#!/bin/bash

assert_is_instance() {
  local usage=$1
  local name=$2
  local instance=$3
  local check_link=$4

  if [ -z "$name" ]
  then
    $usage "Missing required option -n."
  fi

  if [ -z "$instance" ]
  then
    $usage "Missing required option -i."
  fi

  if [ ! -d $name/$instance ]
  then
    echo "No such instance: $name/$instance."  >&2
    exit 1
  fi

  if [ "$check_link" != "no" ]
  then
    if [ ! -e $name/$instance/current ]
    then
      echo "Missing 'current' link." >&2
      exit 1
    fi
  fi
}

list_apps() {
  filter_name=$1; shift
  filter_instnace=$1; shift
  vars="$@"

  sort $apps/.app/var/list | while read line
  do
    echo $line | (IFS=:; while read name instance version junk
    do
      if [ -n "$filter_name" -a "$filter_name" != "$name" ]
      then
        continue
      fi

      if [ -n "$filter_instance" -a "$filter_instance" != "$instance" ]
      then
        continue
      fi

      local line=""
      IFS=" "; for var in $vars
      do
        case $var in
          name) x=$name;;
          instance) x=$instance;;
          version) x=$version;;
          current_version) x=`find_current_version $name $instance`;;
          *) x="";;
        esac

        if [ -z "$line" ]
        then
          line="$line$x"
        else
          line="$line:$x"
        fi
      done
      echo $line
    done)
  done
}

find_current_version() {
  name=$1
  instance=$2

  if [ ! -L $apps/$name/$instance/current ]
  then
    return 0
  fi

  (
    cd $apps/$name/$instance
    ls -l current | sed -n "s,.* current -> versions/\(.*\)/root,\1,p"
  )
}

find_versions() {
  name=$1
  instance=$2

  if [ ! -d $apps/$name/$instance/versions ]
  then
    return 0
  fi

  (
    cd $apps/$name/$instance/versions
    ls -1d *
  )
}