//---------------------------------------------------------------------------
#include "tokenize.h"
#include "CommonCheck.h"    // <- IsName
//---------------------------------------------------------------------------

#include <locale>
#include <fstream>

#include <stdlib.h>     // <- strtoul


std::vector<std::string> Files;
struct TOKEN *tokens, *tokens_back;

struct DefineSymbol
{
    char *name;
    char *value;
    struct DefineSymbol *next;
};
static struct DefineSymbol * dsymlist;

static void Define(const char Name[], const char Value[])
{
    if (!(Name && Name[0]))
        return;

    if (!(Value && Value[0]))
        return;

    // Is 'Value' a decimal value..
    bool dec = true, hex = true;
    for (int i = 0; Value[i]; i++)
    {
        if ( ! std::isdigit(Value[i]) )
            dec = false;

        if ( ! std::isxdigit(Value[i]) && (!(i==1 && Value[i]=='x')))
            hex = false;
    }

    if (!dec && !hex)
        return;

    char *strValue = strdup(Value);

    if (!dec && hex)
    {
        char str[50];
        unsigned long value = strtoul(Value+2, NULL, 16);
        free(strValue);
        strValue = strdup(itoa(value, str, 10));
    }

    DefineSymbol *NewSym = new DefineSymbol;
    memset(NewSym, 0, sizeof(DefineSymbol));
    NewSym->name = strdup(Name);
    NewSym->value = strValue;
    NewSym->next = dsymlist;
    dsymlist = NewSym;
}


static void addtoken(const char str[], const unsigned int lineno, const unsigned int fileno)
{
    if (str[0] == 0)
        return;

    // Replace hexadecimal value with decimal
    char str2[50];
    memset(str2, 0, sizeof(str2));
    if (strncmp(str,"0x",2)==0)
    {
        unsigned int value = strtoul(str+2, NULL, 16);
        itoa(value, str2, 10);
    }

    TOKEN *newtoken  = new TOKEN;
    memset(newtoken, 0, sizeof(TOKEN));
    newtoken->str    = strdup(str2[0] ? str2 : str);
    newtoken->linenr = lineno;
    newtoken->FileIndex = fileno;
    if (tokens_back)
    {
        tokens_back->next = newtoken;
        tokens_back = newtoken;
    }
    else
    {
        tokens = tokens_back = newtoken;
    }

    // Check if str is defined..
    for (DefineSymbol *sym = dsymlist; sym; sym = sym->next)
    {
        if (strcmp(str,sym->name)==0)
        {
            free(newtoken->str);
            newtoken->str = strdup(sym->value);
            break;
        }
    }
}
//---------------------------------------------------------------------------

static void combine_2tokens(TOKEN *tok, const char str1[], const char str2[])
{
    if (!(tok && tok->next))
        return;
    if (strcmp(tok->str,str1) || strcmp(tok->next->str,str2))
        return;

    free(tok->str);
    free(tok->next->str);
    tok->str = (char *)malloc(strlen(str1)+strlen(str2)+1);
    strcpy(tok->str, str1);
    strcat(tok->str, str2);

    TOKEN *toknext = tok->next;
    tok->next = toknext->next;
    delete toknext;
}
//---------------------------------------------------------------------------

void Tokenize(const char FileName[])
{
    // Has this file been tokenized already?
    for (unsigned int i = 0; i < Files.size(); i++)
    {
        if ( stricmp(Files[i].c_str(), FileName) == 0 )
            return;
    }

    std::ifstream fin(FileName);
    if (!fin.is_open())
        return;

    unsigned int CurrentFile = Files.size();
    Files.push_back(FileName);

    unsigned int lineno = 1;
    char CurrentToken[1000];
    memset(CurrentToken, 0, sizeof(CurrentToken));
    char *pToken = CurrentToken;
    for (char ch = (char)fin.get(); !fin.eof(); ch = (char)fin.get())
    {
        if (ch == '#' && !CurrentToken[0])
        {
            std::string line;
            getline(fin,line);
            line = "#" + line;
            if (strncmp(line.c_str(),"#include",8)==0 &&
                line.find("\"") != std::string::npos)
            {
                // Extract the filename
                line.erase(0, line.find("\"")+1);
                line.erase(line.find("\""));

                // Relative path..
                if (strchr(FileName,'\\'))
                {
                    char path[1000];
                    memset(path,0,sizeof(path));
                    const char *p = strrchr(FileName, '\\');
                    memcpy(path, FileName, p-FileName+1);
                    line = path + line;
                }

                addtoken("#include", lineno, CurrentFile);
                addtoken(line.c_str(), lineno, CurrentFile);

                Tokenize(line.c_str());
            }

            else if (strncmp(line.c_str(), "#define", 7) == 0)
            {
                char *strId = NULL;
                enum {Space1, Id, Space2, Value} State;
                State = Space1;
                for (unsigned int i = 8; i < line.length(); i++)
                {
                    if (State==Space1 || State==Space2)
                    {
                        if (std::isspace(line[i]))
                            continue;
                        State = (State==Space1) ? Id : Value;
                    }

                    else if (State==Id && std::isspace(line[i]))
                    {
                        strId = strdup(CurrentToken);
                        memset(CurrentToken, 0, sizeof(CurrentToken));
                        pToken = CurrentToken;
                        State = Space2;
                        continue;
                    }

                    *pToken = line[i];
                    pToken++;
                }

                if (State==Value)
                {
                    Define(strId, CurrentToken);
                }

                pToken = CurrentToken;
                memset(CurrentToken, 0, sizeof(CurrentToken));
                free(strId);
            }

            lineno++;
            continue;
        }

        if (ch == '\n')
        {
            // Add current token..
            addtoken(CurrentToken, lineno++, CurrentFile);
            memset(CurrentToken, 0, sizeof(CurrentToken));
            pToken = CurrentToken;
            continue;
        }

        // Comments..
        if (ch == '/' && !fin.eof())
        {
            // Add current token..
            addtoken(CurrentToken, lineno, CurrentFile);
            memset(CurrentToken, 0, sizeof(CurrentToken));
            pToken = CurrentToken;

            // Read next character..
            ch = (char)fin.get();

            // If '//'..
            if (ch == '/')
            {
                while (!fin.eof() && (char)fin.get()!='\n');
                lineno++;
                continue;
            }

            // If '/*'..
            if (ch == '*')
            {
                char chPrev;
                ch = chPrev = 'A';
                while (!fin.eof() && (chPrev!='*' || ch!='/'))
                {
                    chPrev = ch;
                    ch = (char)fin.get();
                    if (ch == '\n')
                        lineno++;
                }
                continue;
            }

            // Not a comment.. add token..
            addtoken("/", lineno, CurrentFile);
        }

        // char..
        if (ch == '\'')
        {
            // Add previous token
            addtoken(CurrentToken, lineno, CurrentFile);
            memset(CurrentToken, 0, sizeof(CurrentToken));

            // Read this ..
            CurrentToken[0] = ch;
            CurrentToken[1] = (char)fin.get();
            CurrentToken[2] = (char)fin.get();
            if (CurrentToken[1] == '\\')
                CurrentToken[3] = (char)fin.get();

            // Add token and start on next..
            addtoken(CurrentToken, lineno, CurrentFile);
            memset(CurrentToken, 0, sizeof(CurrentToken));
            pToken = CurrentToken;

            continue;
        }

        // String..
        if (ch == '\"')
        {
            addtoken(CurrentToken, lineno, CurrentFile);
            memset(CurrentToken, 0, sizeof(CurrentToken));
            pToken = CurrentToken;
            bool special = false;
            char c = ch;
            do
            {
                // Append token..
                *pToken = c;
                pToken++;

                // Special sequence '\.'
                if (special)
                    special = false;
                else
                    special = (c == '\\');

                // Get next character
                c = (char)fin.get();
            }
            while (special || c != '\"');
            *pToken = '\"';
            addtoken(CurrentToken, lineno, CurrentFile);
            memset(CurrentToken, 0, sizeof(CurrentToken));
            pToken = CurrentToken;
            continue;
        }

        if (strchr("+-*/%&|^?!=<>[](){};:,.",ch))
        {
            addtoken(CurrentToken, lineno, CurrentFile);
            memset(CurrentToken, 0, sizeof(CurrentToken));
            CurrentToken[0] = ch;
            addtoken(CurrentToken, lineno, CurrentFile);
            memset(CurrentToken, 0, sizeof(CurrentToken));
            pToken = CurrentToken;
            continue;
        }


        if (std::isspace(ch) || std::iscntrl(ch))
        {
            addtoken(CurrentToken, lineno, CurrentFile);
            pToken = CurrentToken;
            memset(CurrentToken, 0, sizeof(CurrentToken));
            continue;
        }

        *pToken = ch;
        pToken++;
    }

    // Combine tokens..
    for (TOKEN *tok = tokens; tok && tok->next; tok = tok->next)
    {
        combine_2tokens(tok, "<", "<");
        combine_2tokens(tok, ">", ">");

        combine_2tokens(tok, "&", "&");
        combine_2tokens(tok, "|", "|");

        combine_2tokens(tok, "+", "=");
        combine_2tokens(tok, "-", "=");
        combine_2tokens(tok, "*", "=");
        combine_2tokens(tok, "/", "=");
        combine_2tokens(tok, "&", "=");
        combine_2tokens(tok, "|", "=");

        combine_2tokens(tok, "=", "=");
        combine_2tokens(tok, "!", "=");
        combine_2tokens(tok, "<", "=");
        combine_2tokens(tok, ">", "=");

        combine_2tokens(tok, ":", ":");
        combine_2tokens(tok, "-", ">");

        combine_2tokens(tok, "private", ":");
        combine_2tokens(tok, "protected", ":");
        combine_2tokens(tok, "public", ":");
    }

    
    // Replace constants..
    for (TOKEN *tok = tokens; tok; tok = tok->next)
    {
        if (strcmp(tok->str,"const"))
            continue;

        const char *sym=NULL, *num=NULL;
        if (match(tok,"const int var = num ;"))
        {
            sym = getstr(tok,2);
            num = getstr(tok,4);
        }
        else if (match(tok,"const unsigned int var = num ;"))
        {
            sym = getstr(tok,3);
            num = getstr(tok,5);
        }
        if (sym && num)
        {
            for (TOKEN *tok2 = gettok(tok,6); tok2; tok2 = tok2->next)
            {
                if (strcmp(tok2->str,sym) == 0)
                {
                    free(tok2->str);
                    tok2->str = strdup(num);
                }
            }
        }
    }

    // Replace 'sizeof'..
    for (TOKEN *tok = tokens; tok; tok = tok->next)
    {
        if (strcmp(tok->str,"sizeof") != 0)
            continue;

        if (match(tok, "sizeof ( unsigned"))
        {
            TOKEN *tok1 = tok->next;
            TOKEN *tok2 = tok1->next;
            tok1->next = tok2->next;
            free(tok2->str);
            delete tok2;
        }


        if (match(tok, "sizeof ( type * )"))
        {
            free(tok->str);
            char str[10];
            tok->str = strdup(itoa(sizeof(char *), str, 10));

            for (int i = 0; i < 4; i++)
            {
                TOKEN *next = tok->next;
                tok->next = next->next;
                free(next->str);
                delete next;
            }
        }

        else if (match(tok, "sizeof ( type )"))
        {
            int size = -1;
            const char *type = getstr(tok, 2);
            if (strcmp(type,"char")==0)
                size = sizeof(char);
            if (strcmp(type,"double")==0)
                size = sizeof(char);
            if (strcmp(type,"int")==0)
                size = sizeof(int);
            if (size < 0)
                continue;

            free(tok->str);
            char str[10];
            tok->str = strdup(itoa(size, str, 10));

            for (int i = 0; i < 3; i++)
            {
                TOKEN *next = tok->next;
                tok->next = next->next;
                free(next->str);
                delete next;
            }
        }
    }
}
//---------------------------------------------------------------------------







//---------------------------------------------------------------------------
// Helper functions for handling the tokens list
//---------------------------------------------------------------------------

TOKEN *findtoken(TOKEN *tok1, const char *tokenstr[])
{
    for (TOKEN *ret = tok1; ret; ret = ret->next)
    {
        unsigned int i = 0;
        TOKEN *tok = ret;
        while (tokenstr[i])
        {
            if (!tok)
                return NULL;
            if (*(tokenstr[i]) && strcmp(tokenstr[i],tok->str))
                break;
            tok = tok->next;
            i++;
        }
        if (!tokenstr[i])
            return ret;
    }
    return NULL;
}
//---------------------------------------------------------------------------

bool match(TOKEN *tok, const std::string pattern)
{
    if (!tok)
        return false;

    const char *p = pattern.c_str();
    while (*p)
    {
        char str[50];
        char *s = str;
        while (*p==' ')
            p++;
        while (*p && *p!=' ')
        {
            *s = *p;
            s++;
            p++;
        }
        *s = 0;
        if (str[0] == 0)
            return true;

        if (strcmp(str,"var")==0 || strcmp(str,"type")==0)
        {
            if (!IsName(tok->str))
                return false;
        }
        else if (strcmp(str,"num")==0)
        {
            if (!std::isdigit(tok->str[0]))
                return false;
        }
        else if (strcmp(str, tok->str) != 0)
            return false;

        tok = tok->next;
        if (!tok)
            return false;
    }
    return true;
}
//---------------------------------------------------------------------------

TOKEN *gettok(TOKEN *tok, int index)
{
    while (tok && index>0)
    {
        tok = tok->next;
        index--;
    }
    return tok;
}
//---------------------------------------------------------------------------

const char *getstr(TOKEN *tok, int index)
{
    tok = gettok(tok, index);
    return tok ? tok->str : "";
}
//---------------------------------------------------------------------------