#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <windows.h>

#define DUMP

char toescape(char c)
{
    switch(c) {
    case '7': return '\7';
    case '(':  return '(';
    case ')':  return ')';
    case 't':  return '\t';
    case 'n':  return '\n';
    case 'r':  return '\r';
    case '\\': return '\\';
    case '\"': return '\"';
    }
    return c;
}

char todigit(char c)
{
    char d = toupper(c);
    if(d >= '0' && d <= '9') d = d - '0';
    else d = d - 'A' + 10;
    return d;
}

int isescape(char c)
{
    if(c == '(' || c == ')' || c == 't' || c == 'n' || c == 'r' || c == '\\' || c == '\"') return 1;
    return 0;
}

int findString(char* str, char* find)
{
    for(unsigned int i=0; i<strlen(str); i++){
        if(!strncmp(str+i,find,strlen(find))) return i;
    }
    return -1;
}

void dump(unsigned char* str, int sn)
{
    for(int i=0; i<sn; i++){ printf("%02x, ",str[i]); }
    printf(" : %s \n",str);
}

#define BOM ((wchar_t)0xFEFF) // UTF-16 BOM

int isEnglish(char* str, int sn)
{
    for(int i=0; i<sn; i++){ if(!isascii(str[i])) return 0; }
    return 1;
}

void wcs2sjis(char* str, char* sjis, int sn)
{
    if(isEnglish(str,sn)){
        memset(sjis,0,sizeof(sjis));
        strncpy(sjis,str,strlen(str)+1);
        return;
    }
    wchar_t string[2048];
    wchar_t *dest = string;
    for(int i=0; i<sn; i++){
        wchar_t wc = (wchar_t)(((unsigned char)str[i] << 8) | (unsigned char)str[i+1]);
        if(wc != BOM) *dest++ = wc;
        i++;
    }
    *dest = L'\0';
    memset(sjis,0,sizeof(sjis));
    int nLen = ::WideCharToMultiByte(CP_ACP, 0, string, -1, NULL, 0, NULL, NULL );
    ::WideCharToMultiByte(CP_ACP, 0, string, -1, sjis, nLen, NULL, NULL );
}


int getPDFString(char* dst, char* src, int si, char* find)
{
    int b_esc = 0,ci = 0;
    int b_start = 0;
    memset(dst,0,sizeof(dst));
    for(unsigned int i=si+strlen(find); i<strlen(src); i++){ if(src[i] != ' ') { si = i; break; } }
    for(unsigned int i=si; i<strlen(src); i++){
        if(src[i] == '(') { b_start = 1; si = i+1; break; }
        else if(src[i] == '<') { b_start = 2; si = i+1; break; }
        else if(src[i] != '(' && src[i] != '<') { si = i; break; }
        
    }
    int iskip = (b_start == 2) ? 2 : 1;
    for(unsigned int i=si; i<strlen(src); i+=iskip){
        if(!b_esc && src[i] == '\\'){ b_esc = 1; continue; }
        if(b_esc){
            b_esc = 0;
            if(isescape(src[i])){
                dst[ci++] = toescape(src[i]);
#ifdef DUMP
                printf("[\\%c], ",src[i]);
#endif
                continue; }
            unsigned int ii, di = 0;
            char dv[10]; memset(dv,0,sizeof(dv));
            int b_flag = 0;
            for(ii=i; b_flag != 1; ii++){
                if(!(src[ii] >= '0' && src[ii] <= '9')) { b_flag = 1; continue; }
                if(ii == i+3){ b_flag = 1; continue; }
                dv[di++] = src[ii];
            }
            char *es;
            int base8 = strtol(dv,&es,8);
            dst[ci++] = base8;
            printf("[\\%o], ",base8);
            i = ii-2;
            continue;
        }
        if(src[i] == ')' && b_start == 1) break;
        if(src[i] == '>' && b_start == 2) break;
        if((src[i] == ' ' || src[i] == '/') && b_start == 0) break;
        if(b_start == 2) {
            if(src[i] == '0' && src[i] == '0') { dst[ci++] = 0; printf("0, "); continue; }    
            dst[ci++] = (todigit(src[i])<<4) + todigit(src[i+1]);
#ifdef DUMP
            printf("([%d,%02x,%c]: %c%c), ",(unsigned char)dst[ci-1],(unsigned char)dst[ci-1],dst[ci-1],src[i],src[i+1]);
#endif
        } else {
            dst[ci++] = src[i];
#ifdef DUMP
            printf("%c[%02x], ",src[i],(unsigned char)src[i]);
#endif
        }
    }
#ifdef DUMP
    printf("\n");
#endif
    return ci;
}

int main()
{
    const int BUFSIZE = 2048;
    FILE* fp = fopen("src.pdf","rb");
    char readbuf[BUFSIZE];
    if(fp == NULL) return 0;
    int count = 0;
    int b_title = 0, b_author = 0, b_count = 0;
    char title[BUFSIZE],author[BUFSIZE],scount[BUFSIZE];
    char title_s[BUFSIZE],author_s[BUFSIZE],scount_s[BUFSIZE];
    memset(readbuf,0,sizeof(readbuf));
    memset(title,0,sizeof(title));
    memset(author,0,sizeof(author));
    memset(scount,0,sizeof(scount));
    memset(title_s,0,sizeof(title));
    memset(author_s,0,sizeof(author));
    memset(scount_s,0,sizeof(scount_s));

    while(fgets(readbuf,BUFSIZE,fp)){
        int si = 0;
        if((si = findString(readbuf,"/Title")) >= 0 && b_title == 0){
            int cn = getPDFString(title,readbuf,si,"/Title");
            wcs2sjis(title,title_s,cn);
#ifdef DUMP
            printf("title: "); dump((unsigned char*)title,cn);
#endif
            b_title = 1;
        }
        if((si = findString(readbuf,"/Author")) >= 0 && b_author == 0){
            int cn = getPDFString(author,readbuf,si,"/Author");
            wcs2sjis(author,author_s,cn);
#ifdef DUMP
            printf("author: "); dump((unsigned char*)author,cn);
#endif
            b_author = 1;
        }
        if((si = findString(readbuf,"/N ")) >= 0 && b_count == 0){
            int cn = getPDFString(scount,readbuf,si,"/N ");
            if(strlen(scount) < 4){
#ifdef DUMP
                printf("count: "); dump((unsigned char*)scount,cn);
#endif
                count = atoi(scount);
                b_count = 1;
            }
        }
        if((si = findString(readbuf,"/Count")) >= 0 && b_count == 0){
            int cn = getPDFString(scount,readbuf,si,"/Count");
#ifdef DUMP
            printf("count: "); dump((unsigned char*)scount,cn);
#endif
            count = atoi(scount);
            b_count = 1;
        }
        if(b_title && b_author && b_count) break;
        memset(readbuf,0,sizeof(readbuf));
    }
    fclose(fp);
    
    if(b_title) printf("title is %s\n",title_s);
    if(b_author) printf("author is %s\n",author_s);
    if(b_count) printf("count is %d\n",count);

    return 0;
}