#!/usr/bin/env bash
set -eu
[ "${BASH_VERSINFO[0]}" -ge 3 ] && set -o pipefail

PLUGIN_DIR="$(dirname "${BASH_SOURCE[0]}")/.."

# shellcheck source=/dev/null
source "$PLUGIN_DIR/lib/helpers.sh"

check_shasum() {
    local archive_file_name=$1
    local authentic_checksum_file=$2
    local authentic_checksum=""

    authentic_checksum=$(<"$authentic_checksum_file")

    if command -v sha256sum >/dev/null 2>&1; then
        sha256sum \
            -c <<<"$authentic_checksum  $archive_file_name"
    elif command -v shasum >/dev/null 2>&1; then
        shasum \
        -a 256 \
        -c <<<"$authentic_checksum  $archive_file_name"
    else
        fail "sha256sum or shasum is not available for use"
    fi
}

download_golang () {
    local version=$1
    local download_path=$2
    local platform=""
    local arch=""

    platform=$(get_platform)
    arch=$(get_arch)
    download_url="https://dl.google.com/go/go${version}.${platform}-${arch}.tar.gz"

    http_code=$(curl -I -w '%{http_code}' -s -o /dev/null "$download_url")
    if [ "$http_code" -eq 404 ] || [ "$http_code" -eq 403 ]; then
        fail "URL: ${download_url} returned status ${http_code}"
    fi

    curl "$download_url" -o "${download_path}/archive.tar.gz"
    curl "${download_url}.sha256" -o "${download_path}/archive.tar.gz.sha256"

    echo 'verifying checksum'
    if ! check_shasum "${download_path}/archive.tar.gz" "${download_path}/archive.tar.gz.sha256"; then
        fail "Authenticity of package archive can not be assured. Exiting."
    else
      msg "checksum verified"
    fi
}

download_golang "$ASDF_INSTALL_VERSION" "$ASDF_DOWNLOAD_PATH"