+/*
+ * Flush a line of text. A "line" is loosely defined as being something
+ * that should be followed by a newline, regardless of whether it's
+ * broken apart by newlines getting there. A line can also be a
+ * fragment of a columnar list.
+ *
+ * Specifically, a line is whatever's in p->buf of length p->col, which
+ * is zeroed after this function returns.
+ *
+ * The variables TERMP_NOLPAD, TERMP_LITERAL and TERMP_NOBREAK are of
+ * critical importance here. Their behaviour follows:
+ *
+ * - TERMP_NOLPAD: when beginning to write the line, don't left-pad the
+ * offset value. This is useful when doing columnar lists where the
+ * prior column has right-padded.
+ *
+ * - TERMP_NOBREAK: this is the most important and is used when making
+ * columns. In short: don't print a newline and instead pad to the
+ * right margin. Used in conjunction with TERMP_NOLPAD.
+ *
+ * In-line line breaking:
+ *
+ * If TERMP_NOBREAK is specified and the line overruns the right
+ * margin, it will break and pad-right to the right margin after
+ * writing. If maxrmargin is violated, it will break and continue
+ * writing from the right-margin, which will lead to the above
+ * scenario upon exit.
+ *
+ * Otherwise, the line will break at the right margin. Extremely long
+ * lines will cause the system to emit a warning (TODO: hyphenate, if
+ * possible).
+ */
+void
+flushln(struct termp *p)
+{
+ size_t i, j, vsz, vis, maxvis, mmax, bp;
+
+ /*
+ * First, establish the maximum columns of "visible" content.
+ * This is usually the difference between the right-margin and
+ * an indentation, but can be, for tagged lists or columns, a
+ * small set of values.
+ */
+
+ assert(p->offset < p->rmargin);
+ maxvis = p->rmargin - p->offset;
+ mmax = p->maxrmargin - p->offset;
+ bp = TERMP_NOBREAK & p->flags ? mmax : maxvis;
+ vis = 0;
+
+ /*
+ * If in the standard case (left-justified), then begin with our
+ * indentation, otherwise (columns, etc.) just start spitting
+ * out text.
+ */
+
+ if ( ! (p->flags & TERMP_NOLPAD))
+ /* LINTED */
+ for (j = 0; j < p->offset; j++)
+ putchar(' ');
+
+ for (i = 0; i < p->col; i++) {
+ /*
+ * Count up visible word characters. Control sequences
+ * (starting with the CSI) aren't counted. A space
+ * generates a non-printing word, which is valid (the
+ * space is printed according to regular spacing rules).
+ */
+
+ /* FIXME: make non-ANSI friendly. */
+
+ /* LINTED */
+ for (j = i, vsz = 0; j < p->col; j++) {
+ if (isspace((u_char)p->buf[j]))
+ break;
+ else if (27 == p->buf[j]) {
+ assert(j + 4 <= p->col);
+ j += 3;
+ } else
+ vsz++;
+ }
+
+ /*
+ * Do line-breaking. If we're greater than our
+ * break-point and already in-line, break to the next
+ * line and start writing. If we're at the line start,
+ * then write out the word (TODO: hyphenate) and break
+ * in a subsequent loop invocation.
+ */
+
+ if ( ! (TERMP_NOBREAK & p->flags)) {
+ if (vis && vis + vsz > bp) {
+ putchar('\n');
+ for (j = 0; j < p->offset; j++)
+ putchar(' ');
+ vis = 0;
+ } else if (vis + vsz > bp)
+ warnx("word breaks right margin");
+
+ /* TODO: hyphenate. */
+
+ } else {
+ if (vis && vis + vsz > bp) {
+ putchar('\n');
+ for (j = 0; j < p->rmargin; j++)
+ putchar(' ');
+ vis = p->rmargin - p->offset;
+ } else if (vis + vsz > bp)
+ warnx("word breaks right margin");
+
+ /* TODO: hyphenate. */
+ }
+
+ /*
+ * Write out the word and a trailing space. Omit the
+ * space if we're the last word in the line or beyond
+ * our breakpoint.
+ */
+
+ for ( ; i < p->col; i++) {
+ if (isspace((u_char)p->buf[i]))
+ break;
+ putchar(p->buf[i]);
+ }
+ vis += vsz;
+ if (i < p->col && vis <= bp) {
+ putchar(' ');
+ vis++;
+ }
+ }
+
+ /*
+ * If we've overstepped our maximum visible no-break space, then
+ * cause a newline and offset at the right margin.
+ */
+
+ if ((TERMP_NOBREAK & p->flags) && vis >= maxvis) {
+ if ( ! (TERMP_NONOBREAK & p->flags)) {
+ putchar('\n');
+ for (i = 0; i < p->rmargin; i++)
+ putchar(' ');
+ }
+ p->col = 0;
+ return;
+ }
+
+ /*
+ * If we're not to right-marginalise it (newline), then instead
+ * pad to the right margin and stay off.
+ */
+
+ if (p->flags & TERMP_NOBREAK) {
+ if ( ! (TERMP_NONOBREAK & p->flags))
+ for ( ; vis < maxvis; vis++)
+ putchar(' ');
+ } else
+ putchar('\n');
+
+ p->col = 0;
+}
+
+
+/*
+ * A newline only breaks an existing line; it won't assert vertical
+ * space. All data in the output buffer is flushed prior to the newline
+ * assertion.
+ */
+void
+newln(struct termp *p)
+{
+
+ p->flags |= TERMP_NOSPACE;
+ if (0 == p->col) {
+ p->flags &= ~TERMP_NOLPAD;
+ return;
+ }
+ flushln(p);
+ p->flags &= ~TERMP_NOLPAD;
+}
+
+
+/*
+ * Asserts a vertical space (a full, empty line-break between lines).
+ * Note that if used twice, this will cause two blank spaces and so on.
+ * All data in the output buffer is flushed prior to the newline
+ * assertion.
+ */
+void
+vspace(struct termp *p)
+{
+
+ newln(p);
+ putchar('\n');
+}
+
+
+/*
+ * Break apart a word into "pwords" (partial-words, usually from
+ * breaking up a phrase into individual words) and, eventually, put them
+ * into the output buffer. If we're a literal word, then don't break up
+ * the word and put it verbatim into the output buffer.
+ */
+void
+word(struct termp *p, const char *word)
+{
+ size_t i, j, len;
+
+ if (p->flags & TERMP_LITERAL) {
+ pword(p, word, strlen(word));
+ return;
+ }
+
+ len = strlen(word);
+ assert(len > 0);
+
+ if (mdoc_isdelim(word)) {
+ if ( ! (p->flags & TERMP_IGNDELIM))
+ p->flags |= TERMP_NOSPACE;
+ p->flags &= ~TERMP_IGNDELIM;
+ }
+
+ /* LINTED */
+ for (j = i = 0; i < len; i++) {
+ if ( ! isspace((u_char)word[i])) {
+ j++;
+ continue;
+ }
+
+ /* Escaped spaces don't delimit... */
+ if (i > 0 && isspace((u_char)word[i]) &&
+ '\\' == word[i - 1]) {
+ j++;
+ continue;
+ }
+
+ if (0 == j)
+ continue;
+ assert(i >= j);
+ pword(p, &word[i - j], j);
+ j = 0;
+ }
+ if (j > 0) {
+ assert(i >= j);
+ pword(p, &word[i - j], j);
+ }
+}
+
+
+/*
+ * This is the main function for printing out nodes. It's constituted
+ * of PRE and POST functions, which correspond to prefix and infix
+ * processing. The termpair structure allows data to persist between
+ * prefix and postfix invocations.
+ */
+static void
+body(struct termp *p, struct termpair *ppair,
+ const struct mdoc_meta *meta,
+ const struct mdoc_node *node)
+{
+ int dochild;
+ struct termpair pair;
+
+ /* Pre-processing. */
+
+ dochild = 1;
+ pair.ppair = ppair;
+ pair.type = 0;
+ pair.offset = pair.rmargin = 0;
+ pair.flag = 0;
+ pair.count = 0;
+
+ if (MDOC_TEXT != node->type) {
+ if (termacts[node->tok].pre)
+ if ( ! (*termacts[node->tok].pre)(p, &pair, meta, node))
+ dochild = 0;
+ } else /* MDOC_TEXT == node->type */
+ word(p, node->data.text.string);
+
+ /* Children. */
+
+ if (TERMPAIR_FLAG & pair.type)
+ p->flags |= pair.flag;
+
+ if (dochild && node->child)
+ body(p, &pair, meta, node->child);
+
+ if (TERMPAIR_FLAG & pair.type)
+ p->flags &= ~pair.flag;
+
+ /* Post-processing. */
+
+ if (MDOC_TEXT != node->type)
+ if (termacts[node->tok].post)
+ (*termacts[node->tok].post)(p, &pair, meta, node);
+
+ /* Siblings. */
+
+ if (node->next)
+ body(p, ppair, meta, node->next);
+}
+
+
+static void
+footer(struct termp *p, const struct mdoc_meta *meta)
+{
+ struct tm *tm;
+ char *buf, *os;
+
+ if (NULL == (buf = malloc(p->rmargin)))
+ err(1, "malloc");
+ if (NULL == (os = malloc(p->rmargin)))
+ err(1, "malloc");
+
+ tm = localtime(&meta->date);
+
+#ifdef __OpenBSD__
+ if (NULL == strftime(buf, p->rmargin, "%B %d, %Y", tm))
+#else
+ if (0 == strftime(buf, p->rmargin, "%B %d, %Y", tm))
+#endif
+ err(1, "strftime");
+
+ (void)strlcpy(os, meta->os, p->rmargin);
+
+ /*
+ * This is /slightly/ different from regular groff output
+ * because we don't have page numbers. Print the following:
+ *
+ * OS MDOCDATE
+ */
+
+ vspace(p);
+
+ p->flags |= TERMP_NOSPACE | TERMP_NOBREAK;
+ p->rmargin = p->maxrmargin - strlen(buf);
+ p->offset = 0;
+
+ word(p, os);
+ flushln(p);
+
+ p->flags |= TERMP_NOLPAD | TERMP_NOSPACE;
+ p->offset = p->rmargin;
+ p->rmargin = p->maxrmargin;
+ p->flags &= ~TERMP_NOBREAK;
+
+ word(p, buf);
+ flushln(p);
+
+ free(buf);
+ free(os);
+}
+
+
+static void
+header(struct termp *p, const struct mdoc_meta *meta)
+{
+ char *buf, *title, *bufp;
+
+ p->rmargin = p->maxrmargin;
+ p->offset = 0;
+
+ if (NULL == (buf = malloc(p->rmargin)))
+ err(1, "malloc");
+ if (NULL == (title = malloc(p->rmargin)))
+ err(1, "malloc");
+
+ /*
+ * The header is strange. It has three components, which are
+ * really two with the first duplicated. It goes like this:
+ *
+ * IDENTIFIER TITLE IDENTIFIER
+ *
+ * The IDENTIFIER is NAME(SECTION), which is the command-name
+ * (if given, or "unknown" if not) followed by the manual page
+ * section. These are given in `Dt'. The TITLE is a free-form
+ * string depending on the manual volume. If not specified, it
+ * switches on the manual section.
+ */
+
+ assert(meta->vol);
+ (void)strlcpy(buf, meta->vol, p->rmargin);
+
+ if (meta->arch) {
+ (void)strlcat(buf, " (", p->rmargin);
+ (void)strlcat(buf, meta->arch, p->rmargin);
+ (void)strlcat(buf, ")", p->rmargin);
+ }
+
+ (void)snprintf(title, p->rmargin, "%s(%d)",
+ meta->title, meta->msec);
+
+ for (bufp = title; *bufp; bufp++)
+ *bufp = toupper((u_char)*bufp);
+
+ p->offset = 0;
+ p->rmargin = (p->maxrmargin - strlen(buf)) / 2;
+ p->flags |= TERMP_NOBREAK | TERMP_NOSPACE;
+
+ word(p, title);
+ flushln(p);
+
+ p->flags |= TERMP_NOLPAD | TERMP_NOSPACE;
+ p->offset = p->rmargin;
+ p->rmargin = p->maxrmargin - strlen(title);
+
+ word(p, buf);
+ flushln(p);
+
+ p->offset = p->rmargin;
+ p->rmargin = p->maxrmargin;
+ p->flags &= ~TERMP_NOBREAK;
+ p->flags |= TERMP_NOLPAD | TERMP_NOSPACE;
+
+ word(p, title);
+ flushln(p);
+
+ p->rmargin = p->maxrmargin;
+ p->offset = 0;
+ p->flags &= ~TERMP_NOSPACE;
+
+ free(title);
+ free(buf);
+}
+
+
+/*
+ * Determine the symbol indicated by an escape sequences, that is, one
+ * starting with a backslash. Once done, we pass this value into the
+ * output buffer by way of the symbol table.
+ */
+static void
+nescape(struct termp *p, const char *word, size_t len)
+{
+ struct termenc *enc;
+
+ switch (len) {
+ case (1):
+ enc = termenc1;
+ break;
+ case (2):
+ enc = termenc2;
+ break;
+ default:
+ warnx("unsupported %zu-byte escape sequence", len);
+ return;
+ }
+
+ for ( ; enc->enc; enc++)
+ if (0 == memcmp(enc->enc, word, len)) {
+ symbola(p, enc->sym);
+ return;
+ }
+
+ warnx("unsupported %zu-byte escape sequence", len);
+}
+
+
+/*
+ * Handle an escape sequence: determine its length and pass it to the
+ * escape-symbol look table. Note that we assume mdoc(3) has validated
+ * the escape sequence (we assert upon badly-formed escape sequences).
+ */
+static void
+pescape(struct termp *p, const char *word, size_t *i, size_t len)
+{
+ size_t j;
+
+ (*i)++;
+ assert(*i < len);
+
+ if ('(' == word[*i]) {
+ (*i)++;
+ assert(*i + 1 < len);
+ nescape(p, &word[*i], 2);
+ (*i)++;
+ return;
+
+ } else if ('*' == word[*i]) {
+ /* XXX - deprecated! */
+ (*i)++;
+ assert(*i < len);
+ switch (word[*i]) {
+ case ('('):
+ (*i)++;
+ assert(*i + 1 < len);
+ nescape(p, &word[*i], 2);
+ (*i)++;
+ return;
+ case ('['):
+ break;
+ default:
+ nescape(p, &word[*i], 1);
+ return;
+ }
+
+ } else if ('[' != word[*i]) {
+ nescape(p, &word[*i], 1);
+ return;
+ }
+
+ (*i)++;
+ for (j = 0; word[*i] && ']' != word[*i]; (*i)++, j++)
+ /* Loop... */ ;
+
+ assert(word[*i]);
+ nescape(p, &word[*i - j], j);
+}
+
+
+/*
+ * Handle pwords, partial words, which may be either a single word or a
+ * phrase that cannot be broken down (such as a literal string). This
+ * handles word styling.
+ */
+static void
+pword(struct termp *p, const char *word, size_t len)
+{
+ size_t i;
+
+ if ( ! (TERMP_NOSPACE & p->flags) &&
+ ! (TERMP_LITERAL & p->flags))
+ chara(p, ' ');
+
+ if ( ! (p->flags & TERMP_NONOSPACE))
+ p->flags &= ~TERMP_NOSPACE;
+
+ /*
+ * XXX - if literal and underlining, this will underline the
+ * spaces between literal words.
+ */
+
+ if (p->flags & TERMP_BOLD)
+ stylea(p, TERMSTYLE_BOLD);
+ if (p->flags & TERMP_UNDERLINE)
+ stylea(p, TERMSTYLE_UNDER);
+
+ for (i = 0; i < len; i++) {
+ if ('\\' == word[i]) {
+ pescape(p, word, &i, len);
+ continue;
+ }
+ chara(p, word[i]);
+ }
+
+ if (p->flags & TERMP_BOLD ||
+ p->flags & TERMP_UNDERLINE)
+ stylea(p, TERMSTYLE_CLEAR);
+}
+
+
+/*
+ * Add a symbol to the output line buffer.
+ */
+static void
+symbola(struct termp *p, enum tsym sym)
+{
+
+ assert(p->symtab[sym].sym);
+ stringa(p, p->symtab[sym].sym, p->symtab[sym].sz);
+}
+
+
+/*
+ * Add a style to the output line buffer.
+ */
+static void
+stylea(struct termp *p, enum tstyle style)
+{
+
+ assert(p->styletab[style].sym);
+ stringa(p, p->styletab[style].sym, p->styletab[style].sz);
+}
+
+
+/*
+ * Like chara() but for arbitrary-length buffers. Resize the buffer by
+ * a factor of two (if the buffer is less than that) or the buffer's
+ * size.
+ */
+static void
+stringa(struct termp *p, const char *c, size_t sz)
+{
+ size_t s;
+
+ if (0 == sz)
+ return;
+
+ s = sz > p->maxcols * 2 ? sz : p->maxcols * 2;
+
+ assert(c);
+ if (p->col + sz >= p->maxcols) {
+ p->buf = realloc(p->buf, s);
+ if (NULL == p->buf)
+ err(1, "realloc");
+ p->maxcols = s;
+ }
+
+ (void)memcpy(&p->buf[p->col], c, sz);
+ p->col += sz;
+}
+
+
+/*
+ * Insert a single character into the line-buffer. If the buffer's
+ * space is exceeded, then allocate more space by doubling the buffer
+ * size.
+ */
+static void
+chara(struct termp *p, char c)
+{
+
+ if (p->col + 1 >= p->maxcols) {
+ p->buf = realloc(p->buf, p->maxcols * 2);
+ if (NULL == p->buf)
+ err(1, "malloc");
+ p->maxcols *= 2;
+ }
+ p->buf[(p->col)++] = c;
+}