package Apache::StockProfile;

use strict;
use diagnostics;

use Apache::Constants qw(OK);
use Apache::DBI;
use Apache::Session::DBI;
use CGI::Apache;

sub handler {
    # Get the Apache request object
    my $r = shift;

    my $max_stocks = 5;

    # Create a pseudo-CGI object, for easy form handling
    my $query = new CGI::Apache;

    # Recover the user's session, if it exists
    my $id = $r->header_in('Cookie');
    $id =~ s|SESSION_ID=(\w*)|$1|;

    my %session;

    tie %session, 'Apache::Session::DBI', $id,
    {
     DataSource => 'dbi:mysql:test:localhost:3306',
     UserName   => '',
     Password   => ''
    };

    # Connect to the database
    my $dbh = DBI->connect("DBI:mysql:test");
    my @symbols = ();

    # Now retrieve a list of current stocks
    my $sql = "SELECT DISTINCT symbol FROM StockValues ";
    $sql .=   "ORDER BY symbol ";

    # Prepare the query
    my $sth = $dbh->prepare($sql);
    if (!$sth)
    {
	$r->print("<P>Error preparing query.</P>");
	$r->print("<P>SQL was \"$sql\".</P>\n");
	$dbh->disconnect;
	return OK;
    }

    # Send the query
    my $result = $sth->execute;
    if (!$result)
    {
	$r->print("<P>Error executing query.</P>");
	$r->print("<P>SQL was \"$sql\".</P>\n");
	$sth->finish;
	$dbh->disconnect;
	return OK;
    }

    # Retrieve results
    if ($sth->rows)
    {
	while (my $row = $sth->fetchrow_arrayref)
	{
	    my ($symbol) = @{$row};
	    push @symbols, $symbol;
	}
    }

    # If we received a POST request, then store the new values in the
    # user profile
    if ($r->method eq "POST")
    {
	# Read the basic elements
	$session{email} = $query->param("email");
	$session{name} = $query->param("name");

	# Read symbols and number of shares into %portfolio
	my %portfolio = ();

	foreach my $counter (1 .. $max_stocks)
	{
	    my $symbol = $query->param("symbol-" . $counter);
	    my $shares = $query->param("shares-" . $counter);

	    next unless $symbol;
	    next unless $shares;

	    # Make sure that we only store non-zero values!
	    $portfolio{$symbol} = $shares;
	}
	# Now read all of the symbols into our session
	$session{portfolio} = \%portfolio;
    }

    # ------------------------------------------------------------
    # No matter what, we retrieve session information

    # Retrieve session information, if it exists
    my $email = $session{email};
    my $name = $session{name};

    my %portfolio = defined $session{portfolio} ? %{$session{portfolio}} : ();

    # ------------------------------------------------------------
    # Output a useful HTTP header, with the session cookie
    my $session_cookie = "SESSION_ID=$session{_session_id};";
    $r->header_out("Set-Cookie" => $session_cookie);
    $r->content_type("text/html");
    $r->send_http_header;

    # Create an HTML form that can be used to modify the profile
    $r->print('<HTML>', "\n");
    $r->print('<Head><Title>User profile</Title></Head>', "\n");
    $r->print('<Body>', "\n");

    # Provide a link for viewing current holdings
    $r->print('<P><a href="/stock-report">View your holdings</a>', "\n");

    # Create the form with which users can change their profile
    $r->print('<Form method="POST" action="/stock-profile">', "\n");

    $r->print('<Table>', "\n");

    # Create a short header
    $r->print("<tr>\n");
    $r->print("<td colspan=\"2\"><H2>User information</H2></td>\n\n");
    $r->print("</tr>\n\n\n");

    # Name
    $r->print("<tr>\n");
    $r->print("<td>Name:</td>\n\n");
    $r->print("<td><input type=\"text\" name=\"name\" ");
    $r->print("value=\"$name\"></td>\n\n");
    $r->print("</tr>\n\n\n");

    # E-mail address
    $r->print("<tr>\n");
    $r->print("<td>E-mail address:</td>\n\n");
    $r->print("<td><input type=\"text\" name=\"email\" ");
    $r->print("value=\"$email\"></td>\n\n");
    $r->print("</tr>\n\n\n");

    # Create a short header
    $r->print("<tr>\n");
    $r->print("<td colspan=\"2\"><H2>Portfolio holdings</H2></td>\n\n");
    $r->print("</tr>\n\n\n");

    # Print the current portfolio
    my $counter = 0;
    foreach my $symbol (sort keys %portfolio)
    {
	# Advance the counter
	$counter++;

	my $shares = $portfolio{$symbol};

	# Symbol
	$r->print("<tr>\n");

	$r->print("<td>Symbol</td>\n\n");

	$r->print("<td><select name=\"symbol-$counter\">\n");
	$r->print("<option value=\"\">Select a security\n");
	foreach my $iterate_symbol (@symbols)
	{
	    $r->print("<option value=\"$iterate_symbol\"");
	    $r->print(" selected") if ($symbol eq $iterate_symbol);
	    $r->print(">$iterate_symbol\n");
	}
	$r->print("</select>\n");

	$r->print("</td>\n\n");

	# Shares
	$r->print("<td>Shares</td>\n\n");

	$r->print("<td>");
	$r->print("<input type=\"text\" name=\"shares-$counter\" ");
	$r->print("value=\"$shares\">");
	$r->print("</td>\n\n");

	$r->print("</tr>\n\n\n");
    }

    # We always want to provide $max_stocks spaces for symbols and 
    # shares, so we continue until $counter gets to $max_stocks
    while ($counter++ < $max_stocks)
    {
	# Symbol
	$r->print("<td>Symbol</td>\n\n");

	$r->print("<td><select name=\"symbol-$counter\">\n");
	$r->print("<option value=\"\">Select a security\n");
	foreach my $iterate_symbol (@symbols)
	{
	    $r->print("<option value=\"$iterate_symbol\"");
	    $r->print(">$iterate_symbol\n");
	}
	$r->print("</select>\n");

	$r->print("</td>\n\n");

	# Shares
	$r->print("<td>Shares</td>\n\n");
	$r->print("<td><input type=\"text\" ");
	$r->print("name=\"shares-$counter\"></td>\n\n");

	$r->print("</tr>\n\n\n");
    }

    # Submit button
    $r->print("<tr>\n");
    $r->print("<td><input type=\"submit\" value=\"Set profile\">\n");
    $r->print("</tr>\n\n\n");

    $r->print('</Table>', "\n");

    # Finish the HTML
    $r->print('</Body>', "\n");
    $r->print('</Form>', "\n");
    return OK;
}

1;