#!/usr/bin/perl

use strict;
use warnings;
use Getopt::Long;

my $report;
my $dir;
my $help;

GetOptions("r=s", => \$report,
		   "d=s", => \$dir,
		   "h" => \$help);

if($help) {
	print qq["Help:
		-r <path to the Downloaded csv>, input report.
		-d <path to the reports directory>, input directory to search for reports.
		-h , print this help and exit.\n];
	exit;
}

die "You must specify either a report or a directory.\n" unless ($report || $dir);

if($report && $dir) {
	die "Specify the path to a report file or to a reports directory, not to both at the same time. See help.\n";
}

if($report) {
	die "Invalid filename: $report. Exiting. $!\n" unless (-f $report);
}

my @files;
if($dir) {
	die "Invalid directory: $dir. Exiting. $!\n" unless (-d $dir);
	opendir(DIR, $dir) or die "Couldn't open directory $dir: $!\n";
	@files = (readdir DIR) or die "Couldn't read directory $dir: $!\n";
	closedir(DIR) or die "Couldn't close directory $dir: $!\n";
} elsif ($report) {
	@files = $report;
	$dir = '.';
}

my $hours;
my $total_hours = 0;
my %categories;

foreach (@files) {
	next if ($_ =~m/^\.+$/);
	next if (-d $_);
	my $line_count = 0;
	if(!(open FILE, '<', "$dir/$_")) {
		print "Couldn't open file $_: $!\nSkipping it.\n";
		next;
	}
	while(!eof(FILE)) {
		defined(my $line = readline FILE) or die "Couldn't open $_. $!\n";
		if (!$line_count) {
			if(!($line =~ m/.*Hours.*\,.*Description.*/)) {
				print "File $_ is not a valid report. Skipping it.\n";
				close FILE;
				last;
			}
		}

		if ($line =~ m/([0-9]+)\:([0-9]+).*\,.*\[(.*)\]/) {
			$hours = $1 + $2 / 60.0;
			$total_hours += $hours;

			my $category = $3;
			if ($categories{$category}) {
				$categories{$category} += $hours;
			} else {
				$categories{$category} = $hours;
			}
		}
		$line_count++;
	}
	close FILE or die $!;
}

foreach my $key (keys %categories) {
	print qq[Project $key: $categories{$key}\n];
}
print qq[Total hours: $total_hours\n];