fzf chooser instead of hardcoded commands

Instead of deleting hardcoded commands in filterHistory, sort commands
by usage and let the user select in fzf. If fzf is not installed, show
the most used ones and let the user select manually.
Keep the first occurence in the history for stuff like autosuggestions.

.local/bin/filterHistory

@@ -12,30 +12,39 @@
 [ -e "$1" ] || { echo "File does not exist" >&2; exit 1; }
 [ "$(stat -c '%a' "$1")" = "600" ] || { echo "File does not look like a history file" >&2; exit 1; }
 
-declare -a COMMANDS
-COMMANDS=('ls' \
-          'll' \
-          'l' \
-          ':q' \
-          ':Q' \
-          'exit' \
-          'cd' \
-          'cd ~' \
-          'cd .' \
-          'cd ..' \
-          'gs' \
-          'git status' \
-          'gd' \
-          'gpush' \
-          'git pull' \
-          'cmake .. && make' \
-          'exec zsh' \
-          'python3' \
-          'clear' \
-)
+# Sort the commands per number of occurrences
+most_used="$(\
+	cut -d';' -f2 "$1" \
+	| sort \
+	| uniq -c \
+	| sort -nr \
+)"
 
-printf '%s\n' "${COMMANDS[@]}" | column
-echo "Are you a 100% sure you want to delete these commands from $1? (Type out yes)"
+declare -a commands
+if command -v fzf >/dev/null 2>&1; then
+	# Let the user pick in fzf from the most used commands
+	readarray -t commands < <(\
+		fzf -m --reverse --height 50% <<<"$most_used" \
+		| sed -E 's/^[ \t]*[0-9]+ //' \
+	)
+else
+	echo "Most used commands:"
+	offset="$(head -1 <<<"$most_used" | sed -E 's/^( *[0-9]+).*$/\1/' | wc -m)"
+	for (( i = 0; i < $offset - $(wc -m <<<"count"); i++ )); do
+		echo -n " "
+	done
+	echo "count command"
+	head <<<"$most_used"
+	echo -n "You do not have fzf installed. Please type out the commands you"
+	echo -n " want to delete manually and finish by pressing Ctrl+D."
+	echo
+	readarray commands
+	echo
+fi
+
+[ "${#commands}" -gt 0 ] || exit 0
+printf '%s\n' "${commands[@]}" | column -x
+echo "Please confirm the deletion of these commands in $1 ('yes')"
 read yn
 [ "$yn" = "yes" ] || exit 1
 
@@ -44,9 +53,15 @@ cp "$1" "$tempd/$(basename "$1")"
 echo "Backup created at $tempd/$(basename "$1")"
 echo
 
-for c in "${COMMANDS[@]}"; do
-	c="$(echo "$c" | sed 's/\./\\./g; s/\//\\\//g')"
-	sed -Ei "/^: [0-9]+:[0-9]+;${c}\$/d" "$1"
+for c in "${commands[@]}"; do
+	# Escape all characters that sed could misinterpret.
+	pattern="^: [0-9]+:[0-9]+;$(sed -E 's/[./?+|()*\\]|\[|\]/\\&/g' <<<"$c")\$"
+	# Find first occurrence of the command in the history file
+	first="$(grep -Enm1 "$pattern" "$1" | cut -d: -f1)"
+
+	# Delete all lines beginning from the line after the first occurrence that
+	# contain (exactly) the command.
+	sed -Ei "$((first + 1)),\$ { /$pattern/d }" "$1"
 	echo "$c deleted"
 done