#!/bin/sh

reponame="$(basename "$(readlink -f .)")"

FORMAT="%C(auto)%h by %an (%ah: %s) sig: %G? %GS 0x%GK https://jfr.im/git/$reponame/commitdiff/%h"
H2I="https://h2i:ef199c443ca3f1f49709dbe79c3758273658fb7cfbb2ff88ab97ef9aedd6bb30@chat.2948.ca/h2i/null"

ref="$1"
old="$2"
new="$3"

if [ "$old" = "0000000000000000000000000000000000000000" ]; then # new branch
	commits="created with $(git describe --always "$new")"
elif [ "$new" = "0000000000000000000000000000000000000000" ]; then # deleted branch
	commits="deleted from $(git describe --always "$old")"
elif [ "$old" = "$(git merge-base "$old" "$new")" ]; then # fast-forward update
	commits="updated from $(git describe --always "$old") -> $(git describe --always "$new")"
elif [ "$new" = "$(git merge-base "$old" "$new")" ]; then # rollback
	commits="!! rolled back to $(git describe --always "$new") erasing history through $(git describe --always "$old")"
else # commit --amend, rebase, or similar
	commits="!! rewrote history from $(git describe --always "$(git merge-base "$old" "$new")") -> $(git describe --always "$new") erasing history through $(git describe --always "$old")"
fi

curl -sS -d "[$reponame] $ref $commits" "$H2I" >/dev/null

if [ "$old" = "0000000000000000000000000000000000000000" ]; then
	git show --no-show-signature --no-patch --pretty="tformat:$FORMAT" "$new"
else
	git log --no-show-signature --pretty="tformat:$FORMAT" "$old".."$new"
fi | while read line; do
		curl -sS -d "$line" "$H2I" >/dev/null
done