<?php

namespace Modules\EcommerceFinance\Repositories;

use Illuminate\Database\ConnectionInterface;
use Illuminate\Database\DatabaseManager;
use Illuminate\Support\Facades\Schema;
use RuntimeException;

/** 店铺维度报表只读取团队共享业务镜像。 */
class StoreReportRepository
{
    public const BILLS_DATASET = 'store-report.platform-bills';
    public const LIFECYCLES_DATASET = 'store-report.store-lifecycles';

    private const DEFAULT_EXPIRES_AT = '2999-01-01';

    private readonly ConnectionInterface $connection;

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

    /**
     * @param array<int,array<string,mixed>> $stores
     * @return array<int,array<string,mixed>>
     */
    public function rows(array $stores, ?int $reportYear = null): array
    {
        if ($stores === []) {
            return [];
        }

        [$billGeneration, $lifecycleGeneration] = $this->activeGenerations();
        $reportYear ??= (int) now()->format('Y');
        if ($reportYear < 2000 || $reportYear > 2999) {
            throw new RuntimeException('店铺维度报表年份无效。');
        }

        $names = array_values(array_unique(array_filter(array_map(
            static fn (array $row): string => trim((string) ($row['erp_store_name'] ?? '')),
            $stores,
        ))));
        $lifecycles = $this->lifecycles($names, $lifecycleGeneration);
        $lifecycleSales = $this->lifecycleSales($names, $billGeneration, $lifecycleGeneration);
        $fallbackSales = $this->fallbackSales(array_values(array_diff($names, array_keys($lifecycles))), $billGeneration);
        $rows = [];

        foreach ($stores as $store) {
            $storeName = trim((string) ($store['erp_store_name'] ?? ''));
            if ($storeName === '') {
                continue;
            }

            $periods = $lifecycles[$storeName] ?? [[
                'company_name' => $store['company_name'] ?? null,
                'effective_at' => $store['opened_at'] ?? sprintf('%d-01-01', $reportYear),
                'expires_at' => self::DEFAULT_EXPIRES_AT,
                'lifecycle_id' => null,
            ]];

            foreach ($periods as $period) {
                $saleData = $period['lifecycle_id'] === null
                    ? ($fallbackSales[$storeName] ?? ['period' => 0.0, 'months' => []])
                    : $this->combinedSales($lifecycleSales, (array) ($period['lifecycle_ids'] ?? [$period['lifecycle_id']]));
                $monthly = [];
                for ($month = 1; $month <= 12; $month++) {
                    $monthly[sprintf('sales_%02d', $month)] = (float) (
                        $saleData['months'][sprintf('%d-%02d', $reportYear, $month)] ?? 0
                    );
                }
                $rollingMonths = collect(range(12, 1))->map(
                    static fn (int $monthsAgo): string => now()->startOfMonth()->subMonthsNoOverflow($monthsAgo)->format('Y-m'),
                )->all();
                $recentMonths = collect(range(3, 1))->map(
                    static fn (int $monthsAgo): string => now()->startOfMonth()->subMonthsNoOverflow($monthsAgo)->format('Y-m'),
                )->values()->all();

                $rows[] = [
                    ...$store,
                    'store_id' => $store['store_id'] ?? $storeName,
                    'status' => $this->status($store['store_status'] ?? null),
                    'entity' => $period['company_name'] ?: ($store['company_name'] ?? null),
                    'effective_at' => $this->date($period['effective_at'] ?? null, sprintf('%d-01-01', $reportYear)),
                    'invalid_at' => $this->date($period['expires_at'] ?? null, self::DEFAULT_EXPIRES_AT),
                    'period_sales' => (float) $saleData['period'],
                    'store_sales_12m' => array_sum(array_map(
                        static fn (string $month): float => (float) ($saleData['months'][$month] ?? 0),
                        $rollingMonths,
                    )),
                    'recent_three_month_sales_1' => (float) ($saleData['months'][$recentMonths[0]] ?? 0),
                    'recent_three_month_sales_2' => (float) ($saleData['months'][$recentMonths[1]] ?? 0),
                    'recent_three_month_sales_3' => (float) ($saleData['months'][$recentMonths[2]] ?? 0),
                    ...$monthly,
                ];
            }
        }

        return $rows;
    }

    /** @return array{0:string,1:string} */
    private function activeGenerations(): array
    {
        $schema = Schema::connection($this->connection->getName());
        foreach (['store_report_import_states', 'store_report_bill_rows', 'store_report_lifecycle_rows'] as $table) {
            if (! $schema->hasTable($table)) {
                throw new RuntimeException('店铺维度报表共享镜像尚未完成迁移。');
            }
        }

        $states = $this->connection->table('store_report_import_states')
            ->whereIn('dataset_key', [self::BILLS_DATASET, self::LIFECYCLES_DATASET])
            ->get(['dataset_key', 'status', 'active_generation', 'row_count'])
            ->keyBy('dataset_key');

        foreach ([self::BILLS_DATASET, self::LIFECYCLES_DATASET] as $dataset) {
            $state = $states->get($dataset);
            if ($state === null || empty($state->active_generation)) {
                $label = $dataset === self::BILLS_DATASET ? '账单' : '主体历史';
                $rows = number_format((int) ($state->row_count ?? 0));
                throw new RuntimeException("店铺维度报表中央同步中：{$label}已写入 {$rows} 行，完整数据就绪后自动显示。");
            }
        }

        return [
            (string) $states->get(self::BILLS_DATASET)->active_generation,
            (string) $states->get(self::LIFECYCLES_DATASET)->active_generation,
        ];
    }

    /** @return array<string,array<int,array<string,mixed>>> */
    private function lifecycles(array $names, string $generation): array
    {
        $result = [];
        foreach (array_chunk($names, 500) as $chunk) {
            $rows = $this->connection->table('store_report_lifecycle_rows')
                ->where('generation', $generation)
                ->whereIn('erp_store_name', $chunk)
                ->orderBy('erp_store_name')->orderBy('effective_at')->orderBy('id')
                ->get(['id', 'erp_store_name', 'company_name', 'effective_at', 'expires_at']);

            foreach ($rows as $row) {
                $result[(string) $row->erp_store_name][] = [
                    'lifecycle_id' => (int) $row->id,
                    'company_name' => $row->company_name,
                    'effective_at' => $row->effective_at,
                    'expires_at' => $row->expires_at,
                ];
            }
        }

        foreach ($result as $storeName => $periods) {
            $normalized = [];
            foreach ($periods as $period) {
                $last = array_key_last($normalized);
                if ($last !== null
                    && (string) ($normalized[$last]['company_name'] ?? '') === (string) ($period['company_name'] ?? '')) {
                    $normalized[$last]['lifecycle_ids'][] = $period['lifecycle_id'];
                    continue;
                }
                $period['lifecycle_ids'] = [$period['lifecycle_id']];
                $normalized[] = $period;
            }
            foreach ($normalized as $index => &$period) {
                $period['expires_at'] = $period['expires_at']
                    ?: ($normalized[$index + 1]['effective_at'] ?? self::DEFAULT_EXPIRES_AT);
            }
            unset($period);
            $result[$storeName] = $normalized;
        }

        return $result;
    }

    /** @return array<string,array{period:float,months:array<string,float>}> */
    private function lifecycleSales(array $names, string $billGeneration, string $lifecycleGeneration): array
    {
        $result = [];
        $month = $this->monthExpression('b.occurred_at');
        foreach (array_chunk($names, 500) as $chunk) {
            $placeholders = implode(',', array_fill(0, count($chunk), '?'));
            $rows = $this->connection->select(
                "WITH lifecycle_periods AS (
                    SELECT id, erp_store_name, effective_at,
                           COALESCE(expires_at,
                               LEAD(effective_at) OVER (PARTITION BY erp_store_name ORDER BY effective_at, id),
                               '2999-01-01 00:00:00') AS computed_expires_at
                    FROM store_report_lifecycle_rows
                    WHERE generation = ?
                 )
                 SELECT l.id AS lifecycle_id, {$month} AS bill_month,
                        SUM(COALESCE(b.income, 0)) AS income_total
                 FROM lifecycle_periods AS l
                 INNER JOIN store_report_bill_rows AS b
                   ON b.generation = ? AND b.store_name = l.erp_store_name AND b.occurred_at IS NOT NULL
                  AND b.occurred_at >= COALESCE(l.effective_at, '1000-01-01 00:00:00')
                  AND b.occurred_at < l.computed_expires_at
                 WHERE l.erp_store_name IN ($placeholders)
                 GROUP BY l.id, {$month}",
                [$lifecycleGeneration, $billGeneration, ...$chunk],
            );
            $this->collectSales($result, $rows, 'lifecycle_id');
        }

        return $result;
    }

    /** @return array<string,array{period:float,months:array<string,float>}> */
    private function fallbackSales(array $names, string $generation): array
    {
        $result = [];
        $month = $this->monthExpression('occurred_at');
        foreach (array_chunk($names, 500) as $chunk) {
            $placeholders = implode(',', array_fill(0, count($chunk), '?'));
            $rows = $this->connection->select(
                "SELECT store_name, {$month} AS bill_month,
                        SUM(COALESCE(income, 0)) AS income_total
                 FROM store_report_bill_rows
                 WHERE generation = ? AND store_name IN ($placeholders) AND occurred_at IS NOT NULL
                 GROUP BY store_name, {$month}",
                [$generation, ...$chunk],
            );
            $this->collectSales($result, $rows, 'store_name');
        }

        return $result;
    }

    /** @param array<string,array{period:float,months:array<string,float>}> $result */
    private function collectSales(array &$result, array $rows, string $keyColumn): void
    {
        foreach ($rows as $row) {
            $key = (string) $row->{$keyColumn};
            $result[$key]['period'] = ($result[$key]['period'] ?? 0.0) + (float) $row->income_total;
            $result[$key]['months'][(string) $row->bill_month] = (float) $row->income_total;
        }
    }

    /** @param array<string,array{period:float,months:array<string,float>}> $sales */
    private function combinedSales(array $sales, array $ids): array
    {
        $combined = ['period' => 0.0, 'months' => []];
        foreach ($ids as $id) {
            $row = $sales[(string) $id] ?? ['period' => 0.0, 'months' => []];
            $combined['period'] += (float) $row['period'];
            foreach ($row['months'] as $month => $amount) {
                $combined['months'][$month] = ($combined['months'][$month] ?? 0.0) + (float) $amount;
            }
        }
        return $combined;
    }

    private function monthExpression(string $column): string
    {
        return $this->connection->getDriverName() === 'sqlite'
            ? "strftime('%Y-%m', {$column})"
            : "DATE_FORMAT({$column}, '%Y-%m')";
    }

    private function date(mixed $value, string $fallback): string
    {
        $value = trim((string) ($value ?? ''));
        return $value === '' ? $fallback : substr($value, 0, 10);
    }

    private function status(mixed $value): ?string
    {
        return match ((string) $value) {
            '0', '正常' => '开店中',
            '3', '关闭中' => '关店中',
            '6', '已关闭' => '关店',
            default => $value === null || $value === '' ? null : (string) $value,
        };
    }
}