<?php
/**
 * @file
 * Provides primary Drupal hook implementations.
 *
 * @author Tj Holowaychuk <http://www.350designs.com/>
 * @author Jimmy Berry ("boombatower", http://drupal.org/user/214218)
 * @package Chart
 */

/*
 * Misc
 */
define('CHART_URI', '//chart.googleapis.com/chart');

/*
 * Chart types.
 */
define('CHART_TYPE_LINE', 'lc');
define('CHART_TYPE_LINE_NO_AXIS', 'ls');
define('CHART_TYPE_LINE_XY', 'lxy');
define('CHART_TYPE_BAR_H', 'bhs');
define('CHART_TYPE_BAR_V', 'bvs');
define('CHART_TYPE_BAR_H_GROUPED', 'bhg');
define('CHART_TYPE_BAR_V_GROUPED', 'bvg');
define('CHART_TYPE_PIE', 'p');
define('CHART_TYPE_PIE_3D', 'p3');
define('CHART_TYPE_PIE_CONCENTRIC', 'pc');
define('CHART_TYPE_VENN', 'v');
define('CHART_TYPE_SCATTER', 's');
define('CHART_TYPE_MAP', 't');
define('CHART_TYPE_RADAR', 'r');
define('CHART_TYPE_RADAR_FILLED', 'rs');
define('CHART_TYPE_GMETER', 'gom');
define('CHART_TYPE_QR', 'qr');

/*
 * Marker types.
 */
define('CHART_MARKER_ARROW', 'a');
define('CHART_MARKER_CROSS', 'c');
define('CHART_MARKER_DIAMOND', 'd');
define('CHART_MARKER_CIRCLE', 'o');
define('CHART_MARKER_SQUARE', 's');
define('CHART_MARKER_VERTICAL_LINE_X', 'v');
define('CHART_MARKER_VERTICAL_LINE_TOP', 'V');
define('CHART_MARKER_HORIZONTAL_LINE', 'h');
define('CHART_MARKER_X', 'x');

/*
 * Axis.
 */
define('CHART_AXIS_X_BOTTOM', 'x');
define('CHART_AXIS_X_TOP', 't');
define('CHART_AXIS_Y_LEFT', 'y');
define('CHART_AXIS_Y_RIGHT', 'r');

/**
 * Alignment.
 */
define('CHART_ALIGN_LEFT', -1);
define('CHART_ALIGN_CENTER', 0);
define('CHART_ALIGN_RIGHT', 1);

/**
 * Legend Position
 */
define('CHART_LEGEND_BOTTOM', 'b');
define('CHART_LEGEND_TOP', 't');
define('CHART_LEGEND_BOTTOM_VERTICAL', 'bv');
define('CHART_LEGEND_TOP_VERTICAL', 'tv');
define('CHART_LEGEND_RIGHT', 'r');
define('CHART_LEGEND_LEFT', 'l');

/*-----------------------------------------------------------------
 * Hook Implementations
 *------------------------------------------------------------------*/

/**
 * Implements hook_permission().
 */
function chart_permission() {
  return array(
    'administer chart' => array(
      'title' => t('Administer chart'),
      'description' => t('Modify chart settings.'),
    ),
  );
}

/**
 * Implements hook_menu().
 */
function chart_menu() {
  $items = array();

  $items['admin/config/media/chart'] = array(
    'title' => 'Chart',
    'description' => 'Modify chart settings.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('chart_settings'),
    'access arguments' => array('administer chart'),
  );

  return $items;
}

/**
 * Implements hook_theme().
 */
function chart_theme($existing, $type, $theme, $path) {
  return array(
    'chart' => array(
      'render element' => 'chart',
    ),
  );
}

/*-----------------------------------------------------------------
 * Public API
 *------------------------------------------------------------------*/

/**
 * Renders a chart element.
 *
 * @param $variables
 *   An associative array containing:
 *   - chart: An associative array definining a chart.
 */
function theme_chart($variables) {
  $chart = $variables['chart'];
  if (chart_build($chart)) {
    $chart['#attributes']['id'] = 'chart-' . $chart['#chart_id'];
    $chart['#attributes']['class'][] = 'chart';

    return theme('image', array('path' => chart_url($chart), 'attributes' => $chart['#attributes'], 'alt' => $chart['#title'] ? $chart['#title'] : t('Chart')));
  }
  return '';
}

/**
 * Returns the chart URL.
 *
 * @param array $chart
 *
 * @return mixed
 *   - Success: Chart image markup
 *    - Failure: FALSE
 */
function chart_url($chart) {
  if ($data = chart_build($chart)) {
    return url(CHART_URI, array('query' => $data, 'external' => TRUE));
  }
  return FALSE;
}


/**
 * Copies rendered chart image.
 *
 * @param array $chart
 *   Chart API structure
 *
 * @param string $name
 *   (optional) Filename WITHOUT extension.
 *   when NULL #chart_id is used.
 *
 * @param string $dest
 *   (optional) A string containing the path to verify. If this value is
 *   omitted, Drupal's 'files/charts' directory will be used.
 *
 * @param string $replace
 *   (optional) Replace behavior when the destination file already exists.
 *     - FILE_EXISTS_REPLACE: Replace the existing file
 *     - FILE_EXISTS_RENAME: Appends _{incrementing number} until the filename is unique
 *     - FILE_EXISTS_ERROR: Do nothing and return FALSE.
 *
 * @return bool/string
 *   Returns FALSE on failure, and file path on success.
 */
function chart_copy($chart, $name = NULL, $dest = 'charts', $replace = FILE_EXISTS_REPLACE) {
  if (!chart_build($chart)) {
    return FALSE;
  }

  if ($dest = file_create_path($dest)) {
    if (file_prepare_directory($dest, FILE_CREATE_DIRECTORY)) {
      // Defaults
      $name = is_null($name) ? $chart['#chart_id'] : $name;

      // Generate temp image
      $tempname = tempnam(file_directory_temp(), 'tmp_');
      $filename = file_create_path($dest) . '/' . $name . '.png';
      $png      = imagecreatefrompng(chart_url($chart));
      $fh       = fopen($tempname, 'w+');
      imagepng($png, $tempname);

      // Copy temp image to new location
      if (!file_copy($tempname, $filename, $replace)) {
        _chart_error(t('Failed to copy chart image.'));
        return FALSE;
      }

      // Remove temp image
      fclose($fh);
    }
    return $filename;
  }

  return FALSE;
}

/**
 * Build chart query data.
 *
 * @param $chart
 *   An associative array defining a chart which may contain the following
 *   keys.
 *   - #chart_id: Unique chart indentifier.
 *   - #type: (cht) The chart type, see chart_types().
 *   - #data: An array of data.
 *   - #title: (chtt) (Optional) The chart title.
 *   - #size: (chs) (Optional) An associative array containing keys: #width and
 *       #height.
 *   - #legends: (chdl) (Optional) An array of legends.
 *   - #legend_position: (chdlp) (Optional) ...
 *   - #labels: (chl) (Optional) An array of labels.
 *   - #adjust_resolution: (Optional) TRUE if the resolution of data should be
 *       automatically adjusted, an associative array containing #adjust which
 *       should be equal to previous description and #max to adjust data by.
 *   - #line_styles: (chls) (Optional) An array of line styles.
 *   - #grid_lines: (chg) (Optional) An array of grid line information.
 *   - #shape_markers: (chm) (Optional) A single or an array of shape markers.
 *   - #data_colors: (chco) (Optional) An array of data colors.
 *   - #chart_fill: (chf) (Optional) A single or an array of chart fill colors.
 *   - #mixed_axis_labels: (chxt) (Optional) An array of mixed axis labels.
 *   - #mixed_axis_label_styles: (chxs) (Optional) An array of mixed axis label
 *       styles.
 *   - #bar_size: (chbh) (Optional) 'a' for automatic, 'r' for relative, or an
         array using keys: #size and #spacing.
 *   - #countries: (chld) (Optional) An array of countries.
 *   - #georange: (chtm) (Optional) The geographical scope.
 *
 * @return mixed
 *   Associative array of query data, otherwise FALSE.
 * @see _chart_append()
 */
function chart_build($chart) {
  $charts = &drupal_static(__FUNCTION__, array());

  if (empty($chart['#chart_id'])) {
    trigger_error('Charts must provide a #chart_id.', E_USER_ERROR);
    return FALSE;
  }
  // Hide charts with no data.
  if (empty($chart['#data'])) {
    return FALSE;
  }

  // If the chart has not been built then proceed to build it.
  if (!isset($charts[$chart['#chart_id']])) {
    // Merge optional parameters defaults.
    $chart += array(
      '#title' => '',
      '#size' => '',
      '#legends' => array(),
      '#legend_position' => '',
      '#labels' => array(),
      '#adjust_resolution' => FALSE,
      '#line_styles' => array(),
      '#grid_lines' => array(),
      '#shape_markers' => array(),
      '#data_colors' => array(),
      '#chart_fill' => array(),
      '#mixed_axis_labels' => array(),
      '#mixed_axis_label_styles' => array(),
      '#bar_size' => '',
      '#countries' => array(),
      '#georange' => '',
    );

    // Allow modules to alter a chart after defaults have been added.
    drupal_alter('chart', $chart);

    // Adjust resolution if option is enabled.
    if (!empty($chart['#adjust_resolution'])) {
      if ($chart['#adjust_resolution'] === TRUE) {
        _chart_adjust_resolution($chart['#chart_id'], $chart['#data']);
      }
      elseif ($chart['#adjust_resolution']['#adjust'] == TRUE) {
        _chart_adjust_resolution($chart['#chart_id'], $chart['#data'], $chart['#adjust_resolution']['#max']);
      }
    }

    $data = array();
    $data['chd'] = 't:' . _chart_encode_data($chart['#data']);

    _chart_append('cht',   $chart['#type'],                    $data);
    _chart_append('chs',   $chart['#size'],                    $data);
    _chart_append('chtt',  $chart['#title'],                   $data);
    _chart_append('chl',   $chart['#labels'],                  $data);
    _chart_append('chdl',  $chart['#legends'],                 $data);
    _chart_append('chdlp', $chart['#legend_position'],         $data);
    _chart_append('chls',  $chart['#line_styles'],             $data);
    _chart_append('chg',   $chart['#grid_lines'],              $data);
    _chart_append('chm',   $chart['#shape_markers'],           $data);
    _chart_append('chco',  $chart['#data_colors'],             $data);
    _chart_append('chf',   $chart['#chart_fill'],              $data);
    _chart_append('chxt',  $chart['#mixed_axis_labels'],       $data);
    _chart_append('chxs',  $chart['#mixed_axis_label_styles'], $data);
    _chart_append('chbh',  $chart['#bar_size'],                $data);
    _chart_append('chld',  $chart['#countries'],               $data);
    _chart_append('chtm',  $chart['#georange'],                $data);

    $charts[$chart['#chart_id']] = $data;
  }
  return $charts[$chart['#chart_id']];
}

/*-----------------------------------------------------------------
 * Page Callbacks
 *------------------------------------------------------------------*/

/**
 * Settings form page callback handler.
 */
function chart_settings($form, &$form_state) {
  $form['overrides'] = array(
    '#type' => 'fieldset',
    '#title' => t('Overrides'),
    '#collapsible' => TRUE,
    '#collapsed' => FALSE,
  );
  // @todo: overrides global / per theme
  $form['overrides']['chart_global_bg'] = array(
    '#type' => 'textfield',
    '#title' => t('Global Background Color'),
    '#description' => t('Specify a global background color for all charts. When set this will take precedence over any custom value which is useful for highly themed sites.'),
    '#default_value' => variable_get('chart_global_bg', ''),
  );
  $form['overrides']['chart_max_width'] = array(
    '#type' => 'textfield',
    '#title' => t('Max Width'),
    '#description' => t('Max chart width.'),
    '#default_value' => variable_get('chart_max_width', ''),
  );
  $form['overrides']['chart_max_height'] = array(
    '#type' => 'textfield',
    '#title' => t('Max Height'),
    '#description' => t('Max chart height.'),
    '#default_value' => variable_get('chart_max_height', ''),
  );

  return system_settings_form($form);
}


/**
 * Settings page validation.
 */
function chart_settings_validate($form, &$form_state) {
  if (!empty($form_state['values']['chart_global_bg']) && !preg_match('/[a-fA-F0-9]{6}/is', $form_state['values']['chart_global_bg'])) {
    form_set_error('chart_global_bg', t('Invalid color. Formatted as RRGGBB with no pound sign.'));
  }
  if (!empty($form_state['values']['chart_max_width']) && !is_numeric($form_state['values']['chart_max_width'])) {
    form_set_error('chart_max_width', t('Width must be an integer.'));
  }
  if (!empty($form_state['values']['chart_max_height']) && !is_numeric($form_state['values']['chart_max_height'])) {
    form_set_error('chart_max_height', t('Height must be an integer.'));
  }
}

/*-----------------------------------------------------------------
 * Helpers
 *------------------------------------------------------------------*/

/**
 * Encode an array of data.
 *
 * Missing data placeholder 'NULL' is replaced
 * the appropriate placeholder.
 *
 * @return string
 */
function _chart_encode_data($data) {
  $output = '';
  if (count($data)) {
    foreach ($data as $k => $v) {
      if (is_array($v) || is_object($v)) {
        $output .= '|';
        $output .= _chart_encode_data($v);
      }
      else {
        if (is_numeric($v)) {
          $output .= $v . ',';
        }
        else {
          $output .= '-1,';
        }
      }
    }
  }

  return trim($output, '|,');
}

/**
 * Adjusts chart data transforming values so that they may
 * be represented properly within the given resolution
 * for the selected encoding type.
 */
function _chart_adjust_resolution($chart_id, &$data, $max_value = NULL) {
  $max = &drupal_static(__FUNCTION__, array());

  if (count($data)) {
    // Set max data value
    if (!isset($max[$chart_id])) {
      $max[$chart_id] = isset($max_value) ? $max_value : _chart_get_max($data);
      $max[$chart_id] += $max[$chart_id] * 0.05; // Add a margin.
    }

    // Encoding resolution
    $resoluton = 100;

    // When the max is larger than the resolution
    // we need to scale down the values
    if ($max[$chart_id] > $resoluton) {
      $divider = $max[$chart_id] / $resoluton;
    }
    elseif ($max[$chart_id] > 0) {
      $multiplier = $resoluton / $max[$chart_id];
    }

    foreach ($data as $k => $v) {
      if (is_array($v)) {
        _chart_adjust_resolution($chart_id, $data[$k]);
      }
      else {
        if (is_numeric($v)) {
          // Adjust values
          if ($v >= $max) {
            $data[$k] = $resoluton;
          }
          else {
            // Multiply or divide data values to adjust them to the resolution
            if (isset($divider)) {
              $data[$k] = floor($v / $divider);
            }
            elseif (isset($multiplier)) {
              $data[$k] = floor($v * $multiplier);
            }
            else {
              $data[$k] = $v;
            }
          }
        }
      }
    }
  }
}

/**
 * When the value passed is valid append a chart API
 * attribute and parsed values to $data.
 */
function _chart_append($attr, $value, &$data) {
  // Size and fill contain defaults, all other attributes must be set
  if (!$value && $attr != 'chs' && $attr != 'chf') {
    return;
  }

  switch ($attr) {
    // Type
    case 'cht':
      $data[$attr] = $value;
      break;

      // Size
    case 'chs':
      if (_chart_is_valid_size($value)) {
        $width  = $value['#width'];
        $height = $value['#height'];
      }
      else {
        $width  = 300;
        $height = 150;
      }
      _chart_override_aspect($width, $height);
      $data[$attr] = $width . 'x' . $height;
      break;

      // Labels
    case 'chl':
      $data[$attr] = implode('|', $value);
      break;

      // Color
    case 'chco':
      $data[$attr] = implode(',', $value);
      break;

      // Chart and background fill
    case 'chf':
      if (variable_get('chart_global_bg', FALSE) || !isset($value)) {
        $data[$attr] = implode(',', chart_fill('bg', trim(variable_get('chart_global_bg', 'FFFFFF'), '#')));
      }
      else {
        $data[$attr] = implode(',', $value);
      }
      break;

      // Chart title
    case 'chtt':
      if (is_array($value)) {
        $data[$attr]   = $value['#title'];
        if (!isset($data['chts'])) {
          $data['chts'] = '';
        }
        $data['chts'] .= isset($value['#color']) ? $value['#color'] : '000000';
        $data['chts'] .= ',';
        $data['chts'] .= isset($value['#size']) ? $value['#size'] : 14;
      }
      else {
        $data[$attr] = $value;
      }
      break;

    default:

      // Legends
    case 'chdl':
      $data[$attr] = implode('|', $value);
      break;

      // Legend's position
    case 'chdlp':
      $data[$attr] = $value;
      break;

      // Line styles
    case 'chls':
      $styles = array();

      if (count($value)) {
        foreach ($value as $k => $v) {
          $tmp_style = array();

          if (!is_array($v)) {
            // Style parameters
            $tmp_style[] = $v;
          }
          else {
            // Array of styles
            $styles[] = implode(',', $v);
          }

          if (count($tmp_style)) {
            $styles[] = implode(',', $tmp_style);
          }
        }
      }

      if (count($styles)) {
        $data[$attr] = implode('|', $styles);
      }
      break;

      // Grid lines
    case 'chg':
      $data[$attr] = implode(',', $value);
      break;

      // Shape markers
    case 'chm':
      if (count($value)) {
        $markers = array();
        foreach ($value as $marker) {
          $markers[] = implode(',', $marker);
        }
        $data[$attr] = implode('|', $markers);
      }
      else {
        $data[$attr] = implode(',', $value);
      }
      break;

      // Bar chart bar sizing
    case 'chbh':
      if (!isset($data[$attr])) {
        $data[$attr] = '';
      }
      //If not array, use as is.
      if (!is_array($value)) {
        $data[$attr] .= $value;
      }
      else {
        $data[$attr] .= implode(',', array($value['#size'], $value['#spacing']));
      }
      break;

      // Mixed axis positions, labels and styles
      // @todo: refactor
    case 'chxt':
      $index     = 0;
      $positions = array();
      $types     = array();
      $regular   = array();

      // Seperate regular labels and generate range labels
      if (count($value)) {
        foreach ($value as $axis => $indices) {
          if (count($indices)) {
            ksort($indices);
            foreach ($indices as $i => $labels) {
              if (count($labels)) {
                foreach ($labels as $j => $label) {
                  // Regular
                  if (isset($label['#label'])) {
                    // Array of labels
                    if (is_array($label['#label'])) {
                      foreach ($label['#label'] as $l) {
                        $regular[$axis][$i][] = is_array($l) ? $l : array('#label' => $l, '#position' => NULL);
                      }
                    }
                    else {
                      $regular[$axis][$i][] = $label;
                    }
                  }
                  // Range
                  elseif (isset($label['#start']) && isset($label['#end'])) {
                    if (!isset($data['chxr'])) {
                      $data['chxr'] = '';
                    }

                    $data['chxr'] .= $index . ',' . $label['#start'] . ',' . $label['#end'] . '|';
                    $types[] = $axis;
                    $index++;
                  }
                }
              }
            }
          }
        }
      }
      // Generate regular labels
      if (count($regular)) {
        foreach ($regular as $axis => $indices) {
          if (count($indices)) {
            if (!isset($data['chxl'])) {
              $data['chxl'] = '';
            }
            foreach ($indices as $i => $labels) {
              $types[] = $axis;
              $data['chxl'] .= $index . ':';
              if (count($labels)) {
                foreach ($labels as $j => $label) {
                  $data['chxl'] .= '|' . $label['#label'];
                  $positions[$index]['data'][] = isset($label['#position']) ? $label['#position'] : 0;
                  if ($label['#position']) {
                    $positions[$index]['set'] = TRUE;
                  }
                }
              }
              $data['chxl'] .= '|';
              $index++;
            }
          }
        }
      }
      // Generate positions
      if (count($positions)) {
        foreach ($positions as $i => $position) {
          if (isset($position['set']) && $position['set'] == TRUE) {
            if (!isset($data['chxp'])) {
              $data['chxp'] = '';
            }
            $data['chxp'] .= $i . ',' . implode(',', $position['data']) .  '|';
          }
        }
      }

      $data['chxt'] = implode(',', $types);
      $data['chxl'] = isset($data['chxl']) ? rtrim($data['chxl'], '|') : '';
      $data['chxr'] = isset($data['chxr']) ? rtrim($data['chxr'], '|') : '';
      $data['chxp'] = isset($data['chxp']) ? rtrim($data['chxp'], '|') : '';
      break;

      // Mixed axis label styles
    case 'chxs':
      if (count($value)) {
        $styles = array();
        foreach ($value as $i => $style) {
          $styles[] = implode(',', $style);
        }
        $data[$attr] = implode('|', $styles);
      }
      break;

      // Geographical Scope
    case 'chtm':
      $data[$attr] = $value;
      break;

      // Country List
    case 'chld':
      $data[$attr] = implode('', $value);
      break;
  }
}

/**
 * Return the max value of a single level array.
 */
function _chart_get_max($array) {
  rsort($array, SORT_NUMERIC);
  $max = is_array($array[0]) ? 1 : $array[0];

  if (count($array)) {
    foreach ($array as $k => $v) {
      if (is_array($v)) {
        rsort($v, SORT_NUMERIC);
        if ($v[0] > $max) {
          $max = $v[0];
        }
      }
    }
  }

  return $max;
}

/**
 * Override the default chart aspect ratio.
 */
function _chart_override_aspect(&$width, &$height) {
  $decrement  = 20;
  $max_width  = variable_get('chart_max_width',   FALSE);
  $max_height = variable_get('chart_max_height', FALSE);

  if (!$max_width && !$max_height) {
    return;
  }

  // Width
  if ($max_width) {
    while ($width > $max_width) {
      $width  -= $decrement;
      $height -= $decrement;
    }
  }
  // Height
  if ($max_height) {
    while ($height > $max_height) {
      $width  -= $decrement;
      $height -= $decrement;
    }
  }
}

/**
 * Admin error.
 */
function _chart_error($message, $admin = TRUE) {
  if ($admin) {
    if (user_access('administer chart')) {
      drupal_set_message(t('Chart API error: ') . $message, 'error');
    }
  }
  else {
    drupal_set_message($message, 'error');
  }
}

/**
 * Check if chart data is below size limit.
 */
function _chart_is_valid_size($size) {
  if (!empty($value)) {
    return FALSE;
  }
  if (!is_numeric($size['#width']) && !is_numeric($size['#height'])) {
    return FALSE;
  }

  if (($size['#width'] * $size['#height']) >= 300000) {
    watchdog('chart', '#width X #height of chart is greater than or equal to 300,000 pixels, chart size set to default.');
    return FALSE;
  }

  return TRUE;
}

/**
 * Get the available color schemes.
 *
 * @see hook_chart_color_schemes()
 * @see hook_chart_color_schemes_alter()
 */
function chart_color_schemes() {
  $schemes = &drupal_static(__FUNCTION__);

  if (!$schemes) {
    // Allow modules to define color schemes.
    $schemes = module_invoke_all('chart_color_schemes');

    // Provide the default color scheme.
    $schemes['default'] = array(
      'FF8000',
      'FFC080',
      'FFDFBF',
      'FFC080',
      'FFCC00',
      'FFE500',
      'FFF9BF',
      '78c0e9',
      '179ce8',
      '30769e',
      'c8e9fc',
      'ecf8ff',
      '00ccff',
      '4086AA',
      '91C3DC',
      '87907D',
      'AAB6A2',
      '555555',
      '666666',
      '21B6A8',
      '177F75',
      'B6212D',
      '7F171F',
      'B67721',
      '7F5417',
    );

    // Allow modules to alter color schemes.
    drupal_alter('chart_color_schemes', $schemes);
  }
  return $schemes;
}

/*-----------------------------------------------------------------
 * Label Utils
 *------------------------------------------------------------------*/

/**
 * Title
 *
 * @param string $title
 *
 * @param string $color
 *
 * @param int $size
 *
 * @return array
 */
function chart_title($title, $color = '000000', $size = 14) {
  return array(
      '#title' => $title,
      '#color' => $color,
      '#size'  => $size,
    );
}

/**
 * Create a mixed axis label.
 *
 * Labels must be nested by axis and index:
 * @code
 *   $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][0][] = chart_mixed_axis_label(t('Monday'));
 *   $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][0][] = chart_mixed_axis_label(t('Tuesday'));
 *   $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][0][] = chart_mixed_axis_label(t('Wednesday'));
 *   $chart['#mixed_axis_labels'][CHART_AXIS_Y_LEFT][1][] = chart_mixed_axis_range_label(0, 50);
 *   $chart['#mixed_axis_labels'][CHART_AXIS_Y_LEFT][2][] = chart_mixed_axis_label(t('Min'));
 *   $chart['#mixed_axis_labels'][CHART_AXIS_Y_LEFT][2][] = chart_mixed_axis_label(t('Max'));
 * @endcode
 *
 * @param mixed $label
 *   - string: A single label
 *   - array: An array of label strings, or an assoc array containing #label and #position
 *
 * @param int $position
 *   (optional) An integer between 0 - 100 representing where the label should appear along the axis.
 *   0 representing bottom and left, 100 representing top and right. When one label within a given set
 *   is given a position, the remaining labels in the set must have a position.
 *
 * @return array
 */
function chart_mixed_axis_label($label, $position = NULL) {
  return array(
    '#label'    => $label,
    '#position' => $position,
  );
}

/**
 * Create a mixed axis range label.
 *
 * Labels must be nested by axis and index:
 * @code
 *   $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][0][] = chart_mixed_axis_label(t('Monday'));
 *   $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][0][] = chart_mixed_axis_label(t('Tuesday'));
 *   $chart['#mixed_axis_labels'][CHART_AXIS_X_BOTTOM][0][] = chart_mixed_axis_label(t('Wednesday'));
 *   $chart['#mixed_axis_labels'][CHART_AXIS_Y_LEFT][1][] = chart_mixed_axis_range_label(0, 50);
 *   $chart['#mixed_axis_labels'][CHART_AXIS_Y_LEFT][2][] = chart_mixed_axis_label(t('Min'));
 *   $chart['#mixed_axis_labels'][CHART_AXIS_Y_LEFT][2][] = chart_mixed_axis_label(t('Max'));
 * @endcode
 *
 * @param string $start
 *
 * @param string $end
 *
 * @return array
 */
function chart_mixed_axis_range_label($start, $end) {
  return array(
    '#start' => $start,
    '#end'   => $end,
  );
}

/**
 * Create a mixed axis for a corresponding label set index.
 *
 * @param int $index
 *
 * @param string $color
 *
 * @param int $font_size
 *
 * @param int $alignment
 *   - CHART_ALIGN_LEFT
 *   - CHART_ALIGN_CENTER
 *   - CHART_ALIGN_RIGHT
 *
 * @return array
 */
function chart_mixed_axis_label_style($index, $color, $font_size = 12, $alignment = CHART_ALIGN_CENTER) {
  return array(
    '#index'     => $index,
    '#color'     => $color,
    '#font_size' => $font_size,
    '#alignment' => $alignment,
  );
}

/*-----------------------------------------------------------------
 * Style Utils
 *------------------------------------------------------------------*/

/**
 * Chart size
 *
 * @return array
 */
function chart_size($width, $height) {
  return array(
    '#width'  => $width,
    '#height' => $height
  );
}

/**
 * Data Colors
 *
 * @param array $colors
 *
 * @return array
 */
function chart_data_colors($colors) {
  return $colors;
}

/**
 * Line Style
 *
 * @param int $line_thickness
 *
 * @param int $segment_length
 *
 * @param int $blank_segment_length
 *
 * @return array
 */
function chart_line_style($line_thickness = 1, $segment_length = 1, $blank_segment_length = 0) {
  return array(
    '#line_thickness'       => $line_thickness,
    '#segment_length'       => $segment_length,
    '#blank_segment_length' => $blank_segment_length,
  );
}

/**
 * Grid Lines
 *
 * @param int $x_step
 *   Space in pixels in which to step the horizontal lines.
 *
 * @param int $y_step
 *   Space in pixels in which to step the virtical lines.
 *
 * @param int $segment_length
 *   (optional) Visibile segment length in pixels.
 *
 * @param int $blank_segment_length
 *   (optional) Blank segment length in pixels.
 *
 * @return array
 */
function chart_grid_lines($x_step, $y_step, $segment_length = 1, $blank_segment_length = 3) {
  return array(
    '#x_step'               => $x_step,
    '#y_step'               => $y_step,
    '#segment_length'       => $segment_length,
    '#blank_segment_length' => $blank_segment_length,
  );
}

/**
 * Shape Marker
 *
 * @param int $index
 *   (optional) The index of the line on which to draw the marker.
 *
 * @param float $point
 *   (optional) Floating point value that specifies on which data point
 *   the marker will be drawn.
 *
 * @param string $type
 *   - CHART_MARKER_ARROW
 *   - CHART_MARKER_CROSS
 *   - CHART_MARKER_DIAMOND
 *   - CHART_MARKER_CIRCLE
 *   - CHART_MARKER_SQUARE
 *   - CHART_MARKER_VERTICAL_LINE_X
 *   - CHART_MARKER_VERTICAL_LINE_TOP
 *   - CHART_MARKER_HORIZONTAL_LINE
 *   - CHART_MARKER_X
 *
 * @param int $size
 *   (optional) Marker size in pixels.
 *
 * @param string $color
 *
 * @return array
 */
function chart_shape_marker($index = 0, $point = 0, $type = 'o', $size = 20, $color = '000000') {
  return array(
    '#type'  => $type,
    '#color' => $color,
    '#index' => $index,
    '#point' => $point,
    '#size'  => $size,
  );
}

/**
 * Range Marker
 *
 * @param int $start
 *
 * @param int $end
 *
 * @param bool $virtical
 *
 * @param string $color
 *
 * @return array
 */
function chart_range_marker($start, $end, $virtical = TRUE, $color = '000000') {
  return array(
    '#start'    => $start,
    '#end'      => $end,
    '#virtical' => $virtical,
    '#color'    => $color,
  );
}

/**
 * Bar chart bar sizing.
 *
 * @param int $size
 *   (optional) Height or width of the bar.
 *
 * @param int $spacing
 *   (optional) Pixel spacing between bars.
 *
 * @return array
 */
function chart_bar_size($size = 40, $spacing = 20) {
  return array(
    '#size'    => $size,
    '#spacing' => $spacing,
  );
}

/**
 * Solid Fill
 *
 * @param int $type
 *   (optional) 'bg' or 'c'
 *
 * @param string $color
 *
 * @return array
 */
function chart_fill($type = 'c', $color = '000000') {
  return array(
    '#type'      => $type,
    '#fill_type' => 's',
    '#color'     => $color,
  );
}

/**
 * Linear Gradient
 *
 * @param int $type
 *   (optional) 'bg' or 'c'
 *
 * @param int $color
 *
 * @param int $offset
 *   (optional) Cpecify at what point the color is pure where: 0 specifies the right-most
 *   chart position and 1 the left-most.
 *
 * @return array
 */
function chart_linear_gradient($type = 'c', $color = '000000', $offset = 0) {
  return array(
    '#type'      => $type,
    '#fill_type' => 'lg',
    '#color'     => $color,
  );
}

/**
 * Linear Stripes
 *
 * @param int $type
 *   (optional) 'bg' or 'c'
 *
 * @param int $color
 *
 * @param int $angle
 *   (optional) Specifies the angle of the gradient between 0 (horizontal) and 90 (vertical).
 *
 * @param float $width
 *   (optional) Must be between 0 and 1 where 1 is the full width of the chart. Stripes are
 *   repeated until the chart is filled.
 *
 * @return array
 */
function chart_linear_stripes($type = 'c', $color = '000000', $angle = 0, $width = 0.25) {
  return array(
    '#type'      => $type,
    '#fill_type' => 'ls',
    '#angle'     => $angle,
    '#color'     => $color,
    '#width'     => $width,
  );
}

/*-----------------------------------------------------------------
 * Color Schemes
 *------------------------------------------------------------------*/

/**
 * Supplies a unique color.
 *
 * When an assoc array color scheme is provided
 * $content_id can be used to sync the color to
 * the data rendered. Otherwise the next available
 * color in the stack is assigned to $content_id
 *
 * @param string $content_id
 *
 * @param string $scheme
 *   (optional) Color scheme.
 *
 * @return string
 *   hex RGB value
 */
function chart_unique_color($content_id, $scheme = 'default') {
  $colors_used = &drupal_static(__FUNCTION__);
  $colors = chart_color_schemes();

  // Revert to default color schema if $schema has not been registered.
  if (!isset($colors[$scheme])) {
    $scheme = 'default';
  }

  // Associative color is available
  if (isset($colors[$scheme][$content_id])) {
    return $colors[$scheme][$content_id];
  }
  // The content_id has already been mapped
  elseif (isset($colors_used[$scheme][$content_id])) {
    return $colors_used[$scheme][$content_id];
  }
  else {
    // No used colors yet use the first one in the scheme
    // and map it to the content id
    if (!is_array($colors_used)) {
      $colors_used[$scheme][$content_id] = array_shift($colors[$scheme]);

      return $colors_used[$scheme][$content_id];
    }
    // Get the avilable colors left in the scheme
    // and map the remaining colors that are used
    else {
      $available_colors = array_diff($colors[$scheme], (array) $colors_used[$scheme]);
      $colors_used[$scheme][$content_id] = array_shift($available_colors);

      return $colors_used[$scheme][$content_id];
    }
  }

  return '000000';
}

/**
 * Get a map of chart types to human-readable names.
 *
 * @return
 *   An associative array of chart types.
 */
function chart_types() {
  return array(
    CHART_TYPE_LINE => t('Line'),
    CHART_TYPE_LINE_NO_AXIS => t('Line - no axis'),
    CHART_TYPE_LINE_XY => t('Line - XY'),
    CHART_TYPE_BAR_H => t('Bar - Horizontal'),
    CHART_TYPE_BAR_V => t('Bar - Vertical'),
    CHART_TYPE_BAR_H_GROUPED => t('Bar - Grouped Horizontal'),
    CHART_TYPE_BAR_V_GROUPED => t('Bar - Grouped Vertical'),
    CHART_TYPE_PIE => t('Pie'),
    CHART_TYPE_PIE_3D => t('Pie - 3D'),
    CHART_TYPE_PIE_CONCENTRIC => t('Pie - Concentric'),
    CHART_TYPE_VENN => t('Venn Diagram'),
    CHART_TYPE_SCATTER => t('Scatter plot'),
    CHART_TYPE_MAP => t('Map'),
    CHART_TYPE_RADAR => t('Radar'),
    CHART_TYPE_RADAR_FILLED => t('Radar - filled'),
    CHART_TYPE_GMETER => t('Goole-o-meter'),
    CHART_TYPE_QR => t('QR code'),
  );
}