#!/usr/bin/php
<?php
/** DomFramework
  * @package domframework
  * @author Dominique Fournier <dominique@fournier38.fr>
  */

require_once ("domframework/dblayeroo.php");

/** modelGraph
  * Allow to create the relational graph of an existing database
  * Use GraphViz to generate the graph
  * Request the database DSN to operate
  */
class modelgraph
{
  // PROPERTIES
  /** The connected object dblayeroo
    */
  private $db;
  /** The output file
    */
  private $output;

  /** The constructor wait for $dsn
    * @param string $dsn The DSN to connect to database
    * @param string $output The output file to generate
    */
  public function __construct ($dsn, $username, $password, $output)
  // {{{
  {
    $this->output = $output;
    $this->db = new \dblayeroo ($dsn, $username, $password);
    $this->graphvizCommande ();
  }
  // }}}

  /** Generate the output file
    */
  public function generate ()
  // {{{
  {
    $tables = array ();
    foreach ($this->db->listTables () as $table)
    {
      $tables[$table] = $this->db->getTableSchema ($table);
    }
    $d = "digraph G {\n";
    $d .= "  node [shape=box];\n";
    $d .= "  rankdir=RL\n";

    // Generate the tables objects with the fields
    foreach ($tables as $table => $schema)
    {
      $d .= "  /** TABLE '$table' */\n";
      $d .= "  \"$table\" [\n";
      $d .= "    shape = \"plaintext\"\n";
      $d .= "    label = <";
      $d .= "<TABLE BORDER=\"0\" CELLBORDER=\"1\" CELLSPACING=\"0\">\n";
      // Display the name of the table as title
      $d .= "       <TR><TD COLSPAN=\"3\" BGCOLOR=\"#00B0E0\">";
      $d .= "$table</TD></TR>\n";
      // Display the fields
      $i = 0;
      foreach ($schema["fields"] as $field => $params)
      {
        $d .= "       <TR>\n";
        $d .= "<TD SIDES=\"TBL\" PORT=\"OUT-$field\">";
        if (key_exists ($field, $schema["foreign"]))
        {
          // Foreign Key
          $d .= "<FONT COLOR=\"#F02020\">!</FONT>";
        }
        elseif (key_exists ("primary", $schema) &&
            $field === $schema["primary"])
          $d .= "&#128273;"; // Primary key found
        elseif (in_array ("not null", $params))
          $d .= "<FONT COLOR=\"#00B0E0\">&#9670;</FONT>"; // NOT NULL
        else
          $d .= "&#9671;";
        $d .= "</TD>\n";
        $d .= "<TD ALIGN=\"LEFT\" SIDES=\"TB\">";
        $d .= $field;
        $d .= "</TD>\n";
        $d .= "<TD ALIGN=\"LEFT\" PORT=\"IN-$field\" SIDES=\"TBR\">";
        $d .= $params[0];
        $d .= "</TD>\n";
        $d .= "</TR>\n";
        $i++;
      }
      $d .= "</TABLE>>\n";
      $d .= "  ];\n";
    }
    // Generate the links between the tables
    foreach ($tables as $table => $schema)
    {
      // "node1":"f2" -> "node5":"f0" [];
      foreach ($schema["foreign"] as $field => $params)
      {
        $d .= "\"$table\":\"OUT-$field\" -> \"". $params[0].
              "\":\"IN-".$params[1]."\" ";
        $d .= "[];\n";
      }
    }
    $d .= "}\n";
    //echo $d;
    $this->createJPG ($d);
  }
  // }}}

  /** Look for the dot command
    * @return the full path of 'dot' command
    */
  private function graphvizCommande ()
  // {{{
  {
    foreach (explode (":", getenv ("PATH")) as $path)
    {
      if (file_exists ("$path/dot"))
        return "$path/dot";
    }
    throw new \Exception ("Can not find 'dot' executable. Install graphviz",
    500);
  }
  // }}}

  /** Generate the JPEG file with graphviz
    * @param string $content The content of the GV file
    */
  private function createJPG ($content)
  // {{{
  {
    $tmp = tempnam ("/tmp", "modelgraph_");
    file_put_contents ($tmp, $content);
    $cmd = $this->graphvizCommande (). " -T jpeg $tmp ".
           "-o ".escapeshellarg ($this->output)." 2>&1";
    exec ($cmd, $output);
    unlink ($tmp);
    if (!empty ($output))
    {
      echo "ERROR : ".implode ("\n", $output);
      exit (2);
    }
  }
  // }}}
}


// MAIN PROGRAM
if (isset ($argv[1]) && $argv[1] === "-h")
{
  echo "Create the ER Diagram of a SQL database\n";
  echo "Usage : \n";
  echo $argv[0]." DSN username password outputfile.jpg\n";
  echo "DSN Examples : 'mysql:dbname=databaseName'\n";
}
if (! isset ($argv[1]))
  die ("No DSN provided\n");
if (! isset ($argv[2]))
  die ("No username provided\n");
if (! isset ($argv[3]))
  die ("No password provided\n");
if (! isset ($argv[4]))
  die ("No output file provided\n");
$modelgraph = new modelgraph ($argv[1], $argv[2], $argv[3], $argv[4]);
$modelgraph->generate ();