#!/usr/bin/perl

use strict;
use warnings;
use v5.14;

use DBI;
use POSIX qw(strftime);

my $dbh = DBI->connect("dbi:SQLite:dbname=rss2html.sqlite", "", "");
$dbh->{sqlite_unicode} = 1;
my $feed_id = $ARGV[0];
my $issued
    = $dbh->selectcol_arrayref(
	"select issued from items where feed_id=? order by issued", {}, $feed_id
      );

my @dt;
for (1 .. $#{$issued}) {
    push @dt, $issued->[$_] - $issued->[$_-1];
}
@dt = sort { $a <=> $b } @dt;
my $c = 0;
for (@dt) {
    $c++;
    printf("%14s %8d %5.1f%%\n", hr($_), $_, $c * 100 / @dt);
}

sub hr {
    my ($s) = $_;
    my $hr = "";
    if ($s > 86400) {
	my $d = int ($s / 86400);
	$hr .= $d . "d";
	$s -= $d * 86400;
    }
    if ($hr || $s > 3600) {
	my $h = int ($s / 3600);
	$hr .= sprintf("%02dh", $h);
	$s -= $h * 3600;
    }
    if ($hr || $s > 60) {
	my $m = int ($s / 60);
	$hr .= sprintf("%02dm", $m);
	$s -= $m * 60;
    }
    $hr .= sprintf("%02ds", $s);
    return $hr;
}