#include "token822.h"

#include "alloc.h"
#include "genalloc.h"
#include "str.h"
#include "stralloc.h"

static struct token822 comma = {TOKEN822_COMMA};

void token822_reverse(token822_alloc *ta)
{
  int n = ta->len - 1;
  struct token822 temp;

  for (int i = 0; i + i < n; ++i) {
    temp = ta->t[i];
    ta->t[i] = ta->t[n - i];
    ta->t[n - i] = temp;
  }
}

static int needspace(int t1, int t2)
{
  if (!t1) return 0;
  if (t1 == TOKEN822_COLON) return 1;
  if (t1 == TOKEN822_COMMA) return 1;
  if (t2 == TOKEN822_LEFT) return 1;

  switch (t1) {
    case TOKEN822_ATOM:
    case TOKEN822_LITERAL:
    case TOKEN822_QUOTE:
    case TOKEN822_COMMENT:
      switch (t2) {
        case TOKEN822_ATOM:
        case TOKEN822_LITERAL:
        case TOKEN822_QUOTE:
        case TOKEN822_COMMENT: return 1;
      }
  }
  return 0;
}

static int atomok(char ch)
{
  switch (ch) {
    case ' ':
    case '\t':
    case '\r':
    case '\n':
    case '(':
    case '[':
    case '"':
    case '<':
    case '>':
    case ';':
    case ':':
    case '@':
    case ',':
    case '.':  return 0;
  }
  return 1;
}

static void atomcheck(struct token822 *t)
{
  int i;
  char ch;

  for (i = 0; i < t->slen; ++i) {
    ch = t->s[i];
    if ((ch < 32) || (ch > 126) || (ch == ')') || (ch == ']') || (ch == '\\')) {
      t->type = TOKEN822_QUOTE;
      return;
    }
  }
}

int token822_unparse(stralloc *sa, token822_alloc *ta, unsigned int linelen)
{
  struct token822 *t;
  int len;
  int ch;
  int i;
  int j;
  int lasttype;
  int newtype;
  char *s;
  char *lineb;
  char *linee;

  len = 0;
  lasttype = 0;

  for (i = 0; i < ta->len; ++i) {
    t = ta->t + i;
    newtype = t->type;
    if (needspace(lasttype, newtype)) ++len;
    lasttype = newtype;

    switch (newtype) {
      case TOKEN822_COMMA: len += 3; break;
      case TOKEN822_AT:
      case TOKEN822_DOT:
      case TOKEN822_LEFT:
      case TOKEN822_RIGHT:
      case TOKEN822_SEMI:
      case TOKEN822_COLON: ++len; break;
      case TOKEN822_ATOM:
      case TOKEN822_QUOTE:
      case TOKEN822_LITERAL:
      case TOKEN822_COMMENT:
        if (t->type != TOKEN822_ATOM) len += 2;
        for (j = 0; j < t->slen; ++j) {
          switch (ch = t->s[j]) {
            case '"':
            case '[':
            case ']':
            case '(':
            case ')':
            case '\\':
            case '\r':
            case '\n': ++len;
            default:   ++len;
          }
        }
        break;
    }
  }
  len += 2;

  if (!stralloc_ready(sa, len)) return -1;

  s = sa->s;
  lineb = s;
  linee = 0;

  lasttype = 0;

  for (i = 0; i < ta->len; ++i) {
    t = ta->t + i;
    newtype = t->type;
    if (needspace(lasttype, newtype)) *s++ = ' ';
    lasttype = newtype;

    switch (newtype) {
      case TOKEN822_COMMA: *s++ = ',';
#define NSUW                                           \
  s[0] = '\n';                                         \
  s[1] = ' ';                                          \
  if (linee && (!linelen || (s - lineb <= linelen))) { \
    while (linee < s) {                                \
      linee[0] = linee[2];                             \
      ++linee;                                         \
    }                                                  \
    linee -= 2;                                        \
  } else {                                             \
    if (linee) lineb = linee + 1;                      \
    linee = s;                                         \
    s += 2;                                            \
  }
        NSUW break;
      case TOKEN822_AT:    *s++ = '@'; break;
      case TOKEN822_DOT:   *s++ = '.'; break;
      case TOKEN822_LEFT:  *s++ = '<'; break;
      case TOKEN822_RIGHT: *s++ = '>'; break;
      case TOKEN822_SEMI:  *s++ = ';'; break;
      case TOKEN822_COLON: *s++ = ':'; break;
      case TOKEN822_ATOM:
      case TOKEN822_QUOTE:
      case TOKEN822_LITERAL:
      case TOKEN822_COMMENT:
        if (t->type == TOKEN822_QUOTE) *s++ = '"';
        if (t->type == TOKEN822_LITERAL) *s++ = '[';
        if (t->type == TOKEN822_COMMENT) *s++ = '(';

        for (j = 0; j < t->slen; ++j) {
          switch (ch = t->s[j]) {
            case '"':
            case '[':
            case ']':
            case '(':
            case ')':
            case '\\':
            case '\r':
            case '\n': *s++ = '\\';
            default:   *s++ = ch;
          }
        }
        if (t->type == TOKEN822_QUOTE) *s++ = '"';
        if (t->type == TOKEN822_LITERAL) *s++ = ']';
        if (t->type == TOKEN822_COMMENT) *s++ = ')';
        break;
    }
  }
  NSUW-- s;
  sa->len = s - sa->s;
  return 1;
}

int token822_unquote(stralloc *sa, token822_alloc *ta)
{
  struct token822 *t;
  int len;
  int i;
  int j;
  char *s;

  len = 0;

  for (i = 0; i < ta->len; ++i) {
    t = ta->t + i;
    switch (t->type) {
      case TOKEN822_COMMA:
      case TOKEN822_AT:
      case TOKEN822_DOT:
      case TOKEN822_LEFT:
      case TOKEN822_RIGHT:
      case TOKEN822_SEMI:
      case TOKEN822_COLON:   ++len; break;
      case TOKEN822_LITERAL: len += 2;
      case TOKEN822_ATOM:
      case TOKEN822_QUOTE:   len += t->slen;
    }
  }

  if (!stralloc_ready(sa, len)) return -1;

  s = sa->s;

  for (i = 0; i < ta->len; ++i) {
    t = ta->t + i;
    switch (t->type) {
      case TOKEN822_COMMA: *s++ = ','; break;
      case TOKEN822_AT:    *s++ = '@'; break;
      case TOKEN822_DOT:   *s++ = '.'; break;
      case TOKEN822_LEFT:  *s++ = '<'; break;
      case TOKEN822_RIGHT: *s++ = '>'; break;
      case TOKEN822_SEMI:  *s++ = ';'; break;
      case TOKEN822_COLON: *s++ = ':'; break;
      case TOKEN822_ATOM:
      case TOKEN822_QUOTE:
      case TOKEN822_LITERAL:
        if (t->type == TOKEN822_LITERAL) *s++ = '[';
        for (j = 0; j < t->slen; ++j) *s++ = t->s[j];
        if (t->type == TOKEN822_LITERAL) *s++ = ']';
        break;
      case TOKEN822_COMMENT: break;
    }
  }
  sa->len = s - sa->s;
  return 1;
}

int token822_parse(token822_alloc *ta, stralloc *sa, stralloc *buf)
{
  int i;
  int salen;
  int level;
  struct token822 *t;
  int numtoks;
  int numchars;
  char *cbuf;

  salen = sa->len;

  numchars = 0;
  numtoks = 0;

  for (i = 0; i < salen; ++i) {
    switch (sa->s[i]) {
      case '.':
      case ',':
      case '@':
      case '<':
      case '>':
      case ':':
      case ';':  ++numtoks; break;
      case ' ':
      case '\t':
      case '\r':
      case '\n': break;
      case ')':
      case ']':
        return 0;
        /* other control chars and non-ASCII chars are also bad, in theory */
      case '(':
        level = 1;
        while (level) {
          if (++i >= salen) return 0;
          switch (sa->s[i]) {
            case '(': ++level; break;
            case ')': --level; break;
            case '\\':
              if (++i >= salen) return 0;
            default: ++numchars;
          }
        }
        ++numtoks;
        break;
      case '"':
        level = 1;
        while (level) {
          if (++i >= salen) return 0;
          switch (sa->s[i]) {
            case '"': --level; break;
            case '\\':
              if (++i >= salen) return 0;
            default: ++numchars;
          }
        }
        ++numtoks;
        break;
      case '[':
        level = 1;
        while (level) {
          if (++i >= salen) return 0;
          switch (sa->s[i]) {
            case ']': --level; break;
            case '\\':
              if (++i >= salen) return 0;
            default: ++numchars;
          }
        }
        ++numtoks;
        break;
      default:
        do {
          if (sa->s[i] == '\\')
            if (++i >= salen) break;
          ++numchars;
          if (++i >= salen) break;
        } while (atomok(sa->s[i]));
        --i;
        ++numtoks;
    }
  }

  if (!token822_ready(ta, numtoks)) return -1;
  if (!stralloc_ready(buf, numchars)) return -1;
  cbuf = buf->s;
  ta->len = numtoks;

  t = ta->t;

  for (i = 0; i < salen; ++i) {
    switch (sa->s[i]) {
      case '.':
        t->type = TOKEN822_DOT;
        ++t;
        break;
      case ',':
        t->type = TOKEN822_COMMA;
        ++t;
        break;
      case '@':
        t->type = TOKEN822_AT;
        ++t;
        break;
      case '<':
        t->type = TOKEN822_LEFT;
        ++t;
        break;
      case '>':
        t->type = TOKEN822_RIGHT;
        ++t;
        break;
      case ':':
        t->type = TOKEN822_COLON;
        ++t;
        break;
      case ';':
        t->type = TOKEN822_SEMI;
        ++t;
        break;
      case ' ':
      case '\t':
      case '\r':
      case '\n': break;
      case '(':
        t->type = TOKEN822_COMMENT;
        t->s = cbuf;
        t->slen = 0;
        level = 1;
        while (level) {
          ++i; /* assert: < salen */
          switch (sa->s[i]) {
            case '(':  ++level; break;
            case ')':  --level; break;
            case '\\': ++i; /* assert: < salen */
            default:   *cbuf++ = sa->s[i]; ++t->slen;
          }
        }
        ++t;
        break;
      case '"':
        t->type = TOKEN822_QUOTE;
        t->s = cbuf;
        t->slen = 0;
        level = 1;
        while (level) {
          ++i; /* assert: < salen */
          switch (sa->s[i]) {
            case '"':  --level; break;
            case '\\': ++i; /* assert: < salen */
            default:   *cbuf++ = sa->s[i]; ++t->slen;
          }
        }
        ++t;
        break;
      case '[':
        t->type = TOKEN822_LITERAL;
        t->s = cbuf;
        t->slen = 0;
        level = 1;
        while (level) {
          ++i; /* assert: < salen */
          switch (sa->s[i]) {
            case ']':  --level; break;
            case '\\': ++i; /* assert: < salen */
            default:   *cbuf++ = sa->s[i]; ++t->slen;
          }
        }
        ++t;
        break;
      default:
        t->type = TOKEN822_ATOM;
        t->s = cbuf;
        t->slen = 0;
        do {
          if (sa->s[i] == '\\')
            if (++i >= salen) break;
          *cbuf++ = sa->s[i];
          ++t->slen;
          if (++i >= salen) break;
        } while (atomok(sa->s[i]));
        atomcheck(t);
        --i;
        ++t;
    }
  }
  return 1;
}

static int gotaddr(token822_alloc *taout, token822_alloc *taaddr, int (*callback)(token822_alloc *))
{
  int i;

  if (callback(taaddr) != 1) return 0;

  if (!token822_readyplus(taout, taaddr->len)) return 0;

  for (i = 0; i < taaddr->len; ++i) taout->t[taout->len++] = taaddr->t[i];

  taaddr->len = 0;
  return 1;
}

int token822_addrlist(
    token822_alloc *taout, token822_alloc *taaddr, token822_alloc *ta, int (*callback)())
{
  struct token822 *t;
  struct token822 *beginning;
  int ingroup;
  int wordok;

  taout->len = 0;
  taaddr->len = 0;

  if (!token822_readyplus(taout, 1)) return -1;
  if (!token822_readyplus(taaddr, 1)) return -1;

  ingroup = 0;
  wordok = 1;

  beginning = ta->t + 2;
  t = ta->t + ta->len - 1;

  /* rfc 822 address lists are easy to parse from right to left */

#define FLUSH      \
  if (taaddr->len) \
    if (!gotaddr(taout, taaddr, callback)) return -1;
#define FLUSHCOMMA                                    \
  if (taaddr->len) {                                  \
    if (!gotaddr(taout, taaddr, callback)) return -1; \
    if (!token822_append(taout, &comma)) return -1;   \
  }
#define ADDRLEFT \
  if (!token822_append(taaddr, t--)) return -1;
#define OUTLEFT \
  if (!token822_append(taout, t--)) return -1;

  while (t >= beginning) {
    switch (t->type) {
      case TOKEN822_SEMI:
        FLUSHCOMMA
        if (ingroup) return 0;
        ingroup = 1;
        wordok = 1;
        break;
      case TOKEN822_COLON:
        FLUSH
        if (!ingroup) return 0;
        ingroup = 0;
        while ((t >= beginning) && (t->type != TOKEN822_COMMA)) OUTLEFT
        if (t >= beginning) OUTLEFT
        wordok = 1;
        continue;
      case TOKEN822_RIGHT:
        FLUSHCOMMA
        OUTLEFT
        while ((t >= beginning) && (t->type != TOKEN822_LEFT)) ADDRLEFT
        /* important to use address here even if it's empty: <> */
        if (!gotaddr(taout, taaddr, callback)) return -1;
        if (t < beginning) return 0;
        OUTLEFT
        while (
            (t >= beginning)
            && ((t->type == TOKEN822_COMMENT) || (t->type == TOKEN822_ATOM)
                || (t->type == TOKEN822_QUOTE) || (t->type == TOKEN822_AT) || (t->type == TOKEN822_DOT)))
          OUTLEFT
        wordok = 0;
        continue;
      case TOKEN822_ATOM:
      case TOKEN822_QUOTE:
      case TOKEN822_LITERAL:
        if (!wordok) FLUSHCOMMA
        wordok = 0;
        ADDRLEFT
        continue;
      case TOKEN822_COMMENT:
        /* comment is lexically a space; shouldn't affect wordok */
        break;
      case TOKEN822_COMMA:
        FLUSH
        wordok = 1;
        break;
      default:
        wordok = 1;
        ADDRLEFT
        continue;
    }
    OUTLEFT
  }
  FLUSH
  ++t;
  while (t > ta->t)
    if (!token822_append(taout, --t)) return -1;

  token822_reverse(taout);
  return 1;
}