<?php

namespace App\Http\Controllers\Business;

use App\Traits\Companies;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Routing\Controller;
use Illuminate\Validation\ValidationException;
use Modules\EcommerceFinance\Services\AccountMappingCoa;
use Modules\EcommerceFinance\Services\AccountMappingStore;
use Modules\EcommerceFinance\Services\AccountMappingValidator;
use Modules\EcommerceFinance\Services\AccountMappingWorkbookImporter;
use RuntimeException;
use Symfony\Component\HttpFoundation\StreamedResponse;

/**
 * 财务规则 · 科目映射表的维护接口。
 *
 * 表里存的是「科目对 + 方向基准」，不存最终借贷方向；方向在记账时按账单实际收支代入。
 * 本控制器只负责：增、改、删、导入追加、导出、模板、校验。
 */
class AccountMappingActions extends Controller
{
    use Companies;

    public function __construct(
        private readonly AccountMappingStore $store,
        private readonly AccountMappingValidator $validator,
        private readonly AccountMappingCoa $coa,
        private readonly AccountMappingWorkbookImporter $importer,
    ) {
        $this->middleware('auth');
        $this->middleware('company.identify');
    }

    /** 全量规则 + 校验结果 + 筛选项 */
    public function index(): JsonResponse
    {
        return response()->json($this->payload());
    }

    public function store(Request $request): JsonResponse
    {
        $values = $this->payloadValues($request);
        if (trim((string) ($values['platform'] ?? '')) === '' || trim((string) ($values['item'] ?? '')) === '') {
            throw ValidationException::withMessages(['platform' => '平台和账单项目不能为空。']);
        }

        $this->store->create($values, $this->userId());

        return response()->json(['message' => '已新增 1 条规则。'] + $this->payload());
    }

    public function update(Request $request, int $id): JsonResponse
    {
        if ($this->store->find($id) === null) {
            throw ValidationException::withMessages(['id' => '这条规则已经不存在了，请刷新页面。']);
        }

        $this->store->update($id, $this->payloadValues($request), $this->userId());

        return response()->json(['message' => '已保存。'] + $this->payload());
    }

    public function destroy(int $id): JsonResponse
    {
        if (! $this->store->destroy($id, $this->userId())) {
            throw ValidationException::withMessages(['id' => '这条规则已经不存在了，请刷新页面。']);
        }

        return response()->json(['message' => '已删除 1 条规则。'] + $this->payload());
    }

    /**
     * 导入预览：只解析、不落盘。
     *
     * 单独一条路由、且不挂 throttle:import —— 因为平台对「导入」限的是 1 次/分钟，
     * 而页面上「预览 → 确认导入」天然要发两次请求，预览走限流必然 429。
     */
    public function preview(Request $request): JsonResponse
    {
        return response()->json($this->previewPayload($this->workbookFile($request)));
    }

    /**
     * 导入落盘。带 ?dry_run=1 时行为同 preview（保留兼容）。
     */
    public function import(Request $request): JsonResponse
    {
        $file = $this->workbookFile($request);

        if ($request->boolean('dry_run')) {
            return response()->json($this->previewPayload($file));
        }

        $parsed = $this->importer->parse($file);
        $result = $this->store->importRows($parsed['rows'], $request->boolean('overwrite'), $this->userId());
        $message = "导入完成：识别 {$result['total']} 行，新增 {$result['created']} 条，更新 {$result['updated']} 条，跳过重复 {$result['skipped']} 条。";

        return response()->json(['message' => $message, 'result' => $result] + $this->payload());
    }

    /**
     * 取上传的工作簿。
     *
     * 这里**故意不用** `mimes:xlsx,xls,csv`：那个规则靠 libmagic 嗅探真实类型，
     * 而只有两三行的 CSV 会被猜成 `text/plain`、扩展名算成 `txt`，于是合法文件被拒
     * （实测 2 行 231B 的 csv 报「必须是 xlsx, xls, csv 的文件」）。按扩展名判就稳。
     */
    protected function workbookFile(Request $request)
    {
        $request->validate([
            'import' => ['required', 'file', 'max:10240'],
        ], [
            'import.required' => '请先选择要导入的文件。',
            'import.file' => '请选择要导入的文件。',
            'import.max' => '文件不能超过 10MB。',
        ]);

        $file = $request->file('import');
        $extension = mb_strtolower((string) $file->getClientOriginalExtension());

        if (! in_array($extension, ['xlsx', 'xls', 'csv'], true)) {
            throw ValidationException::withMessages([
                'import' => '只支持 xlsx、xls、csv 三种格式，当前是「' . $extension . '」。',
            ]);
        }

        return $file;
    }

    /**
     * @param \Illuminate\Http\UploadedFile $file
     * @return array<string,mixed>
     */
    protected function previewPayload($file): array
    {
        $parsed = $this->importer->parse($file);
        $rows = $parsed['rows'];

        $existing = [];
        foreach ($this->store->all() as $rule) {
            $existing[$this->store->keyOf($rule)] = true;
        }

        $fresh = [];
        $duplicated = [];
        foreach ($rows as $row) {
            $key = $this->store->keyOf($row);
            if (isset($existing[$key])) {
                $duplicated[$key] = ($duplicated[$key] ?? 0) + 1;
            } else {
                $fresh[$key] = true;
                $existing[$key] = true;
            }
        }

        return [
            'dry_run' => true,
            'sheet' => $parsed['sheet'],
            'total' => count($rows),
            'can_create' => count($fresh),
            'can_overwrite' => count($duplicated),
            'duplicate_keys' => array_slice(array_keys($duplicated), 0, 20),
            'sample' => array_slice($rows, 0, 6),
        ];
    }

    /** 恢复成初始 112 条 */
    public function reset(): JsonResponse
    {
        $total = $this->store->reset($this->userId());

        return response()->json(['message' => "已恢复为初始 {$total} 条规则。"] + $this->payload());
    }

    /** 账套科目（一级 + 各一级下的明细），供下拉使用 */
    public function accounts(): JsonResponse
    {
        $level1 = $this->coa->level1();
        $children = [];
        foreach ($level1 as $account) {
            $children[$account['code']] = $this->coa->descendants($account['code']);
        }

        return response()->json(['level1' => $level1, 'children' => $children]);
    }

    /** 按当前表导出 CSV（Excel 可直接打开） */
    public function export(): StreamedResponse
    {
        $rules = $this->store->all();

        return response()->streamDownload(function () use ($rules): void {
            $csv = fopen('php://output', 'w');
            if ($csv === false) {
                throw new RuntimeException('无法创建导出文件。');
            }
            fputs($csv, chr(0xEF) . chr(0xBB) . chr(0xBF));
            fputcsv($csv, array_values(AccountMappingStore::LABELS));

            foreach ($rules as $rule) {
                $row = [];
                foreach (array_keys(AccountMappingStore::LABELS) as $field) {
                    $row[] = $this->csvText($rule[$field] ?? '');
                }
                fputcsv($csv, $row);
            }
            fclose($csv);
        }, '科目映射表_' . now()->format('Ymd_His') . '.csv', [
            'Content-Type' => 'text/csv; charset=UTF-8',
            'Cache-Control' => 'private, no-store',
        ]);
    }

    /** 导入模板（表头 + 两条示例，并且这一份可以直接改完再导回来） */
    public function template(): StreamedResponse
    {
        $samples = [
            ['得物', '平台服务费', '平台服务费', '0.06', '费用', '销售费用', '平台佣金', '其他货币资金', '', '支出基准'],
            ['淘宝', '交易收入', '订单', '-', '收入', '其他货币资金', '', '主营业务收入', '', '收入基准'],
        ];

        return response()->streamDownload(function () use ($samples): void {
            $csv = fopen('php://output', 'w');
            if ($csv === false) {
                throw new RuntimeException('无法创建模板文件。');
            }
            fputs($csv, chr(0xEF) . chr(0xBB) . chr(0xBF));
            fputcsv($csv, array_values(AccountMappingStore::LABELS));
            foreach ($samples as $sample) {
                fputcsv($csv, $sample);
            }
            fclose($csv);
        }, '科目映射表_导入模板.csv', [
            'Content-Type' => 'text/csv; charset=UTF-8',
            'Cache-Control' => 'private, no-store',
        ]);
    }

    /** @return array<string,mixed> */
    private function payload(): array
    {
        $rules = $this->store->all();
        $validated = $this->validator->validate($rules);

        $rows = [];
        foreach ($rules as $rule) {
            $rows[] = $rule + ['issues' => $validated['issues'][(int) $rule['id']] ?? []];
        }

        return [
            'rules' => $rows,
            'summary' => $validated['summary'],
            'options' => $this->store->options(),
            'events' => $this->store->events(20),
        ];
    }

    /** @return array<string,string> */
    private function payloadValues(Request $request): array
    {
        $input = (array) $request->input('values', $request->all());

        return $this->store->normalize($input);
    }

    private function userId(): ?int
    {
        return user_id() ? (int) user_id() : null;
    }

    private function csvText(mixed $value): string
    {
        $value = (string) $value;

        return preg_match('/^[=+\-@\t\r]/u', $value) === 1 ? "\t" . $value : $value;
    }
}