<?php
/** Neutral local control/privacy of retained inbound calendars. No provider or paid imports. */
namespace Abientot\Repositories;
use Abientot\Support\Db;
use Abientot\Support\TransactionGuard;
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}
final class CalendarConnectionsRepository {
	private static bool $active = false;
	private ResourceCapacityRepository $read;
	private array $epochUsers = array();
	public function __construct() {
		$this->read = new ResourceCapacityRepository();
	}
	public function present(): bool {
		// Fresh reader: never cache an absent/verified store across a caller's mutations.
		if ( ! ( new CalendarBusyRepository() )->present() ) {
			return false;
		}
		global $wpdb;
		$expected = array(
			'calendar_connections'  => array( 'id', 'provider', 'owner_user_id', 'staff_id', 'authority', 'timezone', 'calendars', 'credential', 'enabled', 'consent_revision', 'revision', 'sync_revision', 'coverage_start', 'coverage_end', 'last_attempt', 'last_success', 'next_attempt', 'error_code', 'created_at' ),
			'calendar_busy'         => array( 'id', 'connection_id', 'calendar_digest', 'start_utc', 'end_utc', 'sync_revision' ),
			'calendar_oauth_states' => array( 'token_hash', 'user_id', 'staff_id', 'provider', 'purpose', 'state_payload', 'expires_at' )
		);
		foreach ( $expected as $table => $names ) {
			$actual = array();
			foreach ( Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( 'SHOW COLUMNS FROM %i', $this->read->table( $table ) ), ARRAY_A ), 'retained_capacity_storage_unavailable' ) as $column ) {
				$actual[] = $column['Field'];
				if ( $column['Field'] === 'id' && $column['Extra'] !== 'auto_increment' ) {
					throw new \RuntimeException( 'calendar_retained_shape' );
				}
			}
			sort( $names );
			sort( $actual );
			if ( $names !== $actual ) {
				throw new \RuntimeException( 'calendar_retained_shape' );
			}
			$primary = array();
			foreach ( Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( 'SHOW INDEX FROM %i', $this->read->table( $table ) ), ARRAY_A ), 'retained_capacity_storage_unavailable' ) as $index ) {
				if ( $index['Key_name'] === 'PRIMARY' ) {
					$primary[ (int) $index['Seq_in_index'] ] = $index['Column_name'];
				}
			}
			if ( $primary !== array( 1 => $table === 'calendar_oauth_states' ? 'token_hash' : 'id' ) ) {
				throw new \RuntimeException( 'calendar_retained_primary' );
			}
		}
		foreach ( array( $this->read->table( 'activity_log' ), $wpdb->options ) as $table ) {
			$engine = Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( 'SELECT ENGINE FROM information_schema.TABLES WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME=%s', $table ), ARRAY_A ), 'retained_capacity_storage_unavailable' );
			if ( strtoupper( (string) ( $engine[0]['ENGINE'] ?? '' ) ) !== 'INNODB' ) {
				throw new \RuntimeException( 'calendar_retained_audit_engine' );
			}
		}
		$unique = array();
		foreach ( Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( 'SHOW INDEX FROM %i', $wpdb->options ), ARRAY_A ), 'retained_capacity_storage_unavailable' ) as $index ) {
			if ( (int) $index['Non_unique'] === 0 ) {
				$unique[ $index['Key_name'] ][ (int) $index['Seq_in_index'] ] = $index['Column_name'];
			}
		}
		$found = false;
		foreach ( $unique as $key ) {
			ksort( $key );
			if ( array_values( $key ) === array( 'option_name' ) ) {
				$found = true;
			}
		}
		if ( ! $found ) {
			throw new \RuntimeException( 'calendar_retained_epoch_index' );
		}
		return true;
	}
	private static function number( $value, bool $positive = false ): int {
		if ( ( ! is_int( $value ) && ! is_string( $value ) ) || ! preg_match( '/^(0|[1-9][0-9]*)$/D', (string) $value ) ) {
			throw new \DomainException( 'calendar_retained_input' );
		}
		$parsed = filter_var(
			$value,
			FILTER_VALIDATE_INT,
			array(
				'options' => array(
					'min_range' => $positive ? 1 : 0,
					'max_range' => PHP_INT_MAX - 1
				)
			)
		);
		if ( $parsed === false ) {
			throw new \DomainException( 'calendar_retained_input' );
		}
		return $parsed;
	}
	private static function state( array $row ): array {
		if ( ! in_array( $row['provider'], array( 'google', 'outlook' ), true ) || ! in_array( $row['authority'], array( 'manager', 'own_staff', 'revoked' ), true ) || ! in_array( (string) $row['enabled'], array( '0', '1' ), true ) || ! preg_match( '/^[a-z_]{0,32}$/D', $row['error_code'] ) ) {
			throw new \RuntimeException( 'calendar_retained_state' );
		}
		foreach ( array( 'id', 'staff_id', 'consent_revision', 'revision' ) as $key ) {
			self::number( $row[ $key ], true );
		}
		self::number( $row['sync_revision'] );
		new \DateTimeZone( $row['timezone'] );
		foreach ( array( 'coverage_start', 'coverage_end', 'last_attempt', 'last_success', 'next_attempt' ) as $key ) {
			if ( $row[ $key ] !== null ) {
				$date = \DateTimeImmutable::createFromFormat( '!Y-m-d H:i:s', $row[ $key ], new \DateTimeZone( 'UTC' ) );
				if ( ! $date || $date->format( 'Y-m-d H:i:s' ) !== $row[ $key ] ) {
					throw new \RuntimeException( 'calendar_retained_time' );
				}
			}
		}
		if ( ( $row['coverage_start'] === null ) !== ( $row['coverage_end'] === null ) || ( $row['coverage_start'] !== null && $row['coverage_start'] >= $row['coverage_end'] ) || ( (int) $row['enabled'] === 1 && ( $row['authority'] === 'revoked' || (int) $row['consent_revision'] !== 1 ) ) ) {
			throw new \RuntimeException( 'calendar_retained_state' );
		}
		return $row;
	}
	/** 25 visible rows, plus one continuation sentinel. No secrets/calendar IDs selected. */
	public function listing( int $staff, int $page = 1 ): array {
		self::number( $staff, true );
		self::number( $page, true );
		if ( $page > intdiv( PHP_INT_MAX, 25 ) ) {
			throw new \DomainException( 'calendar_retained_page' );
		}
		if ( ! $this->present() ) {
			return array();
		}
		global $wpdb;
		$rows = Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( 'SELECT id,provider,staff_id,authority,timezone,enabled,consent_revision,revision,sync_revision,coverage_start,coverage_end,last_attempt,last_success,next_attempt,error_code FROM %i WHERE staff_id=%d ORDER BY id DESC LIMIT 26 OFFSET %d', $this->read->table( 'calendar_connections' ), $staff, ( $page - 1 ) * 25 ), ARRAY_A ), 'retained_capacity_storage_unavailable' );
		return array_map( array( self::class, 'state' ), $rows );
	}
	/** Bounded identifiers let managers reach retained profiles after switching to Free. */
	public function staff_ids( int $page = 1 ): array {
		self::number( $page, true );
		if ( $page > 1000000 ) {
			throw new \DomainException( 'calendar_retained_page' );
		}
		if ( ! $this->present() ) {
			return array();
		}
		global $wpdb;
		return array_map( 'intval', array_column( Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( 'SELECT DISTINCT staff_id FROM %i ORDER BY staff_id LIMIT 26 OFFSET %d', $this->read->table( 'calendar_connections' ), ( $page - 1 ) * 25 ), ARRAY_A ), 'retained_capacity_storage_unavailable' ), 'staff_id' ) );
	}
	private function write( $result ): void {
		global $wpdb;
		if ( $result === false || $wpdb->last_error !== '' ) {
			throw new \RuntimeException( 'calendar_retained_write' );
		}
	}
	private function transaction( callable $run ) {
		global $wpdb;
		$owned = ! BookingLock::is_held();
		if ( $owned && ! BookingLock::acquire() ) {
			throw new \RuntimeException( 'calendar_retained_lock' );
		}
		$started    = false;
		$suppressed = $wpdb->suppress_errors( true );
		try {
			if ( self::$active ) {
				throw new \RuntimeException( 'calendar_retained_transaction' );
			}
			TransactionGuard::prepare_write();
			if ( ! $this->present() ) {
				throw new \RuntimeException( 'calendar_retained_missing' );
			}
			$this->write( $wpdb->query( 'START TRANSACTION' ) );
			$started      = true;
			self::$active = true;
			$result       = $run( static fn(): bool=>self::$active && BookingLock::is_held() );
			$this->write( $wpdb->query( 'COMMIT' ) );
			$started = false;
			return $result;
		} catch ( \Throwable $e ) {
			if ( $started ) {
				$wpdb->query( 'ROLLBACK' );
			}
			throw $e;
		} finally {
			self::$active = false;
			$wpdb->suppress_errors( $suppressed );
			foreach ( array_keys( $this->epochUsers ) as $user ) {
				self::clearAuthorityCaches( (int) $user );
			}
			$this->epochUsers = array();
			if ( $owned ) {
				BookingLock::release();
			}
		}
	}
	private function witness( callable $owner ): void {
		if ( ! BookingLock::is_held() || $owner() !== true ) {
			throw new \RuntimeException( 'calendar_retained_owner' );
		}
		if ( ! $this->present() ) {
			throw new \RuntimeException( 'calendar_retained_missing' );
		}
	}
	public static function epochOption( int $user ): string {
		self::number( $user, true );
		return 'abientot_calendar_authority_epoch_' . $user;
	}
	public static function clearAuthorityCaches( int $user ): void {
		$name = self::epochOption( $user );
		wp_cache_delete( $name, 'options' );
		wp_cache_delete( 'alloptions', 'options' );
		wp_cache_delete( 'notoptions', 'options' );
	}
	private function rotateEpoch( int $user, callable $owner ): void {
		$this->witness( $owner );
		global $wpdb;
		$name                      = self::epochOption( $user );
		$epoch                     = bin2hex( random_bytes( 32 ) );
		$this->epochUsers[ $user ] = true;
		$this->write( $wpdb->query( $wpdb->prepare( "INSERT INTO {$wpdb->options} (option_name,option_value,autoload) VALUES (%s,%s,'no') ON DUPLICATE KEY UPDATE option_value=VALUES(option_value),autoload='no'", $name, $epoch ) ) );
		$stored = Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( "SELECT option_value,autoload FROM {$wpdb->options} WHERE option_name=%s", $name ), ARRAY_A ), 'retained_capacity_storage_unavailable' )[0] ?? null;
		if ( ! $stored || ! hash_equals( $epoch, (string) $stored['option_value'] ) || $stored['autoload'] !== 'no' ) {
			throw new \RuntimeException( 'calendar_retained_epoch' );
		}
	}
	private function audit( int $id, string $event ): void {
		global $wpdb;
		$this->write(
			$wpdb->insert(
				$this->read->table( 'activity_log' ),
				array(
					'object_type'  => 'calendar_connection',
					'object_id'    => $id,
					'event'        => $event,
					'actor_type'   => get_current_user_id() ? 'user' : 'system',
					'actor_id'     => get_current_user_id() ?: null,
					'message'      => __( 'Calendar protection changed.', 'abientot' ),
					'context_json' => null,
					'created_at'   => gmdate( 'Y-m-d H:i:s' )
				)
			)
		);
	}
	/** Private mutation only; revisions invalidate network work started under old authority. */
	private function scrub( array $row, callable $owner, bool $erasing ): array {
		$this->witness( $owner );
		self::state( $row );
		global $wpdb;
		$id       = (int) $row['id'];
		$revision = self::number( $row['revision'], true );
		$consent  = self::number( $row['consent_revision'], true );
		$data     = array(
			'enabled'          => 0,
			'authority'        => 'revoked',
			'revision'         => $revision + 1,
			'consent_revision' => $consent + 1,
			'credential'       => '',
			'calendars'        => '',
			'coverage_start'   => null,
			'coverage_end'     => null,
			'last_attempt'     => null,
			'last_success'     => null,
			'next_attempt'     => null,
			'error_code'       => $erasing ? 'erased' : 'disconnected'
		);
		if ( $erasing ) {
			$data['owner_user_id'] = 0;
		}
		$changed = $wpdb->update(
			$this->read->table( 'calendar_connections' ),
			$data,
			array(
				'id'            => $id,
				'revision'      => $revision,
				'owner_user_id' => (int) $row['owner_user_id']
			)
		);
		$this->write( $changed );
		if ( $changed !== 1 ) {
			throw new \RuntimeException( 'calendar_retained_stale' );
		}
		$this->write( $wpdb->delete( $this->read->table( 'calendar_busy' ), array( 'connection_id' => $id ) ) );
		$this->write( $wpdb->query( $wpdb->prepare( 'DELETE FROM %i WHERE user_id=%d AND staff_id=%d AND provider=%s AND purpose=%s', $this->read->table( 'calendar_oauth_states' ), (int) $row['owner_user_id'], (int) $row['staff_id'], $row['provider'], 'connect' ) ) );
		$this->audit( $id, $erasing ? 'calendar_owner_erased' : 'calendar_disconnected_local' );
		$this->witness( $owner );
		return array(
			'connection_id'    => $id,
			'revision'         => $revision + 1,
			'consent_revision' => $consent + 1
		);
	}
	public function disconnect( int $id, int $expected, bool $riskAccepted, ?callable $authority = null ): array {
		self::number( $id, true );
		self::number( $expected, true );
		if ( ! $riskAccepted || ( $authority === null && ! current_user_can( 'abientot_manage_settings' ) ) ) {
			throw new \DomainException( 'calendar_retained_permission' );
		}
		return $this->transaction(
			function ( callable $owner ) use ( $id, $expected, $authority ): array {
				if ( $authority === null && ! current_user_can( 'abientot_manage_settings' ) ) {
								throw new \DomainException( 'calendar_retained_permission' );
				}
				global $wpdb;
				$row = Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( 'SELECT id,provider,staff_id,authority,timezone,enabled,consent_revision,revision,sync_revision,coverage_start,coverage_end,last_attempt,last_success,next_attempt,error_code,owner_user_id FROM %i WHERE id=%d', $this->read->table( 'calendar_connections' ), $id ), ARRAY_A ), 'retained_capacity_storage_unavailable' )[0] ?? null;
				if ( ! $row || (int) $row['revision'] !== $expected ) {
							throw new \DomainException( 'calendar_retained_stale' );
				}
				if ( $authority !== null && $authority( $row ) !== true ) {
							throw new \DomainException( 'calendar_retained_permission' );
				}
				if ( (int) $row['owner_user_id'] > 0 ) {
						$this->rotateEpoch( (int) $row['owner_user_id'], $owner );
				}
				return $this->scrub( $row, $owner, false );
			}
		);
	}
	/** Trusted verified personal-data controller; pass witness to join its checked transaction. */
	public function erase_user( int $user, ?callable $owner = null ): bool {
		self::number( $user, true );
		if ( ! $this->present() ) {
			return false;
		}
		$run = function ( callable $witness ) use ( $user ): bool {
			$this->witness( $witness );
			$this->rotateEpoch( $user, $witness );
			global $wpdb;
			$rows   = Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( 'SELECT id,provider,staff_id,authority,timezone,enabled,consent_revision,revision,sync_revision,coverage_start,coverage_end,last_attempt,last_success,next_attempt,error_code,owner_user_id FROM %i WHERE owner_user_id=%d ORDER BY id', $this->read->table( 'calendar_connections' ), $user ), ARRAY_A ), 'retained_capacity_storage_unavailable' );
			$states = Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( 'SELECT token_hash FROM %i WHERE user_id=%d AND purpose=%s LIMIT 1', $this->read->table( 'calendar_oauth_states' ), $user, 'connect' ), ARRAY_A ), 'retained_capacity_storage_unavailable' );
			foreach ( $rows as $row ) {
				$this->scrub( $row, $witness, true );
			}
			$this->write( $wpdb->query( $wpdb->prepare( 'DELETE FROM %i WHERE user_id=%d AND purpose=%s', $this->read->table( 'calendar_oauth_states' ), $user, 'connect' ) ) );
			$this->witness( $witness );
			return (bool) ( $rows || $states );
		};
		return $owner !== null ? $run( $owner ) : $this->transaction( $run );
	}
	/** Minimal private export; caller supplies verified canonical WP user identity. */
	public function export_user( int $user, int $page = 1 ): array {
		self::number( $user, true );
		self::number( $page, true );
		if ( $page > 1000000 ) {
			throw new \DomainException( 'calendar_retained_page' );
		}
		if ( ! $this->present() ) {
			return array();
		}
		global $wpdb;
		$rows = Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( 'SELECT id,provider,staff_id,authority,timezone,enabled,consent_revision,revision,sync_revision,coverage_start,coverage_end,last_attempt,last_success,next_attempt,error_code FROM %i WHERE owner_user_id=%d ORDER BY id LIMIT 100 OFFSET %d', $this->read->table( 'calendar_connections' ), $user, ( $page - 1 ) * 100 ), ARRAY_A ), 'retained_capacity_storage_unavailable' );
		return array_map( array( self::class, 'state' ), $rows );
	}
	/** Exact connection export for a capability-checked independently verified manual request. */
	public function export_connection( int $id ): array {
		self::number( $id, true );
		if ( ! current_user_can( 'abientot_manage_settings' ) || ! current_user_can( 'abientot_manage_customers' ) ) {
			throw new \DomainException( 'calendar_retained_permission' );
		}
		if ( ! $this->present() ) {
			return array();
		}
		global $wpdb;
		$rows = Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( 'SELECT id,provider,staff_id,authority,timezone,enabled,consent_revision,revision,sync_revision,coverage_start,coverage_end,last_attempt,last_success,next_attempt,error_code FROM %i WHERE id=%d', $this->read->table( 'calendar_connections' ), $id ), ARRAY_A ), 'retained_capacity_storage_unavailable' );
		return array_map( array( self::class, 'state' ), $rows );
	}
	/** Reuse checked local revocation, epoch rotation and stale-work witnesses. */
	public function erase_connection( int $id ): bool {
		self::number( $id, true );
		if ( ! current_user_can( 'abientot_manage_settings' ) || ! current_user_can( 'abientot_manage_customers' ) ) {
			throw new \DomainException( 'calendar_retained_permission' );
		}
		if ( ! $this->present() ) {
			return false;
		}
		return $this->transaction(
			function ( callable $owner ) use ( $id ): bool {
				if ( ! current_user_can( 'abientot_manage_settings' ) || ! current_user_can( 'abientot_manage_customers' ) ) {
					throw new \DomainException( 'calendar_retained_permission' );
				}
				global $wpdb;
				$row = Db::rows( $wpdb->suppress_errors( true ), $wpdb->get_results( $wpdb->prepare( 'SELECT id,provider,staff_id,authority,timezone,enabled,consent_revision,revision,sync_revision,coverage_start,coverage_end,last_attempt,last_success,next_attempt,error_code,owner_user_id FROM %i WHERE id=%d', $this->read->table( 'calendar_connections' ), $id ), ARRAY_A ), 'retained_capacity_storage_unavailable' )[0] ?? null;
				if ( ! $row ) {
					return false;
				}
				if ( (int) $row['owner_user_id'] > 0 ) {
					$this->rotateEpoch( (int) $row['owner_user_id'], $owner );
				}
				$this->scrub( $row, $owner, true );
				return true;
			}
		);
	}
}