# Followers synchronisation (FEP-8fcf, owner decision 2026-10-06): alice's followers-only post tells Mastodon, in a signed
# header, a digest of her followers there; when Mastodon's view differs it reads her roll-call and mends itself. Both ways:
# a follow PrivaPub lost (Mastodon drops it), and a follow Mastodon lost (it sends the Undo PrivaPub then applies). The
# roll-call lists Mastodon's accounts only, and only to a signed request. Needs the mastodon peer.
M=https://mastodon.test:6443
mcurl() { curl -sk --resolve mastodon.test:6443:127.0.0.1 "$@"; }
. "$here/peers/mastodon.sh"
m_rails() { podman exec pasture-mastodon bin/rails runner "$1" 2>/dev/null | tail -1; }
p_mongo() { podman exec pasture-mongo mongosh --quiet PrivaPub --eval "$1"; }

echo "followsync"
AT=$(privapub_token alice_sync)
AH="Authorization: Bearer $AT"
[ -n "$AT" ] && ok "PrivaPub token for alice_sync" || { ko "PrivaPub token for alice_sync"; return 1; }
MT=$(mastodon_token)
MH="Authorization: Bearer $MT"
run=$(date +%s)
alice_acct=$(curl -s -H "$AH" "$P/api/v1/accounts/verify_credentials")
alice_id=$(echo "$alice_acct" | j "print(d['id'])")
alice_uri=$(echo "$alice_acct" | j "print(d['url'])" | sed 's|/@|/peasants/|')
alice_followers() { curl -s -H "$AH" "$P/api/v1/accounts/verify_credentials" | j "print(d['followers_count'])"; }
alice_on_m=$(mcurl -H "$MH" "$M/api/v2/search?q=@alice_sync@privapub.test&resolve=true&type=accounts" | j "print(d['accounts'][0]['id'])")
# (from Mastodon's database: its API caches relationships a day, and the scenario changes them behind its back)
m_follows() { m_rails "puts Follow.exists?(account: Account.find_local(\"mastouser\"), target_account: Account.find_by(uri: \"$alice_uri\")) ? \"True\" : \"False\""; }
mastouser_uri=$(m_rails 'puts ActivityPub::TagManager.instance.uri_for(Account.find_local("mastouser"))')
follow_from_m() {
	mcurl -o /dev/null -X POST -H "$MH" "$M/api/v1/accounts/$alice_on_m/follow"
	until_true 45 '[ "$(m_follows)" = "True" ] && [ "$(alice_followers)" = "1" ]'
}
quiet_post() { curl -s -o /dev/null -X POST -H "$AH" "$P/api/v1/statuses" -d "status=$1&visibility=private"; }

[ "$(m_follows)" = "True" ] || follow_from_m
[ "$(m_follows)" = "True" ] && [ "$(alice_followers)" = "1" ] && ok "mastouser follows alice" || ko "mastouser never followed alice"

echo "  the roll-call"
[ "$(pfetch -s -o /dev/null -w '%{http_code}' -H 'Accept: application/activity+json' "$alice_uri/groupies/roll-call")" = "401" ] \
	&& ok "an unsigned roll-call is refused" || ko "the roll-call answered an unsigned request"

echo "  a follow PrivaPub lost"
p_mongo "db.Follower.deleteMany({LocalActorId:'$alice_id', ActorURI:'$mastouser_uri'})" >/dev/null
[ "$(alice_followers)" = "0" ] && ok "PrivaPub forgets mastouser" || ko "PrivaPub still counts mastouser"
# (nothing goes to Mastodon for a follower PrivaPub does not know of: alice names mastouser, so her post still goes there)
quiet_post "@mastouser@mastodon.test for my followers $run"
until_true 60 '[ "$(m_follows)" = "False" ]' && ok "Mastodon reads alice's roll-call and drops the follow" || ko "Mastodon still has mastouser following alice"

echo "  a follow Mastodon lost"
follow_from_m && ok "mastouser follows alice again" || ko "mastouser could not follow alice again"
m_rails "a = Account.find_local(\"mastouser\"); t = Account.find_by(uri: \"$alice_uri\"); Follow.where(account: a, target_account: t).destroy_all" >/dev/null
[ "$(m_follows)" = "False" ] && ok "Mastodon forgets the follow" || ko "Mastodon still has the follow"
quiet_post "for my followers again $run"
until_true 60 '[ "$(alice_followers)" = "0" ]' && ok "Mastodon reads the roll-call and undoes the follow PrivaPub had" || ko "PrivaPub still counts mastouser"