<?php
/**
 * WPSEO plugin file.
 *
 * @package WPSEO\Admin
 */

/**
 * Represents the proxy for communicating with the database.
 */
class WPSEO_Database_Proxy {

	/**
	 * Holds the table name.
	 *
	 * @var string
	 */
	protected $table_name;

	/**
	 * Determines whether to suppress errors or not.
	 *
	 * @var bool
	 */
	protected $suppress_errors = true;

	/**
	 * Determines if this table is multisite.
	 *
	 * @var bool
	 */
	protected $is_multisite_table = false;

	/**
	 * Holds the last suppressed state.
	 *
	 * @var bool
	 */
	protected $last_suppressed_state;

	/**
	 * Holds the WordPress database object.
	 *
	 * @var wpdb
	 */
	protected $database;

	/**
	 * Sets the class attributes and registers the table.
	 *
	 * @param wpdb   $database           The database object.
	 * @param string $table_name         The table name that is represented.
	 * @param bool   $suppress_errors    Should the errors be suppressed.
	 * @param bool   $is_multisite_table Should the table be global in multisite.
	 */
	public function __construct( $database, $table_name, $suppress_errors = true, $is_multisite_table = false ) {
		$this->table_name         = $table_name;
		$this->suppress_errors    = (bool) $suppress_errors;
		$this->is_multisite_table = (bool) $is_multisite_table;
		$this->database           = $database;

		// If the table prefix was provided, strip it as it's handled automatically.
		$table_prefix = $this->get_table_prefix();
		if ( ! empty( $table_prefix ) && strpos( $this->table_name, $table_prefix ) === 0 ) {
			$this->table_prefix = substr( $this->table_name, strlen( $table_prefix ) );
		}

		if ( ! $this->is_table_registered() ) {
			$this->register_table();
		}
	}

	/**
	 * Inserts data into the database.
	 *
	 * @param array $data   Data to insert.
	 * @param null  $format Formats for the data.
	 *
	 * @return false|int Total amount of inserted rows or false on error.
	 */
	public function insert( array $data, $format = null ) {
		$this->pre_execution();

		$result = $this->database->insert( $this->get_table_name(), $data, $format );

		$this->post_execution();

		return $result;
	}

	/**
	 * Updates data in the database.
	 *
	 * @param array $data         Data to update on the table.
	 * @param array $where        Where condition as key => value array.
	 * @param null  $format       Optional. data prepare format.
	 * @param null  $where_format Optional. Where prepare format.
	 *
	 * @return false|int False when the update request is invalid, int on number of rows changed.
	 */
	public function update( array $data, array $where, $format = null, $where_format = null ) {
		$this->pre_execution();

		$result = $this->database->update( $this->get_table_name(), $data, $where, $format, $where_format );

		$this->post_execution();

		return $result;
	}

	/**
	 * Upserts data in the database.
	 *
	 * Performs an insert into and if key is duplicate it will update the existing record.
	 *
	 * @param array $data         Data to update on the table.
	 * @param array $where        Unused. Where condition as key => value array.
	 * @param null  $format       Optional. Data prepare format.
	 * @param null  $where_format Deprecated. Where prepare format.
	 *
	 * @return false|int False when the upsert request is invalid, int on number of rows changed.
	 */
	public function upsert( array $data, array $where = null, $format = null, $where_format = null ) {
		if ( $where_format !== null ) {
			_deprecated_argument( __METHOD__, '7.7.0', 'The where_format argument is deprecated' );
		}

		$this->pre_execution();

		$update  = array();
		$keys    = array();
		$columns = array_keys( $data );
		foreach ( $columns as $column ) {
			$keys[]   = '`' . $column . '`';
			$update[] = sprintf( '`%1$s` = VALUES(`%1$s`)', $column );
		}

		$query = sprintf(
			'INSERT INTO `%1$s` (%2$s) VALUES ( %3$s ) ON DUPLICATE KEY UPDATE %4$s',
			$this->get_table_name(),
			implode( ', ', $keys ),
			implode( ', ', array_fill( 0, count( $data ), '%s' ) ),
			implode( ', ', $update )
		);

		$result = $this->database->query(
			$this->database->prepare(
				$query,
				array_values( $data )
			)
		);

		$this->post_execution();

		return $result;
	}

	/**
	 * Deletes a record from the database.
	 *
	 * @param array      $where  Where clauses for the query.
	 * @param null|array $format Formats for the data.
	 *
	 * @return false|int
	 */
	public function delete( array $where, $format = null ) {
		$this->pre_execution();

		$result = $this->database->delete( $this->get_table_name(), $where, $format );

		$this->post_execution();

		return $result;
	}

	/**
	 * Executes the given query and returns the results.
	 *
	 * @param string $query The query to execute.
	 *
	 * @return array|null|object The resultset
	 */
	public function get_results( $query ) {
		$this->pre_execution();

		$results = $this->database->get_results( $query );

		$this->post_execution();

		return $results;
	}

	/**
	 * Creates a table to the database.
	 *
	 * @param array $columns The columns to create.
	 * @param array $indexes The indexes to use.
	 *
	 * @return bool True when creation is successful.
	 */
	public function create_table( array $columns, array $indexes = array() ) {
		$create_table = sprintf(
			'CREATE TABLE IF NOT EXISTS %1$s ( %2$s ) %3$s',
			$this->get_table_name(),
			implode( ',', array_merge( $columns, $indexes ) ),
			$this->database->get_charset_collate()
		);

		$this->pre_execution();

		$is_created = (bool) $this->database->query( $create_table );

		$this->post_execution();

		return $is_created;
	}

	/**
	 * Checks if there is an error.
	 *
	 * @return bool Returns true when there is an error.
	 */
	public function has_error() {
		return ( $this->database->last_error !== '' );
	}

	/**
	 * Executed before a query will be ran.
	 */
	protected function pre_execution() {
		if ( $this->suppress_errors ) {
			$this->last_suppressed_state = $this->database->suppress_errors();
		}
	}

	/**
	 * Executed after a query has been ran.
	 */
	protected function post_execution() {
		if ( $this->suppress_errors ) {
			$this->database->suppress_errors( $this->last_suppressed_state );
		}
	}

	/**
	 * Returns the full table name.
	 *
	 * @return string Full table name including prefix.
	 */
	public function get_table_name() {
		return $this->get_table_prefix() . $this->table_name;
	}

	/**
	 * Returns the prefix to use for the table.
	 *
	 * @return string The table prefix depending on the database context.
	 */
	protected function get_table_prefix() {
		if ( $this->is_multisite_table ) {
			return $this->database->base_prefix;
		}

		return $this->database->get_blog_prefix();
	}

	/**
	 * Registers the table with WordPress.
	 *
	 * @return void
	 */
	protected function register_table() {
		$table_name      = $this->table_name;
		$full_table_name = $this->get_table_name();

		$this->database->$table_name = $full_table_name;

		if ( $this->is_multisite_table ) {
			$this->database->ms_global_tables[] = $table_name;
			return;
		}

		$this->database->tables[] = $table_name;
	}

	/**
	 * Checks if the table has been registered with WordPress.
	 *
	 * @return bool True if the table is registered, false otherwise.
	 */
	protected function is_table_registered() {
		if ( $this->is_multisite_table ) {
			return in_array( $this->table_name, $this->database->ms_global_tables, true );
		}

		return in_array( $this->table_name, $this->database->tables, true );
	}
}
