<?php
/**
 * @package AKSRT
 */

namespace AKSRT\Ledger;

defined('ABSPATH') || exit;

final class LedgerCommand {
	/**
	 * @param array<int,array{user_id:int,asset:string,delta_minor:int,entry_type:string,counterparty_user_id?:int,remark?:string}> $entries
	 * @param array<string,mixed> $metadata
	 */
	public function __construct(
		public readonly string $operation_key,
		public readonly string $reason,
		public readonly array $entries,
		public readonly string $ref_type = '',
		public readonly string $ref_key = '',
		public readonly int $actor_user_id = 0,
		public readonly array $metadata = []
	) {}

	/**
	 * @param array<string,mixed> $metadata
	 */
	public static function transfer(
		string $operation_key,
		string $reason,
		int $sender_id,
		int $recipient_id,
		AssetType|string $asset,
		int $gross_minor,
		int $fee_minor,
		string $ref_type = '',
		string $ref_key = '',
		string $sender_remark = '',
		string $recipient_remark = '',
		array $metadata = []
	): self {
		$asset = AssetType::from_value($asset);
		if ($sender_id <= 0 || $recipient_id <= 0 || $sender_id === $recipient_id || $gross_minor <= 0 || $fee_minor < 0 || $fee_minor >= $gross_minor) {
			throw new \InvalidArgumentException('ledger_transfer_invalid');
		}
		$net_minor = $gross_minor - $fee_minor;
		$entries = [[
			'user_id' => $sender_id,
			'asset' => $asset->value,
			'delta_minor' => -$net_minor,
			'entry_type' => 'transfer_out',
			'counterparty_user_id' => $recipient_id,
			'remark' => $sender_remark,
		]];
		if ($fee_minor > 0) {
			$entries[] = [
				'user_id' => $sender_id,
				'asset' => $asset->value,
				'delta_minor' => -$fee_minor,
				'entry_type' => 'fee',
				'counterparty_user_id' => $recipient_id,
				'remark' => __('转账手续费', 'aksrt'),
			];
		}
		$entries[] = [
			'user_id' => $recipient_id,
			'asset' => $asset->value,
			'delta_minor' => $net_minor,
			'entry_type' => 'transfer_in',
			'counterparty_user_id' => $sender_id,
			'remark' => $recipient_remark,
		];
		$metadata['gross_minor'] = $gross_minor;
		$metadata['fee_minor'] = $fee_minor;
		$metadata['net_minor'] = $net_minor;
		return new self($operation_key, $reason, $entries, $ref_type, $ref_key, $sender_id, $metadata);
	}

	public function validate() {
		if ($this->operation_key === '' || strlen($this->operation_key) > 191 || !preg_match('/^[A-Za-z0-9:._-]+$/', $this->operation_key)) {
			return new \WP_Error('aksrt_ledger_operation_key', __('账务操作标识无效', 'aksrt'), ['status' => 400]);
		}
		if ($this->reason === '' || strlen($this->reason) > 64 || sanitize_key($this->reason) !== $this->reason) {
			return new \WP_Error('aksrt_ledger_reason', __('账务原因无效', 'aksrt'), ['status' => 400]);
		}
		if ($this->entries === []) {
			return new \WP_Error('aksrt_ledger_entries', __('账务明细不能为空', 'aksrt'), ['status' => 400]);
		}
		if ($this->actor_user_id < 0) {
			return new \WP_Error('aksrt_ledger_actor', __('账务操作者无效', 'aksrt'), ['status' => 400]);
		}
		foreach ($this->entries as $entry) {
			try {
				AssetType::from((string) ($entry['asset'] ?? ''));
			} catch (\ValueError $e) {
				return new \WP_Error('aksrt_ledger_asset', __('资产类型无效', 'aksrt'), ['status' => 400]);
			}
			$user_id = $entry['user_id'] ?? null;
			$delta_minor = $entry['delta_minor'] ?? null;
			$entry_type = $entry['entry_type'] ?? null;
			if (!is_int($user_id) || $user_id <= 0
				|| !is_int($delta_minor) || $delta_minor === 0 || $delta_minor === PHP_INT_MIN
				|| !is_string($entry_type) || $entry_type === '' || strlen($entry_type) > 32 || sanitize_key($entry_type) !== $entry_type
			) {
				return new \WP_Error('aksrt_ledger_entry', __('账务明细无效', 'aksrt'), ['status' => 400]);
			}
			if (isset($entry['counterparty_user_id']) && (!is_int($entry['counterparty_user_id']) || $entry['counterparty_user_id'] <= 0)) {
				return new \WP_Error('aksrt_ledger_entry', __('账务明细无效', 'aksrt'), ['status' => 400]);
			}
		}
		return true;
	}

	public function payload_hash(): string {
		$payload = [
			'reason' => $this->reason,
			'entries' => $this->entries,
			'ref_type' => $this->ref_type,
			'ref_key' => $this->ref_key,
			'actor_user_id' => $this->actor_user_id,
			'metadata' => $this->metadata,
		];
		self::sort_recursive($payload);
		return hash('sha256', (string) wp_json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES));
	}

	private static function sort_recursive(array &$value): void {
		foreach ($value as &$item) {
			if (is_array($item)) {
				self::sort_recursive($item);
			}
		}
		unset($item);
		if (!array_is_list($value)) {
			ksort($value);
		}
	}
}