#!/bin/bash
# Part of SMLinux distribution
# Package build file generator

# Copyright (c) 2022 PktSurf <smlinux@pktsurf.in>

# 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.

# Abort on any error
set -e

# Date format
filedate="$(date +%Y%m%d%H%M%S)"

# Archive files
archivefiles=( *.tar.* *.zip *.t?z )

# Function to generate usage options
mkusage() {
   cat << EOF

mksm is a tool to generate SMLinux-compatible package build files. It currently
supports generation of build files for sources that support compilation using:
-> Make
-> Autoconf
-> Cmake
-> Meson

Usage: mksm <application_name> <application_version> <build_system>

**You must be inside the directory containing source tarball when running mksm.**. 
For example if you want to build glib 2.60.0, 

$ mkdir glib && cd glib
$ wget <glib-source-tarball-URL>
$ ls 
... 
glib-2.60.0.tar.xz
...

$ mksm glib 2.60.0 meson

EOF
}

# If/else to check if first argument is set. If it isn't, invoke mkusage
# function and exit
if [ -z $1 ] ; then
  mkusage
  exit 0
fi
  

# Explanation same as above, but this time, if first argument is set then
# set use it as a value for $appname variable
if [ -n "$1" ] ; then
  if [ "$1" = "-h" ] || [ "$1" = "-help" ] || [ "$1" = "--help" ] ; then
    mkusage
    exit 0
  else
    appname="$1"
   fi
fi

# If/else to check if second argument is set. If it is, set it as a value
# for $version variable. If it isn't, throw an error and exit.
if [ -n "$2" ] ; then
  version="$2"
else
  echo "Version not defined. Kindly define it. Exiting!"
  exit 1
fi

# If/else to check if third argument is set. If it is, set it as a value for
# $buildsys variable. If it isn't, throw an error and exit.
if [ -n "$3" ] ; then
  if [ "$3" = "make" ] ; then
     buildsys="make" 
  elif [ "$3" = "autoconf" ] ; then
     buildsys="autoconf" 
  elif [ "$3" = "cmake" ] ; then
     buildsys="cmake" 
  elif [ "$3" = "meson" ] ; then
     buildsys="meson" 
  else 
     echo "ERROR: Invalid build system. Aborting!"
     exit 1
  fi
else
  echo "Build system not defined. Kindly define one from make, autoconf, cmake or meson. Exiting!"
  exit 1
fi

# If $appname, $version and $buildsys variables are set, generate a build file.
if [ -n "$appname" ] && [ -n "$version" ] && [ -n "$buildsys" ] ; then
  echo "Generating build file for application '"$appname"' version '"$version"' which uses build system '"$buildsys"'..."
  echo ""
  echo "Current directory is $PWD"
  echo ""

  # Copy the sample build file based on the build system argument passed
  if [ -f "$appname.SMBuild" ] ; then
    echo "Found an existing $appname.SMBuild in the current directory." 
    echo "Backing it up inside a directory 'old' and creating a new one here." 
    mkdir -p old
    mv "$appname.SMBuild" old/"$appname.SMBuild.$filedate"
  fi
   
   # This one came in handy:
   # https://unix.stackexchange.com/questions/505949/expanding-only-certain-variables-inside-a-heredoc
   # Expand variables in this heredoc
   cat << EOF > $appname.SMBuild
app=$appname
version=$version
build=1sml
homepage=""
download=""
desc=""
requires="musl"
EOF
   
   # Single-quoted 'EOF' prevents variables from being expanded in this heredoc
   cat << 'EOF' >> $appname.SMBuild
   
build() {
  mkandenterbuilddir
  rm -rf $app-$version

  tar xf $srcdir/$app-$version.tar.?z*
  cd $app-$version
  fixbuilddirpermissions

EOF
   
   # Again prevent variables from being expanded in this heredoc
   gen_autoconf() {
     cat << 'EOF' >> $appname.SMBuild
  ./configure \
    --prefix="" \
    --sysconfdir=/etc

  make 
  make install DESTDIR=$pkg

  cp LICENSE $pkgdocs/

  mkfinalpkg
}

EOF
}

   gen_make() {
    cat << 'EOF' >> $appname.SMBuild
  make
  make install DESTDIR=$pkg

  cp LICENSE $pkgdocs/

  mkfinalpkg
}

EOF
}
   # And again
   gen_cmake() {
    cat << 'EOF' >> $appname.SMBuild
  mkdir smbuild && cd smbuild
  cmake .. \
    -DCMAKE_INSTALL_PREFIX="/" \
    -DCMAKE_C_FLAGS="$CFLAGS" \
    -DCMAKE_CXX_FLAGS="$CXXFLAGS" \
    -Wno-dev

  make
  make install DESTDIR=$pkg
  
  cp ../LICENSE $pkgdocs/

  mkfinalpkg
}

EOF
}
   
   # Again :)
   gen_meson() {
    cat << 'EOF' >> $appname.SMBuild
  mkdir smbuild && cd smbuild
  meson .. \
    --prefix="/" 

  ninja
  DESTDIR="$pkg" ninja install

  cp ../LICENSE $pkgdocs/

  mkfinalpkg
}

EOF
}

   case "$buildsys" in 
      autoconf) gen_autoconf ;;
      make) gen_make ;;
      cmake) gen_cmake ;;
      meson) gen_meson ;;
   esac

   chmod +x $appname.SMBuild
   echo "...done"
   echo ""

fi

# Generate sha512sums in the build file

  echo "Adding new sha512sums in $appname.SMBuild..."
  printf '\n' >> "$appname".SMBuild
  printf 'sha512sums="\n' >> "$appname".SMBuild

  # File types
  files=( *.tar.* *.zip *.t?z *.patch *.diff *.c *.h )

  # Checksum digest to be used along with arguments
  checksumbinary="sha512sum"

  for file in ${files[@]} ; do
     if [ -f "$file" ] ; then
       $checksumbinary $file >> "$appname".SMBuild
     fi
  done
  printf '"' >> "$appname".SMBuild
  exit 0