#!/bin/bash
set -e

if [ "$(gh config get extensions.codeql.debug)" = "true" ] ; then
    set -x
fi

error() {
    echo "ERROR: $*" 1>&2
    exit 1
}

rootdir="$(dirname "$0")"
channel="$(gh config get extensions.codeql.channel)"
version="$(gh config get extensions.codeql.version)"

if [ -z "$1" ]; then
    cat <<EOF
GitHub command-line wrapper for the CodeQL CLI.

Usage:
    gh codeql set-channel [release|nightly]     # default: release
    gh codeql set-version [version]             # default: latest
    gh codeql list-versions                     # list all available versions for current channel
    gh codeql list-installed                    # list installed versions for current channel
    gh codeql cleanup <version>                 # delete a specific downloaded version
    gh codeql cleanup-all                       # delete all installed versions for all channels
    gh codeql download [version]                # download a specific version (default: latest)
    gh codeql debug [on|off]                    # enable/disable debug output for gh extension
    gh codeql <anything else>                   # pass arguments to CodeQL CLI

Current channel: ${channel:-not specified}.
Current version: ${version:-not specified}.
EOF
    exit 0
fi

if [ -z "$channel" ] || [ "$channel" = "release" ] ; then
    channel="release"
    repo=github/codeql-cli-binaries
elif [ "$channel" = "nightly" ] ; then
    repo=dsp-testing/codeql-cli-nightlies
else
    error "Channel must be 'release' or 'nightly'."
fi

# determine platform using OSTYPE
platform="$(gh config get extensions.codeql.platform)"
if [[ -z "$platform" ]] ; then
    if [[ "$OSTYPE" == "darwin"* ]] ; then
        platform=osx64
    elif [[ "$OSTYPE" == "linux"* ]] ; then
        platform=linux64
    elif [[ "$OSTYPE" == "win"* ]] || [[ $OSTYPE == "cygwin" ]] || [[ "$OSTYPE" == "msys" ]] ; then
        platform=win64
    else
        error "Couldn't determine platform from OSTYPE='$OSTYPE'. Consider setting extensions.codeql.platform."
    fi
fi

# Handle debug command.
if [ "$1" = "debug" ] ; then
    if [ "$2" = "on" ] ; then
        gh config set extensions.codeql.debug true
    elif [ "$2" = "off" ] ; then
        gh config set extensions.codeql.debug false
    else
        error "Invalid debug command: '$2'."
    fi
    exit 0
fi

# Handle list-versions command.
if [ "$1" = "list-versions" ]; then
    gh api "repos/$repo/releases" --paginate --jq ".[].tag_name"
    exit 0
fi

# Handle set-channel command.
if [ "$1" = "set-channel" ]; then
    if [ "$2" != "release" ] && [ "$2" != "nightly" ]; then
        error "Invalid channel: '$2'."
    fi
    old_channel="$(gh config get extensions.codeql.channel)"
    if [ "${old_channel:-release}" != "$2" ] ; then
        gh config set extensions.codeql.channel "$2"
        gh config set extensions.codeql.version ""
        echo "Switched to $2 channel. Any pinned version has been unset."
    else
        echo "Channel already set to $2."
    fi
    exit 0
fi

function download() {
    local version="$1"
    if [ -z "$version" ] || [ "$version" = "latest" ]; then
        version=$(gh api "repos/$repo/releases/latest" --jq '.tag_name')
    fi
    if [ -x "$rootdir/dist/$channel/$version/codeql" ] ; then
        # Already downloaded.
        return 0
    fi
    id=$(gh api "repos/$repo/releases" --paginate --jq ".[] | select(.tag_name == \"$version\") | .id" | head -n1)
    if [ -z "$id" ]; then
        error "Version '$1' not found."
    fi
    mkdir -p "$rootdir/dist/$channel"
    tempdir="$(mktemp -d "$rootdir/dist/$channel/temp_$version.XXXXXXXX")"
    trap 'rm -rf "$tempdir"' EXIT
    echo "Downloading CodeQL CLI version $version..."
    curl -L -o "$tempdir/codeql-$platform.zip" "https://github.com/$repo/releases/download/$version/codeql-$platform.zip"
    # The below is neater but cannot be made to display a progress bar at the moment:
    # gh release download -R "$repo" "$version" --pattern "codeql-$platform.zip" --dir "$tempdir"
    echo "Unpacking CodeQL CLI version $version..."
    unzip -oq "$tempdir/codeql-$platform.zip" -d "$tempdir"
    mv "$tempdir/codeql" "$rootdir/dist/$channel/$version"
    rm -rf "$tempdir"
}

function set_version() {
    local version="$1"
    if [ -z "$version" ]; then
        error "Version must be specified. Use 'latest' to automatically determine the latest version."
    elif [ "$version" = "latest" ]; then
        version="$(gh api "repos/$repo/releases/latest" --jq ".tag_name")"
    else
        # Versions in github/codeql-cli-binaries have tags prefixed with v, which the user might have omitted.
        # If necessary, we add it in here.
        repoName=${repo#*/}
        repoOwner=${repo%/*}
        version="$(gh api graphql -f query='{
            repository(owner: "'"$repoOwner"'", name: "'"$repoName"'") {
                asEntered: release(tagName: "'"$version"'") {
                    tagName
                }
                vPrefixed: release(tagName: "v'"$version"'") {
                    tagName
                }
            }
        }' --jq '[.data.repository.[] | values][0].tagName')"
        if [ -z "$version" ] ; then
            error "Unknown version: '$1'."
        fi
    fi
    download "$version"
    gh config set extensions.codeql.version "$version"
}

# Handle the download command.
if [ "$1" = "download" ]; then
    download "$2"
    exit 0
fi    

# Handle the set-version command.
if [ "$1" = "set-version" ]; then
    set_version "$2"
    version="$(gh config get extensions.codeql.version)"
    exec "$rootdir/dist/$channel/$version/codeql" version
fi

# Handle the list-installed command.
if [ "$1" = "list-installed" ]; then
    ( cd "$rootdir/dist/$channel" ; find . -mindepth 1 -maxdepth 1 -type d | cut -c3- ; )
    exit 0
fi

# Handle the cleanup command.
if [ "$1" = "cleanup" ]; then
    if [ -z "$2" ]; then
        error "Version must be specified."
    elif [ ! -d "$rootdir/dist/$channel/$2" ]; then
        error "Version '$2' not found."
    fi
    rm -rf "$rootdir/dist/$channel/$2"
    exit 0
fi

# Handle the cleanup-all command
if [ "$1" = "cleanup-all" ]; then
    rm -rf "$rootdir/dist"
    exit 0
fi

if [ -z "$version" ]; then
    set_version latest
    version="$(gh config get extensions.codeql.version)"
fi
download "$version"
export CODEQL_DIST="$rootdir/dist/$channel/$version"
exec "$rootdir/dist/$channel/$version/codeql" "$@"