<?php

namespace Nest\Database\Query\Join;

use Nest\Database\Query\Where\ConditionBuilder;

class JoinBuilder
{
	const string INNER = "INNER";
	const string OUTER = "OUTER";
	const string LEFT = "LEFT";
	const string RIGHT = "RIGHT";

	/**
	 * @param mixed $query The calling query.
	 * @param string $type Join type (INNER, OUTER, LEFT, RIGHT, ...).
	 * @param string $table The table to join.
	 */
	public function __construct(protected mixed $query, public readonly string $type, public readonly string $table)
	{}

	/**
	 * ON conditions of the JOIN clause.
	 * @var ConditionBuilder[]
	 */
	protected array $on = [];

	/**
	 * Reset ON conditions.
	 * @return $this
	 */
	public function resetOn(): static
	{
		$this->on = [];
		return $this;
	}

	/**
	 * Add a ON condition.
	 * @param string|callable $column The column of the condition, or a condition builder callable.
	 * @param string $operator The operator of the condition (or the value column if no value is passed).
	 * @param string|null $valueColumn The value column of the condition.
	 * @return mixed The query.
	 */
	public function on(string|callable $column, string $operator, string $valueColumn = null): mixed
	{
		if (is_callable($column))
		{ // Callable condition builder.
			$this->on[] = $column(new ConditionBuilder());
		}
		else
		{ // Simple condition, registering it.
			if (!empty($operator) && empty($valueColumn))
			{ // If there are 2 parameters, considering the second one as the value, with default operator.
				$valueColumn = $operator;
				// Default operator: "=".
				$operator = "=";
			}

			// Create the simple condition.
			$this->on[] = (new ConditionBuilder())->column($column)->operator($operator)->column($valueColumn);
		}

		return $this->query;
	}

	/**
	 * Get join conditions.
	 * @return ConditionBuilder[] ON conditions of the JOIN clause.
	 */
	public function getConditions(): array
	{
		return $this->on;
	}
}