#pragma once

#ifndef __nasver
#define __nasver "10.1"
#endif

#include <cstdint>
#include <iostream>
#include <fstream>
#include <cstring>
#include <cmath>
#include <vector>

using i32=std::int32_t;
using i64=std::int64_t;
using u8=std::uint8_t;
using u16=std::uint16_t;
using u32=std::uint32_t;
using u64=std::uint64_t;
using usize=std::size_t;
using f64=double;
using std::string;

const u32 STACK_DEPTH=1024;

inline f64 hex2f(const char* str) {
    f64 ret=0;
    for(;*str;++str) {
        if ('0'<=*str && *str<='9') {
            ret=ret*16+(*str-'0');
        } else if ('a'<=*str && *str<='f') {
            ret=ret*16+(*str-'a'+10);
        } else if ('A'<=*str && *str<='F') {
            ret=ret*16+(*str-'A'+10);
        } else {
            return nan("");
        }
    }
    return ret;
}

inline f64 oct2f(const char* str) {
    f64 ret=0;
    while('0'<=*str && *str<'8') {
        ret=ret*8+(*str++-'0');
    }
    if (*str) {
        return nan("");
    }
    return ret;
}

// we have the same reason not using atof here just as andy's interpreter does.
// it is not platform independent, and may have strange output.
// so we write a new function here to convert str to number manually.
// but this also makes 0.1+0.2==0.3, not another result that you may get in other languages.
inline f64 dec2f(const char* str) {
    f64 ret=0,negative=1,num_pow=0;
    while('0'<=*str && *str<='9') {
        ret=ret*10+(*str++-'0');
    }
    if (!*str) {
        return ret;
    }
    if (*str=='.') {
        if (!*++str) {
            return nan("");
        }
        num_pow=0.1;
        while('0'<=*str && *str<='9') {
            ret+=num_pow*(*str++-'0');
            num_pow*=0.1;
        }
        if (!*str) {
            return ret;
        }
    }
    if (*str!='e' && *str!='E') {
        return nan("");
    }
    if (!*++str) {
        return nan("");
    }
    if (*str=='-' || *str=='+') {
        negative=(*str++=='-'? -1:1);
    }
    if (!*str) {
        return nan("");
    }
    num_pow=0;
    while('0'<=*str && *str<='9') {
        num_pow=num_pow*10+(*str++-'0');
    }
    if (*str) {
        return nan("");
    }
    return ret*std::pow(10,negative*num_pow);
}

f64 str2num(const char* str) {
    bool negative=false;
    f64 res=0;
    if (*str=='-' || *str=='+') {
        negative=(*str++=='-');
    }
    if (!*str) {
        return nan("");
    }
    if (str[0]=='0' && str[1]=='x') {
        res=hex2f(str+2);
    } else if (str[0]=='0' && str[1]=='o') {
        res=oct2f(str+2);
    } else {
        res=dec2f(str);
    }
    return negative?-res:res;
}

i32 utf8_hdchk(const char head) {
    // RFC-2279 but now we use RFC-3629 so nbytes is less than 4
    const u8 c=(u8)head;
    if ((c>>5)==0x06) { // 110x xxxx (10xx xxxx)^1
        return 1;
    }
    if ((c>>4)==0x0e) { // 1110 xxxx (10xx xxxx)^2
        return 2;
    }
    if ((c>>3)==0x1e) { // 1111 0xxx (10xx xxxx)^3
        return 3;
    }
    return 0;
}

string chrhex(const char c) {
    const char hextbl[]="0123456789abcdef";
    return {hextbl[(c&0xf0)>>4],hextbl[c&0x0f]};
}

string rawstr(const string& str,const usize maxlen=0) {
    string ret("");
    for(auto i:str) {
#ifdef _WIN32
        // windows doesn't output unicode normally, so we output the hex
        if (i<=0) {
            ret+="\\x"+chrhex(i);
            continue;
        }
#endif
        switch(i) {
            case '\0':  ret+="\\0"; break;
            case '\a':  ret+="\\a"; break;
            case '\b':  ret+="\\b"; break;
            case '\t':  ret+="\\t"; break;
            case '\n':  ret+="\\n"; break;
            case '\v':  ret+="\\v"; break;
            case '\f':  ret+="\\f"; break;
            case '\r':  ret+="\\r"; break;
            case '\033':ret+="\\e"; break;
            case '\"':  ret+="\\\"";break;
            case '\'':  ret+="\\\'";break;
            case '\\':  ret+="\\\\";break;
            default:    ret+=i;     break;
        }
    }
    if (maxlen && ret.length()>maxlen) {
        ret=ret.substr(0,maxlen)+"...";
    }
    return ret;
}

#include "nasal_gc.h" // declarations of var and nasal_gc