#!/usr/bin/awk

#

# Copyright (c) 2003 Peter Stuge <stuge-mdoc2man@cdy.org>

#

# Permission to use, copy, modify, and distribute this software for any

# purpose with or without fee is hereby granted, provided that the above

# copyright notice and this permission notice appear in all copies.

#

# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

# Dramatically overhauled by Tim Kientzle.  This version almost

# handles library-style pages with Fn, Ft, etc commands.  Still

# a lot of problems...

BEGIN {

  displaylines = 0

  trailer = ""

  out = ""

  sep = ""

  nextsep = " "

}

# Add a word with appropriate preceding whitespace

# Maintain a short queue of the expected upcoming word separators.

function add(str) {

  out=out sep str

  sep = nextsep

  nextsep = " "

}

# Add a word with no following whitespace

# Use for opening punctuation such as '('

function addopen(str) {

  add(str)

  sep = ""

}

# Add a word with no preceding whitespace

# Use for closing punctuation such as ')' or '.'

function addclose(str) {

  sep = ""

  add(str)

}

# Add a word with no space before or after

# Use for separating punctuation such as '='

function addpunct(str) {

  sep = ""

  add(str)

  sep = ""

}

# Emit the current line so far

function endline() {

  addclose(trailer)

  trailer = ""

  if(length(out) > 0) {

    print out

    out=""

  }

  if(displaylines > 0) {

    displaylines = displaylines - 1

    if (displaylines == 0)

      dispend()

  }

  # First word on next line has no preceding whitespace

  sep = ""

}

function linecmd(cmd) {

  endline()

  add(cmd)

  endline()

}

function breakline() {

  linecmd(".br")

}

# Start an indented display

function dispstart() {

  linecmd(".RS 4")

}

# End an indented display

function dispend() {

  linecmd(".RE")

}

# Collect rest of input line

function wtail() {

  retval=""

  while(w

    if(length(retval))

      retval=retval " "

    retval=retval words[++w]

  }

  return retval

}

function splitwords(l, dest, n, o, w) {

  n = 1

  delete dest

  while (length(l) > 0) {

    sub("^[ \t]*", "", l)

    if (match(l, "^\"")) {

      l = substr(l, 2)

      o = index(l, "\"")

      if (o > 0) {

	w = substr(l, 1, o-1)

	l = substr(l, o+1)

	dest[n++] = w

      } else {

	dest[n++] = l

	l = ""

      }

    } else {

      o = match(l, "[ \t]")

      if (o > 0) {

	w = substr(l, 1, o-1)

	l = substr(l, o+1)

	dest[n++] = w

      } else {

	dest[n++] = l

	l = ""

      }

    }

  }

  return n-1

}

! /^\./ {

  out = $0

  endline()

  next

}

/^\.\\"/ { next }

{

  sub("^\\.","")

  nwords=splitwords($0, words)

  # TODO: Instead of iterating 'w' over the array, have a separate

  # function that returns 'next word' and use that.  This will allow

  # proper handling of double-quoted arguments as well.

  for(w=1;w<=nwords;w++) {

    if(match(words[w],"^Li$")) { # Literal; rest of line is unformatted

      dispstart()

      displaylines = 1

    } else if(match(words[w],"^Dl$")) { # Display literal

      dispstart()

      displaylines = 1

    } else if(match(words[w],"^Bd$")) { # Begin display

      if(match(words[w+1],"-literal")) {

        dispstart()

	linecmd(".nf")

	displaylines=10000

	w=nwords

      }

    } else if(match(words[w],"^Ed$")) { # End display

      displaylines = 0

      dispend()

    } else if(match(words[w],"^Ns$")) { # Suppress space after next word

      nextsep = ""

    } else if(match(words[w],"^No$")) { # Normal text

      add(words[++w])

    } else if(match(words[w],"^Dq$")) { # Quote

      addopen("``")

      add(words[++w])

      while(w

	add(words[++w])

      addclose("''")

    } else if(match(words[w],"^Do$")) {

      addopen("``")

    } else if(match(words[w],"^Dc$")) {

      addclose("''")

    } else if(match(words[w],"^Oo$")) {

      addopen("[")

    } else if(match(words[w],"^Oc$")) {

      addclose("]")

    } else if(match(words[w],"^Ao$")) {

      addopen("<")

    } else if(match(words[w],"^Ac$")) {

      addclose(">")

    } else if(match(words[w],"^Dd$")) {

      date=wtail()

      next

    } else if(match(words[w],"^Dt$")) {

      id=wtail()

      next

    } else if(match(words[w],"^Ox$")) {

      add("OpenBSD")

    } else if(match(words[w],"^Fx$")) {

      add("FreeBSD")

    } else if(match(words[w],"^Nx$")) {

      add("NetBSD")

    } else if(match(words[w],"^St$")) {

      if (match(words[w+1], "^-p1003.1$")) {

         w++

         add("IEEE Std 1003.1 (``POSIX.1'')")

      } else if(match(words[w+1], "^-p1003.1-96$")) {

         w++

         add("ISO/IEC 9945-1:1996 (``POSIX.1'')")

      } else if(match(words[w+1], "^-p1003.1-88$")) {

         w++

         add("IEEE Std 1003.1-1988 (``POSIX.1'')")

      } else if(match(words[w+1], "^-p1003.1-2001$")) {

         w++

         add("IEEE Std 1003.1-2001 (``POSIX.1'')")

      } else if(match(words[w+1], "^-susv2$")) {

         w++

         add("Version 2 of the Single UNIX Specification (``SUSv2'')")

      }

    } else if(match(words[w],"^Ex$")) {

      if (match(words[w+1], "^-std$")) {

         w++

         add("The \\fB" name "\\fP utility exits 0 on success, and >0 if an error occurs.")

      }

    } else if(match(words[w],"^Os$")) {

      add(".TH " id " \"" date "\" \"" wtail() "\"")

    } else if(match(words[w],"^Sh$")) {

      section=wtail()

      add(".SH " section)

      linecmd(".ad l")

    } else if(match(words[w],"^Xr$")) {

      add("\\fB" words[++w] "\\fP(" words[++w] ")" words[++w])

    } else if(match(words[w],"^Nm$")) {

      if(match(section,"SYNOPSIS"))

        breakline()

      if(w >= nwords)

	n=name

      else if (match(words[w+1], "^[A-Z][a-z]$"))

	n=name

      else if (match(words[w+1], "^[.,;:]$"))

	n=name

      else {

        n=words[++w]

        if(!length(name))

          name=n

      }

      if(!length(n))

        n=name

      add("\\fB\\%" n "\\fP")

    } else if(match(words[w],"^Nd$")) {

      add("\\- " wtail())

    } else if(match(words[w],"^Fl$")) {

      add("\\fB\\-" words[++w] "\\fP")

    } else if(match(words[w],"^Ar$")) {

      addopen("\\fI")

      if(w==nwords)

	add("file ...\\fP")

      else

	add(words[++w] "\\fP")

    } else if(match(words[w],"^Cm$")) {

      add("\\fB" words[++w] "\\fP")

    } else if(match(words[w],"^Op$")) {

      addopen("[")

      option=1

      trailer="]" trailer

    } else if(match(words[w],"^Pp$")) {

      linecmd(".PP")

    } else if(match(words[w],"^An$")) {

      endline()

    } else if(match(words[w],"^Ss$")) {

      add(".SS")

    } else if(match(words[w],"^Ft$")) {

      if (match(section, "SYNOPSIS")) {

	breakline()

      }

      add("\\fI" wtail() "\\fP")

      if (match(section, "SYNOPSIS")) {

	breakline()

      }

    } else if(match(words[w],"^Fn$")) {

      ++w

      F = "\\fB\\%" words[w] "\\fP("

      Fsep = ""

      while(w

	++w

	if (match(words[w], "^[.,:]$")) {

	  --w

	  break

	}

	gsub(" ", "\\ ", words[w])

	F = F Fsep "\\fI\\%"  words[w] "\\fP"

	Fsep = ", "

      }

      add(F ")")

      if (match(section, "SYNOPSIS")) {

	addclose(";")

      }

    } else if(match(words[w],"^Fo$")) {

      w++

      F = "\\fB\\%" words[w] "\\fP("

      Fsep = ""

    } else if(match(words[w],"^Fa$")) {

      w++

      gsub(" ", "\\ ", words[w])

      F = F Fsep "\\fI\\%"  words[w] "\\fP"

      Fsep = ", "

    } else if(match(words[w],"^Fc$")) {

      add(F ")")

      if (match(section, "SYNOPSIS")) {

	addclose(";")

      }

    } else if(match(words[w],"^Va$")) {

      w++

      add("\\fI" words[w] "\\fP")

    } else if(match(words[w],"^In$")) {

      w++

      add("\\fB#include <" words[w] ">\\fP")

    } else if(match(words[w],"^Pa$")) {

      addopen("\\fI")

      w++

      if(match(words[w],"^\\."))

	add("\\&")

      add(words[w] "\\fP")

    } else if(match(words[w],"^Dv$")) {

      add(".BR")

    } else if(match(words[w],"^Em|Ev$")) {

      add(".IR")

    } else if(match(words[w],"^Pq$")) {

      addopen("(")

      trailer=")" trailer

    } else if(match(words[w],"^Aq$")) {

      addopen("\\%<")

      trailer=">" trailer

    } else if(match(words[w],"^Brq$")) {

      addopen("{")

      trailer="}" trailer

    } else if(match(words[w],"^S[xy]$")) {

      add(".B " wtail())

    } else if(match(words[w],"^Ic$")) {

      add("\\fB")

      trailer="\\fP" trailer

    } else if(match(words[w],"^Bl$")) {

      oldoptlist=optlist

      linecmd(".RS 5")

      if(match(words[w+1],"-bullet"))

	optlist=1

      else if(match(words[w+1],"-enum")) {

	optlist=2

	enum=0

      } else if(match(words[w+1],"-tag"))

	optlist=3

      else if(match(words[w+1],"-item"))

	optlist=4

      else if(match(words[w+1],"-bullet"))

	optlist=1

      w=nwords

    } else if(match(words[w],"^El$")) {

      linecmd(".RE")

      optlist=oldoptlist

    } else if(match(words[w],"^It$")&&optlist) {

      if(optlist==1)

	add(".IP \\(bu")

      else if(optlist==2)

	add(".IP " ++enum ".")

      else if(optlist==3) {

	add(".TP")

        endline()

	if(match(words[w+1],"^Pa$|^Ev$")) {

	  add(".B")

	  w++

	}

      } else if(optlist==4)

	add(".IP")

    } else if(match(words[w],"^Xo$")) {

      # TODO: Figure out how to handle this

    } else if(match(words[w],"^Xc$")) {

      # TODO: Figure out how to handle this

    } else if(match(words[w],"^[=]$")) {

      addpunct(words[w])

    } else if(match(words[w],"^[[{(]$")) {

      addopen(words[w])

    } else if(match(words[w],"^[\\])}.,;:]$")) {

      addclose(words[w])

    } else {

      add(words[w])

    }

  }

  if(match(out,"^\\.[^a-zA-Z]"))

    sub("^\\.","",out)

  endline()

}