#!/usr/bin/php
<?php

/**
 * DomFramework
 * @package domframework
 * @author Dominique Fournier <dominique@fournier38.fr>
 */

require_once(__DIR__ . "/../src/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 $username The username to connect to database
     * @param string $password The password to connect to database
     * @param string $output The output file to generate
     */
    public function __construct($dsn, $username, $password, $output)
    {
        $this->output = $output;
        $this->db = new Domframework\Dblayeroo($dsn, $username, $password);
        $this->graphvizCommande();
    }

    /**
     * Generate the output file
     */
    public function generate()
    {
        $tables = [];
        foreach ($this->db->listTables() as $table) {
            $tables[$table] = $this->db->getTableSchema($table);
        }
        $d = "digraph G {\n";
        $d .= "  graph [\n";
        $d .= "    label = <" .
              "<B>Database " . $this->db->databasename() . "</B><BR/>" .
              "<B>" . date("Y-m-d") . "</B>" .
              ">\n";
        $d .= "  ]\n";
        $d .= "  node [\n";
        $d .= "    shape=box\n";
        $d .= "    fontname = \"helvetica\"\n";
        $d .= "  ];\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 = <\n";
            $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;";
                } elseif (in_array("not null", $params)) {
                    // Primary key found
                    $d .= "<FONT COLOR=\"#00B0E0\">&#9670;</FONT>";
                } else {
                    // NOT NULL
                    $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();