<?php

namespace App\Services;

use Carbon\CarbonImmutable;
use Illuminate\Database\DatabaseManager;
use Illuminate\Support\Collection;
use Illuminate\Support\Str;
use InvalidArgumentException;
use RuntimeException;

class ErpRequestReportService
{
    public const DINGTALK_TOKEN_CONFIG_KEY = 'erp_request_report.dingtalk_token';

    private const REPORT_TIMEZONE = 'Asia/Shanghai';

    // Keep a margin below DingTalk's text-message limit for transport overhead.
    private const MAX_MESSAGE_BYTES = 18_000;

    public function __construct(
        private DatabaseManager $database,
        private DingTalkService $dingTalkService,
        private ConfigService $configService
    ) {}

    /**
     * @param  string|null  $date  单日（Y-m-d），与 from/to 互斥
     * @param  string|null  $from  开始时间（Y-m-d 或 Y-m-d H:i:s），含
     * @param  string|null  $to  结束时间（Y-m-d 或 Y-m-d H:i:s）；仅日期时含整天，含时分秒时含该时刻
     */
    public function sendReport(?string $date = null, ?string $from = null, ?string $to = null): array
    {
        $token = trim((string) $this->configService->get(self::DINGTALK_TOKEN_CONFIG_KEY));

        if ($token === '') {
            throw new RuntimeException('未配置 ERP 请求日报的钉钉机器人 Token');
        }

        [$start, $end] = $this->resolvePeriod($date, $from, $to);
        $periodLabel = $this->formatPeriodLabel($start, $end);

        $records = $this->database->connection('agentslave')
            ->table('request_records')
            ->selectRaw("agents.name as agent_name, agents.code as agent_code, SUBSTRING_INDEX(request_records.request_uri, '?', 1) as request_uri, COUNT(*) as request_count")
            ->leftJoin('agents', 'agents.id', '=', 'request_records.user_id')
            ->where('request_records.created', '>=', $start->toDateTimeString())
            ->where('request_records.created', '<', $end->toDateTimeString())
            ->where('request_records.request_uri', 'like', '/openapi/erp/%')
            ->groupByRaw("agents.id, agents.name, agents.code, SUBSTRING_INDEX(request_records.request_uri, '?', 1)")
            ->orderBy('agents.name')
            ->orderBy('agents.code')
            ->orderByRaw("SUBSTRING_INDEX(request_records.request_uri, '?', 1)")
            ->get();

        $messages = $this->formatMessages($periodLabel, $records);
        $messageCount = count($messages);

        foreach ($messages as $index => $message) {
            if (! $this->dingTalkService->sendTextToToken($token, $message)) {
                throw new RuntimeException(sprintf('ERP 请求日报第 %d/%d 条发送到钉钉失败', $index + 1, $messageCount));
            }
        }

        return [
            'date' => $periodLabel,
            'from' => $start->toDateTimeString(),
            'to' => $end->subSecond()->toDateTimeString(),
            'company_count' => $records->groupBy(fn ($record) => $record->agent_name."\0".$record->agent_code)->count(),
            'request_count' => $records->sum('request_count'),
        ];
    }

    /**
     * @return array{0: CarbonImmutable, 1: CarbonImmutable} half-open interval [start, end)
     */
    private function resolvePeriod(?string $date, ?string $from, ?string $to): array
    {
        $date = $this->normalizeOption($date);
        $from = $this->normalizeOption($from);
        $to = $this->normalizeOption($to);

        if ($date !== null && ($from !== null || $to !== null)) {
            throw new InvalidArgumentException('--date 不能与 --from/--to 同时使用');
        }

        if ($date !== null) {
            if (! $this->isDateOnly($date)) {
                throw new InvalidArgumentException('--date 仅支持 Y-m-d 格式');
            }

            $start = CarbonImmutable::parse($date, self::REPORT_TIMEZONE)->startOfDay();

            return [$start, $start->addDay()];
        }

        if ($from === null && $to === null) {
            $start = CarbonImmutable::now(self::REPORT_TIMEZONE)->subDay()->startOfDay();

            return [$start, $start->addDay()];
        }

        if ($from === null || $to === null) {
            throw new InvalidArgumentException('--from 与 --to 需要同时指定');
        }

        $start = $this->parseBound($from, isStart: true);
        $end = $this->parseBound($to, isStart: false);

        if ($end->lessThanOrEqualTo($start)) {
            throw new InvalidArgumentException('结束时间必须晚于开始时间');
        }

        return [$start, $end];
    }

    private function parseBound(string $value, bool $isStart): CarbonImmutable
    {
        $parsed = CarbonImmutable::parse($value, self::REPORT_TIMEZONE);

        if ($this->isDateOnly($value)) {
            return $isStart ? $parsed->startOfDay() : $parsed->startOfDay()->addDay();
        }

        return $isStart ? $parsed : $parsed->addSecond();
    }

    private function isDateOnly(string $value): bool
    {
        return (bool) preg_match('/^\d{4}-\d{2}-\d{2}$/', $value);
    }

    private function normalizeOption(?string $value): ?string
    {
        if ($value === null) {
            return null;
        }

        $value = trim($value);

        return $value === '' ? null : $value;
    }

    private function formatPeriodLabel(CarbonImmutable $start, CarbonImmutable $end): string
    {
        $inclusiveEnd = $end->subSecond();
        $isFullDayStart = $start->format('H:i:s') === '00:00:00';
        $isFullDayEnd = $inclusiveEnd->format('H:i:s') === '23:59:59';
        $spansSingleDay = $start->toDateString() === $inclusiveEnd->toDateString();

        if ($isFullDayStart && $isFullDayEnd && $spansSingleDay) {
            return $start->toDateString();
        }

        if ($isFullDayStart && $isFullDayEnd) {
            return $start->toDateString().' ~ '.$inclusiveEnd->toDateString();
        }

        return $start->format('Y-m-d H:i:s').' ~ '.$inclusiveEnd->format('Y-m-d H:i:s');
    }

    /**
     * @return array<int, string>
     */
    private function formatMessages(string $periodLabel, Collection $records): array
    {
        $title = "{$periodLabel} ERP OpenAPI 请求统计";

        if ($records->isEmpty()) {
            return ["{$title}\n无请求记录"];
        }

        $messages = [$title];

        foreach ($records->groupBy(fn ($record) => $record->agent_name."\0".$record->agent_code) as $companyRecords) {
            $first = $companyRecords->first();
            $company = trim(($first->agent_name ?: '未知机构').' '.($first->agent_code ?: ''));

            $this->appendCompanyRecords($messages, $title, $company, $companyRecords);
        }

        if (count($messages) === 1) {
            return $messages;
        }

        return array_map(
            fn (string $message, int $index) => "{$message}（第 ".($index + 1).'/'.count($messages).' 条）',
            $messages,
            array_keys($messages)
        );
    }

    private function appendCompanyRecords(array &$messages, string $title, string $company, Collection $records): void
    {
        foreach ($records->values() as $index => $record) {
            $line = $this->formatRequestLine($record);
            $messageIndex = array_key_last($messages);
            $isFirstRecord = $index === 0;
            $addition = $isFirstRecord
                ? "\n\n{$company}\n{$line}"
                : "\n{$line}";

            if (strlen($messages[$messageIndex].$addition) <= self::MAX_MESSAGE_BYTES) {
                $messages[$messageIndex] .= $addition;

                continue;
            }

            $messages[] = "{$title}\n\n{$company}\n{$line}";
        }
    }

    private function formatRequestLine(object $record): string
    {
        $uri = explode('?', (string) $record->request_uri, 2)[0];
        $uri = preg_replace('/[\\x00-\\x1F\\x7F]/u', '', $uri) ?? '';

        return Str::limit($uri, 1_000, '…')." {$record->request_count}次";
    }
}