<?php
/**
 * @package    Joomla.Component.Builder
 *
 * @created    4th September, 2022
 * @author     Llewellyn van der Merwe <https://dev.vdm.io>
 * @git        Joomla Component Builder <https://git.vdm.dev/joomla/Component-Builder>
 * @copyright  Copyright (C) 2015 Vast Development Method. All rights reserved.
 * @license    GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace VDM\Joomla\Abstraction;


use VDM\Joomla\Utilities\StringHelper;
use VDM\Joomla\Utilities\ArrayHelper;
use VDM\Joomla\Interfaces\TableInterface as Table;
use VDM\Joomla\Interfaces\ModelInterface;


/**
 * Base Model
 * 
 * @since 3.2.0
 */
abstract class Model implements ModelInterface
{
	/**
	 * Last ID
	 *
	 * @var    array
	 * @since 3.2.0
	 */
	protected array $last;

	/**
	 * Search Table
	 *
	 * @var    Table
	 * @since 3.2.0
	 */
	protected Table $table;

	/**
	 * Table Name
	 *
	 * @var    string
	 * @since 3.2.0
	 */
	protected string $tableName;

	/**
	 * The switch to control the behaviour of empty values
	 *
	 * @var    bool
	 * @since 3.2.2
	 */
	protected bool $allowEmpty = true;

	/**
	 * Constructor
	 *
	 * @param Table         $table        The search table object.
	 * @param string|null   $tableName    The table
	 * @param bool|null     $allowEmpty   The switch to control the behaviour of empty values (default true)
	 *
	 * @since 3.2.0
	 */
	public function __construct(Table $table, ?string $tableName = null, ?bool $allowEmpty = null)
	{
		$this->table = $table;
		if ($tableName !== null)
		{
			$this->setTable($tableName);
		}
		if ($allowEmpty !== null)
		{
			$this->setAllowEmpty($allowEmpty);
		}
	}

	/**
	 * Set the current active table
	 *
	 * @param string $table The table that should be active
	 *
	 * @return self
	 * @since 3.2.2
	 */
	public function table(string $table): self
	{
		$this->setTable($table);

		return $this;
	}

	/**
	 * Model the value
	 *          Example: $this->value(value, 'value_key', 'table_name');
	 *
	 * @param   mixed          $value    The value to model
	 * @param   string         $field    The field key
	 * @param   string|null    $table    The table
	 *
	 * @return  mixed
	 * @since 3.2.0
	 */
	abstract public function value($value, string $field, ?string $table = null);

	/**
	 * Model a value of multiple items
	 *          Example: $this->values(Array, 'value_key', 'table_name');
	 *
	 * @param   array|null    $items    The array of values
	 * @param   string        $field    The field key
	 * @param   string|null   $table    The table
	 *
	 * @return  array|null
	 * @since 3.2.2
	 */
	public function values(?array $items, string $field, ?string $table = null): ?array
	{
		// check if this is a valid table
		if (ArrayHelper::check($items))
		{
			// set the table name
			if (empty($table))
			{
				$table = $this->getTable();
			}

			// validate if field exist in table
			if (!$this->table->exist($table, $field))
			{
				return null;
			}

			// value counter
			$value_number = 0;

			// check if this is a valid table
			$item_bucket = [];

			foreach ($items as $value)
			{
				if (!$this->validateBefore($value, $field, $table))
				{
					continue;
				}

				$value = $this->value($value, $field, $table);

				if (!$this->validateAfter($value, $field, $table))
				{
					continue;
				}

				$item_bucket[] = $value;

				$value_number++;
			}

			// do we have any values left
			if ($value_number > 0)
			{
				return $item_bucket;
			}
		}

		return null;
	}

	/**
	 * Model the values of an item
	 *          Example: $this->item(Object, 'table_name');
	 *
	 * @param   object|null    $item      The item object
	 * @param   string|null    $table     The table
	 *
	 * @return  object|null
	 * @since 3.2.0
	 */
	public function item(?object $item, ?string $table = null): ?object
	{
		// we must have an object
		if (empty($item))
		{
			return null;
		}

		// set the table name
		if (empty($table))
		{
			$table = $this->getTable();
		}

		if (($fields = $this->getTableFields($table, true)) !== null)
		{
			// field counter
			$field_number = 0;

			// check if this is a valid table
			$item_bucket = new \stdClass();

			foreach ($fields as $field)
			{
				// model a value if it exists
				if(isset($item->{$field}))
				{
					if (!$this->validateBefore($item->{$field}, $field, $table))
					{
						continue;
					}

					$item->{$field} = $this->value($item->{$field}, $field, $table);

					if (!$this->validateAfter($item->{$field}, $field, $table))
					{
						continue;
					}

					$item_bucket->{$field} = $item->{$field};

					$field_number++;
				}
			}

			// all items must have more than one field or its empty (1 = key)
			if ($field_number > 1)
			{
				return $item_bucket;
			}
		}

		return null;
	}

	/**
	 * Model the values of multiple items
	 *          Example: $this->items(Array, 'table_name');
	 *
	 * @param   array|null    $items    The array of item objects
	 * @param   string|null    $table     The table
	 *
	 * @return  array|null
	 * @since 3.2.0
	 */
	public function items(?array $items = null, ?string $table = null): ?array
	{
		// check if this is a valid table
		if (ArrayHelper::check($items))
		{
			// set the table name
			if (empty($table))
			{
				$table = $this->getTable();
			}

			foreach ($items as $id => &$item)
			{
				// model the item
				if (($item = $this->item($item, $table)) !== null)
				{
					// add the last ID
					$this->last[$table] = $item->id ?? $this->last[$table] ?? null;
				}
				else
				{
					unset($items[$id]);
				}
			}

			if (ArrayHelper::check($items))
			{
				return $items;
			}
		}

		return null;
	}

	/**
	 * Model the values of an row
	 *          Example: $this->item(Array, 'table_name');
	 *
	 * @param   array|null     $item      The item array
	 * @param   string|null    $table     The table
	 *
	 * @return  array|null
	 * @since 3.2.0
	 */
	public function row(?array $item, ?string $table = null): ?array
	{
		// we must have an array
		if (empty($item))
		{
			return null;
		}

		// set the table name
		if (empty($table))
		{
			$table = $this->getTable();
		}

		if (($fields = $this->getTableFields($table, true)) !== null)
		{
			// field counter
			$field_number = 0;

			// check if this is a valid table
			$item_bucket = [];

			foreach ($fields as $field)
			{
				// model a value if it exists
				if(isset($item[$field]))
				{
					if (!$this->validateBefore($item[$field], $field, $table))
					{
						continue;
					}

					$item[$field] = $this->value($item[$field], $field, $table);

					if (!$this->validateAfter($item[$field], $field, $table))
					{
						continue;
					}

					$item_bucket[$field] = $item[$field];

					$field_number++;
				}
			}

			// all items must have more than one field or its empty (1 = id or guid)
			if ($field_number > 1)
			{
				return $item_bucket;
			}
		}

		return null;
	}

	/**
	 * Model the values of multiple rows
	 *          Example: $this->items(Array, 'table_name');
	 *
	 * @param   array|null     $items    The array of item array
	 * @param   string|null    $table    The table
	 *
	 * @return  array|null
	 * @since 3.2.0
	 */
	public function rows(?array $items = null, ?string $table = null): ?array
	{
		// check if this is a valid table
		if (ArrayHelper::check($items))
		{
			// set the table name
			if (empty($table))
			{
				$table = $this->getTable();
			}

			foreach ($items as $id => &$item)
			{
				// model the item
				if (($item = $this->row($item, $table)) !== null)
				{
					// add the last ID
					$this->last[$table] = $item['id'] ?? $this->last[$table] ?? null;
				}
				else
				{
					unset($items[$id]);
				}
			}

			if (ArrayHelper::check($items))
			{
				return $items;
			}
		}

		return null;
	}

	/**
	 * Get last modeled ID
	 *          Example: $this->last('table_name');
	 *
	 * @param   string|null     $table     The table
	 *
	 * @return  int|null
	 * @since 3.2.0
	 */
	public function last(?string $table = null): ?int
	{
		// set the table name
		if (empty($table))
		{
			$table = $this->getTable();
		}

		// check if this is a valid table
		if ($table && isset($this->last[$table]))
		{
			return $this->last[$table];
		}

		return null;
	}

	/**
	 * Set the current active table
	 *
	 * @param string   $tableName  The table name
	 *
	 * @return  void
	 * @since 3.2.2
	 */
	public function setTable(string $tableName): void
	{
		$this->tableName = $tableName;
	}

	/**
	 * Set the switch to control the behaviour of empty values
	 *
	 * @param bool   $allowEmpty  The switch
	 *
	 * @return  void
	 * @since 3.2.2
	 */
	public function setAllowEmpty(bool $allowEmpty): void
	{
		$this->allowEmpty = $allowEmpty;
	}

	/**
	 * Get the current active table
	 *
	 * @return  string
	 * @since 3.2.0
	 */
	protected function getTable(): string
	{
		return $this->tableName;
	}

	/**
	 * Get the switch to control the behaviour of empty values
	 *
	 * @return  bool
	 * @since 3.2.2
	 */
	protected function getAllowEmpty(): bool
	{
		return $this->allowEmpty;
	}

	/**
	 * Get the current active table's fields (including defaults)
	 *
	 * @param   string  $table     The area
	 * @param   bool    $default   Add the default fields
	 *
	 * @return  array
	 * @since 3.2.0
	 */
	protected function getTableFields(string $table, bool $default = false): ?array
	{
		return $this->table->fields($table, $default);
	}

	/**
	 * Validate before the value is modelled (basic, override in child class)
	 *
	 * @param   mixed         $value   The field value
	 * @param   string|null   $field     The field key
	 * @param   string|null   $table   The table
	 *
	 * @return  bool
	 * @since 3.2.0
	 */
	abstract protected function validateBefore(&$value, ?string $field = null, ?string $table = null): bool;

	/**
	 * Validate after the value is modelled (basic, override in child class)
	 *
	 * @param   mixed         $value   The field value
	 * @param   string|null   $field     The field key
	 * @param   string|null   $table   The table
	 *
	 * @return  bool
	 * @since 3.2.0
	 */
	abstract protected function validateAfter(&$value, ?string $field = null, ?string $table = null): bool;
}