# #!/bin/bash

#=================================================
# Globals variables
#=================================================

# -q aims to disable the display of 'Debian GNU/Linux' each time a command is ran
arg_ssh="-tt -q"

#=================================================
# RUNNING SNAPSHOT
#=================================================

CREATE_LXC_SNAPSHOT () {
    # Create a temporary snapshot

    local snapname=$1

    start_timer
    # Check all the witness files, to verify if them still here
    check_witness_files >&2

    # Stop the container, before its snapshot
    sudo lxc-stop --name $LXC_NAME >&2

    # Remove swap files to avoid killing the CI with huge snapshots.
    local swap_file="$LXC_ROOTFS/swap_$app_id"
    if sudo test -e "$swap_file"
    then
        sudo swapoff "$swap_file"
        sudo rm "$swap_file"
    fi

    # Check if the snapshot already exist
    if [ ! -e "$LXC_SNAPSHOTS/$snapname" ]
    then
        log_debug "$snapname doesn't exist, its first creation can takes a little while." >&2
        # Create the snapshot.
        sudo lxc-snapshot --name $LXC_NAME >> "$complete_log" 2>&1

        # lxc always creates the first snapshot it can creates.
        # So if snap1 doesn't exist and you try to create snap_foo, it will be named snap1.
        if [ "$snapname" != "snap1" ] && [ ! -e "$LXC_SNAPSHOTS/$snapname" ]
        then
            # Rename snap1
            sudo mv "$LXC_SNAPSHOTS/snap1" "$LXC_SNAPSHOTS/$snapname"
        fi
    fi

    # Update the snapshot with rsync to clone the current lxc state
    sudo rsync --acls --archive --delete --executability --itemize-changes --xattrs "$LXC_ROOTFS/" "$LXC_SNAPSHOTS/$snapname/rootfs/" > /dev/null 2>> "$complete_log"

    stop_timer 1

    # Restart the container, after the snapshot
    LXC_START "true" >&2
}

LOAD_LXC_SNAPSHOT () {
    # Use a temporary snapshot, if it already exists
    # $1 = Name of the snapshot to use
    local snapshot=$1

    log_debug "Restoring snapshot $snapshot"

    start_timer
    # Fix the missing hostname in the hosts file...
    echo "127.0.0.1 $LXC_NAME" | sudo tee --append "$LXC_SNAPSHOTS/$snapshot/rootfs/etc/hosts" > /dev/null

    # Restore this snapshot.
    sudo rsync --acls --archive --delete --executability --itemize-changes --xattrs "$LXC_SNAPSHOTS/$snapshot/rootfs/" "$LXC_ROOTFS/" > /dev/null 2>> "$complete_log"
    local ret=$?

    stop_timer 1

    return $ret
}

#=================================================

is_lxc_running () {
    sudo lxc-info --name=$LXC_NAME | grep --quiet "RUNNING"
}

LXC_INIT () {
    # Clean previous remaining swap files
    sudo swapoff $LXC_ROOTFS/swap_* 2>/dev/null
    sudo rm --force $LXC_ROOTFS/swap_*
    sudo swapoff $LXC_SNAPSHOTS/snap0/rootfs/swap_* 2>/dev/null
    sudo rm --force $LXC_SNAPSHOTS/snap0/rootfs/swap_*
    sudo swapoff $LXC_SNAPSHOTS/snap_afterinstall/rootfs/swap_* 2>/dev/null
    sudo rm --force $LXC_SNAPSHOTS/snap_afterinstall/rootfs/swap_*

    LXC_PURGE_SNAPSHOTS

    # Initialize LXC network

    # Activate the bridge
    echo "Initialize network for LXC."
    sudo ifup $LXC_BRIDGE --interfaces=/etc/network/interfaces.d/$LXC_BRIDGE | tee --append "$complete_log" 2>&1

    # Activate iptables rules
    echo "Activate iptables rules."
    sudo iptables --append FORWARD --in-interface $LXC_BRIDGE --out-interface $MAIN_NETWORK_INTERFACE --jump ACCEPT | tee --append "$complete_log" 2>&1
    sudo iptables --append FORWARD --in-interface $MAIN_NETWORK_INTERFACE --out-interface $LXC_BRIDGE --jump ACCEPT | tee --append "$complete_log" 2>&1
    sudo iptables --table nat --append POSTROUTING --source $LXC_NETWORK.0/24 --jump MASQUERADE | tee --append "$complete_log" 2>&1
}

LXC_PURGE_SNAPSHOTS() {
    LXC_STOP

    for SNAP in $(sudo ls $LXC_SNAPSHOTS/snap_*install 2>/dev/null)
    do
        sudo lxc-snapshot -n $LXC_NAME -d $(basename $SNAP)
    done
}

LXC_START () {
    # Start the lxc container and execute the given command in it
    local cmd=$1

    start_timer
    # Try to start the container 3 times.
    local max_try=3
    local i=0
    while [ $i -lt $max_try ]
    do
        i=$(( $i +1 ))
        # Start the container and log the booting process in ./lxc_boot.log
        # Try to start only if the container is not already started
        if ! is_lxc_running; then
            log_debug "Start the LXC container" >> "$complete_log"
            sudo lxc-start --name=$LXC_NAME --daemon --logfile "./lxc_boot.log" | tee --append "$complete_log" 2>&1
        else
            log_debug "A LXC container is already running"
        fi

        # Try to connect 5 times
        local j=0
        for j in `seq 1 5`
        do
            log_debug "." >> "$complete_log"
            # Try to connect with ssh to check if the container is ready to work.
            if ssh $arg_ssh -o ConnectTimeout=10 $LXC_NAME "exit 0" > /dev/null 2>&1; then
                # Break the for loop if the container is ready.
                break
            fi
            sleep 1
        done

        [ "$(uname -m)" == "aarch64" ] && sleep 30

    done
    stop_timer 1
    start_timer

    # Copy the package into the container.
    rsync -rq --delete "$package_path" "$LXC_NAME": >> "$complete_log" 2>&1

    # Execute the command given in argument in the container and log its results.
    ssh $arg_ssh $LXC_NAME "$cmd" | tee -a "$complete_log"

    # Store the return code of the command
    local returncode=${PIPESTATUS[0]}

    log_debug "Return code: $return_code"

    stop_timer 1
    # Return the exit code of the ssh command
    return $returncode
}

LXC_STOP () {
    if is_lxc_running;
    then
        log_debug "Stop the LXC container"
        sudo lxc-stop --name=$LXC_NAME | tee --append "$complete_log" 2>&1
    fi
}

LOAD_LXC_SNAPSHOT () {
    snapname=$1

    LXC_STOP

    log_debug "Restoring snapshot $snapname"
    sudo rsync --acls --archive --delete --executability --itemize-changes --xattrs "$LXC_SNAPSHOTS/$snapname/rootfs/" "$LXC_ROOTFS/" > /dev/null 2>> "$complete_log"
}