Add diffs to results posts

diffs.sh

#!/bin/sh -eu
# NB: Contains literal tabs

caption() {
	python -c '
from os             import getenv
from sys            import argv
from telegram       import Bot
from telegram.error import BadRequest, TimedOut

bot = Bot(token=getenv("TOKEN"))
while True:
	try:
		bot.edit_message_caption(chat_id=getenv("CHAT"),
		                         message_id=argv[1],
		                         caption=argv[2],
		                         parse_mode="HTML")
	except BadRequest:
		break
	except TimedOut:
		pass
	else:
		break
' "$@"
}

SG="lines%10==1 && lines%100!=11"
DU="lines%10>=2 && lines%10<=4 && (lines%100<10 || lines%100>=20)"

ROOT=https://alexshpilkin.github.io/uk-pres2019/
DIFF="diff -u1 -F^region"
prev=

( cd Updates; ls results.*; ) | \
while read -r curr; do
	if [ -z "$prev" ]; then prev=$curr; continue; fi  # First file
	diff=${curr%.tsv}.html
	if [ -f "Diffs/$diff" ]; then prev=$curr; continue; fi  # Exported
	echo "export $diff"
	tac Updates/.hat | while IFS='	' read -r msgid digest file; do
		if [ "$file" = "$curr" ]; then
			if [ "$file" != "$curr" ] || [ "$msgid" = ! ]; then
				echo "zombie $curr"; continue
			fi

			lines=$(diff -y --suppress-common-lines \
			             "Updates/$prev" "Updates/$curr" | \
			        wc -l)

			$DIFF --color=always "Updates/$prev" "Updates/$curr" | \
			/usr/share/git/diff-highlight/diff-highlight | \
			aha -t "$DIFF $prev $curr" | tr -d '\r' > "Diffs/$diff"
			cd Diffs
			git add "$diff"
			git commit -m "Add $diff"
			git push
			cd ..

			if   (( $SG )); then caption="$lines изменение"
			elif (( $DU )); then caption="$lines изменения"
			else                 caption="$lines изменений"
			fi
			caption "$msgid" "<a href='$ROOT$diff'>$caption</a>"
		fi
	done
	prev=$curr
done