<?php
/**
 * Contacts only from SSA Basic 1.6.12.33 appointments-only support/export JSON.
 * Source: SSA_Support_Status_Api::get_export_code; SSA_Appointment_Model schema;
 * SSA_Upgrade::migrate_paid_to_free_customer_info. No edition/license provenance proof.
 * Settings, types, appointments, metadata, payments and consent are never imported.
 */
namespace Abientot\Import\SourceAdapters;
use Abientot\Import\{Csv, Service};
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}
final class SSAFree {
	private const FIELDS = array( 'id', 'appointment_type_id', 'rescheduled_from_appointment_id', 'rescheduled_to_appointment_id', 'group_id', 'author_id', 'customer_id', 'customer_information', 'customer_timezone', 'customer_locale', 'start_date', 'end_date', 'title', 'description', 'payment_method', 'payment_received', 'mailchimp_list_id', 'google_calendar_id', 'google_calendar_event_id', 'web_meeting_password', 'web_meeting_id', 'web_meeting_url', 'allow_sms', 'status', 'date_created', 'date_modified', 'expiration_date', 'public_edit_url', 'public_token', 'staff_ids', 'selected_resources', 'label_id', 'rescheduling_note', 'meta', 'payments' );
	public static function normalize( string $bytes ): array {
		if ( $bytes === '' || strlen( $bytes ) > Csv::BYTES || ! preg_match( '//u', $bytes ) ) {
			throw new \DomainException( 'import_source_format' );
		}
		if ( str_starts_with( $bytes, "\xef\xbb\xbf" ) ) {
			$bytes = substr( $bytes, 3 );
		}
		try {
			$root = json_decode( $bytes, false, 8, JSON_THROW_ON_ERROR );
		} catch ( \JsonException $error ) {
			throw new \DomainException( 'import_source_format' );
		}
		$offset = 0;
		self::unique_keys( $bytes, $offset );
		if ( ! $root instanceof \stdClass ) {
			throw new \DomainException( 'import_source_format' );
		}
		$root = (array) $root;
		$keys = array_keys( $root );
		sort( $keys );
		if ( $keys !== array( 'appointment_meta', 'appointments', 'resource_appointments', 'staff_appointments' ) ) {
			throw new \DomainException( 'import_source_format' );
		}
		if ( $root['appointment_meta'] !== array() ) {
			throw new \DomainException( 'import_source_format' );
		}
		// SSA_Missing::__call returns null for absent premium root models in Basic.
		foreach ( array( 'staff_appointments', 'resource_appointments' ) as $key ) {
			if ( $root[ $key ] !== array() && $root[ $key ] !== null ) {
					throw new \DomainException( 'import_source_format' );
			}
		}
		$appointments = $root['appointments'];
		if ( ! is_array( $appointments ) || array_values( $appointments ) !== $appointments || ! $appointments || count( $appointments ) > Csv::ROWS ) {
			throw new \DomainException( 'import_rows' );
		}
		$contacts   = array();
		$identities = array();
		$ids        = array();
		foreach ( $appointments as $appointment ) {
			if ( ! $appointment instanceof \stdClass ) {
				throw new \DomainException( 'import_source_format' );
			}
			$row = (array) $appointment;
			if ( array_diff( array_keys( $row ), self::FIELDS ) || array_diff( array( 'id', 'appointment_type_id', 'customer_information', 'start_date', 'end_date', 'status' ), array_keys( $row ) ) ) {
				throw new \DomainException( 'import_source_format' );
			}
			$id = Service::integer( $row['id'], 1 );
			Service::integer( $row['appointment_type_id'], 1 );
			if ( isset( $ids[ $id ] ) ) {
					throw new \DomainException( 'import_duplicate_source' );
			}
			$ids[ $id ] = true;
			// Native prepare_item_for_response enriches every exported row, even in Basic.
			// Disabled paid features return [] here, not the root-level Missing-model null.
			foreach ( array( 'staff_ids', 'selected_resources', 'meta', 'payments' ) as $key ) {
				if ( array_key_exists( $key, $row ) && $row[ $key ] !== array() ) {
					throw new \DomainException( 'import_source_format' );
				}
			}
			foreach ( array( 'public_edit_url', 'public_token', 'rescheduling_note' ) as $key ) {
				if ( array_key_exists( $key, $row ) && ! is_string( $row[ $key ] ) ) {
					throw new \DomainException( 'import_source_format' );
				}
			}
			foreach ( $row as $key => $value ) {
				if ( in_array( $key, array( 'customer_information', 'staff_ids', 'selected_resources', 'meta', 'payments' ), true ) ) {
					continue;
				}
				if ( ! is_scalar( $value ) && $value !== null || is_string( $value ) && ( strlen( $value ) > Csv::CELL || preg_match( '/[\x00-\x1f]/', $value ) ) ) {
					throw new \DomainException( 'import_source_format' );
				}
			}
			foreach ( array( 'group_id', 'payment_method', 'payment_received', 'mailchimp_list_id', 'google_calendar_id', 'google_calendar_event_id', 'web_meeting_password', 'web_meeting_id', 'web_meeting_url', 'allow_sms' ) as $key ) {
				if ( isset( $row[ $key ] ) && ! in_array( $row[ $key ], array( '', false, 0, '0', '0.00' ), true ) ) {
					throw new \DomainException( 'import_source_format' );
				}
			}
			foreach ( array( 'start_date', 'end_date' ) as $key ) {
				$date = $row[ $key ];
				if ( ! is_string( $date ) ) {
					throw new \DomainException( 'import_source_format' );
				}
				$instant = \DateTimeImmutable::createFromFormat( '!Y-m-d H:i:s', $date, new \DateTimeZone( 'UTC' ) );
				if ( ! $instant || $instant->format( 'Y-m-d H:i:s' ) !== $date ) {
					throw new \DomainException( 'import_source_format' );
				}
			}
			if ( ! is_string( $row['status'] ) || ! in_array( $row['status'], array( 'booked', 'canceled', 'abandoned', 'pending_form' ), true ) ) {
				throw new \DomainException( 'import_source_format' );
			}
			$information = $row['customer_information'];
			if ( ! $information instanceof \stdClass ) {
				throw new \DomainException( 'import_customer' );
			}
			$information = (array) $information;
			if ( array_diff( array_keys( $information ), array( 'Name', 'Email', 'Phone' ) ) || ! isset( $information['Name'] ) ) {
					throw new \DomainException( 'import_source_format' );
			}
			$contact    = array(
				'source_key'   => 'contact',
				'display_name' => $information['Name'],
				'email'        => $information['Email'] ?? '',
				'phone'        => $information['Phone'] ?? ''
			);
			$normalized = Service::normalize( 'customers', $contact )['customer'];
			$identity   = $normalized['email'] !== '' ? 'email:' . $normalized['email'] : 'phone:' . $normalized['phone'];
			$key        = 'ssa-contact-' . hash( 'sha256', $identity );
			if ( isset( $contacts[ $key ] ) ) {
				if ( $contacts[ $key ]['normalized'] !== $normalized ) {
					throw new \DomainException( 'import_ambiguous_contact' );
				}
				continue;
			}
			foreach ( array( 'email', 'phone' ) as $field ) {
				if ( $normalized[ $field ] === '' ) {
					continue;
				}
				$identifier = $field . ':' . $normalized[ $field ];
				if ( isset( $identities[ $identifier ] ) && $identities[ $identifier ] !== $key ) {
					throw new \DomainException( 'import_ambiguous_contact' );
				}
				$identities[ $identifier ] = $key;
			}
			$contact          = array(
				'source_key'   => $key,
				'display_name' => $normalized['display_name'],
				'email'        => $normalized['email'],
				'phone'        => $normalized['phone']
			);
			$contacts[ $key ] = array(
				'contact'    => $contact,
				'normalized' => $normalized
			);
		}
		// Stable output independent of source row order, appointment IDs or booking count.
		ksort( $contacts );
		$stream = fopen( 'php://temp', 'w+' ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fopen -- In-memory php://temp stream for fputcsv(); no file is written.
		if ( ! $stream ) {
			throw new \RuntimeException( 'import_storage' );
		}
		try {
			if ( fputcsv( $stream, array( 'source_key', 'display_name', 'email', 'phone' ), ',', '"', '' ) === false ) {
				throw new \RuntimeException( 'import_storage' );
			}
			foreach ( $contacts as $item ) {
				if ( fputcsv( $stream, array_values( $item['contact'] ), ',', '"', '' ) === false ) {
						throw new \RuntimeException( 'import_storage' );
				}
			}
			if ( ! rewind( $stream ) ) {
				throw new \RuntimeException( 'import_storage' );
			}
			$csv = stream_get_contents( $stream );
			if ( ! is_string( $csv ) ) {
					throw new \RuntimeException( 'import_storage' );
			}
			Csv::parse( $csv );
			return array(
				'csv'      => $csv,
				'metadata' => array(
					'format'              => 'ssa_free_contacts_v1',
					'kind'                => 'customers',
					'edition'             => 'shared',
					'scope'               => 'contacts_only',
					'source_appointments' => count( $appointments ),
					'contacts'            => count( $contacts )
				)
			);
		} finally {
			fclose( $stream ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose -- Closes the in-memory php://temp stream.
		}
	}
	/** json_decode otherwise silently overwrites duplicate (including escaped) object keys. */
	private static function unique_keys( string $json, int &$offset ): void {
		self::space( $json, $offset );
		$char = $json[ $offset ];
		if ( $char === '{' ) {
			++$offset;
			self::space( $json, $offset );
			$keys = array();
			if ( $json[ $offset ] === '}' ) {
					++$offset;
					return;
			}
			while ( true ) {
				$key = self::string( $json, $offset );
				if ( isset( $keys[ $key ] ) ) {
						throw new \DomainException( 'import_source_format' );
				}
				$keys[ $key ] = true;
				self::space( $json, $offset );
				++$offset;
				self::unique_keys( $json, $offset );
				self::space( $json, $offset );
				$char = $json[ $offset++ ];
				if ( $char === '}' ) {
						return;
				}
				self::space( $json, $offset );
			}
		}
		if ( $char === '[' ) {
			++$offset;
			self::space( $json, $offset );
			if ( $json[ $offset ] === ']' ) {
					++$offset;
					return;
			}while ( true ) {
					self::unique_keys( $json, $offset );
					self::space( $json, $offset );
				if ( $json[ $offset++ ] === ']' ) {
					return;
				}
			}
		}
		if ( $char === '"' ) {
			self::string( $json, $offset );
			return;
		}
		$length = strlen( $json );
		while ( $offset < $length && ! str_contains( ",]} \t\r\n", $json[ $offset ] ) ) {
			++$offset;
		}
	}
	private static function space( string $json, int &$offset ): void {
		$length = strlen( $json );
		while ( $offset < $length && str_contains( " \t\r\n", $json[ $offset ] ) ) {
			++$offset;
		}
	}
	private static function string( string $json, int &$offset ): string {
		$start  = $offset++;
		$length = strlen( $json );
		while ( $offset < $length ) {
			$char = $json[ $offset++ ];
			if ( $char === '\\' ) {
				++$offset;
			} elseif ( $char === '"' ) {
				return json_decode( substr( $json, $start, $offset - $start ), true, 8, JSON_THROW_ON_ERROR );
			}
		}
		throw new \DomainException( 'import_source_format' );
	}
}