<?php
/*
 * Sparkline PHP Graphing Library
 * Copyright 2004 James Byers <hide@address.com>
 * http://sparkline.org
 *
 * Sparkline is distributed under a BSD License.  See LICENSE for details.
 *
 * $Id: stock_chart.php,v 1.9 2004/11/09 22:32:48 jbyers Exp $
 *
 * stock_chart displays an N-year stock chart sparkline based on Yahoo! data
 * each data point is the day's closing price
 *
 * http://ichart.finance.yahoo.com/table.csv?s=MSFT&a=11&b=31&c=1998&d=11&e=31&f=1999&g=d&ignore=.csv
 * NB: months are zero-based, any error will cause a 404
 *
 * parameters:  s  ticker symbol
 *              y  number of years [1-5]
 *              m  drawing mode, 1 for pretty
 *              
 */

//////////////////////////////////////////////////////////////////////////////
// verify parameters; bad form, but die to text error on failure
//
if (!isset($_GET['s']) ||
    !eregi('^[a-z\^]{1,5}$', $_GET['s'])) {
  die('bad ticker ' . $_GET['s']);
}

if (!isset($_GET['y']) ||
    !is_numeric($_GET['y']) ||
    $_GET['y'] > 5 ||
    $_GET['y'] < 0) {
  die('bad year ' . $_GET['y']);
}

//////////////////////////////////////////////////////////////////////////////
// load and process data from Yahoo! ichart csv source
//
$m  = date('n') - 1;
$d  = date('d');
$y2 = date('Y');
$y1 = $y2 - $_GET['y'];

// data sample:
//   0        1     2     3     4     5        6
//   Date,Open,High,Low,Close,Volume,Adj. Close*
//   5-Nov-04,29.21,29.36,29.03,29.31,95337696,29.31
//
$url = "http://ichart.finance.yahoo.com/table.csv?s=" . $_GET['s'] . "&a=$m&b=$d&c=$y1&d=$m&e=$d&f=$y2&g=d&ignore=.csv";
if (!$data = @file($url)) {
  die('error fetching stock data; verify ticker symbol');
}

//////////////////////////////////////////////////////////////////////////////
// build sparkline using standard flow:
//   construct, set, render, output
//
require_once('../lib/Sparkline_Line.php');

$sparkline = new Sparkline_Line();
$sparkline->SetDebugLevel(DEBUG_NONE);
//$sparkline->SetDebugLevel(DEBUG_ERROR | DEBUG_WARNING | DEBUG_STATS | DEBUG_CALLS, '../log.txt');

if (isset($_GET['b'])) {
  $sparkline->SetColorHtml('background', $_GET['b']);
  $sparkline->SetColorBackground('background');
}

$data = array_reverse($data);
$i = 0;
while (list(, $v) = each($data)) {
  $elements = explode(',', $v);
  if (ereg('^[0-9\.]+$', trim($elements[6]))) {
    $sparkline->SetData($i, $elements[6]);
    $i++;
  }
}

$sparkline->SetYMin(0);

if (isset($_GET['m']) &&
    $_GET['m'] == '0') {
  $sparkline->Render(100, 15);
} else {
  $sparkline->SetLineSize(6); // for renderresampled, linesize is on virtual image
  $sparkline->RenderResampled(100, 15);
}

$sparkline->Output();

?>