#!/usr/bin/env bash
# Daily retention sweep — keeps the newest KEEP_DAYS distinct calendar
# dates of backups, on BOTH local disk and S3, regardless of how old
# those dates are. So a long quiet period leaves backups intact instead
# of letting them age out.
#
# Idempotent. Safe to run on a cron.

set -uo pipefail

CONFIG_DIR="/home/ubuntu/gitea-backups"
LOG="${CONFIG_DIR}/logs/retention.log"
KEEP_DAYS=7

S3_REMOTE="s3"
S3_BUCKET="toqqer-gitea-backup"
RCLONE_CONF="/home/ubuntu/.config/rclone/rclone.conf"

QUIET=0
[[ "${1:-}" == "--quiet" ]] && QUIET=1
log() { printf '%s %s\n' "$(date -u +%FT%TZ)" "$*" >> "$LOG"; }
say() { [[ $QUIET -eq 0 ]] && echo "$*"; log "$*"; }

# ---- S3: keep newest KEEP_DAYS top-level YYYY-MM-DD folders ----
mapfile -t s3_dates < <(
    rclone --config "$RCLONE_CONF" lsd "${S3_REMOTE}:${S3_BUCKET}/" 2>/dev/null \
        | awk '{print $NF}' \
        | grep -E '^[0-9]{4}-[0-9]{2}-[0-9]{2}$' \
        | sort
)
n=${#s3_dates[@]}
if (( n <= KEEP_DAYS )); then
    say "S3: ${n} date-folder(s) present — all kept (limit ${KEEP_DAYS})"
else
    to_delete=$(( n - KEEP_DAYS ))
    deleted=0
    for ((i=0; i<to_delete; i++)); do
        d="${s3_dates[i]}"
        if rclone --config "$RCLONE_CONF" purge "${S3_REMOTE}:${S3_BUCKET}/${d}" 2>>"$LOG"; then
            say "S3: deleted ${d}/"
            deleted=$((deleted+1))
        else
            say "S3: FAIL deleting ${d}/ (see log)"
        fi
    done
    say "S3: kept newest ${KEEP_DAYS} date-folder(s), deleted ${deleted} older"
fi

# ---- LOCAL: same semantics on /home/ubuntu/gitea-backups/{repos,db}/ ----
# All filenames are date-prefixed (YYYY-MM-DDTHH-MM-SSZ...), so we group by
# the leading date and keep files only from the newest KEEP_DAYS dates seen.
mapfile -t local_dates < <(
    {
        find "${CONFIG_DIR}/repos" -type f -name '*.bundle' 2>/dev/null
        find "${CONFIG_DIR}/db"    -type f -name '*.db.gz'  2>/dev/null
    } | grep -oE '[0-9]{4}-[0-9]{2}-[0-9]{2}' | sort -u
)
ln=${#local_dates[@]}
if (( ln <= KEEP_DAYS )); then
    say "LOCAL: ${ln} date(s) present — all kept (limit ${KEEP_DAYS})"
else
    keep_from=$(( ln - KEEP_DAYS ))
    keep_set="$(printf '%s\n' "${local_dates[@]:$keep_from}")"
    deleted_files=0
    while IFS= read -r f; do
        [[ -z "$f" ]] && continue
        fd=$(grep -oE '[0-9]{4}-[0-9]{2}-[0-9]{2}' <<< "$(basename "$f")" | head -1)
        if ! grep -qx "$fd" <<< "$keep_set"; then
            rm -f "$f" && deleted_files=$((deleted_files+1))
        fi
    done < <(
        find "${CONFIG_DIR}/repos" -type f -name '*.bundle' 2>/dev/null
        find "${CONFIG_DIR}/db"    -type f -name '*.db.gz'  2>/dev/null
    )
    find "${CONFIG_DIR}/repos" -mindepth 2 -type d -empty -delete 2>>"$LOG" || true
    say "LOCAL: kept newest ${KEEP_DAYS} date(s), deleted ${deleted_files} file(s)"
fi

exit 0