<?php
/**
 * @package dompdf
 * @link    http://dompdf.github.com/
 * @author  Benj Carson <benjcarson@digitaljunkies.ca>
 * @license http://www.gnu.org/copyleft/lesser.html GNU Lesser General Public License
 */

/**
 * Maps table cells to the table grid.
 *
 * This class resolves borders in tables with collapsed borders and helps
 * place row & column spanned table cells.
 *
 * @access private
 * @package dompdf
 */
class Cellmap {

  /**
   * Border style weight lookup for collapsed border resolution.
   *
   * @var array
   */
  static protected $_BORDER_STYLE_SCORE = array(
    "inset"  => 1,
    "groove" => 2,
    "outset" => 3,
    "ridge"  => 4,
    "dotted" => 5,
    "dashed" => 6,
    "solid"  => 7,
    "double" => 8,
    "hidden" => 9,
    "none"   => 0,
   );

  /**
   * The table object this cellmap is attached to.
   *
   * @var Table_Frame_Decorator
   */
  protected $_table;

  /**
   * The total number of rows in the table
   *
   * @var int
   */
  protected $_num_rows;

  /**
   * The total number of columns in the table
   *
   * @var int
   */
  protected $_num_cols;

  /**
   * 2D array mapping <row,column> to frames
   *
   * @var Frame[][]
   */
  protected $_cells;

  /**
   * 1D array of column dimensions
   *
   * @var array
   */
  protected $_columns;

  /**
   * 1D array of row dimensions
   *
   * @var array
   */
  protected $_rows;

  /**
   * 2D array of border specs
   *
   * @var array
   */
  protected $_borders;

  /**
   * 1D Array mapping frames to (multiple) <row, col> pairs, keyed on frame_id.
   *
   * @var Frame[]
   */
  protected $_frames;

  /**
   * Current column when adding cells, 0-based
   *
   * @var int
   */
  private $__col;

  /**
   * Current row when adding cells, 0-based
   *
   * @var int
   */
  private $__row;
  
  /**
   * Tells wether the columns' width can be modified
   *
   * @var bool
   */
  private $_columns_locked = false;
  
  /**
   * Tells wether the table has table-layout:fixed
   *
   * @var bool
   */
  private $_fixed_layout = false;

  //........................................................................

  function __construct(Table_Frame_Decorator $table) {
    $this->_table = $table;
    $this->reset();
  }
  
  function __destruct() {
    clear_object($this);
  }
  //........................................................................

  function reset() {
    $this->_num_rows = 0;
    $this->_num_cols = 0;

    $this->_cells  = array();
    $this->_frames = array();

    if ( !$this->_columns_locked ) {
      $this->_columns = array();
    }
    
    $this->_rows = array();

    $this->_borders = array();

    $this->__col = $this->__row = 0;
  }

  //........................................................................

  function lock_columns() { 
    $this->_columns_locked = true; 
  }

  function is_columns_locked() {
    return $this->_columns_locked;
  }
  
  function set_layout_fixed($fixed) { 
    $this->_fixed_layout = $fixed; 
  }

  function is_layout_fixed() {
    return $this->_fixed_layout;
  }
  
  function get_num_rows() { return $this->_num_rows; }
  function get_num_cols() { return $this->_num_cols; }

  function &get_columns() {
    return $this->_columns;
  }

  function set_columns($columns) {
    $this->_columns = $columns;
  }

  function &get_column($i) {
    if ( !isset($this->_columns[$i]) ) {
      $this->_columns[$i] = array(
        "x" => 0,
        "min-width" => 0,
        "max-width" => 0,
        "used-width" => null,
        "absolute" => 0,
        "percent" => 0,
        "auto" => true,
      );
    }
    
    return $this->_columns[$i];
  }

  function &get_rows() {
    return $this->_rows;
  }

  function &get_row($j) {
    if ( !isset($this->_rows[$j]) ) {
      $this->_rows[$j] = array(
        "y" => 0,
        "first-column" => 0,
        "height" => null,
      );
    }
    
    return $this->_rows[$j];
  }

  function get_border($i, $j, $h_v, $prop = null) {
    if ( !isset($this->_borders[$i][$j][$h_v]) ) {
      $this->_borders[$i][$j][$h_v] = array(
        "width" => 0,
        "style" => "solid",
        "color" => "black",
      );
    }
    
    if ( isset($prop) ) {
      return $this->_borders[$i][$j][$h_v][$prop];
    }
    
    return $this->_borders[$i][$j][$h_v];
  }

  function get_border_properties($i, $j) {
    return array(
      "top"    => $this->get_border($i,   $j,   "horizontal"), 
      "right"  => $this->get_border($i,   $j+1, "vertical"),
      "bottom" => $this->get_border($i+1, $j,   "horizontal"), 
      "left"   => $this->get_border($i,   $j,   "vertical"),
    );
  }

  //........................................................................

  function get_spanned_cells(DP_Frame $frame) {
    $key = $frame->get_id();

    if ( !isset($this->_frames[$key]) ) {
      throw new DOMPDF_Exception("Frame not found in cellmap");
    }

    return $this->_frames[$key];

  }

  function frame_exists_in_cellmap(DP_Frame $frame) {
    $key = $frame->get_id();
    return isset($this->_frames[$key]);
  }
  
  function get_frame_position(DP_Frame $frame) {
    global $_dompdf_warnings;

    $key = $frame->get_id();

    if ( !isset($this->_frames[$key]) ) {
      throw new DOMPDF_Exception("Frame not found in cellmap");
    }

    $col = $this->_frames[$key]["columns"][0];
    $row = $this->_frames[$key]["rows"][0];

    if ( !isset($this->_columns[$col])) {
      $_dompdf_warnings[] = "Frame not found in columns array.  Check your table layout for missing or extra TDs.";
      $x = 0;
    }
    else {
      $x = $this->_columns[$col]["x"];
    }

    if ( !isset($this->_rows[$row])) {
      $_dompdf_warnings[] = "Frame not found in row array.  Check your table layout for missing or extra TDs.";
      $y = 0;
    }
    else {
      $y = $this->_rows[$row]["y"];
    }

    return array($x, $y, "x" => $x, "y" => $y);
  }

  function get_frame_width(DP_Frame $frame) {
    $key = $frame->get_id();

    if ( !isset($this->_frames[$key]) ) {
      throw new DOMPDF_Exception("Frame not found in cellmap");
    }

    $cols = $this->_frames[$key]["columns"];
    $w = 0;
    foreach ($cols as $i) {
      $w += $this->_columns[$i]["used-width"];
    }
    
    return $w;
  }

  function get_frame_height(DP_Frame $frame) {
    $key = $frame->get_id();

    if ( !isset($this->_frames[$key]) ) {
      throw new DOMPDF_Exception("Frame not found in cellmap");
    }

    $rows = $this->_frames[$key]["rows"];
    $h = 0;
    foreach ($rows as $i) {
      if ( !isset($this->_rows[$i]) )  {
        throw new Exception("The row #$i could not be found, please file an issue in the tracker with the HTML code");
      }
      
      $h += $this->_rows[$i]["height"];
    }
    
    return $h;
  }


  //........................................................................

  function set_column_width($j, $width) {
    if ( $this->_columns_locked ) {
      return;
    }
    
    $col =& $this->get_column($j);
    $col["used-width"] = $width;
    $next_col =& $this->get_column($j+1);
    $next_col["x"] = $next_col["x"] + $width;
  }

  function set_row_height($i, $height) {
    $row =& $this->get_row($i);
    
    if ( $row["height"] !== null && $height <= $row["height"] ) {
      return;
    }

    $row["height"] = $height;
    $next_row =& $this->get_row($i+1);
    $next_row["y"] = $row["y"] + $height;

  }

  //........................................................................


  protected function _resolve_border($i, $j, $h_v, $border_spec) {
    $n_width = $border_spec["width"];
    $n_style = $border_spec["style"];

    if ( !isset($this->_borders[$i][$j][$h_v]) ) {
      $this->_borders[$i][$j][$h_v] = $border_spec;
      return $this->_borders[$i][$j][$h_v]["width"];
    }
    
    $border = &$this->_borders[$i][$j][$h_v];
    
    $o_width = $border["width"];
    $o_style = $border["style"];

    if ( ($n_style === "hidden" ||
          $n_width  >  $o_width ||
          $o_style === "none")

         or

         ($o_width == $n_width &&
          in_array($n_style, self::$_BORDER_STYLE_SCORE) &&
          self::$_BORDER_STYLE_SCORE[ $n_style ] > self::$_BORDER_STYLE_SCORE[ $o_style ]) ) {
      $border = $border_spec;
    }

    return $border["width"];
  }

  //........................................................................

  function add_frame(DP_Frame $frame) {
    
    $style = $frame->get_style();
    $display = $style->display;

    $collapse = $this->_table->get_style()->border_collapse == "collapse";

    // Recursively add the frames within tables, table-row-groups and table-rows
    if ( $display === "table-row" ||
         $display === "table" ||
         $display === "inline-table" ||
         in_array($display, Table_Frame_Decorator::$ROW_GROUPS) ) {

      $start_row = $this->__row;
      foreach ( $frame->get_children() as $child ) {
        $this->add_frame( $child );
      }

      if ( $display === "table-row" ) {
        $this->add_row();
      }

      $num_rows = $this->__row - $start_row - 1;
      $key = $frame->get_id();

      // Row groups always span across the entire table
      $this->_frames[$key]["columns"] = range(0,max(0,$this->_num_cols-1));
      $this->_frames[$key]["rows"] = range($start_row, max(0, $this->__row - 1));
      $this->_frames[$key]["frame"] = $frame;

      if ( $display !== "table-row" && $collapse ) {

        $bp = $style->get_border_properties();

        // Resolve the borders
        for ( $i = 0; $i < $num_rows+1; $i++) {
          $this->_resolve_border($start_row + $i, 0, "vertical", $bp["left"]);
          $this->_resolve_border($start_row + $i, $this->_num_cols, "vertical", $bp["right"]);
        }

        for ( $j = 0; $j < $this->_num_cols; $j++) {
          $this->_resolve_border($start_row, $j, "horizontal", $bp["top"]);
          $this->_resolve_border($this->__row, $j, "horizontal", $bp["bottom"]);
        }
      }


      return;
    }
    
    $node = $frame->get_node();
    
    // Determine where this cell is going
    $colspan = $node->getAttribute("colspan");
    $rowspan = $node->getAttribute("rowspan");

    if ( !$colspan ) {
      $colspan = 1;
      $node->setAttribute("colspan",1);
    }

    if ( !$rowspan ) {
      $rowspan = 1;
      $node->setAttribute("rowspan",1);
    }
    $key = $frame->get_id();

    $bp = $style->get_border_properties();


    // Add the frame to the cellmap
    $max_left = $max_right = 0;

    // Find the next available column (fix by Ciro Mondueri)
    $ac = $this->__col;
    while ( isset($this->_cells[$this->__row][$ac]) ) {
       $ac++;
    }
    
    $this->__col = $ac;

    // Rows:
    for ( $i = 0; $i < $rowspan; $i++ ) {
      $row = $this->__row + $i;

      $this->_frames[$key]["rows"][] = $row;

      for ( $j = 0; $j < $colspan; $j++) {
        $this->_cells[$row][$this->__col + $j] = $frame;
      }

      if ( $collapse ) {
        // Resolve vertical borders
        $max_left = max($max_left, $this->_resolve_border($row, $this->__col, "vertical", $bp["left"]));
        $max_right = max($max_right, $this->_resolve_border($row, $this->__col + $colspan, "vertical", $bp["right"]));
      }
    }

    $max_top = $max_bottom = 0;

    // Columns:
    for ( $j = 0; $j < $colspan; $j++ ) {
      $col = $this->__col + $j;
      $this->_frames[$key]["columns"][] = $col;

      if ( $collapse ) {
        // Resolve horizontal borders
        $max_top = max($max_top, $this->_resolve_border($this->__row, $col, "horizontal", $bp["top"]));
        $max_bottom = max($max_bottom, $this->_resolve_border($this->__row + $rowspan, $col, "horizontal", $bp["bottom"]));
      }
    }

    $this->_frames[$key]["frame"] = $frame;

    // Handle seperated border model
    if ( !$collapse ) {
      list($h, $v) = $this->_table->get_style()->border_spacing;

      // Border spacing is effectively a margin between cells
      $v = $style->length_in_pt($v) / 2;
      $h = $style->length_in_pt($h) / 2;
      $style->margin = "$v $h";

      // The additional 1/2 width gets added to the table proper
    }
    else {
      // Drop the frame's actual border
      $style->border_left_width = $max_left / 2;
      $style->border_right_width = $max_right / 2;
      $style->border_top_width = $max_top / 2;
      $style->border_bottom_width = $max_bottom / 2;
      $style->margin = "none";
    }

    if ( !$this->_columns_locked ) {
      // Resolve the frame's width
      if ( $this->_fixed_layout ) {
        list($frame_min, $frame_max) = array(0, 10e-10);
      }
      else {
        list($frame_min, $frame_max) = $frame->get_min_max_width();
      }
  
      $width = $style->width;

      $val = null;
      if ( is_percent($width) ) {
        $var = "percent";
        $val = (float)rtrim($width, "% ") / $colspan;
      }
      else if ( $width !== "auto" ) {
        $var = "absolute";
        $val = $style->length_in_pt($frame_min) / $colspan;
      }
      
      $min = 0;
      $max = 0;
      for ( $cs = 0; $cs < $colspan; $cs++ ) {
  
        // Resolve the frame's width(s) with other cells
        $col =& $this->get_column( $this->__col + $cs );
  
        // Note: $var is either 'percent' or 'absolute'.  We compare the
        // requested percentage or absolute values with the existing widths
        // and adjust accordingly.
        if ( isset($var) && $val > $col[$var] ) {
          $col[$var] = $val;
          $col["auto"] = false;
        }
  
        $min += $col["min-width"];
        $max += $col["max-width"];
      }
  
      if ( $frame_min > $min ) {
        // The frame needs more space.  Expand each sub-column
        // FIXME try to avoid putting this dummy value when table-layout:fixed
        $inc = ($this->is_layout_fixed() ? 10e-10 : ($frame_min - $min) / $colspan);
        for ($c = 0; $c < $colspan; $c++) {
          $col =& $this->get_column($this->__col + $c);
          $col["min-width"] += $inc;
        }
      }
  
      if ( $frame_max > $max ) {
        // FIXME try to avoid putting this dummy value when table-layout:fixed
        $inc = ($this->is_layout_fixed() ? 10e-10 : ($frame_max - $max) / $colspan);
        for ($c = 0; $c < $colspan; $c++) {
          $col =& $this->get_column($this->__col + $c);
          $col["max-width"] += $inc;
        }
      }
    }

    $this->__col += $colspan;
    if ( $this->__col > $this->_num_cols )
      $this->_num_cols = $this->__col;

  }

  //........................................................................

  function add_row() {

    $this->__row++;
    $this->_num_rows++;

    // Find the next available column
    $i = 0;
    while ( isset($this->_cells[$this->__row][$i]) ) {
      $i++;
    }

    $this->__col = $i;

  }

  //........................................................................

  /**
   * Remove a row from the cellmap.
   *
   * @param Frame
   */
  function remove_row(DP_Frame $row) {

    $key = $row->get_id();
    if ( !isset($this->_frames[$key]) ) {
      return;  // Presumably this row has alredy been removed
    }

    $this->_row = $this->_num_rows--;

    $rows = $this->_frames[$key]["rows"];
    $columns = $this->_frames[$key]["columns"];

    // Remove all frames from this row
    foreach ( $rows as $r ) {
      foreach ( $columns as $c ) {
        if ( isset($this->_cells[$r][$c]) ) {
          $id = $this->_cells[$r][$c]->get_id();
          
          $this->_frames[$id] = null;
          unset($this->_frames[$id]);
          
          $this->_cells[$r][$c] = null;
          unset($this->_cells[$r][$c]);
        }
      }
      
      $this->_rows[$r] = null;
      unset($this->_rows[$r]);
    }

    $this->_frames[$key] = null;
    unset($this->_frames[$key]);

  }

  /**
   * Remove a row group from the cellmap.
   *
   * @param DP_Frame $group  The group to remove
   */
  function remove_row_group(DP_Frame $group) {

    $key = $group->get_id();
    if ( !isset($this->_frames[$key]) ) {
      return;  // Presumably this row has alredy been removed
    }
    
    $iter = $group->get_first_child();
    while ($iter) {
      $this->remove_row($iter);
      $iter = $iter->get_next_sibling();
    }

    $this->_frames[$key] = null;
    unset($this->_frames[$key]);
  }

  /**
   * Update a row group after rows have been removed
   *
   * @param DP_Frame $group    The group to update
   * @param DP_Frame $last_row The last row in the row group
   */
  function update_row_group(DP_Frame $group, DP_Frame $last_row) {

    $g_key = $group->get_id();
    $r_key = $last_row->get_id();

    $r_rows = $this->_frames[$r_key]["rows"];
    $this->_frames[$g_key]["rows"] = range( $this->_frames[$g_key]["rows"][0], end($r_rows) );

  }

  //........................................................................

  function assign_x_positions() {
    // Pre-condition: widths must be resolved and assigned to columns and
    // column[0]["x"] must be set.

    if ( $this->_columns_locked ) {
      return;
    }
    
    $x = $this->_columns[0]["x"];
    foreach ( array_keys($this->_columns) as $j ) {
      $this->_columns[$j]["x"] = $x;
      $x += $this->_columns[$j]["used-width"];
    }

  }

  function assign_frame_heights() {
    // Pre-condition: widths and heights of each column & row must be
    // calcluated

    foreach ( $this->_frames as $arr ) {
      $frame = $arr["frame"];

      $h = 0;
      foreach( $arr["rows"] as $row ) {
        if ( !isset($this->_rows[$row]) ) {
          // The row has been removed because of a page split, so skip it.
          continue;
        }
        
        $h += $this->_rows[$row]["height"];
      }

      if ( $frame instanceof Table_Cell_Frame_Decorator ) {
        $frame->set_cell_height($h);
      }
      else {
        $frame->get_style()->height = $h;
      }
    }

  }

  //........................................................................

  /**
   * Re-adjust frame height if the table height is larger than its content
   */
  function set_frame_heights($table_height, $content_height) {


    // Distribute the increased height proportionally amongst each row
    foreach ( $this->_frames as $arr ) {
      $frame = $arr["frame"];

      $h = 0;
      foreach ($arr["rows"] as $row ) {
        if ( !isset($this->_rows[$row]) ) {
          continue;
        }

        $h += $this->_rows[$row]["height"];
      }
      
      if ( $content_height > 0 ) {
        $new_height = ($h / $content_height) * $table_height;
      }
      else {
        $new_height = 0;
      }

      if ( $frame instanceof Table_Cell_Frame_Decorator ) {
        $frame->set_cell_height($new_height);
      }
      else {
        $frame->get_style()->height = $new_height;
      }
    }

  }

  //........................................................................

  // Used for debugging:
  function __toString() {
    $str = "";
    $str .= "Columns:<br/>";
    $str .= pre_r($this->_columns, true);
    $str .=  "Rows:<br/>";
    $str .= pre_r($this->_rows, true);

    $str .=  "Frames:<br/>";
    $arr = array();
    foreach ( $this->_frames as $key => $val ) {
      $arr[$key] = array("columns" => $val["columns"], "rows" => $val["rows"]);
    }
    
    $str .= pre_r($arr, true);

    if ( php_sapi_name() == "cli" ) {
      $str = strip_tags(str_replace(array("<br/>","<b>","</b>"),
                                    array("\n",chr(27)."[01;33m", chr(27)."[0m"),
                                    $str));
    }
    
    return $str;
  }
}
