#!/bin/bash
# This file is part of GNU TALER.
# Copyright (C) 2014-2023 Taler Systems SA
#
# TALER is free software; you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free Software
# Foundation; either version 2.1, or (at your option) any later version.
#
# TALER is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License along with
# TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
#
# @author Florian Dold
# @author Benedikt Muller
# @author Sree Harsha Totakura
# @author Marcello Stanisci
# @author Christian Grothoff
#
#
# Error checking on
set -eu

# Call with target language as first argument.
function make_config()
{
    cat > "${BUILDDIR}/conf.py" <<EOF
import sys
import os
sys.path.append(os.path.abspath('_exts'))
needs_sphinx = '1.8.5'
extensions = [
    'sphinx.ext.todo',
    'sphinx.ext.imgmath',
    'sphinx_markdown_builder',
]
templates_path = ['_templates']
source_suffix = {
    '.rst': 'restructuredtext',
}
master_doc = '$VERSION_BASENAME'
project = u'$VERSION_BASENAME'
copyright = u'$COPYRIGHT'
version = '$VERSION_BASENAME'
release = '$VERSION_BASENAME'
language = "$LANGUAGE"
exclude_patterns = ['_build', '_exts', 'cf', 'prebuilt']
locale_dirs = ['$LOCALE_DIR/']
gettext_compact = False
pygments_style = 'sphinx'
html_theme = 'epub'
rst_epilog = ""
html_show_sphinx = False
html_theme_options = {
    "relbar1": "false",
    "footer": "false",
}
html_title = "$TITLE"
html_short_title = "$TITLE"
html_use_index = True
html_show_sphinx = False
latex_elements = {
    # The paper size ('letterpaper' or 'a4paper').
    #'papersize': 'letterpaper',

    # The font size ('10pt', '11pt' or '12pt').
    #'pointsize': '10pt',

    # Additional stuff for the LaTeX preamble.
    #'preamble': '',
}
latex_documents = [
    ('$VERSION_BASENAME', '$VERSION_BASENAME.tex',
     '$VERSION_BASENAME', '$VERSION_BASENAME', 'manual'),
]
epub_basename = "$VERSION_BASENAME"
epub_title = "$TITLE"
EOF
}

# Output file given as first argument to stderr, then exit with a failure.
function failcat ()
{
    cat "$1" 1>&2
    exit 1
}


# defaults
AUTHOR="GNU Taler team"
VERSION="exchange-tos-v0"
LOCALE_DIR=$(taler-config -s "PATHS" -o "LOCALEDIR" -f)
OUTPUT=$(taler-config -s "EXCHANGE" -o "TERMS_DIR" -f)
PAPER="a4"
COPYRIGHT="2014-2023 Taler Systems SA (GPLv3+ or GFDL 1.3+)"
INCREMENTAL=0

# Parse command-line options
while getopts ':a:C:hKi:l:L:o:p:t:' OPTION; do
    case "$OPTION" in
        a)
            AUTHOR="$OPTARG"
            ;;
        C)
            COPYRIGHT="$OPTARG"
            ;;
        h)
            echo 'Supported options:'
            echo '  -a AUTHOR     -- set author header' "(default: $AUTHOR)"
            echo '  -C COPYRIGHT  -- set copyright header' "(default: $COPYRIGHT)"
            echo '  -h            -- print this help'
            echo '  -K            -- rebuild only if input is older than output'
            echo '  -i INPUT      -- input file to convert' "(default: $VERSION)"
            echo '  -l LANGUAGE   -- target language to add'
            echo '  -L LOCALE_DIR -- directory with resources for translation' "(default: $LOCALE_DIR)"
            echo '  -o OUTPUT     -- output directory' "(default: $OUTPUT)"
            echo '  -p PAPER      -- paper format' "(default: $PAPER)"
            echo '  -t TITLE      -- title of the document to generate'
            exit 0
            ;;
        l)
            ADD_LANGUAGE="$OPTARG"
            ;;
        L)
            LOCALE_DIR="$OPTARG"
            ;;
        i)
            VERSION="$OPTARG"
            ;;
        o)
            OUTPUT="$OPTARG"
            ;;
        p)
            PAPER="$OPTARG"
            case "$PAPER" in
                a4|letter)
                ;;
                *)
                    echo "Error: Paper format '$PAPER' invalid (use 'a4' or 'letter')" 1>&2
                    exit 1
                    ;;
            esac
            ;;
        t)
            TITLE="$OPTARG"
            ;;
        K)
            INCREMENTAL=1
            ;;
        ?)
        echo "Unrecognized command line option" 1>&2
        exit 1
        ;;
    esac
done

if ! which sphinx-build > /dev/null
then
    echo "Command 'sphinx-build' not found, but required. Please install sphinx." 1>&2
    exit 1
fi

if ! which latexmk > /dev/null
then
    echo "Command 'latexmk' not found, but required. Please install latexmk." 1>&2
    exit 1
fi

if ! which make > /dev/null
then
    echo "Command 'make' not found, but required. Please install make." 1>&2
    exit 1
fi

# We append ".rst" if needed, remove if given on command-line
# shellcheck disable=SC2001
VERSION=$(echo "${VERSION}" | sed -e "s/\.rst$//")

# Sometimes we just want the basename, not the directory.
VERSION_BASENAME=$(basename "${VERSION}")

BUILDDIR=$(mktemp -d /tmp/taler-terms-XXXXXX)
if [ ! -f "${VERSION}.rst" ]
then
    echo "Error: File '${VERSION}.rst' not found. Please check '-i' option." 1>&2
    exit 1
fi

cp "${VERSION}.rst" "${BUILDDIR}/"

if [ -z ${TITLE+x} ]
then
    TITLE=$(head -n1 "${VERSION}.rst")
    echo "Title automatically set to '$TITLE'" 1>&2
fi

if [ -n "${ADD_LANGUAGE+x}" ]
then
    if ! echo "${ADD_LANGUAGE}" | grep -e '^..$' > /dev/null
    then
        echo "Error: Invalid language '${ADD_LANGUAGE}'. Two characters (en, de, fr, ...) expected." 1>&2
        exit 1
    fi
    echo "Adding language files for translations to '${ADD_LANGUAGE}'" 1>&2
    make_config "${ADD_LANGUAGE}"
    sphinx-build \
        -b gettext \
        -D language="${ADD_LANGUAGE}" \
        -d "${BUILDDIR}/.doctrees" \
        "${BUILDDIR}" \
        "${LOCALE_DIR}/${ADD_LANGUAGE}/LC_MESSAGES/" \
        &> "${BUILDDIR}/add-language.log" \
        || failcat "${BUILDDIR}/add-language.log"
    if [ -f "${LOCALE_DIR}/${ADD_LANGUAGE}/LC_MESSAGES/${VERSION_BASENAME}.po" ]
    then
        msgmerge --lang="${ADD_LANGUAGE}" \
                 --no-location \
                 -o "${LOCALE_DIR}/${ADD_LANGUAGE}/LC_MESSAGES/${VERSION_BASENAME}.mrg" \
                 "${LOCALE_DIR}/${ADD_LANGUAGE}/LC_MESSAGES/${VERSION_BASENAME}.po" \
                 "${LOCALE_DIR}/${ADD_LANGUAGE}/LC_MESSAGES/${VERSION_BASENAME}.pot"
        mv "${LOCALE_DIR}/${ADD_LANGUAGE}/LC_MESSAGES/${VERSION_BASENAME}.mrg" \
                 "${LOCALE_DIR}/${ADD_LANGUAGE}/LC_MESSAGES/${VERSION_BASENAME}.po"
    else
        mv "${LOCALE_DIR}/${ADD_LANGUAGE}/LC_MESSAGES/${VERSION_BASENAME}.pot" \
           "${LOCALE_DIR}/${ADD_LANGUAGE}/LC_MESSAGES/${VERSION_BASENAME}.po"
    fi
    rm -f "${LOCALE_DIR}/${ADD_LANGUAGE}/LC_MESSAGES/${VERSION_BASENAME}.pot"
    echo "Done" 1>&2
    exit 0
fi

# As a heuristic for incremental builds, we only check the text output file.
if [[ "$INCREMENTAL" -eq 1 ]]
then
  if [[ "$VERSION" -ot "${OUTPUT}/buildstamp" ]];
  then
    echo "Not rebuilding, input file $VERSION is older than $OUTPUT/buildstamp."
    exit 0
  fi
fi


# shellcheck disable=SC2086
for d in en $(ls -d ${LOCALE_DIR}/?? | grep -v "en" 2> /dev/null || true)
do
    LANGUAGE=$(basename "$d")
    if [ "en" != "${LANGUAGE}" ] && [ ! -f "${LOCALE_DIR}/${LANGUAGE}/LC_MESSAGES/${VERSION_BASENAME}.po" ]
    then
        echo "Skipping language ${LANGUAGE}: no translation for ${VERSION_BASENAME} found."
        continue
    fi
    echo "Generating files at '$OUTPUT' for ETag '$VERSION_BASENAME' and language '${LANGUAGE}' in '${BUILDDIR}':" 1>&2

    make_config "$LANGUAGE"
    mkdir -p "${OUTPUT}/${LANGUAGE}/"

    LBUILD="sphinx-build -D language=${LANGUAGE} -d ${BUILDDIR}/.doctrees"

    echo "$VERSION_BASENAME XML ($LANGUAGE)..." 1>&2
# shellcheck disable=SC2090
    $LBUILD \
        -b xml \
        "${BUILDDIR}" \
        "${BUILDDIR}/xml" \
        &> "${BUILDDIR}/xml-sphinx.log" \
        || failcat "${BUILDDIR}/xml-sphinx.log"
    mv "${BUILDDIR}/xml/${VERSION_BASENAME}.xml" "${OUTPUT}/${LANGUAGE}/${VERSION_BASENAME}.xml"

    echo "$VERSION_BASENAME TXT ($LANGUAGE)..." 1>&2
# shellcheck disable=SC2090
    $LBUILD \
        -b text \
        "${BUILDDIR}" \
        "${BUILDDIR}/txt" \
        &> "${BUILDDIR}/txt-sphinx.log" \
        || failcat "${BUILDDIR}/txt-sphinx.log"
    mv "${BUILDDIR}/txt/${VERSION_BASENAME}.txt" "${OUTPUT}/${LANGUAGE}/${VERSION_BASENAME}.txt"

    echo "$VERSION_BASENAME MD ($LANGUAGE)..." 1>&2
    $LBUILD \
        -b markdown \
        "${BUILDDIR}" \
        "${BUILDDIR}/md" \
        &> "${BUILDDIR}/md-sphinx.log" \
        || failcat "${BUILDDIR}/md-sphinx.log"
    mv "${BUILDDIR}/md/${VERSION_BASENAME}.md" "${OUTPUT}/${LANGUAGE}/${VERSION_BASENAME}.md"

    echo "$VERSION_BASENAME HTML ($LANGUAGE)..." 1>&2
# shellcheck disable=SC2090
    $LBUILD \
        -b html \
        "${BUILDDIR}" \
        "${BUILDDIR}/html" \
        &> "${BUILDDIR}/html-sphinx.log" \
        || failcat "${BUILDDIR}/html-sphinx.log"
    htmlark \
        -o "${OUTPUT}/${LANGUAGE}/${VERSION_BASENAME}.html" \
        "${BUILDDIR}/html/${VERSION_BASENAME}.html"

    echo "$VERSION_BASENAME EPUB ($LANGUAGE)..." 1>&2
# shellcheck disable=SC2090
    $LBUILD \
        -b epub \
        "${BUILDDIR}" \
        "${BUILDDIR}/epub" \
        &> "${BUILDDIR}/epub-sphinx.log" \
        || failcat "${BUILDDIR}/epub-sphinx.log"
    mv "${BUILDDIR}/epub/${VERSION_BASENAME}.epub" "${OUTPUT}/${LANGUAGE}/${VERSION_BASENAME}.epub"

    echo "$VERSION_BASENAME PDF ($LANGUAGE)..." 1>&2
# shellcheck disable=SC2090
    $LBUILD \
        -b latex \
        -D latex_paper_size="${PAPER}" \
        "${BUILDDIR}" \
        "${BUILDDIR}/pdf" \
        &> "${BUILDDIR}/pdf-sphinx.log" \
        || failcat "${BUILDDIR}/pdf-sphinx.log"
    # We pipe in /dev/null in case latexmk
    # asks for input and would hang otherwise.
    make \
        -C "${BUILDDIR}/pdf" \
        all-pdf \
        < /dev/null &> "${BUILDDIR}/pdf-latex.log" \
        || failcat "${BUILDDIR}/pdf-latex.log"
    mv "${BUILDDIR}/pdf/${VERSION_BASENAME}.pdf" "${OUTPUT}/${LANGUAGE}/${VERSION_BASENAME}.pdf"
done

if [[ "$INCREMENTAL" -eq 1 ]]
then
  touch "${OUTPUT}/buildstamp";
fi

echo "Done" 1>&2
exit 0