feat: command to change load order of mods (#27)

* progress

* progress

* feat: progress

* progress

* done, needs more testing, pr -> change all functions to require -n before specifying name -> v0.4 (reindex db)

* testing done

h2mm

@@ -304,6 +304,19 @@ Import mods and database from an archive file (coming from h2mm).
 EOF
 }
 
+function display_order_help() {
+	cat << EOF
+Usage: h2mm order [OPTIONS] [MOD_NAME|MOD_INDEX] <NEW_INDEX>
+Change order of a mod by name or index.
+Options:
+	-i <index>		Index of the mod to order.
+	-n <index>		New index of the mod.
+Usage:
+	h2mm order -n "Example mod" 1
+	h2mm order -i 1 2
+EOF
+}
+
 function display_modpack_list_help() {
 	cat << EOF
 Usage: h2mm modpack-list
@@ -519,8 +532,8 @@ function mod_disable() {
 	fi
 
 	# disable each mod file by adding disabled_ to the start of the filename
-	files=$(get_files_by_entry_from_db "$entry")
+	current_mod_files=$(get_files_by_entry_from_db "$entry")
-	for file in $files; do
+	for file in $current_mod_files; do
 		[[ ! -f "$MODS_DIR/$file" ]] && { log ERROR "Mod file $file does not exist."; exit 1; }
 
 		disabled_file="disabled_$file"
@@ -538,7 +551,7 @@ function mod_disable() {
 	done
 
 	# downgrade mods with greater version number
-	downgrade_mods "$files"
+	downgrade_mods "$current_mod_files"
 
 	# update the database
 	sed -i "/^$mod_index,/s/ENABLED/DISABLED/" "$DB_FILE"
@@ -575,13 +588,13 @@ function mod_enable() {
 
 	[[ "$status" == "ENABLED" ]] && { log ERROR "Mod $mod_name is already enabled."; exit 1; }
 
-	files=$(get_files_by_entry_from_db "$entry")
+	current_mod_files=$(get_files_by_entry_from_db "$entry")
 
 	# upgrade mods with lower version number
-	upgrade_mods "$files"
+	upgrade_mods "$current_mod_files"
 
 	# enable each mod file by removing disabled_ from the start of the filename
-	for file in $files; do
+	for file in $current_mod_files; do
 		enabled_file=$(remove_disabled_prefix "$file")
 
 		# check if the files exists
@@ -836,9 +849,9 @@ function mod_uninstall() {
 	get_mod_name_and_index
 
 	# delete mod files
-	files=$(get_files_by_entry_from_db "$entry")
+	current_mod_files=$(get_files_by_entry_from_db "$entry")
 
-	for file in $files; do
+	for file in $current_mod_files; do
 		[[ ! -f "$MODS_DIR/$file" ]] && { log ERROR "Mod file $file does not exist."; exit 1; }
 
 		log INFO "Removing ${ORANGE}\$MODS_DIR/$file${NC}."
@@ -848,7 +861,7 @@ function mod_uninstall() {
 	done
 
 	# downgrade mods with greater version number, only if the mod is enabled
-	[[ "$status" == "ENABLED" ]] && downgrade_mods "$files"
+	[[ "$status" == "ENABLED" ]] && downgrade_mods "$current_mod_files"
 
 	# remove entry from database
     sed -i "/^$mod_index,/d" "$DB_FILE"
@@ -985,6 +998,173 @@ function mod_import() {
 	log INFO "Mods ${GREEN}successfully${NC} imported."
 }
 
+function mod_order {
+	[[ "$1" == "--help" || "$1" == "-h" ]] && { display_order_help; exit 0; }
+
+	local mod_name=""
+	local mod_index=""
+	local new_index=""
+
+	# parse arguments
+	while [[ $# -gt 0 ]]; do
+		case "$1" in
+			-i)
+				mod_index="$2"; shift 2
+				;;
+			-n)
+				mod_name="$2"; shift 2
+				;;
+			--help|-h)
+				display_order_help; exit 0
+				;;
+			*)
+				new_index="$1"; shift 1
+				;;
+		esac
+	done
+
+	[[ -z "$mod_name" && -z "$mod_index" ]] && { log ERROR "Mod name or index is required to change order."; exit 1; }
+
+	# find mod files
+	get_mod_name_and_index
+
+	# get the number of mods
+	mod_count=$(($(cat "$DB_FILE" | wc -l) - 1))
+
+	# check if the mod is already at the desired index and if new index is valid
+	[[ "$mod_index" == "$new_index" ]] && { log ERROR "Mod $mod_name is already at index $new_index."; exit 1; }
+	[[ $new_index -lt 1 ]] && { log ERROR "Index can not be less than 1."; exit 1; }
+	[[ $new_index -gt $mod_count ]] && { log ERROR "Index can not be more than mod count (${mod_count})."; exit 1; }
+
+	# assert ascending or descending order
+	ascending_order=true
+	[[ $mod_index -gt $new_index ]] && ascending_order=false
+
+	# get entries between the indexes
+	if [[ $ascending_order == true ]]; then
+		entries=$(awk -v mod_index="$mod_index" -v new_index="$new_index" -F, 'NR > 1 && $1 > mod_index && $1 <= new_index {print $0}' "$DB_FILE")
+	else
+		entries=$(awk -v mod_index="$mod_index" -v new_index="$new_index" -F, 'NR > 1 && $1 < mod_index && $1 >= new_index {print $0}' "$DB_FILE")
+	fi
+
+	# get files for the current mod
+	IFS= current_mod_files=$(get_files_by_entry_from_db "$entry"); unset IFS
+
+	# step 1 - count how many replaces need to be done in hash table
+	declare -A replace_count
+	for file in $current_mod_files; do
+		extension=$(get_extension "$file")
+		basename=$(get_basename "$file")
+
+		# if the file has no extension, add the basename to the hash table or increment the count
+		if [[ -z "$extension" ]]; then
+			replace_count["$basename"]=$(( ${replace_count["$basename"]:-0} + 1 ))
+		fi
+	done
+
+	# step 2.1 - iterate over the basenames, find and store the files with the same basenames as the ones we want to upgrade/downgrade
+	declare -A files_to_replace
+	for basename in "${!replace_count[@]}"; do
+		IFS= files_to_replace["$basename"]=$(echo "$entries" | awk -F, '{print $4}' | grep -o "$basename\.patch_[^ ]*"); unset IFS
+	done
+
+	# step 2.2 - reverse sort the files_to_replace if we are in descending order
+	[[ $ascending_order == false ]] && for basename in "${!files_to_replace[@]}"; do
+		files_to_replace["$basename"]=$(echo "${files_to_replace["$basename"]}" | sort -rV)
+	done
+
+	# move current mod files to "t_$file" so we can move the new files to the correct index
+	for file in $current_mod_files; do
+		mv "$MODS_DIR/$file" "$MODS_DIR/t_$file"
+		[[ $? -ne 0 ]] && { log ERROR "Could not move mod file $file."; exit 1; }
+	done
+
+	# step 3 - for every basename in files_to_replace, add replace_count to each file's patch number and move
+	for basename in "${!files_to_replace[@]}"; do
+		files=$(echo "${files_to_replace["$basename"]}" | tr ' ' '\n')
+
+		for file in $files; do
+			basename=$(get_basename "$file")
+			patch_number=$(get_patch_number "$file")
+			extension=$(get_extension "$file")
+
+			# if ascending order, subtract replace_count to the patch number, otherwise add
+			operation="-"; [[ $ascending_order == false ]] && operation="+"
+			new_file="${basename}.patch_$(($patch_number $operation ${replace_count["$basename"]}))${extension}"
+
+			mv "$MODS_DIR/$file" "$MODS_DIR/$new_file"
+			[[ $? -ne 0 ]] && { log ERROR "Could not move mod file $file."; exit 1; }
+
+			log INFO "Reindexing ${ORANGE}$file${NC} to ${GREEN}$new_file${NC}."
+
+			# update db
+			sed -i "s/\(\b$file\b\)/$new_file/" "$DB_FILE"
+		done
+	done
+
+	# step 4 - for every file in current_mod_files, subtract the basename's array size of files_to_replace from the patch number
+	for file in $current_mod_files; do
+		basename=$(get_basename "$file")
+		patch_number=$(get_patch_number "$file")
+		extension=$(get_extension "$file")
+
+		# get size of only files without an extension
+		size=$(echo "${files_to_replace["$basename"]}" | grep -E "${basename}.patch_[0-9]+$" | tr ' ' '\n' | wc -l)
+
+		# in case size is 0, move t_file back to file later
+		new_file=${file}
+
+		if [[ $size -gt 0 ]]; then
+			# if ascending order, add size from the patch number, otherwise subtract
+			operation="+"; [[ $ascending_order == false ]] && operation="-"
+			new_file="${basename}.patch_$(($patch_number $operation $size))${extension}"
+
+			log INFO "Reindexing ${ORANGE}$file${NC} to ${GREEN}$new_file${NC}."
+
+			# dont forget current mod files are prefixed with t_
+			mv "$MODS_DIR/t_$file" "$MODS_DIR/t_$new_file"
+			[[ $? -ne 0 ]] && { log ERROR "Could not move mod file $file."; exit 1; }
+
+			# update file names
+			entry=$(echo "$entry" | sed "s/\(\b$file\b\)/$new_file/")
+		fi
+
+		# move back temp file
+		mv "$MODS_DIR/t_$new_file" "$MODS_DIR/$new_file"
+
+		# update index (will be replaced in db later)
+		entry=$(echo "$entry" | sed "s/^$mod_index,/$new_index,/")
+	done
+
+	# step 5.1 - change current mod to t_index so we can move the other indexes
+	sed -i "s/^$mod_index,/t_$mod_index,/" "$DB_FILE"
+
+	# step 5.2 - reindex the rest of the mods
+	idxs=$(echo "$entries" | awk -F, '{print $1}' | tr ' ' '\n')
+
+	# step 5.3 - reverse sort the idxs if we are in descending order
+	[[ $ascending_order == false ]] && idxs=$(echo "$idxs" | sort -r)
+
+	for idx in $idxs; do
+		# if ascending order, subtract 1 from the index, otherwise add 1
+		operation="-"; [[ $ascending_order == false ]] && operation="+"
+
+		sed -i "s/^$idx,/$(($idx $operation 1)),/" "$DB_FILE"
+	done
+
+	# step 6 - move the entry to the new index
+	sed -i "/^t_$mod_index,/d" "$DB_FILE"
+
+	# weird edge case where the new index is the last index
+	if [[ $((new_index + 1)) -gt $(wc -l < "$DB_FILE") ]]; then
+		echo "$entry" >> "$DB_FILE"
+	else
+		sed -i "$((new_index + 1))i $entry" "$DB_FILE"
+	fi
+
+	log INFO "Mod ${GREEN}successfully${NC} reindexed: $mod_name from $mod_index to $new_index."
+}
+
 # --- Modpacks management ---
 
 function modpack_list() {
@@ -1241,6 +1421,9 @@ function main() {
 		"import"|"im")
 			mod_import "$@"
 			;;
+		"order"|"o")
+			mod_order "$@"
+			;;
 		"modpack-list"|"ml")
 			modpack_list "$@"
 			;;