<?php 

class Database_Manager 
{
    public /*.Database.*/$db;

	function __construct(Database $db) {
		$this->db = $db;
	}

	public function ExecuteAction(/*.array.*/$action, $db_file = "") {
		switch($action["type"]) {
			case "dropTable":
				$this->DropTableQuery($action["table_name"], true);
			break;
			case "createTable":
				$constraints = isset($action["constraints"]) ? $action["constraints"] : NULL;
				$this->CreateTableQuery($action["table_name"], $action["fields"], $constraints);
			break;
            case "addColumn":
            	$this->AddColumn($action["table_name"], $action["column_name"], $action["field"]);
            break;
			case "insert":
				$this->db->insertQuery($action["table_name"], $action["values"]);
			break;
			case "alterReference":
				$this->AlterReference($action["table"], $action["column"], $action["refTable"], $action["refColumn"]);
			break;
			case "renameColumn":
				$this->RenameColumn($action["table"], $action["old_name"], $action["new_name"]);
                break;
			case "executeFile":
                if ($this->db->isPostgres() && isset($action["pgsql"])) {
    				$file = $action["pgsql"];
                } else {
    				$file = $action["source"];
                }

                $stmtList = Tools_SQLStatementExtractor::extractFile(Path::join(dirname($db_file), $file));
                foreach($stmtList as $stmt) {
                    $this->db->executeQuery($stmt);
                }

                break;
			default:
				throw new Exception("unknown action ". $action["type"] . PHP_EOL);
		}
	}

	public function DropTableQuery($table, $cascade=false) {
		$statement = "DROP TABLE IF EXISTS ".$table;
		if ($this->db->isPostgres()&&$cascade) {
			$statement = $statement." CASCADE";
		}
		$this->db->query($statement);
	}

	public function AlterReference($table,$column,$refTable,$refColumn) {
		$this->db->query("ALTER TABLE ".$table." ADD CONSTRAINT ".$table."_".$column."fk"." FOREIGN KEY (".$column.") REFERENCES ".$refTable." (".$refColumn.")");
	}

	//Извлечение информации о полях таблицы
	public function TableInfo($table) {
		$pg = $this->db->isPostgres();
		if ($pg) {
			throw new Exception("Not implemented for postgres");
		} else {
			$results = $this->db->fetchAllArray("PRAGMA table_info(".$table.");");
			if (empty($results)) {
				return null;
            }
			$fields = [];
			foreach ($results as $result) {
				$fields[$result["name"]] = [
                    "type"=> $result["type"],
				    "not_null"=> boolval($result["notnull"]),
				    "constraint"=> ((boolean) $result["pk"]) ? "PRIMARY KEY" : null
                ];
			}
			return $fields;
		}
	}

	public function RenameColumn($table, $old_name, $new_name) {
		$pg = $this->db->isPostgres();
		if ($pg) {
			$this->db->query("ALTER TABLE ".$table." RENAME COLUMN ".$old_name." TO ".$new_name);
		} else {
			$tmp_table = "tmp_" . $table;
			$this->DropTableQuery($tmp_table);
			$table_info = $this->TableInfo($table);

			if (isset($table_info[$new_name])) {
				return;
            }

			/*.array.*/$data = $this->DumpTable($table);

			$this->db->query("ALTER TABLE ".$table." RENAME TO ".$tmp_table.";");
			$table_info[$new_name] = $table_info[$old_name];
			unset($table_info[$old_name]);
			$this->CreateTableQuery($table,$table_info,null);

			foreach ($data as $row) {
				$values = $row['values'];
				$values[$new_name] = $values[$old_name];
				unset($values[$old_name]);
				$this->db->insertQuery($table, $values);
			}
			$this->DropTableQuery($tmp_table);
		}
	}

	//Обновление ключа serial после ручной вставки
	public function UpdateSerial($table,$column) {
		$this->db->query("SELECT setval(pg_get_serial_sequence('".$table."', '".$column."'), coalesce(max(".$column."),0) + 1, false) FROM ".$table);
	}

	public function Column_Definition($name,$data,$pg){
		$constraint = isset($data['constraint'])?" ".$data['constraint']:"";
		$references = "";
		if (isset($data['references'])) {
			$references = " REFERENCES ".$data['references'];
		}
		if (isset($data["not_null"])&&$data["not_null"])
			$constraint .=" NOT NULL";
		$type = $data['type'];
		if (!$pg) {
			if (strtolower($type)=="serial")
				$type = "integer";
			//if (strtolower($type)=="boolean")
			//	$type = "integer";			
		}
		return $name." ".$type.$references.$constraint;
	}

	public function AddColumn($table_name,$column_name,$field){
		$pg = $this->db->isPostgres();
		$q = "ALTER TABLE ".$table_name." ADD COLUMN ".
					$this->Column_Definition($column_name, $field, $pg);
		$this->db->query($q);
	}

    function getConstraintDef($c) {
        if ($c['type'] == 'unique') {
            return "UNIQUE(" . implode(", ", $c['fields']) . ")";
        }
        return "";
    }

	//CreateTableQuery('users',['id'=>['type'=>'integer','constraint'=>'PRIMARY KEY']])
	public function CreateTableQuery($table, $fields, $constraints) {
		$pg = $this->db->isPostgres();
		if ($constraints) {
            if (is_array($constraints)) {
                $constraints = $this->getConstraintDef($constraints);
            }
			$constraints = ", " . $constraints;
        }

		$statement = "CREATE TABLE $table (" . implode(",", 
				array_map(function($name,$data) use ($pg) {
					return $this->Column_Definition($name,$data,$pg);
				}, array_keys($fields), array_values($fields))
			) . " " . $constraints . ")";
		$this->db->query($statement);
	}

	public function DumpTable($table_name) {
		$pg = $this->db->isPostgres();

		/*.array.*/$result = array();
		/*.array.*/$data = $this->db->fetchAllArray("SELECT * FROM ".$table_name.";");

		if (!$pg) {
			$table_fields = $this->TableInfo($table_name);
			foreach ($table_fields as $name => $value) {
				$type = strtolower($value['type']);
				if ($type == "boolean") {
					foreach ($data as &$row) {
                        /*.array.*/$row = $row;
						if (isset($row[$name])) {
							$row[$name] = boolval($row[$name]);
						}
					}
				}
			}
		}
		foreach ($data as $r) {
			$result[] = array(
                "type" => "insert",
				"table_name" => $table_name,
				"values" => $r
            );
		}
		return $result;
	}

	public function GetAllTableNames() {
		$result = [];
		if ($this->db->isPostgres()) {
			$query = "SELECT table_name as name FROM information_schema.tables  WHERE table_schema='public'";
		} else {
			$query = "SELECT * FROM sqlite_master WHERE type='table'";
        }
		$tables = $this->db->fetchAllArray($query);
		foreach ($tables as $table) {
			$result[] = $table['name'];
        }
		return $result;
	}

	public function DumpInserts() {
		$table_names = $this->GetAllTableNames();
		$result = array();
		foreach ($table_names as $table_name) {
			$result = array_merge($result, $this->DumpTable($table_name));
		}
		return $result;
	}
}