#!/bin/sh
#
# CodeIT repository setup.  https://repo.codeit.guru/setup
#
#     curl -fsSL https://repo.codeit.guru/setup | sudo sh
#     curl -fsSL https://repo.codeit.guru/setup | sudo sh -s -- --print
#
# Detects the distribution, downloads the matching codeit-repo-release package
# and installs it. Nothing else: the package is what configures the repository
# and installs the signing keys, so the repository layout and the keys can be
# changed later by shipping a new package rather than by asking every user to
# edit a file they pasted from a web page years ago.

set -eu

PREFIX=https://repo.codeit.guru
PRINT_ONLY=0

# Overridable so the detection can be tested against a captured os-release
# from every distribution we care about, and so this can be pointed at a
# mounted root when working out why a container detected wrongly.
: "${OS_RELEASE:=/etc/os-release}"

for arg in "$@"; do
    case "$arg" in
        --print|--dry-run) PRINT_ONLY=1 ;;
        -h|--help)
            sed -n '2,12p' "$0" | sed 's/^# \{0,1\}//'
            exit 0
            ;;
        *)
            echo "unknown option: $arg" >&2
            echo "usage: setup [--print]" >&2
            exit 2
            ;;
    esac
done

die() { echo "codeit-setup: $*" >&2 ; exit 1 ; }

# --- download --------------------------------------------------------------
# curl on most, wget on minimal Debian images. Both are told to fail loudly on
# a 404 rather than saving the error page as if it were a package.
fetch() {
    url="$1" ; dest="$2"
    if command -v curl > /dev/null 2>&1; then
        curl -fsSL --proto '=https' --tlsv1.2 -o "$dest" "$url"
    elif command -v wget > /dev/null 2>&1; then
        wget -q -O "$dest" "$url"
    else
        die "neither curl nor wget is installed"
    fi
}

# --- which distribution ----------------------------------------------------
FAMILY=
TARGET=

# `rpm -E %{rhel}` first, and not $releasever.
#
# dnf's $releasever is whatever the release package sets, and it is not the
# major version everywhere: RHEL 7 reports "7Server", RHEL 8/9 report "8.10" /
# "9.4", CentOS Stream reports "9-stream", and Amazon Linux reports "2". Every
# one of those produces a 404 against a tree laid out by major version.
# %{rhel} is the EL generation and is what Alma, Rocky, Oracle, CentOS Stream
# and RHEL all agree on.
if command -v rpm > /dev/null 2>&1; then
    rhel=$(rpm -E '%{rhel}' 2>/dev/null || echo '')
    case "$rhel" in
        [0-9]|[0-9][0-9]) FAMILY=el ; TARGET="$rhel" ;;
    esac
fi

if [ -z "$FAMILY" ] && [ -r "$OS_RELEASE" ]; then
    # shellcheck disable=SC1091
    . "$OS_RELEASE"

    case "${ID:-}${ID_LIKE:+ $ID_LIKE}" in
        *debian*|*ubuntu*)
            FAMILY=deb
            # UBUNTU_CODENAME first: derivatives (Mint, Pop!_OS, Zorin) put
            # their own name in VERSION_CODENAME and the Ubuntu one here.
            TARGET="${UBUNTU_CODENAME:-${VERSION_CODENAME:-}}"
            ;;
        *rhel*|*fedora*|*centos*)
            # rpm was missing or %{rhel} was undefined; fall back to the
            # major part of VERSION_ID, which handles "9.4" and "7".
            FAMILY=el
            TARGET="${VERSION_ID%%.*}"
            ;;
    esac
fi

[ -n "$FAMILY" ] || die "could not identify this distribution.
  Please follow the manual instructions at https://codeit.guru/"
[ -n "$TARGET" ] || die "could not identify this release.
  Please follow the manual instructions at https://codeit.guru/"

# --- what we are going to do -----------------------------------------------
if [ "$FAMILY" = el ]; then
    PKG="codeit-repo-release.el$TARGET.rpm"
    if command -v dnf > /dev/null 2>&1; then INSTALL="dnf install -y"
    else                                     INSTALL="yum install -y"
    fi
else
    PKG="codeit-repo-release.$TARGET.deb"
    INSTALL="dpkg -i"
fi
URL="$PREFIX/$PKG"

echo "Detected: $FAMILY / $TARGET"
echo "Package:  $URL"

if [ "$PRINT_ONLY" = 1 ]; then
    echo
    echo "Would run:"
    if [ "$FAMILY" = el ]; then
        echo "  $INSTALL $URL"
    else
        echo "  curl -fsSLO $URL"
        echo "  $INSTALL $PKG && apt-get update"
    fi
    exit 0
fi

[ "$(id -u)" = 0 ] || die "must run as root - pipe into 'sudo sh' rather than 'sh'"

# --- install ---------------------------------------------------------------
if [ "$FAMILY" = el ]; then
    # yum/dnf take the URL directly and handle the download, so there is no
    # temporary file to clean up and no second failure mode.
    $INSTALL "$URL" || die "could not install $PKG.
  If this is a 404, there is no package published for EL $TARGET yet."
    echo
    echo "Done. The CodeIT repository is enabled."
    if [ "$TARGET" = 7 ]; then
        echo "For the nginx mainline branch:"
        echo "  yum-config-manager --enable CodeIT-mainline --save"
    else
        echo "Module streams available:"
        echo "  dnf module enable nginx:codeit-mainline"
        echo "  dnf module enable nginx:codeit-stable"
        echo "  dnf module enable httpd:codeit"
    fi
else
    tmp=$(mktemp -d)
    trap 'rm -rf "$tmp"' EXIT INT TERM
    fetch "$URL" "$tmp/$PKG" || die "could not download $PKG.
  If this is a 404, there is no package published for $TARGET yet."
    $INSTALL "$tmp/$PKG"
    apt-get update
    echo
    echo "Done. The CodeIT repository is enabled."
    echo "The testing suite is installed but disabled; enable it by setting"
    echo "  Enabled: yes  in /etc/apt/sources.list.d/codeit.sources"
fi