<?php

namespace CleantalkSP\Common\DB;

class SQLSchema
{
    /**
     * Schema table prefix
     */
    private static $schema_prefix = 'spbc_';

    /**
     * Set of SQL-schemas for tables in array
     * Set for all websites. Should installed with a main database prefix
     *
     * @var array
     */
    protected static $schemas__common = array();

    /**
     * Set of SQL-schemas for tables in array
     * Set for a blog only. Should installed with a blog database prefix
     *
     * @var array
     */
    protected static $schemas__blog = array();

    /**
     * @var string[]
     */
    protected static $field_standard = array('field' => '', 'type' => '', 'null' => '', 'default' => '', 'extra' => '');

    /**
     * Preprocess requested scheme name
     * Allows both to use prefix (spbc_) or not
     *
     * @param string $name
     *
     * @return string
     */
    private static function processSchemaName($name)
    {
        return strpos($name, self::$schema_prefix) !== false
            ? preg_replace('/.*?spbc_(.+)/', '$1', $name)
            : $name;
    }

    /**
     * Searches and returns schema
     *
     * @param string $table Name of called table
     *
     * @return array      Schema
     */
    public static function getByName($table)
    {
        $schemas__all = static::getAll();
        $table        = static::processSchemaName($table);

        if (array_key_exists($table, $schemas__all)) {
            return $schemas__all[ $table ];
        }
    }


    /**
     * Searches and returns schema of common type
     *
     * @param null|string $table Name of called table
     *
     * @return array                     Array of schemas
     * @throws \Exception                Throws if calling un-existed schema
     * @psalm-suppress PossiblyUnusedMethod
     */
    public static function getAllCommon($table = null)
    {
        return static::$schemas__common;
    }

    /**
     * Searches and returns schema of blog type
     *
     * @param null|string $table Name of called table
     *
     * @return array                     Array of schemas
     * @throws \Exception                Throws if calling un-existed schema
     * @psalm-suppress PossiblyUnusedMethod
     */
    public static function getAllBlog($table = null)
    {
        return static::$schemas__blog;
    }

    /**
     * Returns all schemas of all types
     */
    public static function getAll()
    {
        return array_merge(static::$schemas__common, static::$schemas__blog);
    }

    /**
     * Return all tables names with schema prefix added.
     * Wrapper for self::getBlogTableNames() and self::getCommonTableNames()
     *
     * @param bool $with_schema_prefix
     *
     * @return array
     */
    public static function getAllTableNames($with_schema_prefix = true)
    {
        return array_merge(
            self::getBlogTableNames($with_schema_prefix),
            self::getCommonTableNames($with_schema_prefix)
        );
    }


    /**
     * Return all tables names with schema prefix added.
     *
     * @param bool $with_schema_prefix
     *
     * @return array
     */
    public static function getBlogTableNames($with_schema_prefix = true)
    {
        $table_names = array_keys(static::$schemas__blog);

        if ($with_schema_prefix) {
            foreach ($table_names as &$table_name) {
                $table_name = self::getSchemaPrefix() . $table_name;
            }
        }

        return $table_names;
    }

    /**
     * Return all tables names with schema prefix added.
     *
     * @param bool $with_schema_prefix
     *
     * @return array
     */
    public static function getCommonTableNames($with_schema_prefix = true)
    {
        $table_names = array_keys(static::$schemas__common);

        if ($with_schema_prefix) {
            foreach ($table_names as &$table_name) {
                $table_name = self::getSchemaPrefix() . $table_name;
            }
        }

        return $table_names;
    }

    /**
     * Return scheme prefix
     *
     * @return string
     */
    public static function getSchemaPrefix()
    {
        return self::$schema_prefix;
    }

    /**
     * Return standard column fields for scheme
     *
     * @return string[]
     */
    public static function getFieldStandard()
    {
        return static::$field_standard;
    }
}