#!/usr/bin/env perl

use warnings;
use strict;
use 5.10.0;

use File::HomeDir;

my $rcfile = File::HomeDir->my_home . "/.timelogrc";
# set an unreasonable default, so it's obvious:
our $hourly_rate = 10000;
do $rcfile if -e $rcfile;

my $total_hours = 0;
my $total_expenses = 0;

# while we've got input from a file/stdin, split it into two datestamps
# and feed that to date(1)
while (my $line = <>) {

  chomp($line);

  if ($line =~ m/
    ^
    \s{2,}       # leading whitespace, two or more

    expense:     # the string "expense"

    [ ]          # a space

    \$ ([\d.]+)  # an amount

    [ ]
    -            # a dash with spaces
    [ ]

    (.*?)        # any notes

    $            # eol
  /ix)
  {
    my $expense_amount = $1;
    $total_expenses += $expense_amount;
    my $expense_notes = $2;
    say "* $line";
  }

  # skip things that don't look like a date range - everything else can
  # just be commentary.
  next unless $line =~ m/
    ^
    \s{2,}                  # leading whitespace of two or more chars

    (
      \d{4} - \d{2} - \d{2} # date
    )

    [ ]                     # space

    (
      \d{1,2} : \d{2}       # start timestamp
    )

    [ ] - [ ]               # delimiter

    (
      \d{1,2} : \d{2}       # end timestamp
    )
    $
  /ix;

  my $start_timestamp = "$1 $2";
  my $end_timestamp   = "$1 $3";

  my ($start, $end) = map { get_seconds($_) } ($start_timestamp, $end_timestamp);
  my $interval = $end - $start;
  my $hours = $interval / 3600;
  $total_hours += $hours;
  say sprintf("* $line\t%.3f hours", $hours);

}

my $hourly_total = $total_hours * $hourly_rate;
my $overall_total = $hourly_total + $total_expenses;

print "\n";
say sprintf(
  # extra spaces at end for newline in markdown:
  '%.3f total hours at $%.2f/hr = $%.2f  ',
  $total_hours,
  $hourly_rate,
  $hourly_total
);

say sprintf(
  '$%.2f in expenses',
  $total_expenses
);

print "\n";
say sprintf('**Total due = $%.2f**', $overall_total);

sub get_seconds {
  my ($stamp) = @_;
  my $seconds = `date --date="$stamp" +%s`;
  chomp($seconds);
  return $seconds;
}