#!/bin/bash
#
#   Copyright (c) 2012, Al Stone <ahs3@ahs3.net>
#
#   This program is free software; you can redistribute it and/or
#   modify it under the terms of version 2 (only) of the GNU General
#   Public License as published by the Free Software Foundation.
#
#
#       For each package in a list, run a set of one or more scanners
#       over the source files looking for potential machine dependent
#       code (i.e., portability dependencies).
#

#-- functions
usage () {
        name=$(basename $0)
        echo "$name: scan source files for portability issues"
        echo
        echo "$name --pkglist <filename> --distro <distroname>"
        echo "      [--keep] [--output <filename>] [--workdir <dirname>]"
        echo
        echo "where:"
        echo "    --keep                => if given, do not remove any of"
        echo "                             the downloaded sources (WARNING!"
        echo "                             this is a LOT of GiBs)"
        echo "    --pkglist <filename>  => list of packages to scan,"
        echo "                             one package name per line"
        echo "    --distro <filename>   => one of: fedora, debian"
        echo "    --output <filename>   => where to report results"
        echo "                             (default: scan.results)"
        echo "    --workdir <dirname>   => temporary working directory"
        echo "                             for source trees and other"
        echo "                             stuff (default: ./work)"
}

run_scanners () {
        #-- run all scanners listed in ./scanners
        #   Each file is an independent executable, and will be passed
        #   be passed the working directory, package name, and the full
        #   path to the source tree.  In turn, whatever is executed needs
        #   to return a single output line that has this form:
        #
        #       <scanner-name>: <value>
        #
        #   For example:
        #       Dot-S-Files: 3
        #
        #   The name may not have white space in it, and a value of 0
        #   means the scan worked but found nothing, a value > 0 means
        #   something possibly problematic was found (larger implies more
        #   problematic), and a value of -1 means an error occurred.
        #   
        workdir="$1"
        pkg=$2
        src=$3
        echo >> $output
        echo "Package: $pkg" >> $output
        echo "Source: $(basename $src)" >> $output
        for ii in $(ls scanners)
        do
                result=$(scanners/$ii $workdir $src 2>&1)
                echo "$result" >> $output
        done
}

#-- input argument handling
distro=""
keep="no"
output="scan.results"
pkglist=""
workdir="$(pwd)/work"

while [ $# -gt 0 ]
do
        arg="$1"
        shift
        case $arg in
        --distro)               # which unpacking scheme is needed for source
                if [ $# -gt 0 ]
                then
                        dname=$1
                        shift
                        case $dname in
                        fedora|debian)
                                distro=$dname
                                ;;
                        *)
                                echo "? no such distro: $dname"
                                exit 1
                        esac
                else
                        echo "? must supply distro name"
                        exit 1
                fi
                ;;
        --keep)
                keep="yes"
                ;;
        --output)               # where to store the scan results
                if [ $# -gt 0 ]
                then
                        output=$1
                else
                        echo "? must supply output file name"
                        exit 1
                fi
                ;;
        --pkglist)              # which packages to scan
                if [ $# -gt 0 ]
                then
                        plist=$1
                        shift
                        if [ -f $plist ]
                        then
                                pkglist=$plist
                        else
                                echo "? no such file: $plist"
                                exit 1
                        fi
                else
                        echo "? must supply package list file name"
                        exit 1
                fi
                ;;
        --workdir)              # temporary working dir for source trees
                if [ $# -gt 0 ]
                then
                        workdir=$1
                else
                        echo "? must supply work directory name"
                        exit 1
                fi
                ;;
        *)
                echo "? unknown parameter: $arg"
                usage
                exit 1
        esac
done

if [ -z $distro ]
then
        echo "? --distro is a required parameter"
        exit 1
fi

if [ -z $pkglist ]
then
        echo "? --pkglist is a required parameter"
        exit 1
fi

#-- make sure we know how to handle the distro
#   Each file needs to define a function called get_source that will
#   be passed the working directory and a package name, and that must
#   return the full absolute path to the source tree.
#
#   There must also be a similar remove_source (same parameters) that
#   cleans up and removes all sources for a package.
if [ ! -f packages/$distro ]
then
        echo "? internal error: no script for distro $distro"
        exit 2
fi
source packages/$distro

#-- for each package in the list, scan it and report results
[ ! -d "$workdir" ] && mkdir -p "$workdir"
rm -f $output
cat $pkglist | (
        read line
        while [ "$line" ]
        do
                echo "scanning => $line"
                res=$(get_source "$workdir" $line)
                if [ ! -z "$res" ]
                then
                        run_scanners "$workdir" $line $res
                fi
                if [ $keep == "no" ]
                then
                        remove_source "$workdir" $line
                fi
                read line
        done
)