#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>

#include "mystdlib.h"

static char xlat_table[] = {
  0x00, 0x09, 0x02, 0x03, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
  0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
  0x3c, 0x3d, 0x3e, 0x3f, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b,
  0x4c, 0x4d, 0x4e, 0x4f, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5f,
  0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70,
  0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0xc7, 0xfc, 0xe9, 0xe2, 0xe4, 0xe0,
  0xe5, 0xe7, 0xea, 0xeb, 0xe8, 0xef, 0xee, 0xec, 0xc4, 0xc5, 0xc9, 0xe6, 0xc6, 0xf4, 0xf6, 0xf2,
  0xfb, 0xf9, 0xff, 0xd6, 0xdc, 0xe1, 0xed, 0xf3, 0xfa, 0xf1, 0xd1, 0xdf, 0x5b, 0x5c, 0x5d, 0x60
};

static char cp437_to_iso8859_1_table[] = {
  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
  0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
  0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
  0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
  0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
  0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
  0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
  0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
  0xc7, 0xfc, 0xe9, 0xe2, 0xe4, 0xe0, 0xe5, 0xe7, 0xea, 0xeb, 0xe8, 0xef, 0xee, 0xec, 0xc4, 0xc5,
  0xc9, 0xe6, 0xc6, 0xf4, 0xf6, 0xf2, 0xfb, 0xf9, 0xff, 0xd6, 0xdc, 0xa2, 0xa3, 0xa5, 0x2e, 0x2e,
  0xe1, 0xed, 0xf3, 0xfa, 0xf1, 0xd1, 0xaa, 0xba, 0xbf, 0x2e, 0xac, 0xbd, 0xbc, 0xa1, 0xab, 0xbb,
  0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e,
  0x2e, 0xdf, 0x2e, 0x2e, 0x2e, 0x2e, 0xb5, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e, 0x2e,
  0x2e, 0xb1, 0x2e, 0x2e, 0x2e, 0x2e, 0xf7, 0x2e, 0xb0, 0x2e, 0xb7, 0x2e, 0x2e, 0xb2, 0x2e, 0xa0
};

static struct {
  int    outfiles[15];
  char * vorwahl;
  char * ort;
  char * zip;
} g_state;

void decode_7bit_string( uint8_t const *source, uint8_t *dest )
{
  uint16_t acc = 0, acc_bits = 0;
  while( 1 )
  {
    acc = acc*256+*(source++); ++acc_bits;
again:
    *(dest++) = xlat_table[ 0x7f & ( acc >> acc_bits ) ];
    if( !dest[-1] ) return;
    if( acc_bits == 7 ) { acc_bits = 0; goto again; }
  }
}

void split_to_files( uint8_t *entries, int num_entries )
{
  int entry = 0, column;
  char *e = (char*)entries;

  for( entry = 0; entry < num_entries; ++entry )
  {
    /* mimic flags from telefonbuch v3 */
    write( g_state.outfiles[0], entry ? "02\n" : ( num_entries > 1 ? "01\n" : "00\n" ), 3 );
    dprintf( g_state.outfiles[12], "%s\n", g_state.ort );
    /* Only part of zip code, Zustellpostamt or eastern German code in column 5 (06_unknown) */
    dprintf( g_state.outfiles[13], "%s\n", g_state.zip );

    for( column = 0; column < 11; ++column )
    {
      char * end = strchr( e, '\t' );
      if( end ) {
        *end = '\n';
        if( column == 9 && *e >= '0' && *e <= '9' ) write( g_state.outfiles[column+1], "0", 1 ); /* Augment Vorwahl */
        write( g_state.outfiles[column+1], e, end - e + 1);
        e = end + 1;
      } else
        dprintf( g_state.outfiles[column+1], "%s\n", e);
    }
  }
}

void act_on_record( uint8_t *file, int flag, uint8_t *page, uint16_t record_off )
{
  uint8_t outbuf[8192], *out_dest = outbuf, *record;
  int     num_entries;

  if( record_off > 0x1fff )
  {
    /* Here comes the reference to a blob page */
    int page_nr  = *(uint16_t*)(page + ( record_off ^ 0xffff ) + 1);
    page         = file + 0x800 + 0x2000 * page_nr;
    num_entries  = *(uint16_t*)page;
    record       = page + 0x6;
  }
  else
  {
    record       = page + record_off;
    num_entries  = *(uint16_t*)record;
    if( !flag )
    { /* Flags says whether page has a prefix row */
      record += 2;
      if( *(uint16_t*)record )
      {
        decode_7bit_string( page + *(uint16_t*)record, outbuf );
        out_dest += strlen( (char*)outbuf );
      }
    }
    record += 2;
  }

  decode_7bit_string( record, out_dest );
  split_to_files( outbuf, num_entries );
}

/* Page is always 0x2000 */
void act_on_page( uint8_t *file, uint8_t *page, int page_nr )
{
  int record, flag  = page[0];
  int blob_len      = *(uint16_t*)(page + 0x2);
  int num_records   = *(uint16_t*)(page + 0x4);
  uint16_t * recs   =  (uint16_t*)(page + 0xe);

  /* printf( "  Acting on page %04d with flag %d and %04d records.\n", page_nr, flag, num_records ); */
  (void)page_nr; /* silence warning about unused variable */

  if( !blob_len ) /* Handle blob, pages when they're referenced */
    for( record = 0; record < num_records; ++record )
      act_on_record( file, flag, page + 0xe, recs[record] );
}

void act_on_file( uint8_t *file )
{
  int page, num_pages = *(uint16_t*)(file+0x40);
  int num_records     = *(uint32_t*)(file+0x42);
  char *gasse         = (char *)file + 0x8e;
  char *ort           = gasse + 1 + strlen(gasse);
  char *zip           = ort   + 1 + strlen(ort);
  char *vorwahl       = zip   + 1 + strlen(zip);
  char ort_conv[1024]; int i;

  for(i=0; ort[i]; ++i ) ort_conv[i] = cp437_to_iso8859_1_table[((uint8_t*)ort)[i]]; ort_conv[i] = 0;
  /* printf( "Working on a %04d page and %06d records file, city: %4s %-32s with prefix %s\n", num_pages, num_records, zip, ort_conv, vorwahl ); */

  g_state.ort     = ort_conv;
  g_state.zip     = zip;
  g_state.vorwahl = vorwahl;

  for( page = 0; page < num_pages; ++page )
    act_on_page( file, file + 0x800 + 0x2000 * page, page );
}

int main( )
{
  char filename[1024];
  MAP f;
  int i;

  for( i=0; i<14; ++i )
  {
    sprintf( filename, "%02d_unknown", i+1 );
    g_state.outfiles[i] = open( filename, O_WRONLY | O_APPEND | O_CREAT, 0644 );
  }

  while( fgets( filename, sizeof(filename), stdin ) ) {
    filename[strlen(filename)-1] = 0; /* fgets sucks */
    f = map_file( filename, 1 );

    act_on_file( f->addr );
    unmap_file( &f );
  }

  for( i=0; i<14; ++i )
    close(  g_state.outfiles[i] );

  return 0;
}