#!/bin/bash

run_latehook() {
    echo
    
    # Detect if update downloaded.
    if [[ -f /new_root/mnt/iso-update/.ready-for-update ]]; then
        # Available, rename old /usr and move new /usr to /.
        mv /new_root/usr /new_root/.old.usr
        mv /new_root/mnt/iso-update/squashfs-root/usr /new_root/usr
        
        # Same for /var/lib/pacman.
        mv /new_root/var/lib/pacman /new_root/.old.var.lib.pacman
        mv /new_root/mnt/iso-update/squashfs-root/var/lib/pacman /new_root/var/lib
        
        # Move to /etc stage.
        rm -f /new_root/mnt/iso-update/.ready-for-update
        touch /new_root/mnt/iso-update/.etc-stage
    fi
    
    # Detect if /etc stage is active.
    if [[ -f /new_root/mnt/iso-update/.etc-stage ]]; then
        # Rename existing /etc.
        mv /new_root/etc /new_root/.old.etc &>/dev/null || :
        
        # Create new /etc.
        cp -a /new_root/.old.etc /new_root/etc
        
        # Only copy non-existent files.
        cp -a -n /new_root/mnt/iso-update/squashfs-root/etc/* /new_root/etc
        
        # Update pacman config, and other system files that aren't
        # supposed to be edited.
        cp /new_root/mnt/iso-update/squashfs-root/etc/pacman.conf /new_root/etc
        rm -rf /new_root/etc/pacman.d
        cp -r /new_root/mnt/iso-update/squashfs-root/etc/pacman.d /new_root/etc
        cp /new_root/mnt/iso-update/squashfs-root/etc/blend_release /new_root/etc
        cp /new_root/mnt/iso-update/squashfs-root/etc/os-release /new_root/etc
        cp /new_root/mnt/iso-update/squashfs-root/etc/lsb-release /new_root/etc
        
        # Successful update.
        rm -f /new_root/mnt/iso-update/.etc-stage
        touch /new_root/mnt/iso-update/.successful-update
    fi
    
    # Create overlay directories
    rm -rf /new_root/.blend-overlays /new_root/.blendrw
    
    for i in usr varlibpacman; do
        rm -rf /new_root/.blend-overlays/$i
        mkdir -p /new_root/.blend-overlays/$i
        mkdir -p /new_root/.blend-overlays/$i.workdir
    done
    
    mount -t overlay overlay -o lowerdir=/new_root/usr:/new_root/.blend-overlays/usr /new_root/usr
    mount -t overlay overlay -o lowerdir=/new_root/var/lib/pacman:/new_root/.blend-overlays/varlibpacman /new_root/var/lib/pacman
    
    mkdir -p /new_root/.blendrw
    mount "$(findmnt -n -o SOURCE /new_root)" /new_root/.blendrw
    
    mount -t overlay overlay -o lowerdir=/new_root/usr,upperdir=/new_root/.blend-overlays/usr,workdir=/new_root/.blend-overlays/usr.workdir
        /new_root/.blendrw/usr
    mount -t overlay overlay -o lowerdir=/new_root/var/lib/pacman,upperdir=/new_root/.blend-overlays/varlibpacman,workdir=/new_root/.blend-overlays/varlibpacman.workdir
        /new_root/.blendrw/var/lib/pacman
}