<?php

namespace App\Business;

use App\Models\Business\FundForecast;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Http\Request;
use Illuminate\Pagination\LengthAwarePaginator;
use Illuminate\Support\Facades\Schema;

class FundForecastPage
{
    public const GROUPS = [
        ['key' => 'balance', 'label' => '余额', 'fields' => FundForecast::BALANCE_FIELDS],
        ['key' => 'income', 'label' => '收入', 'fields' => FundForecast::INCOME_FIELDS],
        ['key' => 'expense', 'label' => '支出', 'fields' => FundForecast::EXPENSE_FIELDS],
        ['key' => 'summary', 'label' => '汇总', 'fields' => FundForecast::SUMMARY_FIELDS],
    ];

    public function data(Request $request): array
    {
        $filters = $this->filters($request);

        if (! Schema::hasColumns('business_fund_forecast', ['company_name', 'balance_bank', 'gap_surplus'])) {
            return $this->pendingData($request, $filters);
        }

        $base = FundForecast::query();
        $this->applyFilters($base, $filters);

        $scopeCounts = [
            'all' => (clone $base)->count(),
            'gap' => $this->applyScope(clone $base, 'gap')->count(),
            'unreported' => $this->applyScope(clone $base, 'unreported')->count(),
            'pending_review' => $this->applyScope(clone $base, 'pending_review')->count(),
        ];

        $query = $this->applyScope(clone $base, $filters['view']);
        $summaryQuery = clone $query;
        $rows = $query
            ->orderByDesc('budget_month')
            ->orderBy('company_name')
            ->orderByDesc('id')
            ->paginate(50)
            ->withQueryString();

        $labels = FundForecast::columnLabels();
        $groups = array_map(function (array $group) use ($labels): array {
            $group['columns'] = array_map(
                fn (string $field): array => ['field' => $field, 'label' => $labels[$field]],
                $group['fields'],
            );

            return $group;
        }, self::GROUPS);

        return [
            'ready' => true,
            'filters' => $filters,
            'months' => FundForecast::query()->whereNotNull('budget_month')->where('budget_month', '<>', '')
                ->distinct()->orderByDesc('budget_month')->pluck('budget_month')->all(),
            'regions' => FundForecast::query()->whereNotNull('region')->where('region', '<>', '')
                ->distinct()->orderBy('region')->pluck('region')->all(),
            'rows' => $rows,
            'groups' => $groups,
            'scopeCounts' => $scopeCounts,
            'summary' => [
                'company_count' => (clone $summaryQuery)->whereNotNull('company_name')->where('company_name', '<>', '')
                    ->distinct()->count('company_name'),
                'balance_total' => $this->sumColumns(clone $summaryQuery, FundForecast::BALANCE_FIELDS),
                'income_total' => (float) (clone $summaryQuery)->sum('forecast_month_income'),
                'gap_surplus' => (float) (clone $summaryQuery)->sum('gap_surplus'),
            ],
        ];
    }

    private function pendingData(Request $request, array $filters): array
    {
        $labels = FundForecast::columnLabels();
        $groups = array_map(function (array $group) use ($labels): array {
            $group['columns'] = array_map(
                fn (string $field): array => ['field' => $field, 'label' => $labels[$field]],
                $group['fields'],
            );

            return $group;
        }, self::GROUPS);

        return [
            'ready' => false,
            'filters' => $filters,
            'months' => [],
            'regions' => [],
            'rows' => new LengthAwarePaginator([], 0, 50, max((int) $request->query('page', 1), 1), [
                'path' => $request->url(),
                'query' => $request->query(),
            ]),
            'groups' => $groups,
            'scopeCounts' => ['all' => 0, 'gap' => 0, 'unreported' => 0, 'pending_review' => 0],
            'summary' => ['company_count' => 0, 'balance_total' => 0.0, 'income_total' => 0.0, 'gap_surplus' => 0.0],
        ];
    }

    private function filters(Request $request): array
    {
        $month = trim((string) $request->query('budget_month', ''));
        $month = preg_match('/^\d{4}-(0[1-9]|1[0-2])$/', $month) === 1 ? $month : '';
        $status = trim((string) $request->query('report_status', ''));
        $status = in_array($status, ['待填报', '待审核', '已审核'], true) ? $status : '';
        $view = trim((string) $request->query('view', 'all'));
        $view = in_array($view, ['all', 'gap', 'unreported', 'pending_review'], true) ? $view : 'all';

        return [
            'budget_month' => $month,
            'region' => mb_substr(trim((string) $request->query('region', '')), 0, 64),
            'report_status' => $status,
            'company_name' => mb_substr(trim((string) $request->query('company_name', '')), 0, 191),
            'view' => $view,
        ];
    }

    private function applyFilters(Builder $query, array $filters): void
    {
        if ($filters['budget_month'] !== '') {
            $query->where('budget_month', $filters['budget_month']);
        }
        if ($filters['region'] !== '') {
            $query->where('region', $filters['region']);
        }
        if ($filters['report_status'] !== '') {
            $query->where('report_status', $filters['report_status']);
        }
        if ($filters['company_name'] !== '') {
            $query->where('company_name', 'like', '%' . addcslashes($filters['company_name'], '%_\\') . '%');
        }
    }

    private function applyScope(Builder $query, string $scope): Builder
    {
        return match ($scope) {
            'gap' => $query->where(function (Builder $nested): void {
                $nested->where('has_gap', true)->orWhere('gap_surplus', '<', 0);
            }),
            'unreported' => $query->where(function (Builder $nested): void {
                $nested->whereNull('report_status')->orWhere('report_status', '待填报');
            }),
            'pending_review' => $query->where('report_status', '待审核'),
            default => $query,
        };
    }

    private function sumColumns(Builder $query, array $columns): float
    {
        return array_reduce(
            $columns,
            fn (float $sum, string $column): float => $sum + (float) (clone $query)->sum($column),
            0.0,
        );
    }
}