#!/bin/bash
# Dump the Weather database (ens-forecast) to a per-ISO-week file, keeping the two newest weeks.
set -euo pipefail

cnf=${XDG_CONFIG_HOME:-$HOME/.config}/ens-forecast/dump.cnf
dir=${XDG_DATA_HOME:-$HOME/.local/share}/ens-forecast/dumps
out=$dir/Weather-$(date +%G-W%V).sql.gz
keep=2

umask 077
mkdir -p "$dir"

# Write to a temporary file so a failed dump never replaces a good one
tmp=$(mktemp "$dir/.dump.XXXXXX")
trap 'rm -f "$tmp"' EXIT

mariadb-dump --defaults-extra-file="$cnf" --single-transaction --databases Weather | gzip > "$tmp"
mv "$tmp" "$out"

# Names sort by week, so all but the last $keep are the old ones
dumps=("$dir"/Weather-*.sql.gz)
if (( ${#dumps[@]} > keep )); then
    rm -f -- "${dumps[@]:0:${#dumps[@]}-keep}"
fi