#!usr/bin/env perl

###############
### Modulos ###
###############
use common::sense;
use WWW::Mechanize;
use WWW::Mechanize::PhantomJS;
use WWW::Mechanize::DecodedContent;
use PDF::FromImage;
use Cwd;
use Getopt::Mixed;
use Try::Tiny;

#########################
### Variáveis globais ###
#########################
my $url = WWW::Mechanize->new();
my $phantom = WWW::Mechanize::PhantomJS->new();
my $currentDir = getcwd;
my $login;
my $bookTarget;

###########################
###  Checar argumentos  ###
###########################
Getopt::Mixed::init('l=i login>l b=i book>b h help>h');
while( my( $option, $value, $pretty ) = Getopt::Mixed::nextOption()) {
    OPTION: {
        $option eq 'h' and do {
            &showArgumentsHelp;
            exit;
        };
        $option eq 'l' and do {
            $login = $value;

            last OPTION;
        };
        $option eq 'b' and do {
            $bookTarget = $value;
            last OPTION;
        };
    }
}
Getopt::Mixed::cleanup();

if (!$login) {
    print "Erro: Especifique seu login!\n";
    &showArgumentsHelp;
    exit;
}

if (!$bookTarget) {
    print "Tem certeza que deseja efetuar download de todos os livros? (s/n)\n";
    print "Aviso: Essa ferramenta esta incompleta!\n";
    chomp (my $input = <>);
    if ($input ne 's') {
        &showArgumentsHelp;
        exit;
    }
}

sub showArgumentsHelp {
    print "Argumentos:\n";
    print "-l ou -login: Especifique o login (apenas numeros)\n";
    print "-b ou -book: Especifique o ID do livro (apenas numeros)\n";
    print "  Para descobrir qual o ID do livro que deseja baixar, acesse-o no navegador\n";
    print "  e veja na barra de endereco os numeros apos o 'publications'.\n";
    print "  Se nenhum ID de livro for especificado,\n";
    print "  ira efetuar download de todos (ferramenta incompleta!)\n";
    print "-h ou -help: Mostra essa mensagem de ajuda e finaliza o programa\n";
}

#######################
###  Iniciando BOT  ###
#######################
&login;

sub login {
    $phantom->get("http://bvu.ifce.edu.br/login.php");

    print "Logging... ";

    $phantom->submit_form(
        fields => {
            login => $login,
        }
    );

    # Conferindo o Login
    if($phantom->decoded_content =~ /Fez login com sucesso./gi) {
        print "login done\n\n";
        if (!$bookTarget) {
            &downloadAllBooks;
        } else {
            &downloadBook($bookTarget, $bookTarget);
        }
    } else {
        $phantom->decoded_content =~ /<div class=".*alert-error.*">(.+?)<\/div>/;
        &loginError($1);
    }
}

sub downloadAllBooks {
    # Recolher todos ID's e nomes dos livros
    # TODO: Inacabado! Apenas irá recolher os dos primeiros livros listados
    my @books_id = $phantom->decoded_content =~ /<a href="\/users\/publications\/(\d+)"/g;
    my @books_name = $phantom->decoded_content =~ /.*class="cover">.*<img alt="(.*?)".*>.*>/g;
    my $i = 0;

    print "* Accessing books *\n";
    foreach (@books_id) {
        print "- " . $books_name[$i] . " (" . $_ . ")...\n";
        &downloadBook($_, $books_name[$i]);

        $i++;
        print "\n";
    }
}

# Função para efetuar download das imagens de cada página do livro
sub downloadBook {
    # Declarar variáveis
    my ($bookId, $bookName) = @_;
    my $elementPage2;
    my $srcPage2;
    my @allPagesDir;

    my $pageCheck;
    my $checkChange;

    my $bookDir = $currentDir . '\\' . $bookName;
    mkdir($bookDir);

    # Acessar livro
    $phantom->get("http://ifcefortaleza.bv3.digitalpages.com.br/users/publications/" . $bookId);

    my $countPages = $phantom->eval('RDP.options.pageSetLength');
    print "Total number of pages: " . $countPages . "\n";

    my $elementPage1 = $phantom->eval("\$('.backgroundImg')[0]");
    my $srcPage1 = $elementPage1->get_attribute('src');
    print "Cover...\n";
    $url->mirror($srcPage1, $bookDir . '\\' . '0.png');
    push(@allPagesDir, $bookDir . '\\' . '0.png');
    $phantom->eval('navigate.next_page()');

    for (my $currentPage = 1; $currentPage <= $countPages; $currentPage += 2) {
        # Loop para permitir que o código só seja prosseguido caso a imagem tenha sido alterada
        # É necesário pois a mudança demora um pouco
        while ($checkChange eq '' || $srcPage1 eq $checkChange) {
            try {
                $pageCheck = $phantom->eval("\$('.backgroundImg')[0]");
                $checkChange = $pageCheck->get_attribute('src');
            } catch {
                print "Error when accessing the elements .backgroundImg! Trying again...\n";
            };
        }

        $srcPage1 = $checkChange;
        $url->mirror($srcPage1, $bookDir . '\\' . $currentPage . '.png');
        push(@allPagesDir, $bookDir . '\\' . $currentPage . '.png');
        print "Page " . $currentPage . "/" . $countPages . "...\n";

        $elementPage2 = $phantom->eval("\$('.backgroundImg')[1]");
        try {
            $srcPage2 = $elementPage2->get_attribute('src');
            $url->mirror($srcPage2, $bookDir . '\\' . ($currentPage + 1) . '.png');
            push(@allPagesDir, $bookDir . '\\' . ($currentPage + 1) . '.png');
            print "Page " . ($currentPage + 1) . "/" . $countPages . "...\n";
        } catch {
            print "Erro ao tentar acessar o atributo SRC da pagina a direita. Essa pagina realmente existe?\n";
        };

        $phantom->eval('navigate.next_page()');
    }

    # Gerar PDF
    my $pdf = PDF::FromImage->new;
    $pdf->load_images(@allPagesDir);
    $pdf->write_file($bookDir . '\\' . $bookName . '.pdf');
    print "... pdf creat!\n";

    # Finalizar
    print "* End! *\n";
}

# loginError -> chamado em caso de erro ao tentar logar
sub loginError {
    print "erro ao realizar login!!\n";
    print "Mensagem de erro: @_\n";
    print "Tentar realizar login novamente? (s/n)\n";
    chomp (my $input = <>);

    if ($input eq 's') {
        print "Informe o seu login (apenas numeros): ";
        chomp ($login = <>);
        &login;
    }
}

__END__