#include <iostream>
#include <fstream>
#include <unordered_map>
#include <vector>
#include <string>
#include <functional>
#include <unistd.h>
#include <fcntl.h>

#include "runtime.h"

using namespace std;

extern int g_argc;
extern char **g_argv;

#define BUILTIN_GUARD_STACKSIZE(nm,sz) {if(S.size()<(sz))throw string("Builtin '" nm "' needs " #sz " stack item")+(sz==1?"":"s");}

//please extern this shit with const!
unordered_map<string,function<void(vector<Stackitem>&,unordered_map<string,Stackitem>&)>> builtins={
	{"+",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("+",2)
		Stackitem b=move(S.back()); S.pop_back();
		Stackitem a=move(S.back()); S.pop_back();
		if(!a.isstr&&!b.isstr){
			S.emplace_back(a.intval+b.intval);
			return;
		}
		if(!a.isstr){
			a.strval=to_string(a.intval);
			a.isstr=true;
		}
		if(!b.isstr){
			b.strval=to_string(b.intval);
			b.isstr=true;
		}
		S.emplace_back(a.strval+b.strval);
	}},
	{"-",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("-",2)
		Stackitem b=move(S.back()); S.pop_back();
		Stackitem a=move(S.back()); S.pop_back();
		if(a.isstr||b.isstr)throw string("Builtin '-' cannot accept a string argument");
		S.emplace_back(a.intval-b.intval);
	}},
	{"*",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("*",2)
		Stackitem b=move(S.back()); S.pop_back();
		Stackitem a=move(S.back()); S.pop_back();
		if(a.isstr||b.isstr)throw string("Builtin '*' cannot accept a string argument");
		S.emplace_back(a.intval*b.intval);
	}},
	{"/",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("/",2)
		Stackitem b=move(S.back()); S.pop_back();
		Stackitem a=move(S.back()); S.pop_back();
		if(a.isstr||b.isstr)throw string("Builtin '/' cannot accept a string argument");
		S.emplace_back(a.intval/b.intval);
	}},
	{"%",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("%",2)
		Stackitem b=move(S.back()); S.pop_back();
		Stackitem a=move(S.back()); S.pop_back();
		if(a.isstr||b.isstr){
			cerr<<"modding ";
			if(a.isstr)cerr<<'"'<<a.strval<<'"'; else cerr<<a.intval;
			cerr<<" and ";
			if(b.isstr)cerr<<'"'<<b.strval<<'"'; else cerr<<b.intval;
			cerr<<endl;
		}
		if(a.isstr||b.isstr)throw string("Builtin '%' cannot accept a string argument");
		S.emplace_back(a.intval%b.intval);
	}},
	{"^",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("^",2)
		Stackitem b=move(S.back()); S.pop_back();
		Stackitem a=move(S.back()); S.pop_back();
		if(a.isstr||b.isstr)throw string("Builtin '^' cannot accept a string argument");
		S.emplace_back((int)pow(a.intval,b.intval));
	}},
	{"!",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("!",1)
		Stackitem v=move(S.back()); S.pop_back();
		if(v.isstr)S.emplace_back(!v.strval.size());
		else S.emplace_back(!v.intval);
	}},
	{"=",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("=",2)
		Stackitem b=move(S.back()); S.pop_back();
		Stackitem a=move(S.back()); S.pop_back();
		S.emplace_back(a==b);
	}},
	{"<",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("<",2)
		Stackitem b=move(S.back()); S.pop_back();
		Stackitem a=move(S.back()); S.pop_back();
		if(a.isstr&&b.isstr)S.emplace_back(a.strval<b.strval);
		else if(!a.isstr&&!b.isstr)S.emplace_back(a.intval<b.intval);
		else if(a.isstr)S.emplace_back(a.strval<to_string(b.intval));
		else S.emplace_back(to_string(a.intval)<b.strval);
	}},
	{">",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE(">",2)
		Stackitem b=move(S.back()); S.pop_back();
		Stackitem a=move(S.back()); S.pop_back();
		if(a.isstr&&b.isstr)S.emplace_back(a.strval>b.strval);
		else if(!a.isstr&&!b.isstr)S.emplace_back(a.intval>b.intval);
		else if(a.isstr)S.emplace_back(a.strval>to_string(b.intval));
		else S.emplace_back(to_string(a.intval)>b.strval);
	}},
	{"print",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("print",1)
		Stackitem v=move(S.back()); S.pop_back();
		if(v.isstr)cout<<v.strval<<flush;
		else cout<<v.intval<<flush;
	}},
	{"lf",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("lf",0)
		cout<<endl;
	}},
	{"getline",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("getline",0)
		string line;
		getline(cin,line);
		if(!cin)S.emplace_back(-1);
		else S.emplace_back(line);
	}},
	{"getc",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("getc",0)
		char c=cin.get();
		if(!cin)S.emplace_back(-1);
		else S.emplace_back(string(1,c));
	}},
	{"fprint",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("fprint",2)
		Stackitem file=move(S.back()); S.pop_back();
		Stackitem v=move(S.back()); S.pop_back();
		if(file.isstr)throw string("Second argument to 'fprint' not a number");
		if(v.isstr)write(file.intval,v.strval.data(),v.strval.size());
		else {
			string s=to_string(v.intval);
			write(file.intval,s.data(),s.size());
		}
	}},
	{"flf",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("flf",1)
		Stackitem file=move(S.back()); S.pop_back();
		if(file.isstr)throw string("Argument to 'flf' not a number");
		write(file.intval,"\n",1);
	}},
	{"fgetc",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("fgetc",1)
		Stackitem file=move(S.back()); S.pop_back();
		if(file.isstr)throw string("Argument to 'fgetc' not a number");
		char c;
		int ret=read(file.intval,&c,1);
		if(ret==-1)perror("read");
		if(ret<=0)S.emplace_back(-1);
		else S.emplace_back(string(1,c));
	}},
	{"fopen",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("fopen",2)
		Stackitem mode=move(S.back()); S.pop_back();
		Stackitem fname=move(S.back()); S.pop_back();
		if(!fname.isstr)throw string("First argument to 'fopen' not a string");
		if(!mode.isstr)throw string("Second argument to 'fopen' not a string");
		int oflag=0;
		if(mode.strval.find('r')!=string::npos)oflag|=O_RDONLY;
		if(mode.strval.find('w')!=string::npos){
			if(oflag&O_RDONLY)oflag=(oflag&~O_RDONLY)|O_RDWR;
			else oflag|=O_WRONLY;
		}
		if(mode.strval.find('a')!=string::npos)oflag|=O_APPEND;
		if(mode.strval.find('x')!=string::npos)oflag|=O_EXCL|O_CREAT;
		if(oflag==0)oflag=O_RDONLY;
		int ret=open(fname.strval.c_str(),oflag);
		if(ret<0)perror("open");
		S.emplace_back(ret);
	}},
	{"argc",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("argc",0)
		S.emplace_back(g_argc);
	}},
	{"argvget",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("argvget",1)
		Stackitem idx=move(S.back()); S.pop_back();
		if(idx.isstr)throw string("Argument to 'argvget' not a number");
		if(idx.intval<0||idx.intval>=g_argc)throw string("Argument to 'argvget' out of bounds");
		S.emplace_back(g_argv[idx.intval]);
	}},
	{"dup",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("dup",1)
		S.push_back(S.back());
	}},
	{"pop",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("pop",1)
		S.pop_back();
	}},
	{"swap",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("swap",2)
		Stackitem b=move(S.back()); S.pop_back();
		Stackitem a=move(S.back()); S.pop_back();
		S.push_back(b);
		S.push_back(a);
	}},
	{"store",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("store",2)
		Stackitem name=move(S.back()); S.pop_back();
		if(!name.isstr)throw string("Second argument to 'store' not a string");
		variables[name.strval]=move(S.back());
		S.pop_back();
	}},
	{"get",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("get",1)
		Stackitem name=move(S.back()); S.pop_back();
		if(!name.isstr)throw string("Argument to 'get' not a string");
		S.push_back(variables[name.strval]);
	}},
	//leaves variable with value 0
	{"swapoutvar",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("swapoutvar",1)
		Stackitem name=move(S.back()); S.pop_back();
		if(!name.isstr)throw string("Second argument to 'swapoutvar' not a string");
		S.push_back(move(variables[name.strval]));
		variables[name.strval].intval=0;
	}},
	//positive n: roll OFF top to bottom; negative n: roll off bottom ONTO top
	{"roll",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("roll",1)
		Stackitem ns=move(S.back()); S.pop_back();
		if(ns.isstr)throw string("Argument to 'roll' not a number");
		int n=ns.intval;
		if(S.size()<2)return;
		bool negative=n<0;
		if(negative)n=-n;
		n%=S.size();
		if(n==0)return;
		if(negative){
			vector<Stackitem> tempstore;
			tempstore.reserve(n);
			int ssz=S.size();
			for(int i=ssz-n;i<ssz;i++)tempstore.push_back(move(S[i]));
			S.erase(S.end()-n,S.end());
			S.insert(S.begin(),n,Stackitem());
			for(int i=0;i<n;i++)S[i]=move(tempstore[i]);
		} else {
			//cerr<<"rolling back n="<<n<<endl;
			vector<Stackitem> tempstore;
			tempstore.reserve(n);
			for(int i=0;i<n;i++)tempstore.push_back(move(S[i]));
			S.erase(S.begin(),S.begin()+n);
			for(int i=0;i<n;i++)S.push_back(move(tempstore[i]));
		}
	}},
	//leaves the string on the stack
	{"stridx",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("stridx",2)
		Stackitem idx=move(S.back()); S.pop_back();
		const Stackitem &str=S.back();
		if(!str.isstr)throw string("First argument to 'stridx' not a string");
		if(idx.isstr)throw string("Second argument to 'stridx' not a number");
		if(idx.intval<0||idx.intval>=(int)str.strval.size())throw string("Index argument to 'stridx' out of range");
		S.emplace_back(string(1,str.strval[idx.intval]));
	}},
	//leaves the string on the stack
	{"strlen",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("strlen",1)
		const Stackitem &str=S.back();
		if(!str.isstr)throw string("Argument to 'strlen' not a string");
		S.emplace_back(str.strval.size());
	}},
	//leaves the string on the stack
	{"substr",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("substr",3)
		const Stackitem to=move(S.back()); S.pop_back();
		const Stackitem from=move(S.back()); S.pop_back();
		const Stackitem &str=S.back();
		if(!str.isstr)throw string("First argument to 'substr' not a string");
		if(from.isstr)throw string("Second argument to 'substr' not a number");
		if(to.isstr)throw string("Third argument to 'substr' not a number");
		S.emplace_back(str.strval.substr(from.intval,to.intval-from.intval));
	}},
	{"chr",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("chr",1)
		Stackitem ascii=move(S.back()); S.pop_back();
		if(ascii.isstr)throw string("Argument to 'chr' not a number");
		S.emplace_back(string(1,ascii.intval));
	}},
	{"ord",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("ord",1)
		if(!S.back().isstr)throw string("Argument to 'ord' not a string");
		S.back().isstr=false;
		S.back().intval=(int)S.back().strval[0];
		S.back().strval="";
	}},
	{"stackdump",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("stackdump",0)
		cerr<<"STACKDUMP: ";
		for(const Stackitem &si : S){
			if(si.isstr)cerr<<'"'<<si.strval<<"\" ";
			else cerr<<si.intval<<' ';
		}
		cerr<<endl;
	}},
	{"exit",[](vector<Stackitem> &S,unordered_map<string,Stackitem> &variables){
		BUILTIN_GUARD_STACKSIZE("exit",0)
		exit(0);
	}},
};
#undef BUILTIN_GUARD_STACKSIZE