<?php

namespace TEC\Common\StellarWP\DB\QueryBuilder\Concerns;

use Closure;
use TEC\Common\StellarWP\DB\DB;
use TEC\Common\StellarWP\DB\QueryBuilder\Clauses\RawSQL;
use TEC\Common\StellarWP\DB\QueryBuilder\Clauses\Where;
use TEC\Common\StellarWP\DB\QueryBuilder\QueryBuilder;
use TEC\Common\StellarWP\DB\QueryBuilder\Types\Operator;
use TEC\Common\StellarWP\DB\QueryBuilder\WhereQueryBuilder;


/**
 * @since 1.0.0
 */
trait WhereClause {

	/**
	 * @var Where[]|RawSQL[]|string[]
	 */
	protected $wheres = [];


	/**
	 * @var bool
	 */
	private $includeWhereKeyword = true;

	/**
	 * @param  string|Closure|null  $column  The Closure will receive a StellarWP\DB\QueryBuilder\WhereQueryBuilder instance
	 * @param  string|Closure|array|null|mixed  $value  The Closure will receive a StellarWP\DB\QueryBuilder\QueryBuilder instance
	 * @param  string  $comparisonOperator
	 * @param  string  $logicalOperator
	 *
	 * @return $this
	 */
	private function setWhere( $column, $value, $comparisonOperator, $logicalOperator ) {
		// If the columns is a Closure instance, we will assume the developer
		// wants to begin a nested where statement which is wrapped in parentheses.
		if ( $column instanceof Closure && is_null( $value ) ) {
			$builder = new WhereQueryBuilder();
			call_user_func( $column, $builder );

			// Since this is a nested where statement, we have to remove the starting WHERE keyword
			// which is the first returned array element from the getWhereSQL method
			$wheres = $builder->getSQL();
			array_shift( $wheres );

			$this->wheres[] = sprintf(
				"%s (%s)",
				empty( $this->wheres ) ? null : $logicalOperator,
				implode( ' ', $wheres )
			);
		} // If the value is a Closure instance, we will assume the developer is performing an entire sub-select within the query
		elseif ( $value instanceof Closure ) {
			$builder = new QueryBuilder();
			call_user_func( $value, $builder );

			$this->wheres[] = sprintf(
				"%s %s %s (%s)",
				empty( $this->wheres ) ? null : $logicalOperator,
				$column,
				$comparisonOperator,
				$builder->getSQL()
			);
		} // Standard WHERE clause
		else {
			$this->wheres[] = new Where(
				$column,
				$value,
				$comparisonOperator,
				empty( $this->wheres ) ? null : $logicalOperator
			);
		}

		return $this;
	}

	/**
	 * @param  string|Closure|null  $column  The closure will receive a StellarWP\DB\QueryBuilder\WhereQueryBuilder instance
	 * @param  string|Closure|array|null|mixed  $value  The closure will receive a StellarWP\DB\QueryBuilder\QueryBuilder instance
	 * @param  string  $comparisonOperator
	 *
	 * @return $this
	 */
	public function where( $column, $value = null, $comparisonOperator = '=' ) {
		return $this->setWhere(
			$column,
			$value,
			$comparisonOperator,
			Operator::_AND
		);
	}

	/**
	 * @param  string|Closure  $column
	 * @param  string|Closure|array|null|mixed  $value
	 * @param  string  $comparisonOperator
	 *
	 * @return $this
	 */
	public function orWhere( $column, $value = null, $comparisonOperator = '=' ) {
		return $this->setWhere(
			$column,
			$value,
			$comparisonOperator,
			Operator::_OR
		);
	}

	/**
	 * @param  string  $column
	 * @param  array|Closure  $value
	 *
	 * @return $this
	 */
	public function whereIn( $column, $value ) {
		return $this->where(
			$column,
			$value,
			Operator::IN
		);
	}

	/**
	 * @param  string  $column
	 * @param  array|Closure  $value
	 *
	 * @return $this
	 */
	public function orWhereIn( $column, $value ) {
		return $this->orWhere(
			$column,
			$value,
			Operator::IN
		);
	}

	/**
	 * @param  string  $column
	 * @param  array|Closure  $value
	 *
	 * @return $this
	 */
	public function whereNotIn( $column, $value ) {
		return $this->where(
			$column,
			$value,
			Operator::NOTIN
		);
	}

	/**
	 * @param  string  $column
	 * @param  array|Closure  $value
	 *
	 * @return $this
	 */
	public function orWhereNotIn( $column, $value ) {
		return $this->orWhere(
			$column,
			$value,
			Operator::NOTIN
		);
	}

	/**
	 * @param  string  $column
	 * @param  string|int  $min
	 * @param  string|int  $max
	 *
	 * @return $this
	 */
	public function whereBetween( $column, $min, $max ) {
		return $this->where(
			$column,
			[ $min, $max ],
			Operator::BETWEEN
		);
	}

	/**
	 * @param  string  $column
	 * @param  string|int  $min
	 * @param  string|int  $max
	 *
	 * @return $this
	 */
	public function whereNotBetween( $column, $min, $max ) {
		return $this->where(
			$column,
			[ $min, $max ],
			Operator::NOTBETWEEN
		);
	}

	/**
	 * @param  string  $column
	 * @param  string|int  $min
	 * @param  string|int  $max
	 *
	 * @return $this
	 */
	public function orWhereBetween( $column, $min, $max ) {
		return $this->orWhere(
			$column,
			[ $min, $max ],
			Operator::BETWEEN
		);
	}

	/**
	 * @param  string  $column
	 * @param  string|int  $min
	 * @param  string|int  $max
	 *
	 * @return $this
	 */
	public function orWhereNotBetween( $column, $min, $max ) {
		return $this->orWhere(
			$column,
			[ $min, $max ],
			Operator::NOTBETWEEN
		);
	}

	/**
	 * @param  string  $column
	 * @param  string  $value
	 *
	 * @return $this
	 */
	public function whereLike( $column, $value ) {
		return $this->where(
			$column,
			$value,
			Operator::LIKE
		);
	}

	/**
	 * @param  string  $column
	 * @param  string  $value
	 *
	 * @return $this
	 */
	public function whereNotLike( $column, $value ) {
		return $this->where(
			$column,
			$value,
			Operator::NOTLIKE
		);
	}

	/**
	 * @param  string  $column
	 * @param  mixed  $value
	 *
	 * @return $this
	 */
	public function orWhereLike( $column, $value ) {
		return $this->orWhere(
			$column,
			$value,
			Operator::LIKE
		);
	}

	/**
	 * @param  string  $column
	 * @param  mixed  $value
	 *
	 * @return $this
	 */
	public function orWhereNotLike( $column, $value ) {
		return $this->orWhere(
			$column,
			$value,
			Operator::NOTLIKE
		);
	}

	/**
	 * @param  string  $column
	 *
	 * @return $this
	 */
	public function whereIsNull( $column ) {
		return $this->where(
			$column,
			null,
			Operator::ISNULL
		);
	}

	/**
	 * @param  string  $column
	 *
	 * @return $this
	 */
	public function orWhereIsNull( $column ) {
		return $this->orWhere(
			$column,
			null,
			Operator::ISNULL
		);
	}

	/**
	 * @param  string  $column
	 *
	 * @return $this
	 */
	public function whereIsNotNull( $column ) {
		return $this->where(
			$column,
			null,
			Operator::NOTNULL
		);
	}

	/**
	 * @param  string  $column
	 *
	 * @return $this
	 */
	public function orWhereIsNotNull( $column ) {
		return $this->orWhere(
			$column,
			null,
			Operator::NOTNULL
		);
	}


	/**
	 * @param  Closure  $callback  The closure will receive a StellarWP\DB\QueryBuilder\QueryBuilder instance
	 *
	 * @return $this
	 */
	public function whereExists( $callback ) {
		return $this->where(
			null,
			$callback,
			Operator::EXISTS
		);
	}

	/**
	 * @param  Closure  $callback  The closure will receive a StellarWP\DB\QueryBuilder\QueryBuilder instance
	 *
	 * @return $this
	 */
	public function whereNotExists( $callback ) {
		return $this->where(
			null,
			$callback,
			Operator::NOTEXISTS
		);
	}

	/**
	 * Add raw SQL WHERE clause
	 *
	 * @param $sql
	 * @param ...$args
	 *
	 * @return $this
	 */
	public function whereRaw( $sql, ...$args ) {
		$this->wheres[] = new RawSQL( $sql, $args );

		return $this;
	}

	/**
	 * @return string[]
	 */
	protected function getWhereSQL() {
		// Bailout
		if ( empty( $this->wheres ) ) {
			return [];
		}

		$wheres = [];

		foreach ( $this->wheres as $i => $where ) {
			if ( $where instanceof RawSQL ) {
				if ( $i === 0 ) {
					// If the first element is an instance of RawSQL
					// then we don't need the starting WHERE keyword because we assume that the dev will include that in RawSQL
					$this->includeWhereKeyword = false;
				}
				$wheres[] = $where->sql;
				continue;
			}

			if ( $where instanceof Where ) {
				$wheres[] = $this->buildWhereSQL( $where );
				continue;
			}

			// If the variable $where is not an instance of the Where class
			// it means the SQL is already generated by the Query Builder, so we just return that
			$wheres[] = $where;
		}


		if ( $this->includeWhereKeyword ) {
			return array_merge( ['WHERE'], $wheres );
		}

		return $wheres;
	}

	/**
	 * @param  Where  $where
	 *
	 * @return string
	 */
	private function buildWhereSQL( Where $where ) {
		switch ( $where->comparisonOperator ) {
			// Handle membership conditions
			case Operator::IN:
			case Operator::NOTIN:

				return DB::prepare(
						"%1s %2s %3s",
						$where->logicalOperator,
						$where->column,
						$where->comparisonOperator
					) . ' (' . implode(
						   ',',
						   array_map( function ( $where ) {
							   return DB::prepare( '%s', $where );
						   }, $where->value )
					   ) . ')';

			// Handle BETWEEN conditions
			case Operator::BETWEEN:
			case Operator::NOTBETWEEN:
				list( $min, $max ) = $where->value;

				return DB::prepare(
					"%1s %2s %3s %s AND %s",
					$where->logicalOperator,
					$where->column,
					$where->comparisonOperator,
					$min,
					$max
				);

			// Handle LIKE conditions
			case Operator::LIKE:
			case Operator::NOTLIKE:
				return DB::prepare(
					"%1s %2s %3s %s",
					$where->logicalOperator,
					$where->column,
					$where->comparisonOperator,
					strpos( $where->value, '%' ) !== false
						? $where->value
						: sprintf( '%%%s%%', $where->value )
				);

			// Handle NULL conditions
			case Operator::ISNULL:
			case Operator::NOTNULL:
				return DB::prepare(
					"%1s %2s %3s",
					$where->logicalOperator,
					$where->column,
					$where->comparisonOperator
				);

			// Standard WHERE clause
			default:
				return DB::prepare(
					"%1s %2s %3s %s",
					$where->logicalOperator,
					$where->column,
					$where->comparisonOperator,
					$where->value
				);
		}
	}
}
