#!/bin/sh
# Outputs APT configuration data

set -e

self="$(basename "$0")"

# TODO
# - handle enabling/disabling deb-src
# - currently only handles a single --suite or --profile; allow multiple ones?
# - nicer error messages
# - default output when neither --suite nor --profile is set?
# - support getting/setting --vendor?
# - support setting --mirror-map (for --profile)
# - list Ubuntu security pocket?  Debian security entries?

log() {
    echo "$@" >&2
}

usage() {
    log "$self [--arch=<arch>] [--components=<comp1>,<comp2>] [--mirror=<mirror>] [--suite=<suite>] [--pockets=<pocket1>,<pocket2>]" >&2
    log "$self [--arch=<arch>] [--components=<comp1>,<comp2>] [--profile=<profile>]" >&2
}

die() {
    log "$@"
    exit 1
}

guess_dist_vendor() {
    local dist="$1"

    case "$dist" in
      etch|lenny|squeeze|sid|testing|unstable|experimental)
        echo "debian"
      ;;
      hardy|intrepid|jaunty|karmic|lucid)
        echo "ubuntu"
      ;;
      *)
        die "Unknown vendor for dist=$dist"
      ;;
    esac
}

guess_vendor_arch_mirror() {
    local vendor="$1"
    local arch="$2"

    case "$vendor" in
      bpo)
        echo "http://www.backports.org/backports.org/"
      ;;
      debian)
        echo "http://ftp.us.debian.org/debian/"
      ;;
      ubuntu)
        case "$arch" in
          amd64|i386)
            echo "http://archive.ubuntu.com/ubuntu/"
          ;;
          armel|hppa|ia64|lpia|powerpc|sparc)
            echo "http://ports.ubuntu.com/ubuntu-ports/"
          ;;
          *)
            die "Unknown mirror for Ubuntu and arch=$arch"
          ;;
        esac
      ;;
      *)
        die "Unknown mirror for vendor=$vendor"
      ;;
    esac
}

getopt_output="`getopt -o "" -l arch:,components:,mirror:,suite:,pockets:,profile: -n "$self" -s sh -- "$@"`"

eval set -- "$getopt_output"

arch="`dpkg --print-architecture`"
components="main"
mirror=""
suite=""
pockets=""
vendor=""
profile=""

while :; do
    case "$1" in
      --arch)
        arch="$2"
        shift 2
      ;;
      --components)
        components="$2"
        shift 2
      ;;
      --mirror)
        mirror="$2"
        shift 2
      ;;
      --suite)
        if [ -z "$2" ]; then
            die "Need a suite for --suite"
        fi
        if [ -n "$profile" ]; then
            die "Can't set --suite after --profile"
        fi
        suite="$2"
        shift 2
      ;;
      --pockets)
        pockets="$2"
        shift 2
      ;;
      --vendor)
        vendor="$2"
        shift 2
      ;;
      --profile)
        if [ -z "$2" ]; then
            die "Need a profile for --profile"
        fi
        if [ -n "$suite" ]; then
            die "Can't set --profile after --suite"
        fi
        profile="$2"
        shift 2
      ;;
      --)
        shift
        break
      ;;
      *)
        die "Internal error: unhandled arg $1=$2"
      ;;
    esac
done

case $# in
  0)
    command="sources"
  ;;
  1)
    command="$1"
  ;;
  2)
    usage
    exit 1
  ;;
esac

if [ -z "$suite" ] && [ -z "$profile" ]; then
    die "Please pass --suite or --profile"
fi

if [ -n "$profile" ]; then
    base_dist="${profile%%-*}"
    base_vendor="`guess_dist_vendor "$base_dist"`"
    base_mirror="`guess_vendor_arch_mirror "$base_vendor" "$arch"`"
    case "$base_vendor" in
      debian)
        case "$profile" in
          experimental)
            base_dist="unstable"
            mirror="$base_mirror"
          ;;
          *-backports)
            vendor="bpo"
            mirror="`guess_vendor_arch_mirror "$vendor" "$arch"`"
          ;;
          *-proposed-updates)
            mirror="$base_mirror"
          ;;
          *)
            if [ "$base_dist" != "$profile" ]; then
                die "Unknown Debian based profile=$profile"
            fi
          ;;
        esac
        echo "deb     $base_mirror $base_dist $components"
        if [ -n "$mirror" ]; then
            echo "deb     $mirror $profile $components"
        fi
      ;;
      ubuntu)
        case "$profile" in
          *-backports)
            pockets="updates backports"
          ;;
          *-proposed)
            pockets="updates proposed"
          ;;
          *-updates|*-security)
            pockets="updates"
          ;;
          *)
            if [ "$base_dist" != "$profile" ]; then
                die "Unknown Ubuntu based profile=$profile"
            fi
          ;;
        esac
        echo "deb     $base_mirror $base_dist $components"
        for pocket in $pockets; do
            echo "deb     $base_mirror $base_dist-$pocket $components"
        done
      ;;
    esac
    exit 0
fi

if [ -n "$suite" ]; then
    if [ -z "$mirror" ]; then
        if [ -z "$vendor" ]; then
            vendor="`guess_dist_vendor "$suite"`"
        fi
        mirror="`guess_vendor_arch_mirror "$vendor" "$arch"`"
    fi
    echo "deb     $mirror $suite $components"
    exit 0
fi