#!/usr/bin/perl
use strict;
use Digest::SHA qw(sha256_hex);
use LWP::UserAgent;
use DBI qw(:sql_types);
use Getopt::Long;
use pQuery;

sub init {
    my $driver   = "SQLite";
    my $database = "history.db";
    my $dsn = "DBI:$driver:dbname=$database";
    my $dbh = DBI->connect($dsn, { RaiseError => 1 })
        or die $DBI::errstr;
    print "Opened database successfully\n";
    return $dbh;
}

sub add_History($$$){
    my($url, $signature, $dbh) = @_;
    my $stmt = qq(INSERT INTO visit (url,signature)
        VALUES ("$url", "$signature"));
    my $rv = $dbh->do($stmt) or die $DBI::errstr;
}

sub get_html($) {
    my $ua = new LWP::UserAgent;
    $ua->timeout(120);
    my $url = @_ ;
    my $request = new HTTP::Request('GET', $url);
    my $response = $ua->request($request);
    my $content = $response->content();
    return $content;
}

sub visit($$){
    my ($url, $dbh)= @_;
    my $content = get_html "$url" ;
    return sha256_hex( $content );
}

sub isNew($$$){
    my($url, $signature, $dbh) = @_;
    my $sth = $dbh->prepare("SELECT COUNT(signature) FROM visit WHERE signature=?1 AND url=?2");
    $sth->execute($signature, $url);
    my $refs = $sth->fetchall_arrayref()->[0][0];
    return ($refs)? 0 : 1 ;
}

sub registerIfNew($$){
    my($url, $dbh) = @_;
    my $signature = visit($url, $dbh);

    if( isNew($url, $signature ,$dbh)){
	add_History($url, $signature ,$dbh);
	return 1;
    }
    return 0;
}

sub importFromUrl($){
    my ($url) = @_;
    print "importing $url";
}

sub checkUrl($){
    my($url) = @_;
    my $dbh = init;
    if( registerIfNew($url, $dbh) ){
        importFromUrl($url);
    }
    $dbh->disconnect();
}

sub get_content($$){
    ;
}

sub main($){
    my($file) = @_;
    print "Using file $file\n";
    #checkUrl( $url );
    open(FH, '<', $file) or die $!;
    while(<FH>){
	print "Checking $_";
	checkUrl( $_ );
    }
    close(FH);
}

my $file;
GetOptions ('file=s' => \$file);

main( $file );