#!/usr/bin/env bash

function os_support() {
    echo kubuntu \
    lubuntu \
    macos \
    ubuntu \
    ubuntu-kylin \
    ubuntu-mate \
    ubuntu-budgie \
    ubuntu-studio \
    xubuntu
}

function releases_macos() {
    echo mojave \
    catalina \
    big-sur
}

function releases_ubuntu() {
    echo bionic \
    focal \
    hirsute \
    devel
}

function web_get() {
    local DIR="${2}"
    local FILE=""
    local URL="${1}"
    FILE="${URL##*/}"
    mkdir -p "${DIR}" 2>/dev/null
    if ! wget --quiet --continue --show-progress --progress=bar:force:noscroll "${URL}" -O "${DIR}/${FILE}"; then
        echo "ERROR! Failed to download ${URL}"
        exit 1
    fi
}

function zsync_get() {
    local DIR="${2}"
    local FILE=""
    local URL="${1}"
    FILE="${URL##*/}"
    mkdir -p "${DIR}" 2>/dev/null
    if ! zsync "${URL}.zsync" -o "${DIR}/${FILE}"; then
        echo "ERROR! Failed to download ${URL}.zsync"
        exit 1
    fi

    if [ -e "${DIR}/${FILE}.zs-old" ]; then
        rm -v "${DIR}/${FILE}.zs-old"
    fi
}

function make_vm_dir() {
    if ! mkdir -p "${VM_PATH}" 2>/dev/null; then
      echo "ERROR! Unable to create directory ${VM_PATH}"
    fi
}

function make_vm_config() {
    local IMAGE_FILE=""
    local IMAGE_TYPE=""
    local GUEST=""
    IMAGE_FILE="${1}"
    if [[ "${OS}" == *"ubuntu"* ]]; then
        GUEST="linux"
        IMAGE_TYPE="iso"
    elif [ "${OS}" == "macos" ]; then
        GUEST="macos"
        IMAGE_TYPE="img"
    fi

    if [ ! -e "${OS}-${RELEASE}.conf" ]; then
        echo "Making VM configuration for ${OS}-${RELEASE}..."
        cat << EOF > "${OS}-${RELEASE}.conf"
guest_os="${GUEST}"
${IMAGE_TYPE}="${VM_PATH}/${IMAGE_FILE}"
disk_img="${VM_PATH}/disk.qcow2"
EOF
    fi
}

function start_vm_info() {
    echo
    echo "To start your ${OS} ${RELEASE} virtual machine run:"
    echo "    quickemu --vm ${OS}-${RELEASE}.conf"
    echo
}

function get_macos() {
    local CWD=""
    local MACRECOVERY=""

    case ${RELEASE} in
        high-sierra)
            BOARD_ID="Mac-7BA5B2D9E42DDD94"
            MLB="00000000000J80300";;
        mohave)
            BOARD_ID="Mac-7BA5B2DFE22DDD8C"
            MLB="00000000000KXPG00";;
        catalina)
            BOARD_ID="Mac-CFF7D910A743CAAF"
            MLB="00000000000PHCD00";;
        big-sur)
            BOARD_ID="Mac-E43C1C25D4880AD6"
            MLB="00000000000000000";;
        *) echo "ERROR! Unknown release: ${RELEASE}"
           releases_macos
           exit 1;;
    esac

    # Use a bundled macrecovery if possible
    CWD="$(dirname ${0})"
    if [ -x "${CWD}/macrecovery.py" ]; then
        MACRECOVERY="${CWD}/macrecovery.py"
    elif [ -x /usr/bin/macrecovery ]; then
        MACRECOVERY="/usr/bin/macrecovery"
    else
        web_get "https://raw.githubusercontent.com/acidanthera/OpenCorePkg/master/Utilities/macrecovery/macrecovery.py" "${HOME}/.quickemu"
        MACRECOVERY="python3 ${HOME}/.quickemu/macrecovery.py"
        sed -i 's/\<env python\>/env python3/g' "${MACRECOVERY}"
    fi

    if [ -z "${MACRECOVERY}" ]; then
        echo "ERROR! Can not find a usable macrecovery.py."
        exit 1
    fi

    make_vm_dir

    if [ ! -e "${VM_PATH}/RecoveryImage.chunklist" ]; then
        echo "Downloading ${RELEASE}..."
        ${MACRECOVERY} \
            --board-id "${BOARD_ID}" \
            --mlb "${MLB}" \
            --basename RecoveryImage \
            --outdir "${VM_PATH}" \
            download
    fi

    if [ -e "${VM_PATH}/RecoveryImage.dmg" ] && [ ! -e "${VM_PATH}/RecoveryImage.img" ]; then
        echo "Converting RecoveryImage..."
        qemu-img convert "${VM_PATH}/RecoveryImage.dmg" -O raw "${VM_PATH}/RecoveryImage.img"
    fi

    make_vm_config RecoveryImage.img
    start_vm_info
}

function get_ubuntu() {
    local DEVEL="daily-live"
    local ISO=""
    local PROJECT=""
    local RELEASES=""
    local URL=""

    case ${OS} in
      kubuntu|lubuntu|ubuntu|ubuntu-budgie|ubuntu-mate|xubuntu)
        PROJECT="${OS}";;
      ubuntu-kylin)
        PROJECT="ubuntukylin";;
      ubuntu-studio)
        PROJECT="ubuntustudio"
        DEVEL="dvd";;
      *)
        echo "ERROR! ${OS} is not a recognised Ubuntu flavour."
        exit 1;;
    esac

    if [ "${RELEASE}" == "devel" ]; then
        URL="http://cdimage.ubuntu.com/${PROJECT}/${DEVEL}/current"
    elif [ "${PROJECT}" == "ubuntu" ]; then
        URL="http://releases.ubuntu.com/${RELEASE}"
    else
        URL="http://cdimage.ubuntu.com/${PROJECT}/releases/${RELEASE}/release"
    fi

    RELEASES=$(releases_ubuntu)
    if [[ "${RELEASES}" != *"${RELEASE}"* ]]; then
        echo "ERROR! ${RELEASE} is not a supported release."
        releases_ubuntu
        exit 1
    fi

    make_vm_dir

    echo "Downloading SHA256SUMS..."
    web_get "${URL}/SHA256SUMS" "${VM_PATH}"

    ISO=$(grep 'desktop\|dvd' "${VM_PATH}/SHA256SUMS" | grep amd64 | cut -d' ' -f2 | sed 's|*||g')

    echo "Downloading "${URL}/${ISO}"..."
    if [ "${RELEASE}" == "devel" ]; then
        zsync_get "${URL}/${ISO}" "${VM_PATH}"
    else
        web_get "${URL}/${ISO}" "${VM_PATH}"
        echo "Checking SHA256SUMS..."
        cd "${VM_PATH}"
        if ! sha256sum --check SHA256SUMS --ignore-missing --status; then
            echo "ERROR! ${ISO} doesn't match ${VM_PATH}/SHA256SUMS. Try running 'quickget' again."
            exit 1
        else
            echo "All good."
        fi
        cd ..
    fi

    make_vm_config "${ISO}"
    start_vm_info
}

if [ -n "${1}" ]; then
    OS="${1,,}"
else
    echo "ERROR! You must specify an OS:"
    os_support
    exit 1
fi

if [ -n "${2}" ]; then
    RELEASE="${2,,}"
else
    echo "ERROR! You must specify an OS release name."
    if [ "${OS}" == "macos" ]; then
        releases_macos
    elif [[ "${OS}" == *"ubuntu"* ]]; then
        releases_ubuntu
    fi
    exit 1
fi

VM_PATH="${PWD}/${OS}-${RELEASE}"

if [ "${OS}" == "macos" ]; then
    get_macos
elif [[ "${OS}" == *"ubuntu"* ]]; then
    get_ubuntu
else
    echo "ERROR! You must specify an OS:"
    os_support
    exit 1
fi