<?php
/**
 * Abstract pricing rule base class.
 *
 * @package AICOSO_Dynamic_Pricing_For_WooCommerce
 */

/**
 * Abstract class for all pricing rules.
 */
abstract class DP_AICOSO_Abstract_Pricing_Rule {

	/**
	 * Rule ID.
	 *
	 * @var int
	 */
	protected $rule_id;

	/**
	 * Rule name.
	 *
	 * @var string
	 */
	protected $rule_name;

	/**
	 * Rule type.
	 *
	 * @var string
	 */
	protected $rule_type;

	/**
	 * Rule priority.
	 *
	 * @var int
	 */
	protected $priority = 10;

	/**
	 * Rule conditions.
	 *
	 * @var array
	 */
	protected $conditions = array();

	/**
	 * Price adjustments.
	 *
	 * @var array
	 */
	protected $adjustments = array();

	/**
	 * Rule status.
	 *
	 * @var string
	 */
	protected $status = 'active';

	/**
	 * Start date.
	 *
	 * @var string
	 */
	protected $start_date;

	/**
	 * End date.
	 *
	 * @var string
	 */
	protected $end_date;

	/**
	 * Stop processing after this rule.
	 *
	 * @var bool
	 */
	protected $stop_processing = false;

	/**
	 * Check if rule is applicable.
	 *
	 * @param array $context Context data for evaluation.
	 * @return bool
	 */
	abstract public function is_applicable( $context );

	/**
	 * Calculate price based on rule.
	 *
	 * @param float $original_price Original price.
	 * @param array $context        Context data.
	 * @return float Modified price.
	 */
	abstract public function calculate_price( $original_price, $context );

	/**
	 * Get display price for frontend.
	 *
	 * @param WC_Product $product   Product object.
	 * @param string     $user_role User role.
	 * @return float|string
	 */
	abstract public function get_display_price( $product, $user_role = null );

	/**
	 * Constructor.
	 *
	 * @param array $rule_data Rule data from database.
	 */
	public function __construct( $rule_data = array() ) {
		if ( ! empty( $rule_data ) ) {
			$this->rule_id     = isset( $rule_data['rule_id'] ) ? intval( $rule_data['rule_id'] ) : 0;
			$this->rule_name   = isset( $rule_data['rule_name'] ) ? sanitize_text_field( $rule_data['rule_name'] ) : '';
			$this->rule_type   = isset( $rule_data['rule_type'] ) ? sanitize_text_field( $rule_data['rule_type'] ) : '';
			$this->priority    = isset( $rule_data['priority'] ) ? intval( $rule_data['priority'] ) : 10;
			$this->status      = isset( $rule_data['rule_status'] ) ? sanitize_text_field( $rule_data['rule_status'] ) : 'active';
			$this->start_date  = isset( $rule_data['start_date'] ) ? sanitize_text_field( $rule_data['start_date'] ) : '';
			$this->end_date    = isset( $rule_data['end_date'] ) ? sanitize_text_field( $rule_data['end_date'] ) : '';

			// Decode JSON fields - handle both string and array formats.
			if ( isset( $rule_data['conditions'] ) ) {
				if ( is_array( $rule_data['conditions'] ) ) {
					$this->conditions = $rule_data['conditions'];
				} else {
					$this->conditions = json_decode( $rule_data['conditions'], true );
					if ( null === $this->conditions ) {
						$this->conditions = array();
					}
				}
			} else {
				$this->conditions = array();
			}

			if ( isset( $rule_data['adjustments'] ) ) {
				if ( is_array( $rule_data['adjustments'] ) ) {
					$this->adjustments = $rule_data['adjustments'];
				} else {
					$this->adjustments = json_decode( $rule_data['adjustments'], true );
					if ( null === $this->adjustments ) {
						$this->adjustments = array();
					}
				}
			} else {
				$this->adjustments = array();
			}
		}
	}

	/**
	 * Validate rule configuration.
	 *
	 * @return bool|WP_Error
	 */
	public function validate() {
		if ( empty( $this->rule_name ) ) {
			return new WP_Error( 'invalid_rule', __( 'Rule name is required', 'aicoso-dynamic-pricing-for-woocommerce' ) );
		}

		if ( empty( $this->rule_type ) ) {
			return new WP_Error( 'invalid_rule', __( 'Rule type is required', 'aicoso-dynamic-pricing-for-woocommerce' ) );
		}

		if ( empty( $this->adjustments ) ) {
			return new WP_Error( 'invalid_rule', __( 'At least one price adjustment is required', 'aicoso-dynamic-pricing-for-woocommerce' ) );
		}

		return true;
	}

	/**
	 * Get rule priority.
	 *
	 * @return int
	 */
	public function get_priority() {
		return $this->priority;
	}

	/**
	 * Get rule ID.
	 *
	 * @return int
	 */
	public function get_id() {
		return $this->rule_id;
	}

	/**
	 * Get rule name.
	 *
	 * @return string
	 */
	public function get_name() {
		return $this->rule_name;
	}

	/**
	 * Check if should stop processing after this rule.
	 *
	 * @return bool
	 */
	public function stop_processing() {
		return $this->stop_processing;
	}

	/**
	 * Check if rule should be disabled based on context.
	 *
	 * @param array $context Context data.
	 * @return bool True if rule should be disabled, false otherwise.
	 */
	public function should_disable_rule( $context ) {
		// Check if rule should be disabled when products are on sale.
		if ( isset( $this->adjustments['disable_on_sale'] ) && '1' === $this->adjustments['disable_on_sale'] ) {
			if ( isset( $context['is_on_sale'] ) && $context['is_on_sale'] ) {
				return true;
			}
		}

		// Check if rule should be disabled when coupons are applied.
		if ( isset( $this->adjustments['disable_with_coupons'] ) && '1' === $this->adjustments['disable_with_coupons'] ) {
			if ( isset( $context['has_coupons'] ) && $context['has_coupons'] ) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Debug logging helper.
	 *
	 * @param string $message Log message.
	 * @param array  $data    Additional data to log.
	 */
	protected function debug_log( $message, $data = array() ) {
		if ( defined( 'WP_DEBUG' ) && WP_DEBUG && defined( 'WP_DEBUG_LOG' ) && WP_DEBUG_LOG ) {
			$log_message = '[DP_AICOSO_' . $this->rule_type . '_Rule] ' . $message;
			if ( ! empty( $data ) ) {
				$log_message .= ' | Data: ' . wp_json_encode( $data );
			}
			// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log -- Debug logging only when WP_DEBUG is enabled
			error_log( $log_message );
		}
	}

	/**
	 * Check if all conditions are met.
	 *
	 * @param array $context Context data.
	 * @return bool
	 */
	protected function check_conditions( $context ) {
		if ( empty( $this->conditions ) ) {
			return true;
		}

		// Debug log the conditions being checked.
		$this->debug_log(
			'Checking conditions',
			array(
				'conditions' => $this->conditions,
				'context' => $context,
			)
		);

		foreach ( $this->conditions as $condition ) {
			// Skip empty or invalid conditions.
			if ( empty( $condition ) || ! is_array( $condition ) ) {
				continue;
			}

			// Skip conditions without type.
			if ( ! isset( $condition['type'] ) || empty( $condition['type'] ) ) {
				continue;
			}

			$result = $this->evaluate_condition( $condition, $context );
			$this->debug_log(
				'Condition evaluation result',
				array(
					'condition' => $condition,
					'result' => $result,
				)
			);

			if ( ! $result ) {
				$this->debug_log( 'Condition failed, rule not applicable', $condition );
				return false;
			}
		}

		$this->debug_log( 'All conditions passed' );
		return true;
	}

	/**
	 * Evaluate a single condition.
	 *
	 * @param array $condition Condition data.
	 * @param array $context   Context data.
	 * @return bool
	 */
	protected function evaluate_condition( $condition, $context ) {
		$type     = isset( $condition['type'] ) ? $condition['type'] : '';
		$operator = isset( $condition['operator'] ) ? $condition['operator'] : '=';
		$value    = isset( $condition['value'] ) ? $condition['value'] : '';

		// If value is empty and it's not a presence check, skip the condition.
		if ( '' === $value && ! in_array( $operator, array( 'exists', 'not_exists' ), true ) ) {
			$this->debug_log( 'Skipping condition with empty value', $condition );
			return true;
		}

		switch ( $type ) {
			case 'user_role':
				return $this->check_user_role_condition( $context, $operator, $value );

			case 'quantity':
				return $this->check_quantity_condition( $context, $operator, $value );

			case 'cart_total':
				return $this->check_cart_total_condition( $context, $operator, $value );

			case 'date':
				return $this->check_date_condition( $context, $operator, $value );

			default:
				/**
				 * Filter to evaluate custom conditions.
				 *
				 * @since 1.0.0
				 *
				 * @param bool  $result    The condition result.
				 * @param array $condition The condition data.
				 * @param array $context   The evaluation context.
				 */
				return apply_filters( 'dp_aicoso_evaluate_condition', true, $condition, $context );
		}
	}

	/**
	 * Check user role condition.
	 *
	 * @param array  $context  Context data.
	 * @param string $operator Comparison operator.
	 * @param mixed  $value    Value to compare.
	 * @return bool
	 */
	protected function check_user_role_condition( $context, $operator, $value ) {
		$user_role = isset( $context['user_role'] ) ? $context['user_role'] : 'guest';

		// Handle comma-separated roles if provided as string.
		if ( is_string( $value ) && strpos( $value, ',' ) !== false ) {
			$value = array_map( 'trim', explode( ',', $value ) );
		}

		$this->debug_log(
			'Checking user role condition',
			array(
				'user_role' => $user_role,
				'operator' => $operator,
				'value' => $value,
			)
		);

		switch ( $operator ) {
			case '=':
			case 'equals':
				if ( is_array( $value ) ) {
					return in_array( $user_role, $value, true );
				}
				return $user_role === $value;

			case '!=':
			case 'not_equals':
				if ( is_array( $value ) ) {
					return ! in_array( $user_role, $value, true );
				}
				return $user_role !== $value;

			case 'in':
				return in_array( $user_role, (array) $value, true );

			case 'not_in':
				return ! in_array( $user_role, (array) $value, true );

			default:
				$this->debug_log( 'Unknown operator for user role condition: ' . $operator );
				return false;
		}
	}

	/**
	 * Check quantity condition.
	 *
	 * @param array  $context  Context data.
	 * @param string $operator Comparison operator.
	 * @param mixed  $value    Value to compare.
	 * @return bool
	 */
	protected function check_quantity_condition( $context, $operator, $value ) {
		// First check if cart_quantity is available (for cart-wide quantity checks).
		// Otherwise fall back to individual product quantity.
		if ( isset( $context['cart_quantity'] ) ) {
			$quantity = intval( $context['cart_quantity'] );
		} else {
			$quantity = isset( $context['quantity'] ) ? intval( $context['quantity'] ) : 1;
		}
		$value    = intval( $value );

		$this->debug_log(
			'Checking quantity condition',
			array(
				'quantity' => $quantity,
				'cart_quantity' => isset( $context['cart_quantity'] ) ? $context['cart_quantity'] : 'not set',
				'operator' => $operator,
				'value' => $value,
			)
		);

		switch ( $operator ) {
			case '=':
			case 'equals':
				return $quantity === $value;

			case '!=':
			case 'not_equals':
				return $quantity !== $value;

			case '>':
			case 'greater_than':
				return $quantity > $value;

			case '>=':
			case 'greater_than_or_equal':
				return $quantity >= $value;

			case '<':
			case 'less_than':
				return $quantity < $value;

			case '<=':
			case 'less_than_or_equal':
				return $quantity <= $value;

			default:
				$this->debug_log( 'Unknown operator for quantity condition: ' . $operator );
				return false;
		}
	}

	/**
	 * Check cart total condition.
	 *
	 * @param array  $context  Context data.
	 * @param string $operator Comparison operator.
	 * @param mixed  $value    Value to compare.
	 * @return bool
	 */
	protected function check_cart_total_condition( $context, $operator, $value ) {
		$cart_total = isset( $context['cart_total'] ) ? floatval( $context['cart_total'] ) : 0;

		// Also check cart_subtotal if cart_total is 0.
		if ( 0 === $cart_total && isset( $context['cart_subtotal'] ) ) {
			$cart_total = floatval( $context['cart_subtotal'] );
		}

		$value = floatval( $value );

		$this->debug_log(
			'Checking cart total condition',
			array(
				'cart_total' => $cart_total,
				'operator' => $operator,
				'value' => $value,
			)
		);

		switch ( $operator ) {
			case '=':
			case 'equals':
				return abs( $cart_total - $value ) < 0.01; // Use epsilon for float comparison.
			case '!=':
			case 'not_equals':
				return abs( $cart_total - $value ) >= 0.01;

			case '>':
			case 'greater_than':
				return $cart_total > $value;

			case '>=':
			case 'greater_than_or_equal':
				return $cart_total >= $value;

			case '<':
			case 'less_than':
				return $cart_total < $value;

			case '<=':
			case 'less_than_or_equal':
				return $cart_total <= $value;

			default:
				$this->debug_log( 'Unknown operator for cart total condition: ' . $operator );
				return false;
		}
	}

	/**
	 * Check date condition.
	 *
	 * @param array  $context  Context data.
	 * @param string $operator Comparison operator.
	 * @param mixed  $value    Value to compare.
	 * @return bool
	 */
	protected function check_date_condition( $context, $operator, $value ) {
		$current_time = isset( $context['timestamp'] ) ? $context['timestamp'] : current_time( 'timestamp' );
		$compare_time = strtotime( $value );

		if ( ! $compare_time ) {
			return false;
		}

		switch ( $operator ) {
			case 'after':
				return $current_time > $compare_time;

			case 'before':
				return $current_time < $compare_time;

			case 'between':
				if ( is_array( $value ) && count( $value ) === 2 ) {
					$start = strtotime( $value[0] );
					$end   = strtotime( $value[1] );
					return $current_time >= $start && $current_time <= $end;
				}
				return false;

			default:
				return false;
		}
	}

	/**
	 * Apply price adjustment.
	 *
	 * @param float $price      Original price.
	 * @param array $adjustment Adjustment configuration.
	 * @return float Modified price.
	 */
	protected function apply_adjustment( $price, $adjustment ) {
		$type  = isset( $adjustment['type'] ) ? $adjustment['type'] : 'fixed';
		$value = isset( $adjustment['value'] ) ? floatval( $adjustment['value'] ) : 0;

		switch ( $type ) {
			case 'percentage':
				// Percentage discount.
				$discount = $price * ( $value / 100 );
				return max( 0, $price - $discount );

			case 'fixed':
				// Fixed amount discount.
				return max( 0, $price - $value );

			case 'fixed_price':
				// Set to fixed price.
				return max( 0, $value );

			default:
				/**
				 * Filter the adjusted price.
				 *
				 * @since 1.0.0
				 *
				 * @param float $price      The original price.
				 * @param array $adjustment The adjustment settings.
				 * @param string $type      The adjustment type.
				 * @param float $value      The adjustment value.
				 */
				return apply_filters( 'dp_aicoso_apply_adjustment', $price, $adjustment, $type, $value );
		}
	}

	/**
	 * Check if rule is active within date range.
	 *
	 * @return bool
	 */
	protected function is_within_date_range() {
		$current_time = current_time( 'timestamp' );

		// Check start date.
		if ( ! empty( $this->start_date ) ) {
			$start_time = strtotime( $this->start_date );
			if ( $start_time && $current_time < $start_time ) {
				return false;
			}
		}

		// Check end date.
		if ( ! empty( $this->end_date ) ) {
			$end_time = strtotime( $this->end_date );
			if ( $end_time && $current_time > $end_time ) {
				return false;
			}
		}

		return true;
	}

	/**
	 * Save rule to database.
	 *
	 * @return int|WP_Error Rule ID on success, WP_Error on failure.
	 */
	public function save() {
		global $wpdb;

		// Validate rule.
		$valid = $this->validate();
		if ( is_wp_error( $valid ) ) {
			return $valid;
		}

		$table_name = $wpdb->prefix . 'dp_aicoso_rules';

		// Prepare data for database operations.
		$data = array(
			'rule_name'    => $this->rule_name,
			'rule_type'    => $this->rule_type,
			'rule_status'  => $this->status,
			'priority'     => $this->priority,
			'conditions'   => wp_json_encode( $this->conditions ),
			'adjustments'  => wp_json_encode( $this->adjustments ),
			'start_date'   => $this->start_date,
			'end_date'     => $this->end_date,
		);

		// Format placeholders for data types.
		$format = array( '%s', '%s', '%s', '%d', '%s', '%s', '%s', '%s' );

		if ( $this->rule_id > 0 ) {
			// Update existing rule - $wpdb->update() properly escapes with format parameters.
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery
			$result = $wpdb->update(
				$table_name,
				$data,
				array( 'rule_id' => $this->rule_id ),
				$format,
				array( '%d' )
			);

			if ( false === $result ) {
				return new WP_Error( 'db_error', __( 'Failed to update rule', 'aicoso-dynamic-pricing-for-woocommerce' ) );
			}

			// Clear cache for the updated rule.
			wp_cache_delete( 'dp_aicoso_rule_' . $this->rule_id, 'dp_aicoso_rules' );
			wp_cache_delete( 'dp_aicoso_rules_' . $this->rule_type, 'dp_aicoso_rules' );
		} else {
			// Insert new rule - $wpdb->insert() properly escapes with format parameters.
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery
			$result = $wpdb->insert( $table_name, $data, $format );

			if ( false === $result ) {
				return new WP_Error( 'db_error', __( 'Failed to create rule', 'aicoso-dynamic-pricing-for-woocommerce' ) );
			}

			$this->rule_id = $wpdb->insert_id;

			// Clear cache for the new rule type.
			wp_cache_delete( 'dp_aicoso_rules_' . $this->rule_type, 'dp_aicoso_rules' );
		}

		// Clear cache.
		$this->clear_cache();

		return $this->rule_id;
	}

	/**
	 * Clear related cache.
	 */
	protected function clear_cache() {
		// Clear price cache.
		delete_transient( 'dp_aicoso_rules_' . $this->rule_type );

		// Clear object cache with consistent cache group.
		wp_cache_delete( 'dp_aicoso_rule_' . $this->rule_id, 'dp_aicoso_rules' );
		wp_cache_delete( 'dp_aicoso_rules_' . $this->rule_type, 'dp_aicoso_rules' );

		/**
		 * Action fired when rule cache is cleared.
		 *
		 * @since 1.0.0
		 *
		 * @param int    $rule_id   The rule ID.
		 * @param string $rule_type The rule type.
		 */
		do_action( 'dp_aicoso_rule_cache_cleared', $this->rule_id, $this->rule_type );
	}
}