#!/usr/bin/env bash


read -rd '' splash <<_EOF_
####################################################################################
# MiSTer installation script for Linux by rwk.                                     #
# based on Michael Smith (shmitty) <root@retrospace.be> macOS script               #
#                                                                                  #
# Thanks to rattboi who posted Naomi Peori's MiSTer SD Card Info file on the       #
# SmokeMonster Elite fpga-general discord channel and everyone involved and in and #
# using the MiSTer project.                                                        #
#                                                                                  #
# IMPORTANT: Use this script at your own risk. It WILL WIPE ALL DATA on the device #
# you specify. On standard Linux this is usually /dev/mmcblkX or /dev/sdX but make #
# sure to double check.                                                            #
#                                                                                  #
# Prerequisites:                                                                   #
# * git                                                                            #
# * wget                                                                           #
# * unrar                                                                          #
# * mkfs.exfat                                                                     #
# (install using your packet manager: e.g., apt-get install git wget unrar).       #
# (if something else is missing install it ...)                                    #
####################################################################################

_EOF_
echo "${splash}"

[[ "${EUID}" -ne 0 ]] && { echo "Error: This script needs to be run as root" ; exit 1 ; }

print_block() {
    printf '#%.0s' {1..80} ; echo
    echo "${1}" | fold -s -w 80
    printf '#%.0s' {1..80} ; echo
    echo
}

# Print a formatted error message and exit 1.
die_with_error() {
    error="${1}"

    if [[ -z "${error}" ]]; then
        error="One or more setup commands failed.  Aborting installation."
    fi

    print_block "ERROR: ${error}"

    exit 1
}

# Verify a prerequisite command exists, die if it doesn't.
check_prereqs() {
    for cmd in "${@}"; do
        command -v "${cmd}" >/dev/null 2>&1 || die_with_error "I require '${cmd}' but it's not installed. Aborting."
    done
}

# Sanity checks for temporary directories.
verify_absent_or_directory() {
    for dir in "${@}"; do
        if [[ -e "${dir}" ]] && [[ ! -d "${dir}" ]]; then
            die_with_error "Required temporary path \"${dir}\" exists but is not a directory.  Aborting."
        fi
    done
}

# Script configuration
DOWNLOAD_DIRECTORY="./download"
MNT_DIRECTORY="./mnt_MiSTer_Data"

verify_absent_or_directory "${DOWNLOAD_DIRECTORY}" "${MNT_DIRECTORY}"

# TODO(m): Remove hardcoded versions.
# URLs
RELEASE_URL='https://github.com/MiSTer-devel/SD-Installer-Win64_MiSTer/raw/master/release_20200908.rar'
RECENT_MISTER_URL='https://github.com/MiSTer-devel/Main_MiSTer/raw/master/releases/MiSTer_20210224'
RECENT_MENU_MISTER_URL='https://github.com/MiSTer-devel/Menu_MiSTer/raw/master/releases/menu_20210222.rbf'

# Sanity checks
if [ -z "${1}" ]; then
    USBKEYS=($(
       grep -Hv ^0$ /sys/block/*/removable |
       sed s/removable:.*$/device\\/uevent/ |
       xargs grep -H ^DRIVER=sd |
       sed s/device.uevent.*$/size/ |
       xargs grep -Hv ^0$ |
       cut -d / -f 4
    ))

    echo ""
    echo "Usage: ${0} [DEVICE]"
    echo ""
    echo "Please read README.md and specify an SD card device."
    echo ""
    echo "Available removable storage devices:"
    for dev in "${USBKEYS[@]}" ;do
      echo "${dev}" \"$(
        sed -e s/\ *$//g <"/sys/block/${dev}/device/model"
      )\" ;
    done

    exit 1
fi

# Fail if mount point is a non-empty directory.
if [[ "$(ls -A "${MNT_DIRECTORY}" &> /dev/null)" ]]; then
    die_with_error "Temporary mount directory \"${MNT_DIRECTORY}\" exists and is not empty.  Aborting installation."
fi

# Check prerequisites
check_prereqs git wget unrar mkfs.exfat

# From here on, any non-zero exit code will call die_with_error().  Append any
# line with " || true" to inhibit dying on error.
trap die_with_error ERR

# Set SD card device
DEVICE="${1}"

[[ "${DEVICE}" =~ "/dev/"* ]] || DEVICE="/dev/${DEVICE}"

# Check if the device exists
if [ ! -b "${DEVICE}" ]; then
    echo ""
    echo "Error: Block device ${DEVICE} not found."
    echo ""
    exit 1
fi

echo "This will erase ${DEVICE} are you sure you want to continue ? [y/n]"
IFS="" read -r ans
if [ "${ans}" != "${ans#[Yy]}" ] ;then
    echo "Okay ! Here we go !"
else
    exit 1
fi

mkdir -p ${DOWNLOAD_DIRECTORY}

print_block "Fetching installation files..."
wget -nv --progress=bar --show-progress -O "${DOWNLOAD_DIRECTORY}/release.rar" "${RELEASE_URL}"
echo ""

print_block "Extracting installation files..."
unrar x -y "${DOWNLOAD_DIRECTORY}/release.rar" "${DOWNLOAD_DIRECTORY}"
echo ""

print_block "Unmounting potentially mounted partitions (sudo may ask for your password)"
sudo umount "${DEVICE}"* || true
echo ""

# Note : Uboot and FSBL code is loaded from partition with a2 ID (can be any of the 4 partitions in the MBR) see :
# https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/cyclone-v/cv_5v4.pdf
# Page 3481 (Section A-13) "Flash Memory Devices for Booting"
# However Uboot (the Uboot that comes with MiSTer) will try to boot linux from partition 1
# Here we create a partition 1 that takes all the remaining space of the SD card from sector 4096+
# and partition 2 which spans from sector 2048 to 4095 (for Uboot and the FSBL code)
print_block "Creating SD Card partition table"
sudo sfdisk --force "${DEVICE}" << EOF
4096;
2048,2048
EOF
echo ""
# Having the partitions in reverse order relative to their position on the disk is a bit dodgy, this
# was done so that the first partition could be extended to the end of the disk while the second
# partition would only span 1M ... If someone has a better solution go ahead

# We set the special partition magic ID (a2) as said in the manual using sfdisk and sed
print_block "Setting partition table, sfdisk may complain, don't worry"
sudo sfdisk -d "${DEVICE}" | sed '0,/type=.*$/s//type=7/' | sed '0,/type=.*$/! s/type=.*$/type=a2/' | sudo sfdisk --force "${DEVICE}" || true
echo ""

print_block "Writing uboot image to the UBOOT partition" # Partition 2 (but at the start of the disk)
UBOOT_PART="$(ls "${DEVICE}"*2)"
sudo dd if="${DOWNLOAD_DIRECTORY}/files/linux/uboot.img" of="${UBOOT_PART}" bs=32k
echo ""

print_block "Creating the MiSTer_Data partition" # Partition 1 (since Uboot will load Linux from Part 1, see env)
mkfs.exfat -h 2>&1 | grep -q '\-s ' && \
        sudo mkfs.exfat -s 32 -n "MiSTer_Data" "${DEVICE}"*1 || \
        sudo mkfs.exfat -c 32K -L "MiSTer_Data" "${DEVICE}"*1
echo ""

print_block "Syncing"
sudo sync
echo ""

print_block "Mounting the disk"
mkdir -p "${MNT_DIRECTORY}"
sudo mount -t exfat "${DEVICE}"*1 "${MNT_DIRECTORY}"
echo ""

print_block "Copying MiSTer files..."
cp -Rv "${DOWNLOAD_DIRECTORY}/files/"* "${MNT_DIRECTORY}"
echo ""

print_block "Downloading and installing a recent MiSTer binary..."
wget -nv --progress=bar --show-progress -O "${MNT_DIRECTORY}/MiSTer" "${RECENT_MISTER_URL}"
echo ""

print_block "Downloading and installing a recent MiSTer menu core..."
wget -nv --progress=bar --show-progress -O "${MNT_DIRECTORY}/menu.rbf" "${RECENT_MENU_MISTER_URL}"
echo ""

print_block "Syncing data to SD card before ejection"
sudo sync
echo ""

print_block "Unmounting SD card..."
sudo umount "${MNT_DIRECTORY}"
rmdir "${MNT_DIRECTORY}"
echo ""
echo ""

print_block "All done. Put the SD card into your MiSTer and start it up.
Connect a keyboard to the MiSTer and hit F12 to bring up the menu.
Refer to the MiSTer wiki for further information."