#!/usr/bin/php
<?php
/** DomFramework
  * @package domframework
  * @author Dominique Fournier <dominique@fournier38.fr>
  *
  * SQL Migrate
  * This tool allow to migrate the data from one SQL database to another.
  * The DB engine can also be different.
  *
  * You must have the source DB and create a target DB with all the destination
  * tables available.
  * You must pass one parameter : the configuration file where all the
  * informations will be stored. The file will be created if it doesn't exists.
  */

require_once ("domframework/console.php");
require_once ("domframework/dblayeroo.php");
require_once ("domframework/getopts.php");
require_once ("domframework/config.php");

/** Manage the configuration file
  */
class configuration extends \config
{
  /** The constructor of the configuration set the differents params
    */
  function __construct ()
  {
    $this->default = array (
      "db" => array (
        "srcDSN" => "",
        "srcUser" => null,
        "srcPassword" => null,
        "dstDSN" => "",
        "dstUser" => null,
        "dstPassword" => null,
      ),
      "tables" => array (
      ),
      "tablesRel" => array (
      ),
      "fields" => array (
      ),
      "tablesOrder" => array (
      ),
      "deleteContent" => null,
    );
  }
}

/** The main class
  */
class main
{
  /** The constructor of the class do the main job
    */
  public function __construct ()
  {
    // Manage the Getopts
    $getopts = new getopts ();
    $getopts->add ("Help", "?h", array ("help"), "Help of the software");
    $getopts->add ("Step", "", array ("step:"), "Restart at provided step",
      "StepIdentifier");
    $getopts->add ("Debug", "", array ("debug"), "Display the SQL requests");
    $getopts->add ("Execute", "", array ("execute"),
      "Execute the configuration without requesting data (start at step 5)");
    if ($getopts->get ("Help"))
      die ($getopts->help ());
    if ($getopts->get ("Step"))
    {
      if (intval ($getopts->get ("Step")) < 0 ||
          intval ($getopts->get ("Step")) > 6)
        die ("Invalid Step provided (Must be between 0 and 6)\n");
    }
    if (empty ($getopts->restOfLine ()))
      throw new Exception ("No configuration file provided");
    if (count ($getopts->restOfLine ()) > 1)
      throw new Exception ("Too much configuration file provided");
    $configurationFile = current ($getopts->restOfLine ());
    if (! file_exists ($configurationFile))
      touch ($configurationFile);
    $config = new configuration ();
    $config->confFile = $configurationFile;

    $db = $config->get ("db");
    $tables = $config->get ("tables");
    $tablesRel = $config->get ("tablesRel");
    $fields = $config->get ("fields");
    $tablesOrder = $config->get ("tablesOrder");
    $deleteContent = $config->get ("deleteContent");
    if ($db["srcDSN"] === "" || $db["dstDSN"] === "")
      $step = 0;
    elseif (empty ($tables))
      $step = 1;
    elseif (empty ($tablesRel))
      $step = 2;
    elseif (empty ($fields))
      $step = 3;
    elseif (empty ($tablesOrder))
      $step = 4;
    elseif ($deleteContent === null)
      $step = 5;
    else
      $step = 6;

    if ($getopts->get ("Step"))
      $step = intval ($getopts->get ("Step"));
    if ($getopts->get ("Execute"))
      $step = 5;

    if ($step === 0)
    {
      // Step 0: ask the connection parameters
      echo "#### Entering step 0 : ask the connection parameters\n";
      $srcDSN = $this->ask ("Enter SRC DSN");
      $srcUser = $this->ask ("Enter SRC User");
      $srcPassword = $this->ask ("Enter SRC Password");
      $dstDSN = $this->ask ("Enter DST DSN");
      $dstUser = $this->ask ("Enter DST User");
      $dstPassword = $this->ask ("Enter DST Password");
      if ($srcUser === "")
      {
        $srcUser = null;
        $srcPassword = null;
      }
      if ($dstUser === "")
      {
        $dstUser = null;
        $dstPassword = null;
      }
      $value = array (
        "srcDSN" => $srcDSN,
        "srcUser" => $srcUser,
        "srcPassword" => $srcPassword,
        "dstDSN" => $dstDSN,
        "dstUser" => $dstUser,
        "dstPassword" => $dstPassword,);
      $config->set ("db", $value);
      $db = $config->get ("db");
      $step++;
    }
    if ($step === 1)
    {
      echo "#### Entering step 1: read the existing databases schemes\n";
      $srcDB = new dblayeroo ($db["srcDSN"], $db["srcUser"],
                              $db["srcPassword"]);
      $srcTables = $srcDB->listTables ();
      $dstDB = new dblayeroo ($db["dstDSN"], $db["dstUser"],
                              $db["dstPassword"]);
      $dstTables = $dstDB->listTables ();
      $value = array (
        "srcTables" => $srcTables,
        "dstTables" => $dstTables,
      );
      $config->set ("tables", $value);
      $step++;
      echo "\n";
    }

    echo "#### Connect to the defined databases\n";
    $srcDB = new dblayeroo ($db["srcDSN"], $db["srcUser"],
                            $db["srcPassword"]);
    $dstDB = new dblayeroo ($db["dstDSN"], $db["dstUser"],
                            $db["dstPassword"]);
    echo "\n";

    if ($step == 2)
    {
      echo "#### Entering step 2: ask the relations between tables\n";
      $tables = $config->get ("tables");
      echo "# For each destination table, please provide the source table\n";
      sort ($tables["srcTables"]);
      echo "# Allowed source tables : ". implode (", ", $tables["srcTables"]).
        "\n";
      $value = array ();
      natsort ($tables["dstTables"]);
      foreach ($tables["dstTables"] as $table)
      {
        while (1)
        {
          $value[$table] = $this->ask (
            "Destination Table '$table' filled by source table");
          if (in_array ($value[$table], $tables["srcTables"]) ||
              $value[$table] === "")
            continue 2;
          $this->error ("The table '".$value[$table]." doesn't exists");
          echo "# Allowed source tables : ".
               implode (", ", $tables["srcTables"])."\n";
        }
      }
      $config->set ("tablesRel", $value);
      $step++;
      echo "\n";
    }

    $tablesRel = $config->get ("tablesRel");
    if ($step === 3)
    {
      echo "#### Entering step 3: ask the relation between fields\n";
      echo "# For each destination table, if a source table is provided,\n".
           "# for each field, provide the source SQL request (can be field,\n".
           "# CONCAT(), text between simple quotes, null...)\n";
      if ($config->get("fields"))
        $value = $config->get("fields");
      else
        $value = array ();
      foreach ($tablesRel as $dstTable=>$srcTable)
      {
        echo "- Destination Table '$dstTable': ";
        if ($srcTable === "")
        {
          echo "No source table. SKIPPED\n";
          continue;
        }
        echo "\n";
        $dstSchema = $dstDB->getTableSchema ($dstTable);
        $srcSchema = $srcDB->getTableSchema ($srcTable);
        echo "  List of the allowed fields: ".
          implode (", ", array_keys ($srcSchema["fields"]))."\n";
        foreach (array_keys ($dstSchema["fields"]) as $field)
        {
          if (! key_exists ($dstTable, $value))
            $value[$dstTable] = array ();
          if (! key_exists ($field, $value[$dstTable]))
            $value[$dstTable][$field] = "";
          while (1)
          {
            $oldval = (isset ($config->get("fields")[$dstTable][$field])) ?
               $config->get("fields")[$dstTable][$field] : "";
            $answer = $this->ask (
              "Destination Table '$dstTable' field '$field'", $oldval);
            $value[$dstTable][$field] = $answer;
            if (trim ($value[$dstTable][$field]) !== "")
              break;
            // TODO : Check if the field is valid (think about function)
            $this->error ("The field source must be defined !");
          }
        }
        $config->set ("fields", $value);
      }
      $step++;
      echo "\n";
    }
    $fields = $config->get ("fields");
    if ($step === 4)
    {
      echo "#### Entering step 4: Order the tables by foreign keys\n";
      echo "# The tables with foreign keys constraint must be populated \n".
           "# after the tables depending of them\n";
      $tablesToOrder = array ();
      foreach ($tablesRel as $dstTable=>$srcTable)
      {
        if ($srcTable !== "")
          $tablesToOrder[] = $dstTable;
      }
      while (1)
      {
        echo "# Here are the tables to order: ". implode (",", $tablesToOrder).
             "\n";
        $tablesOrder = $this->ask ("Order the tables, separated by commas");
        $tablesOrder = explode (",", $tablesOrder);
        if (count ($tablesToOrder) === count ($tablesOrder))
          break;
        $this->error ("Not all the tables are ordered");
      }
      $config->set ("tablesOrder", $tablesOrder);
      $step++;
      echo "\n";
    }

    $tablesOrder = $config->get ("tablesOrder");
    if ($step === 5)
    {
      if ($deleteContent === null)
      {
        echo "# The content of the destination tables can be deleted before\n".
             "# adding the source data.\n";
        echo "# Attention: the order is important if there is foreign keys!\n".
             "# Remove the most constraint tables before deleting the less\n".
             "# constraint ones\n";
        echo "# List of the destination tables: ".
             implode (",", array_keys (array_diff ($tablesRel, array ("")))).
             "\n";
        $deleteContent = $this->ask ("Get the list of the tables to be ".
                                     "cleaned, separated by comas");
        $config->set ("deleteContent", $deleteContent);
        $deleteContent = $config->get ("deleteContent");
      }
    }
    if ($deleteContent !== "")
    {
      echo "#### Entering step 5: delete tables content\n";
      foreach (explode (",", $deleteContent) as $table)
      {
        $table = trim ($table);
        echo "- Delete content of table '$table'\n";
        $dstDB->table ($table)->unique (array ())->delete ()->execute ();
      }
      $step = 6;
      echo "\n";
    }
    else
    {
      echo "#### Entering step5: Skipped delete tables content\n";
      $step = 6;
    }
    if ($step === 6)
    {
      echo "#### Entering step 6: populate the destination database with the ".
           "configured data\n";
      foreach ($tablesOrder as $dstTable)
      {
        echo "- Populate table $dstTable:\n";
        // Create the source SQL request. Add the alias name of the destination
        // table to allow to import directely in the destination
        $sql = "SELECT ";
        $i = 0;
        foreach ($fields[$dstTable] as $key=>$val)
        {
          if ($i > 0)
            $sql .= ",";
          $sql .= "$val AS $key";
          $i++;
        }
        $sql .= " FROM ".$tablesRel[$dstTable];
        echo "    $sql\n";
        echo "    ";
        // Define all the variables needed to insert
        $dstSchema = $dstDB->getTableSchema ($dstTable);
        $dstDB->table ($dstTable);
        $dstDB->fields ($dstSchema["fields"]);
        $dstDB->primary ($dstSchema["primary"]);
        foreach ($srcDB->directQuery ($sql) as $row)
        {
          //print_r ($row);
          $dstDB->clearRequest ();
          $dstDB->insert ()
                ->setValues ($row);
          if (! $getopts->get ("Debug"))
            echo ".";
          else
            echo $dstDB->getDisplayQuery ();
          $dstDB->execute ();
        }
        echo "\n";
      }
      $step++;
    }
    // Last step
    echo "#### Entering step $step: End of process\n";
  }

  /** Ask a question to the user and return the answer
    * @param string $question the question message
    * @return string The answer
    */
  public function ask ($question, $proposal = "")
  {
    $console = new console ();
    $console->echo ("$question: ");
    return trim ($console->readline ($proposal));
  }

  /** Display an error to the user
    * @param string $msg The error message to display
    */
  public function error ($msg)
  {
    file_put_contents ("php://stderr", "ERROR: ".$msg."\n");
  }
}

try
{
  $main = new \main ();
}
catch (Exception $e)
{
  file_put_contents ("php://stderr", $e->getMessage ()."\n");
  exit (4);
}