#!/bin/sh
set -eu

OUTPUT_DIR="${OUTPUT_DIR:-/output}"
OUTPUT_FILE="${OUTPUT_FILE:-guide.xml}"
REFRESH_INTERVAL_MINUTES="${REFRESH_INTERVAL_MINUTES:-15}"
RUN_ONCE="${RUN_ONCE:-0}"

log() {
    printf '%s %s\n' "$(date -u '+%Y-%m-%dT%H:%M:%SZ')" "$*"
}

generate() {
    tmp_dir="$OUTPUT_DIR/.f1tv-epg.tmp"
    rm -rf "$tmp_dir"
    mkdir -p "$tmp_dir"

    log "Generating F1TV EPG"
    status=0
    if (cd "$tmp_dir" && python3 -u /app/f1tv_epg.py); then
        if mv -f "$tmp_dir/guide.xml" "$OUTPUT_DIR/$OUTPUT_FILE"; then
            log "EPG written to $OUTPUT_DIR/$OUTPUT_FILE"
        else
            status=$?
            log "Failed to move EPG into place" >&2
        fi
    else
        status=$?
        log "EPG generation failed; keeping existing $OUTPUT_DIR/$OUTPUT_FILE" >&2
    fi

    rm -rf "$tmp_dir"
    return "$status"
}

trap 'log "Stopping"; exit 0' INT TERM

mkdir -p "$OUTPUT_DIR"

if [ "$RUN_ONCE" = "1" ]; then
    generate
    exit $?
fi

case "$REFRESH_INTERVAL_MINUTES" in
    ''|*[!0-9]*)
        log "REFRESH_INTERVAL_MINUTES must be a positive integer" >&2
        exit 1
        ;;
esac

if [ "$REFRESH_INTERVAL_MINUTES" -le 0 ]; then
    log "REFRESH_INTERVAL_MINUTES must be greater than 0" >&2
    exit 1
fi

while true; do
    generate || true
    log "Next EPG refresh in ${REFRESH_INTERVAL_MINUTES}m"
    sleep $((REFRESH_INTERVAL_MINUTES * 60))
done