[arkdep] Implement initial layer command

arkdep

@@ -28,6 +28,7 @@ declare -r dist_load_extensions=0
 declare -r dist_remove_tar_after_deployment=1
 declare -r dist_update_diff_style='list'
 declare -r dist_interactive_mode=1
+declare -r dist_package_layer_command='pacman -Syy --needed --noconfirm'
 
 # systemd-boot configuration
 declare -r boot_entry_title='Arkane Linux - Arkdep'
@@ -134,6 +135,9 @@ if [[ ! $1 == 'init' ]]; then
 	[[ -z ${interactive_mode+x} ]] &&
 		interactive_mode=$dist_interactive_mode &&
 		printf '\e[1;33m<!>\e[0m\e[1m interactive_mode not defined in config, using default\e[0m\n'
+	[[ -z ${package_layer_command+x} ]] &&
+		package_layer_command=$dist_package_layer_command &&
+		printf '\e[1;33m<!>\e[0m\e[1m package_layer_command not defined in config, using default\e[0m\n'
 fi
 
 ## Common functions
@@ -1257,6 +1261,82 @@ deploy () {
 
 }
 
+# Install a package and add it to the layer tracker
+layer () {
+
+	# If no installation candidates provided
+	if [[ $# -eq 1 ]]; then
+		cleanup_and_quit 'No layer candidates provided'
+	fi
+
+	# By default, as it is discouraged, the layer tracker file is only created upon calling this function
+	# Create layer tracker file if it does not yet exist
+	if [[ ! -f $arkdep_dir/layer ]]; then
+		printf "\e[1;33m<!>\e[0m\e[1m Creating new layer tracker file\e[0m\n"
+		touch $arkdep_dir/layer
+	fi
+
+	# Index layer tracker list
+	declare -r layered=($(cat $arkdep_dir/layer))
+
+	# Program list with duplicates removed
+	declare progs_clean=()
+
+	# Check if prog is already in list, if not add to progs_clean
+	if [[ ${#layered[@]} -gt 0 ]]; then
+		for prog in ${@:2}; do
+			for layer in ${layered[@]}; do
+				# If program is already present in layer tracker it can be ignored
+				if [[ $layer == $prog ]]; then
+					printf "\e[1;33m<!>\e[0m\e[1m $prog is already in layer tracker file and will be ignored\e[0m\n"
+					declare layer_matched=1
+					break
+				fi
+			done
+
+			# Add program to layer list unless duplicate
+			if [[ $layer_matched -ne 1 ]]; then
+				progs_clean+=($prog)
+			fi
+
+			unset layer_matched
+		done
+	else
+		progs_clean=(${@:2})
+	fi
+
+	# If progs_clean is zero, error and quit
+	if [[ ${#progs_clean[@]} -eq 0 ]]; then
+		printf "\e[1;33m<!>\e[0m\e[1m All provided layer candidates are already layered\e[0m\n"
+		unlock_and_quit 0
+	fi
+
+	# Notify user of changes and ask for permission if interactive_mode is enabled
+	printf '\e[1;34m-->\e[0m\e[1m The following packages will be layered\e[0m\n'
+	printf "${progs_clean[@]}" | column
+	if [[ $interactive_mode -eq 1 ]]; then
+		read -p 'Proceed with removal? [Y/n] ' remove_confirm
+
+		if [[ ! $remove_confirm =~ ^(y|Y|yes|YES|)$ ]]; then
+			unlock_and_quit 1
+		fi
+	fi
+
+	# Unlock the partition
+	btrfs property set -f -ts / ro false ||
+		cleanup_and_quit 'Failed to unlock root partition'
+
+	# Install the packages
+	$package_layer_command ${progs_clean[@]} ||
+		cleanup_and_quit 'Failed to install requested packages'
+
+	# If installation was successful add to layer tracker file
+	printf ${progs_clean[@]} >> $arkdep_dir/layer
+
+	unlock_and_quit 0
+
+}
+
 [[ $1 == 'init' ]] && init_new_system $2
 [[ $1 == 'teardown' ]] && teardown
 [[ $1 == 'get-available' ]] && get_available
@@ -1265,6 +1345,9 @@ deploy () {
 [[ $1 == 'remove' ]] && remove_deployment $@
 [[ $1 == 'healthcheck' ]] && healthcheck $1
 [[ $1 == 'cleanup' ]] && cleanup
+[[ $1 == 'layer' ]] && layer $@
+[[ $1 == 'layer-ls' ]] && layer-ls
+[[ $1 == 'layer-rm' ]] && layer-rm $@
 
 # No valid params were provided
 printf '\e[1;31m<#>\e[0m\e[1m No valid parameters provided\e[0m\n'