#!/bin/sh

set -e

# Report gaps that contain the target time

target=${1:-3:30}
threshold=${2:-3600}
LOGFILE="${3:-$HOME/keystroke-timestamps.log}"

awk -vtarget="$(date -d "$target" '+%H %M %S')" -vthreshold="$threshold" -vtime_fmt="%F %T" '
  function first_target_after(t) {
    # TODO: Be smarter for targets near DST changes.  :(
    target_on_t_day = mktime(strftime("%Y %m %d ", t) target)
    target_on_prev_day = mktime(strftime("%Y %m %d ", target_on_t_day - 86400) target)
    target_on_next_day = mktime(strftime("%Y %m %d ", target_on_t_day + 86400) target)
    if (target_on_prev_day > t) { return target_on_prev_day }
    if (target_on_t_day    > t) { return target_on_t_day    }
    return target_on_next_day
  }
  $1 <= 67767976233561595 {
    if (prev && $1 - prev > threshold && $1 > first_target_after(prev)) {
      print(strftime(time_fmt, prev), "to", strftime(time_fmt, $1), "was", $1 - prev)
    }
    prev = $1
  }' "$LOGFILE"