#!/bin/bash
################################################################################
# Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
# See https://llvm.org/LICENSE.txt for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
################################################################################
#
# This script will install the llvm toolchain on the different
# Debian and Ubuntu versions

# This script is stored on:
# https://github.com/opencollab/llvm-jenkins.debian.net/blob/master/llvm.sh

set -euxo pipefail

info()  { printf "[info] %s\n" "$*"; }
warn()  { printf "[warn] %s\n" "$*" >&2; }
# error MESSAGE [EXIT_CODE] — default exit code is 1
error() {
    local msg="$1"
    local code="${2:-1}"
    printf "[error] %s\n" "$msg" >&2
    exit "$code"
}

usage() {
    set +x
    echo "Usage: $0 [llvm_major_version] [all] [OPTIONS]" 1>&2
    echo -e "all\t\t\tInstall all packages." 1>&2
    echo -e "-n=code_name\t\tSpecifies the distro codename, for example bionic" 1>&2
    echo -e "-h\t\t\tPrints this help." 1>&2
    echo -e "-m=repo_base_url\tSpecifies the base URL from which to download." 1>&2
    exit $#
}

CURRENT_LLVM_STABLE=22
BASE_URL="https://apt.llvm.org"

NEW_DEBIAN_DISTROS=("trixie" "forky" "unstable")
# Set default values for commandline arguments
# We default to the current stable branch of LLVM
LLVM_VERSION=$CURRENT_LLVM_STABLE
ALL=0
DISTRO=$(lsb_release -is)
VERSION_CODENAME=$(lsb_release -cs)
VERSION=$(lsb_release -sr)
UBUNTU_CODENAME=""
CODENAME_FROM_ARGUMENTS=""
# Obtain VERSION_CODENAME and UBUNTU_CODENAME (for Ubuntu and its derivatives)
source /etc/os-release
DISTRO=${DISTRO,,}

# Downloader abstraction: prefer wget, fall back to curl
download_key() {
    local url="$1"
    if command -v wget &>/dev/null; then
        wget -qO- --retry-connrefused --waitretry=1 --tries=3 "$url"
    elif command -v curl &>/dev/null; then
        curl --proto '=https' --tlsv1.2 -sSf --retry 3 "$url"
    else
        error "Neither wget nor curl found. Install one and retry." 4
    fi
}

check_url() {
    local url="$1"
    if command -v wget &>/dev/null; then
        wget -q --method=HEAD --timeout=15 --tries=3 "$url" &>/dev/null
    elif command -v curl &>/dev/null; then
        curl --proto '=https' --tlsv1.2 -sSf --head --retry 2 "$url" >/dev/null 2>&1
    else
        return 1
    fi
}

# Check if this is a new Debian distro
is_new_debian=0
if [[ "${DISTRO}" == "debian" ]]; then
    for new_distro in "${NEW_DEBIAN_DISTROS[@]}"; do
        if [[ "${VERSION_CODENAME}" == "${new_distro}" ]]; then
            is_new_debian=1
            break
        fi
    done
fi

# Check for required tools
needed_binaries=(lsb_release wget gpg)
# add-apt-repository is not needed for newer Debian distros
if [[ $is_new_debian -eq 0 ]]; then
    needed_binaries+=(add-apt-repository)
fi

missing_binaries=()
for binary in "${needed_binaries[@]}"; do
    if ! command -v "$binary" &>/dev/null; then
        if [[ "$binary" == "wget" ]] && command -v curl &>/dev/null; then
            continue
        fi
        missing_binaries+=("$binary")
    fi
done

if [[ ${#missing_binaries[@]} -gt 0 ]] ; then
    error "Missing required tools: ${missing_binaries[*]}
(hint: apt install lsb-release wget software-properties-common gnupg)
curl is also supported as an alternative to wget" 4
fi

case ${DISTRO} in
    debian)
        # Debian Forky has a workaround because of
        # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1038383
        if [[ "${VERSION}" == "unstable" ]] || [[ "${VERSION}" == "testing" ]] || [[ "${VERSION_CODENAME}" == "forky" ]]; then
            CODENAME=unstable
            LINKNAME=
        else
            # "stable" Debian release
            CODENAME=${VERSION_CODENAME}
            LINKNAME=-${CODENAME}
        fi
        ;;
    *)
        # ubuntu and its derivatives
        if [[ -n "${UBUNTU_CODENAME}" ]]; then
            CODENAME=${UBUNTU_CODENAME}
            if [[ -n "${CODENAME}" ]]; then
                LINKNAME=-${CODENAME}
            fi
        fi
        ;;
esac

# check for long options
for arg in "$@"; do
    case "${arg}" in
        (--help|-h) usage ;;
        (--version) usage error ;;
        (--) break ;;
    esac
done

# read optional command line arguments
if [ "$#" -ge 1 ] && [ "${1::1}" != "-" ]; then
    if [ "$1" != "all" ]; then
        LLVM_VERSION=$1
    else
        # special case for ./llvm.sh all
        ALL=1
    fi
    OPTIND=2
    if [ "$#" -ge 2 ]; then
      if [ "$2" == "all" ]; then
          # Install all packages
          ALL=1
          OPTIND=3
      fi
    fi
fi

while getopts ":hm:n:" arg; do
    case $arg in
    h)
        usage
        ;;
    m)
        BASE_URL=${OPTARG}
        ;;
    n)
        CODENAME=${OPTARG}
        if [[ "${CODENAME}" == "unstable" ]]; then
            # link name does not apply to unstable repository
            LINKNAME=
        else
            LINKNAME=-${CODENAME}
        fi
        CODENAME_FROM_ARGUMENTS="true"
        ;;
    esac
done

if [[ $EUID -ne 0 ]]; then
    error "This script must be run as root!"
fi

declare -A LLVM_VERSION_PATTERNS
LLVM_VERSION_PATTERNS[9]="-9"
LLVM_VERSION_PATTERNS[10]="-10"
LLVM_VERSION_PATTERNS[11]="-11"
LLVM_VERSION_PATTERNS[12]="-12"
LLVM_VERSION_PATTERNS[13]="-13"
LLVM_VERSION_PATTERNS[14]="-14"
LLVM_VERSION_PATTERNS[15]="-15"
LLVM_VERSION_PATTERNS[16]="-16"
LLVM_VERSION_PATTERNS[17]="-17"
LLVM_VERSION_PATTERNS[18]="-18"
LLVM_VERSION_PATTERNS[19]="-19"
LLVM_VERSION_PATTERNS[20]="-20"
LLVM_VERSION_PATTERNS[21]="-21"
LLVM_VERSION_PATTERNS[22]="-22"
LLVM_VERSION_PATTERNS[23]="-23"
LLVM_VERSION_PATTERNS[24]=""

if [ ! ${LLVM_VERSION_PATTERNS[$LLVM_VERSION]+_} ]; then
    error "This script does not support LLVM version $LLVM_VERSION" 3
fi

LLVM_VERSION_STRING=${LLVM_VERSION_PATTERNS[$LLVM_VERSION]}

# join the repository name
if [[ -n "${CODENAME}" ]]; then
    REPO_NAME="deb ${BASE_URL}/${CODENAME}/  llvm-toolchain${LINKNAME}${LLVM_VERSION_STRING} main"
    # check if the repository exists for the distro and version
    if ! check_url "${BASE_URL}/${CODENAME}/"; then
        if [[ -n "${CODENAME_FROM_ARGUMENTS}" ]]; then
            error "Specified codename '${CODENAME}' is not supported by this script." 2
        else
            error "Distribution '${DISTRO}' in version '${VERSION}' is not supported by this script." 2
        fi
    fi
fi


# install everything

if [[ ! -f /etc/apt/trusted.gpg.d/apt.llvm.org.asc ]]; then
    GPG_KEY_URL="https://apt.llvm.org/llvm-snapshot.gpg.key"
    if ! check_url "$GPG_KEY_URL"; then
        error "GPG key not reachable at $GPG_KEY_URL" 2
    fi
    download_key "$GPG_KEY_URL" | tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
fi

if [[ -z "`apt-key list 2> /dev/null | grep -i llvm`" ]]; then
    # Delete the key in the old format
    apt-key del AF4F7421 || true
fi


# Add repository based on distribution
if [[ "${VERSION_CODENAME}" == "bookworm" ]]; then
    # add it twice to workaround:
    # https://github.com/llvm/llvm-project/issues/62475
    add-apt-repository -y "${REPO_NAME}"
    add-apt-repository -y "${REPO_NAME}"
elif [[ $is_new_debian -eq 1 ]]; then
    # workaround missing add-apt-repository in newer Debian and use new source.list format
    SOURCES_FILE="/etc/apt/sources.list.d/http_apt_llvm_org_${CODENAME}_-${VERSION_CODENAME}.sources"
    TEXT_TO_ADD="Types: deb
Architectures: amd64 arm64
Signed-By: /etc/apt/trusted.gpg.d/apt.llvm.org.asc
URIs: ${BASE_URL}/${CODENAME}/
Suites: llvm-toolchain${LINKNAME}${LLVM_VERSION_STRING}
Components: main"
    echo "$TEXT_TO_ADD" | tee -a "$SOURCES_FILE" > /dev/null
else
    add-apt-repository -y "${REPO_NAME}"
fi

apt-get update
PKG="clang-$LLVM_VERSION lldb-$LLVM_VERSION lld-$LLVM_VERSION clangd-$LLVM_VERSION"
if [[ $ALL -eq 1 ]]; then
    # same as in test-install.sh
    # No worries if we have dups
    PKG="$PKG clang-tidy-$LLVM_VERSION clang-format-$LLVM_VERSION clang-tools-$LLVM_VERSION llvm-$LLVM_VERSION-dev lld-$LLVM_VERSION lldb-$LLVM_VERSION llvm-$LLVM_VERSION-tools libomp-$LLVM_VERSION-dev libc++-$LLVM_VERSION-dev libc++abi-$LLVM_VERSION-dev libclang-common-$LLVM_VERSION-dev libclang-$LLVM_VERSION-dev libclang-cpp$LLVM_VERSION-dev liblldb-$LLVM_VERSION-dev libunwind-$LLVM_VERSION-dev"
    if test $LLVM_VERSION -gt 14; then
        PKG="$PKG libclang-rt-$LLVM_VERSION-dev libpolly-$LLVM_VERSION-dev"
    fi
fi
apt-get install -y $PKG