || refR <= 0)
		{
			cout << BOLDRED << "Error ==> " << RESET << "fail to initial reference system" << endl;
			return -1;
		}
	}
	else
	{
		cout << BOLDRED << "Error ==> " << RESET << "fail to initial reference system" << endl;
		return -1;
	}
	return 0;
}

int gmt2msh::getNode(char* filename,double refr,double refR)
{
	ifstream infile;
	if (open_infile(infile,filename)) return -1;

	string temp_str;
	stringstream temp_ss;
	node temp_node;
	triangle temp_tri;
	while (getline(infile,temp_str))
	{
		if (*(temp_str.begin()) == '#') continue;

		if (1 == sscanf(temp_str.c_str(),"> Triangle: %d",&temp_tri.id))
		{
			for (int i = 0; i < 3; i++)
			{
				getline(infile,temp_str);
				temp_ss.str("");
				temp_ss.clear();
				temp_ss << temp_str;
				temp_ss >> temp_node.posis.lon >> temp_node.posis.lat;
				temp_node.posis.rad = refRadius(temp_node.posis.lat,refr,refR);
				temp_node.set(temp_node.posis);
				//查找映射表
				ivm = mapStr.find(temp_str);
				if (ivm == mapStr.end())
				{
					temp_node.id = Nodes.size();
					Nodes.push_back(temp_node);
					temp_tri.index[i] = temp_node.id;
					//添加映射
					mapStr[temp_str] = temp_node.id;
				}
				else temp_tri.index[i] = ivm->second;
			}
		}
		Triangles.push_back(temp_tri);
	}
	infile.close();
}

int gmt2msh::getNode(char* filename,double alti)
{
	ifstream infile;
	if (open_infile(infile,filename)) return -1;

	string temp_str;
	stringstream temp_ss;
	node temp_node;
	triangle temp_tri;
	while (getline(infile,temp_str))
	{
		if (*(temp_str.begin()) == '#') continue;

		if (sscanf(temp_str.c_str(),"> Triangle: %d",&temp_tri.id))
		{
			for (int i = 0; i < 3; i++)
			{
				getline(infile,temp_str);
				temp_ss.str("");
				temp_ss.clear();
				temp_ss << temp_str;
				temp_ss >> temp_node.posic.x >> temp_node.posic.y;
				temp_node.posic.z = alti;
				temp_node.set(temp_node.posic);
				//查找映射表
				ivm = mapStr.find(temp_str);
				if (ivm == mapStr.end())
				{
					temp_node.id = Nodes.size();
					Nodes.push_back(temp_node);
					temp_tri.index[i] = temp_node.id;
					//添加映射
					mapStr[temp_str] = temp_node.id;
				}
				else temp_tri.index[i] = ivm->second;
			}
		}
		Triangles.push_back(temp_tri);
	}
	infile.close();
}

int gmt2msh::outMsh(char* filename)
{
	ofstream outfile;
	if(open_outfile(outfile,filename)) return -1;

	outfile<<"$MeshFormat"<<endl<<"2.2 0 8"<<endl<<"$EndMeshFormat"<<endl<<"$Nodes"<<endl<<Nodes.size()<<endl;
	for (int i = 0; i < Nodes.size(); i++)
	{
		outfile << Nodes.at(i).id << " " << setprecision(16) << Nodes.at(i).posic.x << " " << Nodes.at(i).posic.y << " " << Nodes.at(i).posic.z << endl;
	}
	outfile<<"$EndNodes"<<endl<<"$Elements"<<endl<<Triangles.size()<<endl;
	for (int i = 0; i < Triangles.size(); i++)
	{
		outfile<< Triangles.at(i).id <<" 2 1 0 " << Triangles.at(i).index[0] << " " << Triangles.at(i).index[1] << " " << Triangles.at(i).index[2] << endl;
	}
	outfile<<"$EndElements"<<endl;

	outfile.close();
	return 0;
}