#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "picoc.h"

/* print an integer to a stream without using printf/sprintf */
void IntrinsicPrintInt(int Num, FILE *Stream)
{
    int Div;
    int Remainder = 0;
    int Printing = FALSE;
    
    if (Num < 0)
    {
        fputc('-', Stream);
        Num = -Num;    
    }
    
    if (Num == 0)
        fputc('0', Stream);
    else
    {
        Div = LARGE_INT_POWER_OF_TEN;
        while (Div > 0)
        {
            Remainder = Num / Div;
            if (Printing || Remainder > 0)
            {
                fputc('0' + Remainder, Stream);
                Printing = TRUE;
            }
            Num -= Remainder * Div;
            Div /= 10;
        }
    }
}

/* print a double to a stream without using printf/sprintf */
void IntrinsicPrintFP(double Num, FILE *Stream)
{
    int Exponent = 0;
    
    if (abs(Num) >= 1e7)
        Exponent = log(Num) / LOG10E;
    else if (abs(Num) <= 1e-7)
        Exponent = log(Num) / LOG10E - 0.999999999;
    
    Num /= pow(10.0, Exponent);
    IntrinsicPrintInt((int)Num, Stream);
    fputc('.', Stream);
    for (Num -= (int)Num; Num != 0.0; Num *= 10.0)
        fputc('0' + (int)Num, Stream);
    
    if (Exponent)
    {
        fputc('e', Stream);
        IntrinsicPrintInt(Exponent, Stream);
    }
}

/* intrinsic functions made available to the language */
void IntrinsicPrintInteger(struct Value *ReturnValue, struct Value **Param, int NumArgs)
{
    printf("%d\n", Param[0]->Val->Integer);
}

void IntrinsicPrintf(struct Value *ReturnValue, struct Value **Param, int NumArgs)
{
    struct Value *CharArray = Param[0]->Val->Pointer.Segment;
    char *Format;
    char *FPos;
    struct Value *NextArg = Param[0];
    struct ValueType *FormatType;
    int ArgCount = 1;
    
    if (Param[0]->Val->Pointer.Data.Offset < 0 || Param[0]->Val->Pointer.Data.Offset >= CharArray->Val->Array.Size)
        Format = StrEmpty;
    else
        Format = CharArray->Val->Array.Data + Param[0]->Val->Pointer.Data.Offset;
    
    for (FPos = Format; *FPos != '\0'; FPos++)
    {
        if (*FPos == '%')
        {
            FPos++;
            switch (*FPos)
            {
                case 's': FormatType = CharPtrType; break;
                case 'd': case 'c': FormatType = &IntType; break;
#ifndef NO_FP
                case 'f': FormatType = &FPType; break;
#endif
                case '%': fputc('%', stdout); FormatType = NULL; break;
                case '\0': FPos--; FormatType = NULL; break;
                default:  putchar(*FPos); FormatType = NULL; break;
            }
            
            if (FormatType != NULL)
            { /* we have to format something */
                if (ArgCount >= NumArgs)
                    fputs("XXX", stdout);   /* not enough parameters for format */
                else
                {
                    NextArg = (struct Value *)((void *)NextArg + sizeof(struct Value) + TypeSizeValue(NextArg));
                    if (NextArg->Typ != FormatType)
                        fputs("XXX", stdout);   /* bad type for format */
                    else
                    {
                        switch (*FPos)
                        {
                            case 's':
                            {
                                struct Value *CharArray = NextArg->Val->Pointer.Segment;
                                char *Str;
                                
                                if (NextArg->Val->Pointer.Data.Offset < 0 || NextArg->Val->Pointer.Data.Offset >= CharArray->Val->Array.Size)
                                    Str = StrEmpty;
                                else
                                    Str = CharArray->Val->Array.Data + NextArg->Val->Pointer.Data.Offset;
                                    
                                fputs(Str, stdout); 
                                break;
                            }
                            case 'd': IntrinsicPrintInt(NextArg->Val->Integer, stdout); break;
                            case 'c': fputc(NextArg->Val->Integer, stdout); break;
#ifndef NO_FP
                            case 'f': IntrinsicPrintFP(NextArg->Val->FP, stdout); break;
#endif
                        }
                    }
                }
                
                ArgCount++;
            }
        }
        else
            putchar(*FPos);
    }
}



void IntrinsicSayHello(struct Value *ReturnValue, struct Value **Param, int NumArgs)
{
    printf("Hello\n");
}

struct IntrinsicFunction
{
    void (*Func)(struct Value *, struct Value **, int);
    const char *Prototype;
} Intrinsics[] =
{
    { IntrinsicSayHello,    "void sayhello()" },
    { IntrinsicPrintf,      "void printf(char *, ...)" },
    { IntrinsicPrintInteger,"void printint(int)" },
};

void IntrinsicInit(struct Table *GlobalTable)
{
    struct ParseState Parser;
    int Count;
    char *Identifier;
    struct ValueType *ReturnType;
    struct Value *NewValue;
    void *Tokens;
    const char *IntrinsicName = TableStrRegister("intrinsic");
    
    for (Count = 0; Count < sizeof(Intrinsics) / sizeof(struct IntrinsicFunction); Count++)
    {
        Tokens = LexAnalyse(IntrinsicName, Intrinsics[Count].Prototype, strlen(Intrinsics[Count].Prototype));
        LexInitParser(&Parser, Tokens, IntrinsicName, Count+1, TRUE);
        TypeParse(&Parser, &ReturnType, &Identifier);
        NewValue = ParseFunctionDefinition(&Parser, ReturnType, Identifier, TRUE);
        NewValue->Val->FuncDef.Intrinsic = Intrinsics[Count].Func;
        HeapFree(Tokens);
    }
}

void IntrinsicHostPrintf(const char *Format, ...)
{
    va_list Args;
    
    va_start(Args, Format);
    IntrinsicHostVPrintf(Format, Args);
    va_end(Args);
}

/* printf for compiler error reporting */
void IntrinsicHostVPrintf(const char *Format, va_list Args)
{
    const char *FPos;
    
    for (FPos = Format; *FPos != '\0'; FPos++)
    {
        if (*FPos == '%')
        {
            FPos++;
            switch (*FPos)
            {
            case 's': fputs(va_arg(Args, char *), stdout); break;
            case 'd': IntrinsicPrintInt(va_arg(Args, int), stdout); break;
            case 'c': fputc(va_arg(Args, int), stdout); break;
#ifndef NO_FP
            case 'f': IntrinsicPrintFP(va_arg(Args, double), stdout); break;
#endif
            case '%': fputc('%', stdout); break;
            case '\0': FPos--; break;
            }
        }
        else
            putchar(*FPos);
    }
}