#!/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

set -eux

# read optional command line argument
LLVM_VERSION=8
if [ "$#" -eq 1 ]; then
    LLVM_VERSION=$1
fi

DISTRO=$(lsb_release -is)
VERSION=$(lsb_release -sr)
DIST_VERSION="${DISTRO}_${VERSION}"

if [[ $EUID -ne 0 ]]; then
   echo "This script must be run as root!" 
   exit 1
fi

declare -A LLVM_VERSION_PATTERNS
LLVM_VERSION_PATTERNS[8]="-8"
LLVM_VERSION_PATTERNS[9]="-9"
LLVM_VERSION_PATTERNS[10]=""

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

LLVM_VERSION_STRING=${LLVM_VERSION_PATTERNS[$LLVM_VERSION]}

# find the right repository name for the distro and version
case "$DIST_VERSION" in
    Debian_9* )       REPO_NAME="deb http://apt.llvm.org/stretch/  llvm-toolchain-stretch$LLVM_VERSION_STRING main" ;;
    Debian_10* )      REPO_NAME="deb http://apt.llvm.org/buster/   llvm-toolchain-buster$LLVM_VERSION_STRING  main" ;;
    Debian_unstable ) REPO_NAME="deb http://apt.llvm.org/unstable/ llvm-toolchain$LLVM_VERSION_STRING         main" ;;
    Debian_testing )  REPO_NAME="deb http://apt.llvm.org/unstable/ llvm-toolchain$LLVM_VERSION_STRING         main" ;;
    Ubuntu_16.04 )    REPO_NAME="deb http://apt.llvm.org/xenial/   llvm-toolchain-xenial$LLVM_VERSION_STRING  main" ;;
    Ubuntu_18.04 )    REPO_NAME="deb http://apt.llvm.org/bionic/   llvm-toolchain-bionic$LLVM_VERSION_STRING  main" ;;
    Ubuntu_18.10 )    REPO_NAME="deb http://apt.llvm.org/cosmic/   llvm-toolchain-cosmic$LLVM_VERSION_STRING  main" ;;
    Ubuntu_19.04 )    REPO_NAME="deb http://apt.llvm.org/disco/    llvm-toolchain-disco$LLVM_VERSION_STRING   main" ;;
    * )
        echo "Distribution '$DISTRO' in version '$VERSION' is not supported by this script (${DIST_VERSION})."
        exit 2
esac


cat /etc/apt/sources.list
# install everything
wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | apt-key add -
add-apt-repository "${REPO_NAME}"
cat /etc/apt/sources.list
apt-get update 
apt-get install -y clang-$LLVM_VERSION lldb-$LLVM_VERSION lld-$LLVM_VERSION clangd-$LLVM_VERSION
