<?php
/**
 * Contact Form 7 provider adapter.
 *
 * @package ModelGainWebmcpForms
 */

namespace ModelGain\WordPress\WebmcpForms;

/**
 * Normalizes Contact Form 7 tags into the canonical provider-independent model.
 */
final class ContactForm7Adapter {
	/**
	 * Property value.
	 *
	 * @var PolicyEngine
	 */
	private $policy;

	/**
	 * Perform the documented operation.
	 *
	 * @param PolicyEngine $policy Exposure policy.
	 */
	public function __construct( PolicyEngine $policy ) {
		$this->policy = $policy;
	}

	/**
	 * Discover currently stored Contact Form 7 forms.
	 *
	 * @return FormModel[]
	 */
	public function discover() {
		if ( ! class_exists( 'WPCF7_ContactForm' ) || ! is_callable( array( 'WPCF7_ContactForm', 'find' ) ) ) {
			return array();
		}

		$forms = \WPCF7_ContactForm::find();
		if ( ! is_array( $forms ) ) {
			return array();
		}

		$models = array();
		foreach ( $forms as $form ) {
			if ( is_object( $form ) ) {
				$models[] = $this->normalize( $form );
			}
		}
		return $models;
	}

	/**
	 * Normalize one WPCF7_ContactForm object.
	 *
	 * @param object $contact_form Contact Form 7 form.
	 * @return FormModel
	 */
	public function normalize( $contact_form ) {
		$id    = is_callable( array( $contact_form, 'id' ) ) ? absint( $contact_form->id() ) : 0;
		$title = is_callable( array( $contact_form, 'title' ) ) ? (string) $contact_form->title() : '';
		$tags  = is_callable( array( $contact_form, 'scan_form_tags' ) ) ? $contact_form->scan_form_tags() : false;

		if ( ! is_array( $tags ) ) {
			return new FormModel( $id, $title, 'cf7', array(), array(), 'Contact Form 7 did not provide a readable tag list.' );
		}

		$fields         = array();
		$blocked_fields = array();
		$seen_names     = array();
		foreach ( $tags as $tag ) {
			if ( ! is_object( $tag ) ) {
				$blocked_fields[] = $this->blocked_record( '', 'unknown', 'Malformed provider control.' );
				continue;
			}

			$type = isset( $tag->basetype ) && is_string( $tag->basetype ) && '' !== $tag->basetype ? $tag->basetype : ( isset( $tag->type ) ? (string) $tag->type : '' );
			$type = strtolower( preg_replace( '/\*$/', '', $type ) );
			$name = isset( $tag->name ) ? (string) $tag->name : '';

			if ( $this->is_submit_control( $type ) ) {
				continue;
			}

			$normalized = array(
				'name'          => $name,
				'type'          => $type,
				'label'         => $this->tag_label( $tag, $name ),
				'required'      => $this->is_required( $tag ),
				'options'       => $this->tag_options( $tag ),
				'provider_type' => isset( $tag->type ) ? (string) $tag->type : $type,
			);

			if ( 'select' === $type && $this->has_option( $tag, 'multiple' ) ) {
				$blocked_fields[] = $this->blocked_record( $name, $type, 'Multiple select controls are not supported.' );
				continue;
			}

			$decision = $this->policy->evaluate( $normalized );
			if ( ! empty( $decision['allowed'] ) && isset( $decision['field'] ) && $decision['field'] instanceof Field ) {
				$field = $decision['field'];
				if ( isset( $seen_names[ $field->name() ] ) ) {
					$blocked_fields[] = $this->blocked_record( $field->name(), $type, 'Duplicate field names are not supported.' );
					continue;
				}
				$seen_names[ $field->name() ] = true;
				$fields[]                     = $field;
			} elseif ( isset( $decision['blocked'] ) && is_array( $decision['blocked'] ) ) {
				$blocked_fields[] = $decision['blocked'];
			} else {
				$blocked_fields[] = $this->blocked_record( $name, $type, 'Policy evaluation failed closed.' );
			}
		}

		usort(
			$fields,
			static function ( Field $left, Field $right ) {
				return strcmp( $left->name(), $right->name() );
			}
		);

		$reason = '';
		if ( ! empty( $blocked_fields ) ) {
			$reason = 'One or more Contact Form 7 controls are unsupported or policy-blocked.';
		} elseif ( empty( $fields ) ) {
			$reason = 'No supported human-visible user fields were found.';
		}

		return new FormModel( $id, $title, 'cf7', $fields, $blocked_fields, $reason );
	}

	/**
	 * Perform the documented operation.
	 *
	 * @param object $tag CF7 form tag.
	 * @param string $fallback Fallback label.
	 * @return string
	 */
	private function tag_label( $tag, $fallback ) {
		foreach ( array( 'label', 'labels' ) as $property ) {
			if ( isset( $tag->{$property} ) && is_string( $tag->{$property} ) && '' !== trim( $tag->{$property} ) ) {
				return trim( $tag->{$property} );
			}
		}
		return '' !== $fallback ? $fallback : 'Form field';
	}

	/**
	 * Perform the documented operation.
	 *
	 * @param object $tag CF7 form tag.
	 * @return bool
	 */
	private function is_required( $tag ) {
		$type = isset( $tag->type ) ? (string) $tag->type : '';
		return 0 < strlen( $type ) && '*' === substr( $type, -1 );
	}

	/**
	 * Perform the documented operation.
	 *
	 * @param object $tag CF7 form tag.
	 * @return string[]
	 */
	private function tag_options( $tag ) {
		$values  = isset( $tag->values ) && is_array( $tag->values ) ? $tag->values : array();
		$options = array();
		foreach ( $values as $value ) {
			if ( is_scalar( $value ) && '' !== (string) $value ) {
				$options[] = (string) $value;
			}
		}
		return array_values( array_unique( $options ) );
	}

	/**
	 * Perform the documented operation.
	 *
	 * @param object $tag CF7 form tag.
	 * @param string $option Option name.
	 * @return bool
	 */
	private function has_option( $tag, $option ) {
		return isset( $tag->options ) && is_array( $tag->options ) && in_array( $option, $tag->options, true );
	}

	/**
	 * Perform the documented operation.
	 *
	 * @param string $type CF7 base type.
	 * @return bool
	 */
	private function is_submit_control( $type ) {
		return in_array( $type, array( 'submit', 'button', 'image' ), true );
	}

	/**
	 * Perform the documented operation.
	 *
	 * @param string $name Field name.
	 * @param string $type Provider type.
	 * @param string $reason Block reason.
	 * @return array<string,string>
	 */
	private function blocked_record( $name, $type, $reason ) {
		return array(
			'name'          => (string) $name,
			'provider_type' => (string) $type,
			'reason'        => (string) $reason,
		);
	}
}