#!/bin/bash
# apt-cyg: install tool for Cygwin similar to debian apt-get
#
# The MIT License (MIT)
#
# Copyright (c) 2013 Trans-code Design
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

ARCH=${HOSTTYPE/i6/x}

function wget {
  if command wget -h &>/dev/null
  then
    command wget "$@"
  else
    warn wget is not installed, using lynx as fallback
    set "${*: -1}"
    lynx -source "$1" > "${1##*/}"
  fi
}

function usage {
  hr '
  usage: apt-cyg [command] [options] [packages]

  Commands:
     install     Install packages
     remove      Remove packages
     update      Update setup.ini
     download    Download only - do NOT install or unpack archives
     show        Displays the package records for the named packages
     depends     Performs recursive dependency listings
     rdepends    Display packages which require X to be installed,
                 AKA show reverse dependencies
     list        List packages matching given pattern. If no pattern is given,
                 list all installed packages.
     category    List packages matching given category
     listfiles   List files owned by packages
     search      Search for a filename from installed packages
     searchall   Search for a filename from all available packages

  Options:
     -c, --cache <dir>      set cache
     -f, --file <file>      read package names from file
     -m, --mirror <url>     set mirror
     --help
     --version
  '
}

function version {
  hr '
  apt-cyg version 0.59

  The MIT License (MIT)

  Copyright (c) 2005-9 Stephen Jungels
  '
}

function find-workspace {
  # default working directory and mirror
  
  # work wherever setup worked last, if possible
  cache=$(awk '
  /last-cache/ {
    getline
    print $1
  }
  ' /etc/setup/setup.rc | cygpath -f-)

  mirror=$(awk '
  /last-mirror/ {
    getline
    print $1
  }
  ' /etc/setup/setup.rc)
  mirrordir=$(sed '
  s / %2f g
  s : %3a g
  ' <<< "$mirror")

  mkdir -p "$cache/$mirrordir/$ARCH"
  cd "$cache/$mirrordir/$ARCH"
  if [ -e setup.ini ]
  then
    return 0
  else
    get-setup
    return 1
  fi
}

function get-setup {
  touch setup.ini
  mv setup.ini setup.ini-save
  wget -N $mirror/$ARCH/setup.bz2
  if [ -e setup.bz2 ]
  then
    bunzip2 setup.bz2
    mv setup setup.ini
    echo Updated setup.ini
  else
    echo Error updating setup.ini, reverting
    mv setup.ini-save setup.ini
  fi
}

function check-packages {
  if [[ $pks ]]
  then
    return 0
  else
    echo No packages found
    return 1
  fi
}

function info {
  printf '\e[36m%s\e[m\n' "$*" >&2
}

function warn {
  printf '\e[1;31m%s\e[m\n' "$*" >&2
}

function apt-update {
  if find-workspace
  then
    get-setup
  fi
}

function apt-category {
  check-packages
  find-workspace
  for pkg in "${pks[@]}"
  do
    awk '
    $1 == "@" {
      pck = $2
    }
    $1 == "category:" && $0 ~ query {
      print pck
    }
    ' query="$pks" setup.ini
  done
}

function apt-list {
  find-workspace
  local sbq
  for pkg in "${pks[@]}"
  do
    (( sbq++ )) && echo
    info Searching for installed packages matching "$pkg":
    awk 'NR>1 && $1~ENVIRON["pkg"] && $0=$1' /etc/setup/installed.db
    echo
    info Searching for installable packages matching "$pkg":
    awk '$1 ~ ENVIRON["pkg"] && $0 = $1' RS='\n\n@ ' FS='\n' setup.ini
  done
  (( sbq )) && return
  info The following packages are installed:
  awk 'NR>1 && $0=$1' /etc/setup/installed.db
}

function apt-listfiles {
  check-packages
  find-workspace
  local pkg sbq
  for pkg in "${pks[@]}"
  do
    (( sbq++ )) && echo
    if [ ! -e /etc/setup/"$pkg".lst.gz ]
    then
      download "$pkg"
    fi
    gzip -cd /etc/setup/"$pkg".lst.gz
  done
}

function apt-show {
  find-workspace
  check-packages
  for pkg in "${pks[@]}"
  do
    (( notfirst++ )) && echo
    awk '
    $1 == query {
      print
      fd++
    }
    END {
      if (! fd)
        print "Unable to locate package " query
    }
    ' RS='\n\n@ ' FS='\n' query="$pkg" setup.ini
  done
}

function apt-depends {
  find-workspace
  check-packages
  for pkg in "${pks[@]}"
  do
    awk '
    @include "join"
    $1 == "@" {
      apg = $2
    }
    $1 == "requires:" {
      for (z=2; z<=NF; z++)
        reqs[apg][z-1] = $z
    }
    END {
      prpg(ENVIRON["pkg"])
    }
    function smartmatch(small, large,    values) {
      for (each in large)
        values[large[each]]
      return small in values
    }
    function prpg(fpg) {
      if (smartmatch(fpg, spath)) return
      spath[length(spath)+1] = fpg
      print join(spath, 1, length(spath), " > ")
      if (isarray(reqs[fpg]))
        for (each in reqs[fpg])
          prpg(reqs[fpg][each])
      delete spath[length(spath)]
    }
    ' setup.ini
  done
}

function apt-rdepends {
  find-workspace
  for pkg in "${pks[@]}"
  do
    awk '
    @include "join"
    $1 == "@" {
      apg = $2
    }
    $1 == "requires:" {
      for (z=2; z<=NF; z++)
        reqs[$z][length(reqs[$z])+1] = apg
    }
    END {
      prpg(ENVIRON["pkg"])
    }
    function smartmatch(small, large,    values) {
      for (each in large)
        values[large[each]]
      return small in values
    }
    function prpg(fpg) {
      if (smartmatch(fpg, spath)) return
      spath[length(spath)+1] = fpg
      print join(spath, 1, length(spath), " < ")
      if (isarray(reqs[fpg]))
        for (each in reqs[fpg])
          prpg(reqs[fpg][each])
      delete spath[length(spath)]
    }
    ' setup.ini
  done
}

function apt-download {
  check-packages
  find-workspace
  local pkg sbq
  for pkg in "${pks[@]}"
  do
    (( sbq++ )) && echo
    download "$pkg"
  done
}

function download {
  local pkg digest digactual
  pkg=$1
  # look for package and save desc file

  awk '$1 == pc' RS='\n\n@ ' FS='\n' pc=$pkg setup.ini > desc
  if [ ! -s desc ]
  then
    echo Unable to locate package $pkg
    exit 1
  fi

  # download and unpack the bz2 or xz file

  # pick the latest version, which comes first
  set -- $(awk '$1 == "install:"' desc)
  if (( ! $# ))
  then
    echo 'Could not find "install" in package description: obsolete package?'
    exit 1
  fi

  dn=$(dirname $2)
  bn=$(basename $2)

  # check the md5
  digest=$4
  mkdir -p $cache/$mirrordir/$dn
  cd $cache/$mirrordir/$dn
  wget -nc $mirror/$dn/$bn
  digactual=$(md5sum $bn | awk NF=1)
  if [ $digest != $digactual ]
  then
    echo MD5 sum did not match, exiting
    exit 1
  fi

  tar tf $bn | gzip > /etc/setup/"$pkg".lst.gz
  cd ~-
  mv desc $cache/$mirrordir/$dn
  echo $dn $bn > /tmp/dwn
}

function apt-search {
  check-packages
  echo Searching downloaded packages...
  for pkg in "${pks[@]}"
  do
    key=$(type -P "$pkg" | sed s./..)
    [[ $key ]] || key=$pkg
    for manifest in /etc/setup/*.lst.gz
    do
      if gzip -cd $manifest | grep -q "$key"
      then
        package=$(sed '
        s,/etc/setup/,,
        s,.lst.gz,,
        ' <<< $manifest)
        echo $package
      fi
    done
  done
}

function apt-searchall {
  cd /tmp
  for pkg in "${pks[@]}"
  do
    printf -v qs 'text=1&arch=%s&grep=%s' $ARCH "$pkg"
    wget -O matches cygwin.com/cgi-bin2/package-grep.cgi?"$qs"
    awk '
    {
      if (NR == 1)
        next
      if (mc[$1]++)
        next
      if (/-debuginfo-/)
        next
      print $1
    }
    ' FS=-[[:digit:]] matches
  done
}

function apt-install {
  check-packages
  find-workspace
  local pkg dn bn requires wr package script
  for pkg in "${pks[@]}"
  do

  if grep -q "^$pkg " /etc/setup/installed.db
  then
    echo Package $pkg is already installed, skipping
    continue
  fi
  echo
  echo Installing $pkg

  download $pkg
  read dn bn </tmp/dwn
  echo Unpacking...

  cd $cache/$mirrordir/$dn
  tar -x -C / -f $bn
  # update the package database

  awk '
  ins != 1 && pkg < $1 {
    print pkg, bz, 0
    ins = 1
  }
  1
  END {
    if (ins != 1) print pkg, bz, 0
  }
  ' pkg="$pkg" bz=$bn /etc/setup/installed.db > /tmp/awk.$$
  mv /etc/setup/installed.db /etc/setup/installed.db-save
  mv /tmp/awk.$$ /etc/setup/installed.db

  # recursively install required packages

  requires=$(awk '$1=="requires", $0=$2' FS=': ' desc)
  cd ~-
  wr=0
  if [[ $requires ]]
  then
    echo Package $pkg requires the following packages, installing:
    echo $requires
    for package in $requires
    do
      if grep -q "^$package " /etc/setup/installed.db
      then
        echo Package $package is already installed, skipping
        continue
      fi
      apt-cyg install --noscripts $package || (( wr++ ))
    done
  fi
  if (( wr ))
  then
    info some required packages did not install, continuing
  fi

  # run all postinstall scripts

  (( noscripts )) && continue
  find /etc/postinstall -name '*.sh' | while read script
  do
    echo Running $script
    $script
    mv $script $script.done
  done
  echo Package $pkg installed

  done
}

function apt-remove {
  check-packages
  for pkg in "${pks[@]}"
  do

  if ! grep -q "^$pkg " /etc/setup/installed.db
  then
    echo Package $pkg is not installed, skipping
    continue
  fi

  cygcheck awk bash bunzip2 grep gzip mv sed tar xargs xz | awk '
  /bin/      &&
  !fd[$NF]++ &&
  $0 = $NF
  ' FS='\\' > /tmp/cygcheck.txt

  apt-cyg listfiles $pkg | awk '
  $0 = $NF
  ' FS=/ > /tmp/listfiles.txt

  if grep -xf /tmp/cygcheck.txt /tmp/listfiles.txt
  then
    echo apt-cyg cannot remove package $pkg, exiting
    exit 1
  fi
  if [ ! -e /etc/setup/"$pkg".lst.gz ]
  then
    echo Package manifest missing, cannot remove $pkg. Exiting
    exit 1
  fi
  echo Removing $pkg

  # run preremove scripts

  if [ -e /etc/preremove/"$pkg".sh ]
  then
    /etc/preremove/"$pkg".sh
    rm /etc/preremove/"$pkg".sh
  fi
  gzip -cd /etc/setup/"$pkg".lst.gz | sed '\./$.d;s.^./.' | xargs rm -f
  rm /etc/setup/"$pkg".lst.gz
  rm -f /etc/postinstall/$pkg.sh.done
  awk '$1 != pkg' pkg="$pkg" /etc/setup/installed.db > /tmp/awk.$$
  mv /etc/setup/installed.db /etc/setup/installed.db-save
  mv /tmp/awk.$$ /etc/setup/installed.db
  echo Package $pkg removed

  done
}

function hr {
  sed '
  1d
  $d
  s/  //
  ' <<< "$1"
}

if [ -p /dev/stdin ]
then
  mapfile -t pks
fi

# process options
while (( $# ))
do
  case "$1" in

    --mirror | -m)
      awk -i inplace '
      1
      /last-mirror/ {
        getline
        print "\t" rpc
      }
      ' rpc="$2" /etc/setup/setup.rc
      shift 2
    ;;

    --cache | -c)
      rpc=$(cygpath -aw "$2" | sed 's \\ \\\\ g')
      awk -i inplace '
      1
      /last-cache/ {
        getline
        print "\t" rpc
      }
      ' rpc="$rpc" /etc/setup/setup.rc
      shift 2
    ;;

    --noscripts)
      noscripts=1
      shift
    ;;

    --help)
      usage
      exit 0
    ;;

    --version)
      version
      exit 0
    ;;

    --file | -f)
      if [[ $2 ]]
      then
        mf=$2
        if [ -f "$mf" ]
        then
          mapfile -t pks < "$mf"
        else
          echo File "$mf" not found, skipping
        fi
        shift
      else
        info No file name provided, ignoring $1
      fi
      shift
    ;;

    update)
      command=$1
      shift
    ;;

    install     \
    | remove    \
    | download  \
    | show      \
    | depends   \
    | rdepends  \
    | list      \
    | category  \
    | listfiles \
    | search    \
    | searchall)
      if [[ $command ]]
      then
        pks+=("$1")
      else
        command=$1
      fi
      shift
    ;;

    *)
      pks+=("$1")
      shift
    ;;

  esac
done

set -a

if type -t apt-$command | grep -q function
then
  apt-$command
else
  usage
fi