#!/bin/sh

# Writes files to the current working directory

PYTHON="$(dirname "$0")"/venv/bin/python
if ! test -x "$PYTHON"; then
	echo "Create a virtual environment in $(dirname "$0")/venv first"
	exit 1
fi

previous_file=""

while true; do
	# Get one shot of data
	data="$("$PYTHON" "$(dirname "$0")"/trainmap_backup.py)"
	if test $? -ne 0; then echo "Error: failed to fetch trainmap data" >&2; continue; fi

	timestamp="$(printf '%s\n' "$data" | jq ".timestamp / 1000 | round")"
	if test "$timestamp" = "" || test "$timestamp" -lt 1705410073 || test "$timestamp" -gt 4102441200; then echo "Error: timestamp '$timestamp' invalid" >&2; continue; fi
	file="$(date +%Y-%m-%d --date "@$timestamp").json"

	# Write the data to file
	printf '%s\n' "$data" >> "$file"

	# At the start of a new day, archive the previous day's file
	if test "$previous_file" == ""; then
		previous_file="$file"
	elif test "$file" != "$previous_file"; then
		if test -e "$previous_file.gz"; then
			echo "Warning: $previous_file.gz already exists, not archiving" >&2
		else
			gzip --best "$previous_file"
		fi
		previous_file="$file"
	fi

	# Sleep to start the next request at the next full minute
	seconds="$(date +%S)"
	sleep_for="$("$PYTHON" -c "print(60 - int('$seconds', 10) - 0.5)")"
	sleep "$sleep_for" || true
done