<?php

namespace App\Http\Controllers\Business;

use App\Models\Business\CourierQuoteChange;
use App\Services\Esign\EsignClient;
use App\Support\CourierQuoteChangeService;
use App\Support\CourierQuoteSignatureService;
use App\Support\QuoteManagementSnapshot;
use App\Utilities\SystemAccess;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Routing\Controller;
use Illuminate\View\View;

class CourierQuoteChanges extends Controller
{
    public function __construct(
        private readonly CourierQuoteChangeService $service,
        private readonly QuoteManagementSnapshot $snapshot,
        private readonly CourierQuoteSignatureService $signatureService,
    ) {
    }

    public function index(): View
    {
        $changes = CourierQuoteChange::query()
            ->with(['items', 'version'])
            ->latest('updated_at')
            ->paginate(20);

        return view('business.pages.courier-payables.quote-change-history', [
            'changes' => $changes,
            'canReview' => $this->canReview(),
        ]);
    }

    public function create(Request $request): View
    {
        $quotes = $this->snapshot->load()['quotes'] ?? [];
        abort_if($quotes === [], 422, '尚未导入可用于变更的报价版本。');

        $selectedId = (string) $request->query('source_quote_id', $quotes[0]['id']);
        $source = $this->service->findSourceQuote($selectedId);

        return view('business.pages.courier-payables.quote-change-editor', $this->editorData(null, $quotes, $source));
    }

    public function store(Request $request): RedirectResponse
    {
        $change = $this->service->create($this->validatedChange($request, true), user_id());

        return redirect()->route('business.courier-quote-changes.edit', $change)
            ->with('success', "已保存变更草稿 {$change->number}。原始报价未被修改。");
    }

    public function show(CourierQuoteChange $quoteChange): View
    {
        $quoteChange->load(['items', 'events.actor', 'version.signature']);

        return view('business.pages.courier-payables.quote-change-show', [
            'change' => $quoteChange,
            'canReview' => $this->canReview() && $quoteChange->created_by !== user_id(),
            'canManageSignature' => $this->canReview(),
            'esignConfigured' => EsignClient::configured(),
            'esignEnvironment' => (string) config('services.esign.environment', 'sandbox'),
        ]);
    }

    public function edit(CourierQuoteChange $quoteChange): View
    {
        abort_unless($quoteChange->isEditable() && $quoteChange->created_by === user_id(), 403);
        $quotes = $this->snapshot->load()['quotes'] ?? [];
        $source = $this->service->findSourceQuote($quoteChange->source_quote_id);
        $quoteChange->load('items');

        return view('business.pages.courier-payables.quote-change-editor', $this->editorData($quoteChange, $quotes, $source));
    }

    public function update(Request $request, CourierQuoteChange $quoteChange): RedirectResponse
    {
        $change = $this->service->update($quoteChange, $this->validatedChange($request, false), user_id());

        return redirect()->route('business.courier-quote-changes.edit', $change)
            ->with('success', "已保存变更草稿 {$change->number}。");
    }

    public function submit(CourierQuoteChange $quoteChange): RedirectResponse
    {
        $change = $this->service->submit($quoteChange, user_id());

        return redirect()->route('business.courier-quote-changes.show', $change)
            ->with('success', "{$change->number} 已提交审核。");
    }

    public function approve(CourierQuoteChange $quoteChange): RedirectResponse
    {
        abort_unless($this->canReview(), 403, '当前账号没有报价审核权限。');
        $change = $this->service->approve($quoteChange, user_id());

        $message = "审核完成，已生成新报价版本 {$change->version->version_code}。";

        try {
            $this->signatureService->prepareVersion($change->version, user_id());
            $message .= ' 签署 PDF 已生成并固定校验值。';
        } catch (\Throwable $exception) {
            report($exception);
            $message .= ' 签署 PDF 生成失败，可在详情页重试。';
        }

        if ($change->isRetrospective()) {
            $message .= ' 历史生效已登记，但补差核算尚未执行，请查看核算状态和阻断原因。';
        }

        return redirect()->route('business.courier-quote-changes.show', $change)
            ->with('success', $message);
    }

    public function returnForChanges(Request $request, CourierQuoteChange $quoteChange): RedirectResponse
    {
        abort_unless($this->canReview(), 403, '当前账号没有报价审核权限。');
        $validated = $request->validate([
            'review_note' => ['required', 'string', 'min:2', 'max:1000'],
        ]);
        $change = $this->service->returnForChanges($quoteChange, $validated['review_note'], user_id());

        return redirect()->route('business.courier-quote-changes.show', $change)
            ->with('success', "{$change->number} 已退回发起人修改。");
    }

    private function validatedChange(Request $request, bool $requiresSource): array
    {
        $rules = [
            'change_type' => ['required', 'in:费率调整,面单调整,规则备注,执行日期,其他'],
            'effective_date' => ['required', 'date_format:Y-m-d'],
            'summary' => ['required', 'string', 'min:2', 'max:2000'],
            'items' => ['required', 'array', 'min:1', 'max:500'],
            'items.*.source_cell' => ['required', 'regex:/^[A-Z]+[1-9][0-9]*$/'],
            'items.*.source_row' => ['required', 'integer', 'min:0'],
            'items.*.source_column' => ['required', 'integer', 'min:0'],
            'items.*.region' => ['nullable', 'string', 'max:255'],
            'items.*.weight_band' => ['nullable', 'string', 'max:255'],
            'items.*.charge_item' => ['nullable', 'string', 'max:255'],
            'items.*.original_amount' => ['required', 'numeric', 'min:0', 'decimal:0,4'],
            'items.*.new_amount' => ['required', 'numeric', 'min:0', 'decimal:0,4'],
            'items.*.unit' => ['nullable', 'string', 'max:32'],
            'items.*.note' => ['nullable', 'string', 'max:500'],
        ];

        if ($requiresSource) {
            $rules['source_quote_id'] = ['required', 'string', 'max:32'];
        }

        return $request->validate($rules);
    }

    private function editorData(?CourierQuoteChange $change, array $quotes, array $source): array
    {
        $existingItems = $change?->items->keyBy('source_cell') ?? collect();

        return [
            'change' => $change,
            'quotes' => $quotes,
            'source' => $source,
            'editableCells' => $this->editableCells($source, $existingItems),
        ];
    }

    private function editableCells(array $source, $existingItems): array
    {
        $values = $source['values'];
        $cells = [];

        foreach ($values as $rowIndex => $row) {
            foreach ($row as $columnIndex => $value) {
                if (! is_numeric($value)) {
                    continue;
                }

                $formula = $source['formulas'][$rowIndex][$columnIndex] ?? null;

                if (is_string($formula) && trim($formula) !== '') {
                    continue;
                }

                $cell = $this->columnName($columnIndex) . ($rowIndex + 1);
                $existing = $existingItems->get($cell);
                $cells[] = [
                    'source_cell' => $cell,
                    'source_row' => $rowIndex,
                    'source_column' => $columnIndex,
                    'region' => $this->nearestText($row, $columnIndex - 1) ?? $this->nearestText($row, 0),
                    'weight_band' => $this->headerText($values, $rowIndex, $columnIndex),
                    'charge_item' => $this->headerText($values, $rowIndex, $columnIndex),
                    'original_amount' => number_format((float) $value, 4, '.', ''),
                    'new_amount' => $existing?->new_amount ?? number_format((float) $value, 4, '.', ''),
                    'unit' => $existing?->unit,
                    'note' => $existing?->note,
                    'selected' => $existing !== null,
                ];
            }
        }

        return $cells;
    }

    private function headerText(array $values, int $row, int $column): ?string
    {
        for ($index = $row - 1; $index >= 0; $index--) {
            $candidate = $values[$index][$column] ?? null;

            if (is_string($candidate) && trim($candidate) !== '') {
                return trim($candidate);
            }
        }

        return null;
    }

    private function nearestText(array $row, int $column): ?string
    {
        for ($index = $column; $index >= 0; $index--) {
            $candidate = $row[$index] ?? null;

            if (is_string($candidate) && trim($candidate) !== '') {
                return trim($candidate);
            }
        }

        return null;
    }

    private function columnName(int $column): string
    {
        $name = '';

        do {
            $name = chr(65 + ($column % 26)) . $name;
            $column = intdiv($column, 26) - 1;
        } while ($column >= 0);

        return $name;
    }

    private function canReview(): bool
    {
        return in_array(SystemAccess::roleName(user()), [SystemAccess::SUPER_ADMIN, SystemAccess::ADMIN], true);
    }
}