#!/bin/bash

set -eo pipefail

SCAFFOLD_VERSION=${SCAFFOLD_VERSION:-0.0.2}
RELEASE_INFO_URL=https://forge.cadoles.com/api/v1/repos/wpetit/scaffold/releases/tags/0.0.2

function assert_command_available {
    local command=$1
    local command_path=$(which $command)

    if [ -z "$command_path" ]; then
        echo "The '$command' command could not be found. Please install it before using this script." 1>&2
        exit 1
    fi
}

function fetch_release_info {
    curl -s -H "accept: application/json" -XGET "${RELEASE_INFO_URL}"
}

function get_archive_name {
    local os="$(get_normalized_os)"
    local arch="$(get_normalized_arch)"
    echo "scaffold-${os}-${arch}.tar.gz"
}

function get_normalized_os {
    echo "$(uname -s | tr '[:upper:]' '[:lower:]')"
}

function get_normalized_arch {
    local arch=$(uname -m)
    case $(uname -m) in
        i?86)   arch="386" ;;
        x86_64) arch="amd64" ;;
        arm[4567]*) arch="arm" ;;
        arm[8]*) arch="arm64" ;;
        *) echo 1>&2 "Unsupported architecture '${arch}' !"; exit 1 ;;
    esac
    echo "$arch"
}

function find_attachment_url {
    local release_info=$1
    local expected_attachment_name=$2

    echo "${release_info}" | jq -r ".assets[] | select(.name == \"${expected_attachment_name}\") | .browser_download_url"
}

function download_attachment {
    local attachment_url=$1
    local attachment_name=$2

    curl -o "${attachment_name}" "$attachment_url"
}

function main {
    assert_command_available 'curl'
    assert_command_available 'jq'
    assert_command_available 'tar'
    assert_command_available 'tr'

    local archive_name="$(get_archive_name)"

    echo "Fetching scaffold release '${SCAFFOLD_VERSION}' informations..."
    local release_info="$(fetch_release_info)"

    local archive_url=$(find_attachment_url "$release_info" "$archive_name")

    if [ -z "$archive_url" ]; then
        echo 1>&2 "Could not find archive url !"
        exit 1
    fi

    local tmpdir=$(mktemp -d)

    ( 
        cd "${tmpdir}";
        
        echo "Downloading release file '${archive_name}' to '${tmpdir}'..."
        download_attachment "${archive_url}" "${archive_name}"
        
        echo "Extracting archive..."
        tar -xzf "${archive_name}"
        
        local dirname="$(echo "${archive_name}" | cut -f 1 -d '.')"

        echo "Copying scaffold binary to /usr/local/bin..."
        sudo cp -i "${dirname}/bin/scaffold" /usr/local/bin/
    )

    rm -rf "${tmpdir}"

    echo "Done."
}

main