<?php

namespace Modules\EcommerceFinance\Services;

/**
 * 「店铺维度报表逻辑配置」里可维护的期初主体数据。
 *
 * 首次读取时把 config/store_report_initial_periods.php 的内容复制成设置值，
 * 之后页面的新增、修改、删除都写设置，不再依赖代码文件。
 */
class StoreReportInitialPeriods
{
    private const PREFIX = 'store_report.initial_periods';

    private const EFFECTIVE_AT_KEY = self::PREFIX . '.effective_at';

    public const DEFAULT_EFFECTIVE_AT = '2026-07-01';

    /** @return array{initial_effective_at:string,shops:array<string,array{previous_company:string,company:string,changed_at:string}>} */
    public static function current(): array
    {
        if (! self::seeded()) {
            return self::fromConfig();
        }

        $shops = [];
        foreach (self::storedShopNames() as $name) {
            $rule = self::storedRule($name);
            if ($rule !== null) {
                $shops[$name] = $rule;
            }
        }

        return [
            'initial_effective_at' => self::cleanDate(setting(self::EFFECTIVE_AT_KEY, null)) ?? self::DEFAULT_EFFECTIVE_AT,
            'shops' => self::normalizeShops($shops),
        ];
    }

    public static function effectiveAt(): string
    {
        return self::current()['initial_effective_at'];
    }

    /** @return array<string,array{previous_company:string,company:string,changed_at:string}> */
    public static function shops(): array
    {
        return self::current()['shops'];
    }

    public static function seeded(): bool
    {
        return setting(self::signatureKey(), null) !== null;
    }

    /** 把代码文件里的期初数据固化成可编辑的设置值。 */
    public static function seedFromConfig(): void
    {
        if (self::seeded()) {
            return;
        }

        $config = self::fromConfig();
        $payload = [self::EFFECTIVE_AT_KEY => $config['initial_effective_at']];
        foreach ($config['shops'] as $name => $rule) {
            $payload += self::rulePayload($name, $rule);
        }
        $payload[self::shopListKey()] = implode("\n", array_keys($config['shops']));
        $payload[self::signatureKey()] = (string) count($config['shops']);

        setting($payload)->save();
    }

    /** @param array<string,mixed> $shops */
    public static function saveShops(array $shops, ?string $effectiveAt = null): void
    {
        $current = self::current();
        $normalized = self::normalizeShops($shops);
        $payload = [
            self::EFFECTIVE_AT_KEY => self::cleanDate($effectiveAt) ?? $current['initial_effective_at'],
            self::shopListKey() => implode("\n", array_keys($normalized)),
            self::signatureKey() => (string) count($normalized),
        ];
        foreach ($normalized as $name => $rule) {
            $payload += self::rulePayload($name, $rule);
        }

        setting($payload)->save();

        // 删除本次保存后不再存在的店铺键。
        foreach ($current['shops'] as $name => $rule) {
            if (isset($normalized[$name])) {
                continue;
            }
            self::forgetKeys($name);
        }
    }

    /** @return array{previous_company:string,company:string,changed_at:string}|null */
    public static function shop(string $storeName): ?array
    {
        return self::shops()[trim($storeName)] ?? null;
    }

    /** @param array{previous_company:string,company:string,changed_at:string} $rule */
    public static function putShop(string $storeName, array $rule): void
    {
        $shops = self::shops();
        $shops[trim($storeName)] = $rule;
        self::saveShops($shops);
    }

    public static function forgetShop(string $storeName): void
    {
        $shops = self::shops();
        $name = trim($storeName);
        unset($shops[$name]);
        self::saveShops($shops);
        self::forgetKeys($name);
    }

    /**
     * @return array{initial_effective_at:string,shops:array<string,array{previous_company:string,company:string,changed_at:string}>}
     */
    private static function fromConfig(): array
    {
        return [
            'initial_effective_at' => self::cleanDate(config('store_report_initial_periods.initial_effective_at'))
                ?? self::DEFAULT_EFFECTIVE_AT,
            'shops' => self::normalizeShops((array) config('store_report_initial_periods.shops', [])),
        ];
    }

    /** @param array<string,mixed> $shops */
    private static function normalizeShops(array $shops): array
    {
        $clean = [];
        foreach ($shops as $storeName => $rule) {
            $name = trim((string) $storeName);
            if ($name === '' || ! is_array($rule)) {
                continue;
            }
            $changedAt = self::cleanDate($rule['changed_at'] ?? null);
            if ($changedAt === null) {
                continue;
            }
            $clean[$name] = [
                'previous_company' => trim((string) ($rule['previous_company'] ?? '')),
                'company' => trim((string) ($rule['company'] ?? '')),
                'changed_at' => $changedAt,
            ];
        }

        uasort($clean, static fn (array $left, array $right): int => strcmp($left['changed_at'], $right['changed_at']));

        return $clean;
    }

    private static function cleanDate(mixed $value): ?string
    {
        $value = trim((string) ($value ?? ''));
        if (preg_match('/^\d{4}-\d{2}-\d{2}$/D', $value) !== 1) {
            return null;
        }

        return $value;
    }

    private static function shopKey(string $storeName): string
    {
        return sha1(mb_strtolower(trim($storeName)));
    }

    private static function shopListKey(): string
    {
        return self::PREFIX . '.shop_list';
    }

    private static function signatureKey(): string
    {
        return self::PREFIX . '.seeded';
    }

    private static function ruleKey(string $storeName, string $field): string
    {
        return self::PREFIX . '.shop.' . self::shopKey($storeName) . '.' . $field;
    }

    /** @return list<string> */
    private static function storedShopNames(): array
    {
        $list = setting(self::shopListKey(), '');
        $list = is_array($list) ? implode("\n", $list) : (string) $list;

        return array_values(array_filter(array_map('trim', explode("\n", $list))));
    }

    /** @return array{previous_company:string,company:string,changed_at:string}|null */
    private static function storedRule(string $storeName): ?array
    {
        $changedAt = self::cleanDate(setting(self::ruleKey($storeName, 'changed_at'), null));
        if ($changedAt === null) {
            return null;
        }

        return [
            'previous_company' => trim((string) setting(self::ruleKey($storeName, 'previous_company'), '')),
            'company' => trim((string) setting(self::ruleKey($storeName, 'company'), '')),
            'changed_at' => $changedAt,
        ];
    }

    /**
     * @param array{previous_company:string,company:string,changed_at:string} $rule
     * @return array<string,string>
     */
    private static function rulePayload(string $storeName, array $rule): array
    {
        return [
            self::ruleKey($storeName, 'previous_company') => $rule['previous_company'],
            self::ruleKey($storeName, 'company') => $rule['company'],
            self::ruleKey($storeName, 'changed_at') => $rule['changed_at'],
            self::ruleKey($storeName, 'name') => trim($storeName),
        ];
    }

    private static function forgetKeys(string $storeName): void
    {
        foreach (['previous_company', 'company', 'changed_at', 'name'] as $field) {
            setting()->forget(self::ruleKey($storeName, $field));
        }
        setting()->save();
    }
}