<?php

namespace Modules\EcommerceFinance\Repositories;

use Carbon\CarbonImmutable;
use Illuminate\Database\ConnectionInterface;
use Illuminate\Database\DatabaseManager;
use Illuminate\Support\Facades\Schema;

class TaobaoWechatOpeningBalanceRepository
{
    public const TABLE = 'taobao_wechat_opening_balances';

    public const BASELINE_DATE = '2026-06-30';

    private const BILL_TABLE = 'taobao_wechat_bill_rows';

    private readonly ConnectionInterface $connection;

    public function __construct(DatabaseManager $database)
    {
        $this->connection = $database->connection(
            (string) config('upstream_mirrors.connection', 'business_mirror'),
        );
    }

    /**
     * @return array{balance:?float,date:?string,source:string,store_count:int}
     */
    public function openingBalance(?string $storeName, ?string $periodStart): array
    {
        if (! $this->hasTable(self::TABLE)) {
            return $this->unavailable();
        }

        $query = $this->connection->table(self::TABLE)
            ->where('balance_date', self::BASELINE_DATE);
        if ($storeName !== null && $storeName !== '') {
            $query->where('store_name', $storeName);
        }

        $baseline = (clone $query)->selectRaw(
            'COALESCE(SUM(balance), 0) AS balance, COUNT(*) AS store_count, '
            . 'COUNT(DISTINCT source) AS source_count, MIN(source) AS source'
        )->first();
        $storeCount = (int) ($baseline->store_count ?? 0);
        if ($storeCount === 0) {
            return $this->unavailable();
        }

        $balance = round((float) $baseline->balance, 2);
        $date = self::BASELINE_DATE;
        $source = (int) ($baseline->source_count ?? 0) === 1
            ? (string) $baseline->source
            : 'mixed_opening_sources';
        $start = $this->date($periodStart);

        if ($start !== null && $start->gt('2026-07-01')) {
            $movement = $this->connection->table(self::BILL_TABLE)
                ->where('occurred_at', '>=', '2026-07-01 00:00:00')
                ->where('occurred_at', '<', $start->format('Y-m-d') . ' 00:00:00')
                ->when($storeName !== null && $storeName !== '', function ($query) use ($storeName): void {
                    $query->where('store_name', $storeName);
                })
                ->selectRaw(
                    'COALESCE(SUM(income_amount), 0) AS income, '
                    . 'COALESCE(SUM(expense_amount), 0) AS expense'
                )
                ->first();

            $balance = round(
                $balance + (float) ($movement->income ?? 0) - (float) ($movement->expense ?? 0),
                2,
            );
            $date = $start->subDay()->format('Y-m-d');
            if (! str_ends_with($source, '_carried_forward')) {
                $source .= '_carried_forward';
            }
        }

        return [
            'balance' => $balance,
            'date' => $date,
            'source' => $source,
            'store_count' => $storeCount,
        ];
    }

    /** @return array{balance:null,date:null,source:string,store_count:int} */
    private function unavailable(): array
    {
        return [
            'balance' => null,
            'date' => null,
            'source' => 'unavailable',
            'store_count' => 0,
        ];
    }

    private function date(?string $value): ?CarbonImmutable
    {
        if ($value === null || preg_match('/^\d{4}-\d{2}-\d{2}$/', $value) !== 1) {
            return null;
        }

        $date = CarbonImmutable::createFromFormat('!Y-m-d', $value);

        return $date !== false && $date->format('Y-m-d') === $value ? $date : null;
    }

    private function hasTable(string $table): bool
    {
        return Schema::connection($this->connection->getName())->hasTable($table);
    }
}