#!/bin/sh -e

REQUIRED="pdflatex"
SYNOPSIS="converts markdown-formatted text to PDF, using pdflatex."

THIS=${0##*/}

NEWLINE='
'

err ()  { echo "$*"   | fold -s -w ${COLUMNS:-110} >&2; }
errn () { printf "$*" | fold -s -w ${COLUMNS:-110} >&2; }

usage () {
    err "$1 - $2" # short description
    err "See the $1(1) man page for usage."
}

# Portable which(1).
pathfind () {
    oldifs="$IFS"; IFS=':'
    for _p in $PATH; do
        if [ -x "$_p/$*" ] && [ -f "$_p/$*" ]; then
            IFS="$oldifs"
            return 0
        fi
    done
    IFS="$oldifs"
    return 1
}

for p in pandoc $REQUIRED; do
    pathfind $p || {
        err "You need '$p' to use this program!"
        exit 1
    }
done

CONF=$(pandoc --dump-args "$@" 2>&1) || {
    errcode=$?
    echo "$CONF" | sed -e '/^pandoc \[OPTIONS\] \[FILES\]/,$d' >&2
    [ $errcode -eq 2 ] && usage "$THIS" "$SYNOPSIS"
    exit $errcode
}

OUTPUT=$(echo "$CONF" | sed -ne '1p')
ARGS=$(echo "$CONF" | sed -e '1d')


# As a security measure refuse to proceed if mktemp is not available.
pathfind mktemp || { err "Couldn't find 'mktemp'; aborting."; exit 1;  }

# Avoid issues with /tmp directory on Windows/Cygwin 
cygwin=
cygwin=$(uname | sed -ne '/^CYGWIN/p')
if [ -n "$cygwin" ]; then
    TMPDIR=.
    export TMPDIR
fi

THIS_TEMPDIR=
THIS_TEMPDIR="$(mktemp -d -t $THIS.XXXXXXXX)" || exit 1
readonly THIS_TEMPDIR

trap 'exitcode=$?
      [ -z "$THIS_TEMPDIR" ] || rm -rf "$THIS_TEMPDIR"
      exit $exitcode' 0 1 2 3 13 15

texname=output
logfile=$THIS_TEMPDIR/log

pandoc -s -r markdown -w latex "$@" -o $THIS_TEMPDIR/$texname.tex

if [ "$OUTPUT" = "-" ]; then
    firstinfile="$(echo $ARGS | sed -ne '1p')"
    firstinfilebase="${firstinfile%.*}"
    destname="${firstinfilebase:-stdin}.pdf"
else
    destname="$OUTPUT"
fi

(
    origdir=$(pwd)
    cd $THIS_TEMPDIR
    TEXINPUTS=$origdir:$TEXINPUTS:
    export TEXINPUTS
    finished=no
    runs=0
    while [ $finished = "no" ]; do
      pdflatex -interaction=batchmode $texname.tex >/dev/null || {
        errcode=$?
        err "${THIS}: pdfLaTeX failed with error code $errcode"
        [ -f $texname.log ] && {
          err "${THIS}: error context:"
          sed -ne '/^!/,/^[[:space:]]*$/p' \
            -ne '/^[Ll]a[Tt]e[Xx] [Ww]arning/,/^[[:space:]]*$/p' \
            -ne '/^[Ee]rror/,/^[[:space:]]*$/p' $texname.log >&2
          if grep -q "File \`ucs.sty' not found" $texname.log; then
            err "${THIS}: Please install the 'unicode' package from CTAN:"
            err "  http://www.ctan.org/tex-archive/macros/latex/contrib/unicode/"
          fi
          if grep -q "File \`ulem.sty' not found" $texname.log; then
            err "${THIS}: Please install the 'ulem' package from CTAN:"
            err "  http://www.ctan.org/tex-archive/macros/latex/contrib/misc/ulem.sty"
          fi
        }
        exit $errcode
      }
      if [ $runs -lt 3 ] && 
      ((grep -q "LaTeX Warning: There were undefined references." $texname.log) ||
       (echo "$@" | grep -q -- "--toc\|--table-of-contents")); then
        runs=$(($runs + 1))
        if grep -q "LaTeX Warning:.*[Cc]itation" $texname.log; then
          bibtex $texname 2>&1 >bibtex.err
          if [ $runs -gt 2 ]; then
            if grep -q "error message" bibtex.err ||
            grep -q "Warning" bibtex.err; then
              cat bibtex.err >&2
            fi
          fi
        fi
      else
        finished=yes
      fi
    done
) || exit $?

is_target_exists=
if [ -f "$destname" ]; then
    is_target_exists=1
    mv "$destname" "$destname~" 
fi

mv -f $THIS_TEMPDIR/$texname.pdf "$destname"

errn "Created $destname"
[ -z "$is_target_exists" ] || {
    errn " (previous file has been backed up as $destname~)"
}
err .
