//========================================================================

//

// UnicodeRemapping.cc

//

// Copyright 2018 Glyph & Cog, LLC

//

//========================================================================

#include <aconf.h>

#include <stdio.h>

#include <string.h>

#include "gmem.h"

#include "gmempp.h"

#include "gfile.h"

#include "GString.h"

#include "Error.h"

#include "UnicodeRemapping.h"

//------------------------------------------------------------------------

#define maxUnicodeString 8

struct UnicodeRemappingString {

  Unicode in;

  Unicode out[maxUnicodeString];

  int len;

};

//------------------------------------------------------------------------

static int hexCharVals[256] = {

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 0x

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 1x

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 2x

   0,  1,  2,  3,  4,  5,  6,  7,  8,  9, -1, -1, -1, -1, -1, -1, // 3x

  -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 4x

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 5x

  -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 6x

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 7x

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 8x

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 9x

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // Ax

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // Bx

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // Cx

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // Dx

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // Ex

  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1  // Fx

};

// Parse a <len>-byte hex string <s> into *<val>.  Returns false on

// error.

static GBool parseHex(char *s, int len, Guint *val) {

  int i, x;

  *val = 0;

  for (i = 0; i < len; ++i) {

    x = hexCharVals[s[i] & 0xff];

    if (x < 0) {

      return gFalse;

    }

    *val = (*val << 4) + x;

  }

  return gTrue;

}

//------------------------------------------------------------------------

UnicodeRemapping::UnicodeRemapping() {

  for (int i = 0; i < 256; ++i) {

    page0[i] = (Unicode)i;

  }

  sMap = NULL;

  sMapLen = sMapSize = 0;

}

UnicodeRemapping::~UnicodeRemapping() {

  gfree(sMap);

}

void UnicodeRemapping::addRemapping(Unicode in, Unicode *out, int len) {

  int i, j;

  if (in < 256 && len == 1) {

    page0[in] = out[0];

  } else {

    if (in < 256) {

      page0[in] = 0xffffffff;

    }

    if (sMapLen == sMapSize) {

      sMapSize += 16;

      sMap = (UnicodeRemappingString *)

           greallocn(sMap, sMapSize, sizeof(UnicodeRemappingString));

    }

    i = findSMap(in);

    if (i < sMapLen) {

      memmove(sMap + i + 1, sMap + i,

        (sMapLen - i) * sizeof(UnicodeRemappingString));

    }

    sMap[i].in = in;

    for (j = 0; j < len && j < maxUnicodeString; ++j) {

      sMap[i].out[j] = out[j];

    }

    sMap[i].len = j;

    ++sMapLen;

  }

}

void UnicodeRemapping::parseFile(GString *fileName) {

  FILE *f;

  char buf[256];

  Unicode in;

  Unicode out[maxUnicodeString];

  char *tok;

  int line, n;

  if (!(f = openFile(fileName->getCString(), "r"))) {

    error(errSyntaxError, -1, "Couldn't open unicodeRemapping file '{0:t}'",

    fileName);

    return;

  }

  line = 0;

  while (getLine(buf, sizeof(buf), f)) {

    ++line;

    if (!(tok = strtok(buf, " \t\r\n")) ||

  !parseHex(tok, (int)strlen(tok), &in)) {

      error(errSyntaxWarning, -1,

      "Bad line ({0:d}) in unicodeRemapping file '{1:t}'",

      line, fileName);

      continue;

    }

    n = 0;

    while (n < maxUnicodeString) {

      if (!(tok = strtok(NULL, " \t\r\n"))) {

  break;

      }

      if (!parseHex(tok, (int)strlen(tok), &out[n])) {

  error(errSyntaxWarning, -1,

        "Bad line ({0:d}) in unicodeRemapping file '{1:t}'",

        line, fileName);

  break;

      }

      ++n;

    }

    addRemapping(in, out, n);

  }

  fclose(f);

}

// Determine the location in sMap to insert/replace the entry for [u].

int UnicodeRemapping::findSMap(Unicode u) {

  int a, b, m;

  a = -1;

  b = sMapLen;

  // invariant: sMap[a].in < u <= sMap[b].in

  while (b - a > 1) {

    m = (a + b) / 2;

    if (sMap[m].in < u) {

      a = m;

    } else {

      b = m;

    }

  }

  return b;

}

int UnicodeRemapping::map(Unicode in, Unicode *out, int size) {

  int a, b, m, i;

  if (in < 256 && page0[in] != 0xffffffff) {

    out[0] = page0[in];

    return 1;

  }

  a = -1;

  b = sMapLen;

  // invariant: sMap[a].in < in < sMap[b].in

  while (b - a > 1) {

    m = (a + b) / 2;

    if (sMap[m].in < in) {

      a = m;

    } else if (in < sMap[m].in) {

      b = m;

    } else {

      for (i = 0; i < sMap[m].len && i < size; ++i) {

  out[i] = sMap[m].out[i];

      }

      return i;

    }

  }

  out[0] = in;

  return 1;

}