From bfe3c496941c3568e42e7f764d07112689f349bb Mon Sep 17 00:00:00 2001
From: Gustav Eek <gustav.eek@fripost.org>
Date: Thu, 19 May 2022 19:26:02 +0200
Subject: [PATCH] [event-participant] Improve control flow

Print summary if no STDIN is provided, instead of if input was empty.
Create file if not existing. Create cache if not existing. Update help
accordingly.

TODO Provide arguments as ordinary flags: `-f` for file, `-n` for
"other name", `-c` for cancel, argument can be "comment".

TODO Provide long list option for printing: `-s` for summary.

TODO Provide title row and header row for the CSV-file: `-t` for
setting title.

TODO Provide PGP encryption by default: `-r` for GPG recipiant.
---
 event-participant | 50 +++++++++++++++++++++++++----------------------
 1 file changed, 27 insertions(+), 23 deletions(-)

diff --git a/event-participant b/event-participant
index 8bb525a..534ce69 100755
--- a/event-participant
+++ b/event-participant
@@ -12,7 +12,7 @@ formermost record is reused.
 Add extra participants (email taken as From field) with
 argument +NAME.
 
-If input is empty, also list of particiants is printed.
+If no input is provided, instead list a summary particiants is printed.
 
     echo | event-participant
 
@@ -22,6 +22,11 @@ Help is this message.
 CACHE="$HOME/.cache/${0##*/}/events.csv"
 HEADER="participant,date_att,date_cancel"
 
+if [ ! -f "$CACHE" ]; then
+    mkdir -p $(dirname "$CACHE")
+    echo -n "" > "$CACHE"
+fi
+
 if [[ "$1" == "--help" ]]; then
     echo -e "$HELP" 1>&2
     exit 0
@@ -32,21 +37,30 @@ if [[ "$1" =~ \+.* ]]; then
     shift
 fi
 
-arg_event="$1"
-
-if [ -f "$CACHE" ]; then
-    event=$(tail -1 "$CACHE")
+if [ -n "$1" ]; then
+    event="$1"
+    if [ "$event" != "$(tail -1 "$CACHE")" ];then
+        echo "$event" >> "$CACHE"
+    fi
 else
-    mkdir -p $(dirname "$CACHE")
-    echo -n "" > "$CACHE"
+    event=$(tail -1 "$CACHE")
 fi
-if [ -n "$arg_event" -a "$arg_event" != "$event" ]; then
-    event="$arg_event"
-    echo "$event" >> "$CACHE"
+
+if [ ! -f "$event" ]; then
+    echo -n > "$event"
 fi
-if [ -z "$event" ]; then
-    echo "${0##*/}: E: No event file." 1>&2
-    exit 1
+
+# Print summary, if no input data provided
+
+if test -t 0; then
+    n_t=$(cat "$event" | grep -v "$HEADER"| cut -d, -f2 | grep -v '^$' | wc -l)
+    n_c=$(cat "$event" | grep -v "$HEADER"| cut -d, -f3 | grep -v '^$' | wc -l)
+    n_p=$(( $n_t - $n_c ))
+    if [ -z "$info" ]; then
+        cat "$event" | tr ',' '\t'
+    fi
+    echo -ne "At $event:\n   part: $n_p\n   canc: $n_c\n" 1>&2
+    exit 0
 fi
 
 # Add info, sorted by date and uniq
@@ -77,13 +91,3 @@ echo "${participant},${date}" |
     grep -v "^$" \
         > "$event.sorted"
 mv "$event.sorted" "$event"
-
-# Print summary
-
-n_t=$(cat "$event" | grep -v "$HEADER"| cut -d, -f2 | grep -v '^$' | wc -l)
-n_c=$(cat "$event" | grep -v "$HEADER"| cut -d, -f3 | grep -v '^$' | wc -l)
-n_p=$(( $n_t - $n_c ))
-echo -ne "At $event:\n   part: $n_p\n   canc: $n_c\n" 1>&2
-if [ -z "$info" ]; then
-    cat "$event" | tr ',' '\t'
-fi
-- 
2.39.2