<?php


require_once 'DBSchema/Generic.php';

class MTrackDBSchema_pgsql extends MTrackDBSchema_Generic {
  var $typemap = array(
    'autoinc' => 'SERIAL UNIQUE',
    'timestamp' => 'timestamp with time zone',
    'blob' => 'bytea',
  );

  function alterTable(MTrackDBSchema_Table $from, MTrackDBSchema_Table $to)
  {
    $sql = array();
    $actions = array();

    /* if keys have changed, we drop the old key definitions before changing the columns */
    if (is_array($from->keys)) foreach ($from->keys as $k) {
      if (!isset($to->keys[$k->name]) || $to->keys[$k->name] != $k) {
        if ($k->type == 'primary') {
          $actions[] = "DROP CONSTRAINT {$from->name}_pkey";
        } else {
          $sql[] = "DROP INDEX $k->name";
        }
      }
    }

    foreach ($from->fields as $f) {
      if (!isset($to->fields[$f->name])) {
        $actions[] = "DROP COLUMN $f->name";
        continue;
      }
    }
    foreach ($to->fields as $f) {
      if (isset($from->fields[$f->name])) continue;
      $actions[] = "ADD COLUMN " . $this->computeFieldCreate($f);
    }

    /* changed and new keys */
    if (is_array($from->keys)) foreach ($from->keys as $k) {
      if (isset($to->keys[$k->name]) && $to->keys[$k->name] != $k) {
        if ($k->type == 'primary') {
          $actions[] = "ADD primary key (" . join(', ', $k->fields) . ")";
        } else {
          $sql[] = $this->computeIndexCreate($to, $k);
        }
      }
    }
    if (is_array($to->keys)) foreach ($to->keys as $k) {
      if (isset($from->keys[$k->name])) continue;
      if ($k->type == 'primary') {
        $actions[] = "ADD primary key (" . join(', ', $k->fields) . ")";
      } else {
        $sql[] = $this->computeIndexCreate($to, $k);
      }
    }

    if (count($actions)) {
      $sql[] = "ALTER TABLE $from->name " . join(",\n", $actions);
    }
    echo "Need to alter $from->name\n";
    echo "SQL:\n";
    var_dump($sql);
    foreach ($sql as $s) {
      $this->db->exec($s);
    }
  }
}