#!/bin/bash

# Copyright (c) 2019-2021 Jay Berkenbilt and Kurt Pfeifle
#
# This script is used to build an 'AppImage' from GitHub sources of
# QPDF (see https://appimage.org/). It is used in CI, but it also
# allows Linux users to build such an AppImage on their own systems.
# Please read 'README.md' from the top level Git sources to see what
# preconditions you must meet to build QPDF in general. The same apply
# to build an AppImage. Then follow these three steps:
#
#   1. Clone Git sources:  `git clone https://github.com/qpdf/qpdf.git git.qpdf`
#   2. Change into git dir:  `cd git.qpdf`
#   3. Run this script:  `bash appimage/build-appimage`
#
# The resulting AppImage will be placed in
# './appimage/build/QPDF-x86_64.AppImage'. Read the output of the
# script for hints in case something goes wrong.
#
# You may pass custom options for the configure step by setting them
# into the 'CUSTOM_CONFIGURE' environment variable and exporting it
# before running this script. For example:
#
#      export CUSTOM_CONFIGURE=" --enable-test-compare-images [--more-other-options]"
#
# ATTENTION:
#
#   1. To build the AppImage you should have a working internet
#      connection. Reason: the script downloads the most recent
#      'linuxdeployqt' utility for building the AppImage.
#   2. If you build the AppImage on a too recent Linux distribution,
#      it may only work on the exact distribution you build it on. For
#      an AppImage to work on a wide range of different distributions
#      from the last 3-4 years if should be built on the oldest
#      supported Ubuntu LTS release.

set -ex

# Support for signing the AppImage (only by original maintainer):
sign=
if [ "x$1" == "x--sign" ]; then
    sign=--sign
fi


# Check Ubuntu Distribution
_osversion=$(cat /etc/os-release | grep PRETTY_NAME | awk -F'=' '{print $2}' | sed 's#"##g')

# Warn users building the AppImage locally:
if [[ ! $_osversion =~ Ubuntu\ 18.04.*\ LTS ]]; then
set +x
    echo ""
    #    0         1         2         3         4         5         6         7
    #    01234567890123456789012345678901234567890123456789012345678901234567890123456789
    echo "+===========================================================================+"
    echo "|| WARNING: You are about to build a QPDF AppImage on a system which is    ||"
    echo "|| NOT Ubuntu 18.04 LTS.                                                   ||"
    echo "||                                                                         ||"
    echo "||    It is recommended that you use a distribution that is at least a     ||"
    echo "||    few years old to maximize the number of Linux distributions the      ||"
    echo "||    resulting AppImage will work on. AppImages often don't work on       ||"
    echo "||    distributions older than the one they were built on because of       ||"
    echo "||    standard library differences. The oldest supported Ubuntu LTS is     ||"
    echo "||    a good option.                                                       ||"
    echo "+===========================================================================+"
    echo ""
set -x
fi


# From where do we run this script?
here="$(dirname $(readlink -f "$0"))"
top=$(dirname $here)

# Move to root of GitHub sources:
cd $top

# Set 'appdir' environment variable name:
appdir=$here/build/appdir

# Clean up stuff from previous build attempts:
rm -rf $here/build

# Prepare build of QPDF from sources:
./configure --prefix=/usr --enable-werror \
            --enable-crypto-gnutls --disable-implicit-crypto \
            --enable-show-failed-test-output \
            --enable-html-doc --enable-pdf-doc "$CUSTOM_CONFIGURE"

# Build!
make -j$(nproc)

if [ "$SKIP_TESTS" = "" ]; then
    # Run built-in QPDF checks:
    make -k check
fi

# Prepare AppDir which is the basis for the AppImage:
mkdir -p $appdir

# Install build result into AppDir:
make install DESTDIR=$appdir; find $appdir
make doc-dist DOC_DEST=appdir/usr/share/doc/qpdf

# Change into build directory:
cd $here/build

# Don't bundle developer stuff
rm -rf appdir/usr/include appdir/usr/lib/pkgconfig appdir/usr/lib/*.{a,la,so}

# Copy icon which is needed for desktop integration into place:
for width in 64 128 256 512; do
    dir=appdir/usr/share/icons/hicolor/${width}x${width}/apps
    mkdir -p $dir
    inkscape -z -e qpdf-tmp.png -w $width -b white $top/logo/qpdf.svg
    convert qpdf-tmp.png -gravity center -background white -extent ${width}x${width} $dir/qpdf.png
    rm qpdf-tmp.png
done

# Copy .desktop and .appdata.xml metadata for desktop integration into place:
for i in appdir/usr/share/applications; do
    mkdir -p $i
    cp $top/appimage/qpdf.desktop $i
done
for i in appdir/usr/share/metainfo; do
    mkdir -p $i
    cp $top/appimage/qpdf.appdata.xml $i
done
for i in appdir/usr/share/doc/qpdf; do
    mkdir -p $i
    cp $top/README* $i
    cp $top/NOTICE.md $i/README-notice.md
    cp $top/LICENSE.txt $i
    cp $top/Artistic-2.0 $i/Artistic-LICENSE.txt
    cp $top/ChangeLog $i/README-ChangeLog
    cp $top/TODO $i/README-todo
done

# The following lines are experimental (for debugging; and to test
# support for unexpected future binaries added to QPDF):
for i in /usr/bin/env /bin/less /bin/busybox; do
    cp $i appdir/usr/bin/
done
ls -l /usr/bin/env /bin/less /bin/busybox

# Fetch 'linuxdeployqt' which will transform the AppDir into an AppImage:
wget -c "https://github.com/probonopd/linuxdeployqt/releases/download/continuous/linuxdeployqt-continuous-x86_64.AppImage"
chmod a+x linuxdeployqt*.AppImage

# Set up a clean environment:
unset QTDIR; unset QT_PLUGIN_PATH; unset LD_LIBRARY_PATH

# Let 'linuxdeployqt' do its first stage of work:
./linuxdeployqt*.AppImage appdir/usr/share/applications/*.desktop -bundle-non-qt-libs

# In addition to the main executable, we have additional ones to process
./linuxdeployqt*.AppImage appdir/usr/bin/zlib-flate -bundle-non-qt-libs

# To eventually generate the AppImage we extract the linuxdeployqt
# AppImage to get access to the embedded 'appimagetool':
./linuxdeployqt*.AppImage --appimage-extract

# We want to run our custom AppRun script.
# Replace symlink with custom script
rm appdir/AppRun; cp $top/appimage/AppRun appdir; chmod a+x appdir/AppRun

# If we are not on Ubuntu Trusty, we need to disable 'appstreamcli' validation:
if [[ $_osversion =~ Ubuntu\ 14.04.*\ LTS ]]; then
    appimagetool_param=""
else
    appimagetool_param="-n"
    set +x
    echo ""
    echo " Running 'appimagetool' with '-n' parameter..."
    echo " Reason: this does not seem to be a build running on"
    echo " Ubuntu Trusty 14.04."
    echo " '-n' disables checking of AppStream data by the 'appstreamcli'"
    echo " utility since post-Trusty versions have incompatible changes."
    echo ""
    set -x
fi

# Set up a version string to include in the AppImage name
MAJOR_QPDF_VERSION=$( ./appdir/usr/bin/qpdf --version | grep "qpdf version" | awk '{print $3}' )
declare -a UPDATE_INFO
VERSION=${MAJOR_QPDF_VERSION}
UPDATE_INFO=(-u "gh-releases-zsync|qpdf|qpdf|latest|qpdf-*x86_64.AppImage.zsync")

# Remove the default AppRun/symlink and use our own custom AppRun script
rm appdir/AppRun; cp $top/appimage/AppRun appdir; chmod a+x appdir/AppRun

# Finally, generate the AppImage:
PATH=./squashfs-root/usr/bin:$PATH ./squashfs-root/usr/bin/appimagetool $sign $UPDATE_FLAG ${UPDATE_INFO[*]} $appimagetool_param appdir qpdf-$VERSION-x86_64.AppImage

set +x
# Tell everyone where our result is stored:
echo ""
echo "============================================================================="
echo "  === AppImage is ready in $top/appimage/build ==="
echo "============================================================================="
echo ""