<?php

namespace Modules\EcommerceFinance\Services;

use InvalidArgumentException;
use Modules\EcommerceFinance\Contracts\BusinessMirrorDataset;

class BusinessMirrorDatasetRegistry
{
    /** @return array<string,BusinessMirrorDataset> */
    public function all(): array
    {
        $datasets = [];

        foreach ((array) config('upstream_mirrors.datasets', []) as $key => $definition) {
            $datasets[(string) $key] = $this->make((string) $key, (array) $definition);
        }

        return $datasets;
    }

    public function get(string $key): BusinessMirrorDataset
    {
        $definitions = (array) config('upstream_mirrors.datasets', []);
        $definition = (array) ($definitions[$key] ?? []);

        if ($definition === []) {
            throw new InvalidArgumentException('未知的业务镜像数据集：' . $key);
        }

        return $this->make($key, $definition);
    }

    private function make(string $key, array $definition): BusinessMirrorDataset
    {
        $source = trim((string) ($definition['source_key'] ?? ''));
        $schema = trim((string) ($definition['schema'] ?? ''));
        $object = trim((string) ($definition['object'] ?? ''));
        $target = trim((string) ($definition['target'] ?? ''));
        $keys = array_values(array_filter(array_map('strval', (array) ($definition['keys'] ?? []))));
        $watermark = trim((string) ($definition['watermark'] ?? ''));
        $indexes = array_values(array_map(
            static fn (mixed $columns): array => array_values(array_filter(array_map('strval', (array) $columns))),
            (array) ($definition['indexes'] ?? []),
        ));
        $indexColumns = array_merge(...($indexes ?: [[]]));

        foreach ([$source, $schema, $object, $target, ...$keys, ...$indexColumns] as $identifier) {
            if (preg_match('/^[A-Za-z_][A-Za-z0-9_]*$/', $identifier) !== 1) {
                throw new InvalidArgumentException('业务镜像数据集包含不安全的标识符：' . $key);
            }
        }

        if ($keys === [] || in_array([], $indexes, true) || strlen($target) > 64) {
            throw new InvalidArgumentException('业务镜像数据集缺少稳定键或目标表名过长：' . $key);
        }

        if ($watermark !== '' && preg_match('/^[A-Za-z_][A-Za-z0-9_]*$/', $watermark) !== 1) {
            throw new InvalidArgumentException('业务镜像数据集的增量字段不安全：' . $key);
        }

        return new readonly class($key, $source, $schema, $object, $target, $keys, $watermark ?: null, $indexes) implements BusinessMirrorDataset {
            public function __construct(
                private string $key,
                private string $source,
                private string $schema,
                private string $object,
                private string $target,
                private array $keys,
                private ?string $watermark,
                private array $indexes,
            ) {
            }

            public function key(): string { return $this->key; }
            public function sourceKey(): string { return $this->source; }
            public function sourceSchema(): string { return $this->schema; }
            public function sourceObject(): string { return $this->object; }
            public function targetTable(): string { return $this->target; }
            public function keyColumns(): array { return $this->keys; }
            public function watermarkColumn(): ?string { return $this->watermark; }
            public function indexDefinitions(): array { return $this->indexes; }
        };
    }
}