#!/bin/bash

set -eo pipefail
# Script to generate debian packages for KOReader

command_exists() {
    type "$1" >/dev/null 2>/dev/null
}

link_fonts() {
    syspath="../../../../share/fonts/truetype/$(basename "$1")"
    for FILE in "$1"/*.ttf; do
        ln -snf "${syspath}/${FILE##*/}" "${FILE}"
    done
}

uname_to_debian() {
    case "$1" in
        x86_64) echo "amd64" ;;
        armv7l) echo "armhf" ;;
        aarch64) echo "arm64" ;;
        *) echo "$1" ;;
    esac
}

write_changelog() {
    CHANGELOG_PATH="${1}/share/doc/koreader/changelog.Debian.gz"
    CHANGELOG=$(
        cat <<'END_HEREDOC'
koreader (0.1) unstable; urgency=low

  * Fixes most lintian errors and warnings

 -- Martín Fdez <paziusss@gmail.com>  Thu, 14 May 2020 00:00:00 +0100

koreader (0.0.1) experimental; urgency=low

  * Initial release as Debian package (Closes: https://github.com/koreader/koreader/issues/3108)

 -- Martín Fdez <paziusss@gmail.com>  Tue, 03 Jan 2019 00:00:00 +0100
END_HEREDOC
    )

    echo "${CHANGELOG}" | gzip -cn9 >"${CHANGELOG_PATH}"
    chmod 644 "${CHANGELOG_PATH}"
}

if ! [ -r "${1}" ]; then
    echo "${0}: can't find KOReader archive, please specify a path to a KOReader tar.gz" 1>&2
    exit 1
fi

# Check for required tools.
missing_tools=()
for tool in dpkg-deb fakeroot; do
    if ! command_exists "${tool}"; then
        missing_tools+=("${tool}")
    fi
done
if [[ ${#missing_tools[@]} -ne 0 ]]; then
    echo "${0}: unable to build Debian package, the following tools are missing: ${missing_tools[*]}" 1>&2
    exit 1
fi

mkdir -p tmp-debian/usr
chmod 0755 tmp-debian/usr
tar -xf "${1}" -C tmp-debian/usr
rm -f tmp-debian/usr/README.md
ARCH="$(echo "${1}" | cut -d '-' -f3)"
VERSION="$(cut -f2 -dv "tmp-debian/usr/lib/koreader/git-rev" | cut -f1,2 -d-)"
DEB_ARCH="$(uname_to_debian "${ARCH}")"
BASE_DIR="tmp-debian"

# populate debian control file
mkdir -p "${BASE_DIR}/DEBIAN"
cat >"${BASE_DIR}/DEBIAN/control" <<EOF
Section: graphics
Priority: optional
Depends: libsdl2-2.0-0, fonts-noto-hinted, fonts-droid-fallback, libc6 (>= 2.31)
Architecture: ${DEB_ARCH}
Version: ${VERSION}
Installed-Size: $(du -ks "${BASE_DIR}/usr/" | cut -f 1)
Package: koreader
Maintainer: Martín Fdez <paziusss@gmail.com>
Homepage: https://koreader.rocks
Description: Ebook reader optimized for e-ink screens.
 It can open many formats and provides advanced text adjustments.
 .
 See below for a selection of its many features:
 .
 Supports both fixed page formats (PDF, DjVu, CBT, CBZ) and reflowable e-book formats (EPUB, FB2, Mobi, DOC, CHM, TXT, HTML). 
 Scanned PDF/DjVu documents can be reflowed. Special flow directions for reading double column PDFs and manga.
 .
 Multi-lingual user interface optimized for e-ink screens.
 Highly customizable reader view with complete typesetting options. Multi-lingual hyphenation dictionaries are bundled in.
 .
 Non-Latin script support for books, including the Hebrew, Arabic, Persian, Russian, Chinese, Japanese and Korean languages.
 .
 Unique Book Map and Page Browser features to navigate your book.
 .
 Special multi-page highlight mode with many local and online export options.
 .
 Can synchronize your reading progress across all your KOReader running devices.
 .
 Integrated with Calibre, Wallabag, Wikipedia, Google translate and other content providers.
EOF

# use absolute path to luajit in reader.lua
sed -i 's,./luajit,/usr/lib/koreader/luajit,' "${BASE_DIR}/usr/lib/koreader/reader.lua"

# use debian packaged fonts instead of our embedded ones to save a couple of MB.
# Note: avoid linking against fonts-noto-cjk-extra, cause it weights ~200MB.
link_fonts "${BASE_DIR}/usr/lib/koreader/fonts/noto"

# DroidSansMono has a restrictive license. Replace it with DroidSansFallback
ln -snf ../../../../share/fonts-droid-fallback/truetype/DroidSansFallback.ttf "${BASE_DIR}/usr/lib/koreader/fonts/droid/DroidSansMono.ttf"

# lintian complains if shared libraries have execute rights.
find "${BASE_DIR}" -type f -perm /+x -name '*.so*' -print0 | xargs -0 chmod a-x

# add debian changelog
write_changelog "${BASE_DIR}/usr"

fakeroot dpkg-deb -b "${BASE_DIR}" "koreader-${VERSION}-${DEB_ARCH}.deb"
rm -rf tmp-debian