#!/system/bin/sh

set -e

echo "System Image Upgrader for Ubuntu Touch"
echo "Preparing command file"
if [ ! -e "$1" ]; then
    echo "Command file doesn't exist: $1"
    exit 1
fi
mv $1 $1.applying
COMMAND_FILE=$1.applying

REMOVE_LIST="$COMMAND_FILE"

# Used as a security check to see if we would change the password
DATA_FORMAT=0

# System Mountpoint
SYSTEM_MOUNTPOINT=/cache/system

echo "Starting image upgrader"

# Functions
check_filesystem() {
    # $1 => image to check (partition or device img)
    if [ ! -e $1 ]; then
        echo "Partition/image not found: $1"
        return 1
    fi

    # It's fine for e2fsck to return something different than 0
    set +e
    e2fsck -yf $1
    ret=$?
    # From e2fsck man page:
    # 0 - No errors
    # 1 - File system errors corrected
    if [ $ret -ne 0 ] && [ $ret -ne 1 ]; then
        echo "e2fsck is unable to fix partition/image $1, aborting (return code $ret)"
        exit 1
    fi
    set -e
}

verify_signature() {
    # HACK: ignore all signatures for allowing messing around with
    #return 0

    # $1 => validation keyring name
    # $2 => path to validate

    if [ ! -e $2 ]; then
        echo "File doesn't exist: $2"
        return 1
    fi

    # Check against the blacklist
    if [ -e /tmp/system-image/blacklist/pubring.gpg ]; then
        export GNUPGHOME=/tmp/system-image/blacklist/
        if gpg --ignore-time-conflict --verify $2 >/dev/null 2>&1; then
            echo "File signed by a blacklisted key: $2"
            return 1
        fi
    fi

    # Check against the keyring
    export GNUPGHOME=/tmp/system-image/$1/
    if [ ! -e "$GNUPGHOME" ]; then
        echo "Keyring doesn't exist: $1"
        return 1
    fi

    if gpg --ignore-time-conflict --verify $2 >/dev/null 2>&1; then
        return 0
    fi

    return 1
}

install_keyring() {
    # $1 => full path to tarball
    # $2 => full path to signature

    # Some basic checks
    if [ ! -e "$1" ] || [ ! -e "$2" ]; then
        echo "Missing keyring files: $1 => $2"
        return 1
    fi

    # Unpacking
    TMPDIR=$(mktemp -d -p /tmp/system-image/ tmp.XXXXXXXXXX)
    cd $TMPDIR
    busybox xzcat $1 | busybox tar --numeric-owner -xf -
    if [ ! -e keyring.json ] || [ ! -e keyring.gpg ]; then
        rm -Rf $TMPDIR
        echo "Invalid keyring: $1"
        return 1
    fi

    # Extract the expiry
    keyring_expiry=$(grep "^    \"expiry\": " keyring.json | cut -d: -f2 | sed -e "s/[ \",]//g")
    if [ -n "$keyring_expiry" ] && [ "$keyring_expiry" -lt "$(date +%s)" ]; then
        rm -Rf $TMPDIR
        echo "Keyring expired: $1"
        return 1
    fi

    # Extract the keyring type
    keyring_type=$(grep "^    \"type\": " keyring.json | cut -d: -f2 | sed -e "s/[, \"]//g")
    if [ -z "$keyring_type" ]; then
        rm -Rf $TMPDIR
        echo "Missing keyring type: $1"
        return 1
    fi

    if [ -e /tmp/system-image/$keyring_type ]; then
        rm -Rf $TMPDIR
        echo "Keyring already loaded: $1"
        return 1
    fi

    signer="unknown"
    case "$keyring_type" in
        archive-master)
            signer=""
        ;;

        image-master)
            signer="archive-master"
        ;;

        image-signing|blacklist)
            signer="image-master"
        ;;

        device-signing)
            signer="image-signing"
        ;;
    esac

    if [ -n "$signer" ] && ! verify_signature $signer $2; then
        rm -Rf $TMPDIR
        echo "Invalid signature: $1"
        return 1
    fi

    mkdir /tmp/system-image/$keyring_type
    chmod 700 /tmp/system-image/$keyring_type
    mv $TMPDIR/keyring.gpg /tmp/system-image/$keyring_type/pubring.gpg
    chmod 600 /tmp/system-image/$keyring_type/pubring.gpg
    chown 0:0 /tmp/system-image/$keyring_type/pubring.gpg
    rm -Rf $TMPDIR
    return 0
}

property_write() {
    prop="$1"
    prop_value="$2"
    prop_dir="/data/android-data/property"
    # everything is wiped after a format, let's get a skeleton going
    mkdir -p "$prop_dir"
    chown 0:0 "$prop_dir"
    chmod 700 "$prop_dir"
    echo -n "$prop_value" > "$prop_dir/$prop"
    # properties won't be read if they aren't ro root
    chown 0:0 "$prop_dir/$prop"
    chmod 600 "$prop_dir/$prop"
}

adb_onlock() {
    if [ "$DATA_FORMAT" -eq 0 ]; then
        return 1
    fi

    flag="/data/.adb_onlock"
    # if the param != "true" we just delete the flag
    case $1 in
        true)
            touch "$flag"
        ;;

        false)
            rm -f "$flag"
        ;;

        *)
            echo "Unkown parameter $1, disabling"
            rm -f "$flag"
        ;;
    esac
}

set_password() {
    if [ "$DATA_FORMAT" -eq 0 ]; then
        return 1
    fi
    user="phablet"
    password="$1"
    if [ -z "$password" ]; then
        return 1
    fi
    path=/bin:/usr/bin:/sbin:/usr/sbin
    PATH=$path chroot "$SYSTEM_MOUNTPOINT" /bin/sh -c "echo -n "$user:$password" | chpasswd"
    return 0
}

unset_password() {
    if [ "$DATA_FORMAT" -eq 0 ]; then
        return 1
    fi
    # Needs implementation
}

usb_enable() {
    prop_dir="/data/android-data/property"
    prop="persist.sys.usb.config"
    prop_val="$1"
    # Property value ordering is important here
    grep -q -s mtp "$prop_dir/$prop" && [ "$prop_val" == "adb" ] && prop_val="mtp,adb"
    grep -q -s adb "$prop_dir/$prop" && [ "$prop_val" == "mtp" ] && prop_val="mtp,adb"
    property_write "$prop" "$prop_val"
}

usb_disable() {
    prop_dir="/data/android-data/property"
    prop="persist.sys.usb.config"
    prop_val="$1"
    remain_prop=""
    # Property value ordering is important here
    grep -q -s mtp "$prop_dir/$prop" && [ "$prop_val" == "adb" ] && remain_prop="mtp"
    grep -q -s adb "$prop_dir/$prop" && [ "$prop_val" == "mtp" ] && remain_prop="adb"
    # we should not allow empty properties for the usb config
    [ "$remain_prop" == "" ] && remain_prop="adb"
    property_write "$prop" "$remain_prop"
}

factory_wipe() {
    # only set this flag if coming from a data wipe
    if [ "$DATA_FORMAT" -eq 0 ]; then
        return 1
    fi

    flag="/data/.factory_wipe"
    # if the param != "true" we just delete the flag
    case $1 in
        true)
            touch "$flag"
        ;;

        false)
            rm -f "$flag"
        ;;

        *)
            echo "Unkown parameter $1, disabling"
            rm -f "$flag"
        ;;
    esac
}

# Initialize GPG
rm -Rf /tmp/system-image
mkdir -p /tmp/system-image
if [ -e /etc/system-image/archive-master.tar.xz ]; then
    echo "Loading keyring: archive-master.tar.xz"
    install_keyring /etc/system-image/archive-master.tar.xz /etc/system-image/archive-master.tar.xz.asc
fi

# Check the kernel command line to see whether Ubuntu should be installed to a partition
# or in a file that is loop mounted.
#if grep -q systempart= /proc/cmdline; then
#    USE_SYSTEM_PARTITION=1
#else
#    USE_SYSTEM_PARTITION=0
#fi

# Force usage of system partition for now, the existance of Android 9.0 devices
# with a too small system partition is questionable at this point.
USE_SYSTEM_PARTITION=1

# However, do not use the block device name in the kernel command line, as that is not consistently
# named in booting normal and recovery modes. Expect fstab to have a system mountpoint or use a fallback.
if [ "$USE_SYSTEM_PARTITION" -eq 1 ];then
    SYSTEM_PARTITION=$(grep "^[^#]" /etc/fstab | grep -e "\(/mnt\)*/system\(_root\)*" | cut -f 1 -d\ )
    #Fall back to emmc@android if there's no system in fstab
    if [ "$SYSTEM_PARTITION" == "" ]; then
        SYSTEM_PARTITION="emmc@android"
    fi
fi

# If we are not using the system partition, ensure that /data is mounted
if [ "$USE_SYSTEM_PARTITION" -eq 0 ]; then
    mount /data
fi

# Process the command file
FULL_IMAGE=0
echo "Processing command file"
while read line
do
    set -- $line
    case "$1" in
        format)
            echo "Formatting: $2"
            case "$2" in
                system)
                    FULL_IMAGE=1
                    # Cleanup files left from halium-install
                    rm -f /data/system.img
                    rm -f /data/android-rootfs.img
                    rm -f /data/rootfs.img
                    # Delete ubuntu.img if present. Either its a leftover, or we recreate it
                    rm -f /data/ubuntu.img
                    if [ "$USE_SYSTEM_PARTITION" -eq 1 ];then
                        echo "system partition: $SYSTEM_PARTITION"
                        umount /mnt/system || true
                        mkfs.ext4 $SYSTEM_PARTITION
                    else
                        # We need to use legacy image name here, halium-boot needs this to decide file layout
                        dd if=/dev/zero of=/data/ubuntu.img seek=3M bs=1024 count=0
                        mkfs.ext2 -F /data/ubuntu.img
                    fi
                ;;

                data)
                    if [ "$USE_SYSTEM_PARTITION" -eq 1 ]; then
                        mount /data || true
                    fi

                    for entry in /data/* /data/.writable_image /data/.factory_wipe; do
                        if [ "$USE_SYSTEM_PARTITION" -eq 0 ]; then
                            if [[ ( "$entry" == "/data/ubuntu.img" ) || ( "$entry" == "/data/rootfs.img" ) || ( "$entry" == "/data/system.img" ) || ( "$entry" == "/data/android-rootfs.img" ) ]]; then
                                    continue
                            fi
                        fi

                        # Some devices use /data as /cache, so avoid removing
                        # files that are essential to flashing and upgrading
                        if [ "$entry" == "/data/cache" ]; then
                            continue
                        fi

                        # If this is android-data, inspect closer as we need the
                        # cache "partition" to stay functioning during use of the
                        # system-image-upgrader script. It is bind mounted
                        # and leads to premature cancellation otherwise.
                        if [ "$entry" == "/data/android-data" ]; then
                            for android_data_entry in /data/android-data/*; do
                                if [ "$android_data_entry" != "/data/android-data/cache" ]; then
                                    # recursively unset immutable attribute set to few files
                                    # by vendor services before removal
                                    #chattr -R -i $android_data_entry
                                    rm -Rf $android_data_entry
                                fi
                            done
                        else
                            rm -Rf $entry
                        fi
                    done
                    # mtp is always enabled by default
                    usb_enable mtp
                    DATA_FORMAT=1

                    if [ "$USE_SYSTEM_PARTITION" -eq 1 ]; then
                        umount /data
                    fi
                ;;

                *)
                    echo "Unknown format target: $2"
                ;;
            esac
        ;;

        enable)
            echo "Enabling: $2"
            case "$2" in
                developer_mode)
                    usb_enable adb
                ;;

                mtp)
                    usb_enable mtp
                ;;

                default_password)
                    set_password $3
                ;;

                adb_onlock)
                    adb_onlock true
                ;;

                factory_wipe)
                    factory_wipe true
                ;;

                *)
                    echo "Unknown enable target: $2"
                ;;
            esac
        ;;

        disable)
            echo "Disabling: $2"
            case "$2" in
                developer_mode)
                    usb_disable adb
                ;;

                mtp)
                    usb_disable mtp
                ;;

                default_password)
                    unset_password
                ;;

                adb_onlock)
                    adb_onlock false
                ;;

                factory_wipe)
                    factory_wipe false
                ;;

                *)
                    echo "Unknown disable target: $2"
                ;;
            esac
        ;;

        load_keyring)
            if [ ! -e "/cache/recovery/$2" ] || [ ! -e "/cache/recovery/$3" ]; then
                echo "Skipping missing file: $2"
                continue
            fi
            REMOVE_LIST="$REMOVE_LIST /cache/recovery/$2 /cache/recovery/$3"

            echo "Loading keyring: $2"
            install_keyring /cache/recovery/$2 /cache/recovery/$3

            if [ -e /tmp/system-image/image-master/pubring.gpg ] && \
               [ ! -e /tmp/system-image/blacklist/pubring.gpg ] && \
               [ -e /data/system-data/var/lib/system-image/blacklist.tar.xz ] && \
               [ -e /data/system-data/var/lib/system-image/blacklist.tar.xz.asc ]; then
                echo "Loading blacklist keyring"
                install_keyring /data/system-data/var/lib/system-image/blacklist.tar.xz /data/system-data/var/lib/system-image/blacklist.tar.xz.asc
            fi
        ;;

        mount)
            case "$2" in
                system)
                    mkdir -p "$SYSTEM_MOUNTPOINT"
                    if [ "$USE_SYSTEM_PARTITION" -eq 1 ];then
                        umount $SYSTEM_PARTITION || true
                        umount $SYSTEM_MOUNTPOINT || true
                        umount /mnt/system || true
                        check_filesystem $SYSTEM_PARTITION
                        mount $SYSTEM_PARTITION "$SYSTEM_MOUNTPOINT"
                    else
                        check_filesystem /data/ubuntu.img
                        mount -o loop /data/ubuntu.img "$SYSTEM_MOUNTPOINT/"
                    fi
                ;;

                *)
                    echo "Unknown mount target: $2"
                ;;
            esac
        ;;

        unmount)
            case "$2" in
                system)
                    umount "$SYSTEM_MOUNTPOINT"
                    rmdir "$SYSTEM_MOUNTPOINT"
                ;;

                *)
                    echo "Unknown mount target: $2"
                ;;
            esac
        ;;

        update)
            if [ ! -e "/cache/recovery/$2" ] || [ ! -e "/cache/recovery/$3" ]; then
                echo "Skipping missing file: $2"
                continue
            fi

            REMOVE_LIST="$REMOVE_LIST /cache/recovery/$3"

            if ! verify_signature device-signing /cache/recovery/$3 && \
               ! verify_signature image-signing /cache/recovery/$3; then
                echo "Invalid signature"
                exit 1
            fi

            echo "Applying update: $2"
            cd /cache
            rm -Rf partitions
            rm -Rf data  || true

            # Start by removing any file listed in "removed"
            if [ "$FULL_IMAGE" != "1" ]; then
                busybox xzcat recovery/$2 | busybox tar --numeric-owner -xf - removed >/dev/null 2>&1 || true
                if [ -e removed ]; then
                    while read file; do
                        rm -Rf $file
                    done < removed
                fi
                rm -f removed
            fi

            # Unpack everything else on top of the system partition
            busybox xzcat recovery/$2 | busybox tar --numeric-owner -xf -
            rm -f removed

            # WORKAROUND: fix erroneous vendor symlink
            if [ -h "$SYSTEM_MOUNTPOINT/vendor" ]; then
                VENDOR_SYMLINK_PATH=$(readlink $SYSTEM_MOUNTPOINT/vendor)
                if [ "$VENDOR_SYMLINK_PATH" == "/android/system/vendor" ]; then
                    rm $SYSTEM_MOUNTPOINT/vendor
                    ln -s /android/vendor $SYSTEM_MOUNTPOINT/vendor
                fi
            fi

            # Move things to data
            if [ -d data ]; then
                mv data/* /data/ || true
                rm -Rf data || true
            fi

            # Process partition images
            grep "^/dev" /etc/fstab | while read line; do
                set -- $line

                part=${2##/}
                path=$1

                if [ -e partitions/${part}.img ] && [ -e $path ]; then
                    if simgtest partitions/${part}.img 2>/dev/null; then
                        echo "Flashing sparse ${part} at ${path}"
                        simg2img partitions/${part}.img ${path}
                    else
                        echo "Checking if ${part} at ${path} needs updating..."
                        new_size=$(wc -c < partitions/${part}.img)
                        if ! head -c ${new_size} ${path} | cmp -s partitions/${part}.img; then
                            echo "  Flashing (binary content differs up to ${new_size} bytes)..."
                            cat partitions/${part}.img > ${path}
                        else
                            echo "  Already up-to-date"
                        fi
                    fi
                    sync
                    rm partitions/${part}.img
                fi
            done

            # Remove tarball to free up space, since device tarballs
            # extract partitions/blobs that might fill up cache,
            # this way we ensure we got space for the partitions/blobs
            rm -f recovery/$2
        ;;

        "#")
            # We are processing a command in the script, ignore it
        ;;

        *)
            echo "Unknown command: $1"
        ;;
    esac
done < $COMMAND_FILE

# Remove the update files
for file in $REMOVE_LIST; do
    rm -f $file
done

# If a previous SWAP of 512MB is available, remove
if [ -e /data/SWAP.img ]; then
    echo "Removing obsolete SWAP.img"
    rm -f /data/SWAP.img
fi

# Ensure we have sane permissions
if [ "$USE_SYSTEM_PARTITION" -eq 0 ];then
    chmod 600 /data/ubuntu.img
    chown 0:0 /data/ubuntu.img
fi

touch /data/.last_update || true
sync

echo "Done upgrading..."

# Make sure there are always 5% reserved in /data for root usage
# else filling $HOME can make the system unusable since writable
# files and dirs share the space with $HOME and android does not
# reserve root space in /data for ext4.
# Devices with f2fs can reserve space with setting the
# "reserve_root" mount option.
if [ "$USE_SYSTEM_PARTITION" -eq 1 ]; then
    mount /data
fi

DATA_FS_TYPE=$(grep "/data " /proc/mounts| cut -d ' ' -f3)
if [ "$DATA_FS_TYPE" == "ext4" ]; then
    tune2fs -m 5 $(grep "/data " /proc/mounts| sed -e 's/ .*$//')
fi

# Always unmount unconditionally
umount /data

sync
