<?php

namespace App\Services\Admin\Sms;

use App\Repositories\Admin\Sms\AdminSmsBatchRepository;
use App\Services\SmsService;
use Illuminate\Http\Request;
use Illuminate\Http\UploadedFile;

final class AdminSmsService
{
    public function __construct(
        private readonly AdminSmsBatchRepository $repo,
        private readonly SmsService $smsService,
    ) {}

    /**
     * @param int $adminId
     * @param array $data  컨트롤러 validate 결과
     * @return array ['ok'=>bool, 'batch_id'=>int, 'total'=>int, 'valid'=>int, 'invalid'=>int, 'duplicate'=>int, 'message'=>string]
     */
    public function createBatch(int $adminId, array $data, Request $request): array
    {
        $mode = (string)($data['send_mode'] ?? 'one');
        $from = (string)($data['from_number'] ?? '');
        $msgRaw = (string)($data['message'] ?? '');
        $smsTypeHint = (string)($data['sms_type_hint'] ?? 'auto');

        $scheduleType = (string)($data['schedule_type'] ?? 'now');
        $scheduledAt = null;

        if ($scheduleType === 'schedule') {
            $scheduledAt = !empty($data['scheduled_at']) ? $data['scheduled_at'] : null;
            if ($scheduledAt === null) {
                return ['ok' => false, 'message' => '예약 시간을 입력해 주세요.'];
            }
        }

        // 1) 대상 생성
        try {
            $targets = match ($mode) {
                'one'      => $this->buildTargetsOne((string)($data['to_number'] ?? ''), $msgRaw),
                'many'     => $this->buildTargetsMany(
                    (string)($data['to_numbers_text'] ?? ''),
                    $request->file('to_numbers_csv'),
                    $msgRaw
                ),
                'template' => $this->buildTargetsTemplate(
                    $request->file('template_csv'),
                    $msgRaw
                ),
                default    => throw new \RuntimeException('지원하지 않는 send_mode 입니다.'),
            };
        } catch (\Throwable $e) {
            return ['ok' => false, 'message' => $e->getMessage()];
        }

        $total = $targets['total'];
        $valid = $targets['valid'];
        $invalid = $targets['invalid'];
        $dup = $targets['duplicate'];
        $items = $targets['items']; // seq 포함된 배열

        if ($valid < 1) {
            return ['ok' => false, 'message' => '유효한 수신번호가 없습니다.'];
        }

        // 2) batch insert
        $byteLen = $this->calcBytesCiLike($msgRaw);

        $batchId = $this->repo->insertBatch([
            'admin_user_id'   => $adminId,
            'from_number'     => $from,
            'send_mode'       => $mode,
            'schedule_type'   => $scheduleType,
            'scheduled_at'    => $scheduledAt,

            'message_raw'     => $msgRaw,
            'byte_len'        => $byteLen,
            'sms_type_hint'   => in_array($smsTypeHint, ['auto','sms','mms'], true) ? $smsTypeHint : 'auto',

            'total_count'     => $total,
            'valid_count'     => $valid,
            'duplicate_count' => $dup,
            'invalid_count'   => $invalid,

            'status'          => ($scheduleType === 'schedule') ? 'scheduled' : 'queued',

            'request_ip'      => $request->ip(),
            'user_agent'      => substr((string)$request->userAgent(), 0, 255),
        ]);

        // 3) items bulk insert (예약이면 queued, 즉시도 일단 queued로 넣고 이후 submitted/failed로 업데이트)
        $this->repo->insertItemsChunked($batchId, $items);

        // 4) 즉시 발송이면 실제 provider queue(DB)에 insert (SmsService가 sms_server에 넣음)
        if ($scheduleType === 'now') {
            $this->repo->updateBatch($batchId, ['status' => 'submitting']);

            $submitted = 0;
            $failed = 0;

            foreach ($items as $it) {
                $payload = [
                    'from_number' => $from,
                    'to_number'   => $it['to_number'],
                    'message'     => $it['message_final'],
                    'sms_type'    => $it['sms_type'], // 힌트(최종은 SmsService 내부 기준)
                ];

                $ok = $this->smsService->send($payload, 'lguplus');

                if ($ok) {
                    $submitted++;
                    $this->repo->updateItemBySeq($batchId, (int)$it['seq'], [
                        'status' => 'submitted',
                        'submitted_at' => now()->format('Y-m-d H:i:s'),
                    ]);
                } else {
                    $failed++;
                    $this->repo->updateItemBySeq($batchId, (int)$it['seq'], [
                        'status' => 'failed',
                        'provider_message' => 'SmsService send() returned false',
                    ]);
                }
            }

            $status = 'submitted';
            if ($submitted < 1) $status = 'failed';
            else if ($failed > 0) $status = 'partial';

            $this->repo->updateBatch($batchId, [
                'status' => $status,
                'error_message' => $failed > 0 ? "failed={$failed}" : null,
            ]);
        }

        return [
            'ok' => true,
            'batch_id' => $batchId,
            'total' => $total,
            'valid' => $valid,
            'invalid' => $invalid,
            'duplicate' => $dup,
        ];
    }

    private function buildTargetsOne(string $to, string $message): array
    {
        $digits = $this->normalizePhone($to);
        if (!$this->isValidKrMobile($digits)) {
            return ['total'=>1,'valid'=>0,'invalid'=>1,'duplicate'=>0,'items'=>[]];
        }

        return [
            'total' => 1,
            'valid' => 1,
            'invalid' => 0,
            'duplicate' => 0,
            'items' => [[
                'seq' => 1,
                'to_number' => $digits,
                'message_final' => $message,
                'sms_type' => $this->guessSmsType($message),
                'status' => 'queued',
            ]],
        ];
    }

    private function buildTargetsMany(string $text, ?UploadedFile $csv, string $message): array
    {
        $phones = [];

        // 1) textarea
        if (trim($text) !== '') {
            $parts = preg_split('/[\s,]+/', $text) ?: [];
            foreach ($parts as $p) {
                $d = $this->normalizePhone((string)$p);
                if ($d !== '') $phones[] = $d;
            }
        }

        // 2) csv (첫 컬럼만 phone으로 사용)
        if ($csv instanceof UploadedFile) {
            foreach ($this->readCsvLines($csv) as $row) {
                if (empty($row)) continue;
                $d = $this->normalizePhone((string)($row[0] ?? ''));
                if ($d !== '') $phones[] = $d;
            }
        }

        $total = count($phones);
        $validList = [];
        $invalid = 0;

        foreach ($phones as $p) {
            if ($this->isValidKrMobile($p)) $validList[] = $p;
            else $invalid++;
        }

        $uniq = array_values(array_unique($validList));
        $dup = count($validList) - count($uniq);

        $smsType = $this->guessSmsType($message);
        $items = [];
        $seq = 1;
        foreach ($uniq as $p) {
            $items[] = [
                'seq' => $seq++,
                'to_number' => $p,
                'message_final' => $message,
                'sms_type' => $smsType,
                'status' => 'queued',
            ];
        }

        return [
            'total' => $total,
            'valid' => count($uniq),
            'invalid' => $invalid,
            'duplicate' => $dup,
            'items' => $items,
        ];
    }

    private function buildTargetsTemplate(?UploadedFile $csv, string $message): array
    {
        if (!$csv instanceof UploadedFile) {
            throw new \RuntimeException('템플릿 CSV 파일을 업로드해 주세요.');
        }

        // placeholder 검증: {_text_02_}부터 연속인지
        $idxs = $this->extractTemplateIndexes($message); // [2,3,4...]
        if (empty($idxs)) {
            throw new \RuntimeException('문구에 템플릿 토큰({_text_02_}~)이 없습니다.');
        }
        if ($idxs[0] !== 2) {
            throw new \RuntimeException('첫 템플릿 토큰은 {_text_02_}로 시작해야 합니다.');
        }
        for ($i=0; $i<count($idxs); $i++) {
            if ($idxs[$i] !== (2 + $i)) {
                $need = 2 + $i;
                throw new \RuntimeException("템플릿 토큰 {_text_0{$need}_} 이(가) 없습니다.");
            }
        }

        $needArgs = count($idxs); // 02~ => args 개수
        $lines = $this->readCsvLines($csv);

        $total = 0;
        $invalid = 0;
        $validPhones = [];
        $rowsToBuild = [];

        $lineNo = 0;
        foreach ($lines as $row) {
            $lineNo++;
            if (empty($row)) continue;

            $total++;

            $phone = $this->normalizePhone((string)($row[0] ?? ''));
            if (!$this->isValidKrMobile($phone)) {
                $invalid++;
                continue;
            }

            // args 검증: row[1..needArgs] must exist and not empty
            for ($i=0; $i<$needArgs; $i++) {
                $v = (string)($row[$i+1] ?? '');
                if (trim($v) === '') {
                    throw new \RuntimeException("CSV {$lineNo}라인: {_text_0".(2+$i)."_} 매칭 값이 없습니다.");
                }
            }

            $rowsToBuild[] = [$phone, $row]; // 나중에 치환
            $validPhones[] = $phone;
        }

        $uniqPhones = array_values(array_unique($validPhones));
        $dup = count($validPhones) - count($uniqPhones);

        // phone별 첫 등장 row만 사용(중복 번호는 제거)
        $firstRowByPhone = [];
        foreach ($rowsToBuild as [$phone, $row]) {
            if (!isset($firstRowByPhone[$phone])) {
                $firstRowByPhone[$phone] = $row;
            }
        }

        $items = [];
        $seq = 1;

        foreach ($uniqPhones as $phone) {
            $row = $firstRowByPhone[$phone];

            $msgFinal = $message;
            for ($i=0; $i<$needArgs; $i++) {
                $token = '{_text_0'.(2+$i).'_}';
                $msgFinal = str_replace($token, (string)$row[$i+1], $msgFinal);
            }

            $items[] = [
                'seq' => $seq++,
                'to_number' => $phone,
                'message_final' => $msgFinal,
                'sms_type' => $this->guessSmsType($msgFinal),
                'status' => 'queued',
            ];
        }

        return [
            'total' => $total,
            'valid' => count($items),
            'invalid' => $invalid,
            'duplicate' => $dup,
            'items' => $items,
        ];
    }

    private function normalizePhone(string $v): string
    {
        return preg_replace('/\D+/', '', $v) ?? '';
    }

    private function isValidKrMobile(string $digits): bool
    {
        return (bool) preg_match('/^01\d{8,9}$/', $digits);
    }

    private function extractTemplateIndexes(string $message): array
    {
        preg_match_all('/\{_text_(0[2-9])_\}/', $message, $m);
        $raw = array_unique($m[1] ?? []);
        $idxs = array_map(fn($s) => (int)$s, $raw);
        sort($idxs);
        return $idxs;
    }

    private function guessSmsType(string $message): string
    {
        // SmsService의 기존 기준을 “대충 맞춰”주는 용도(최종 판정은 provider/서비스)
        $len = @mb_strlen($message, 'EUC-KR');
        return ($len !== false && $len > 90) ? 'mms' : 'sms';
    }

    private function calcBytesCiLike(string $str): int
    {
        // CI/JS 방식: ASCII 1, 그 외 2
        $bytes = 0;
        $len = mb_strlen($str, 'UTF-8');
        for ($i=0; $i<$len; $i++) {
            $ch = mb_substr($str, $i, 1, 'UTF-8');
            $ord = unpack('N', mb_convert_encoding($ch, 'UCS-4BE', 'UTF-8'))[1] ?? 0;
            $bytes += ($ord > 127) ? 2 : 1;
        }
        return $bytes;
    }

    /**
     * CSV를 "라인 단위"로 읽어서 배열(row)로 반환
     * - UTF-8/CP949/EUC-KR 어느 정도 허용
     */
    private function readCsvLines(UploadedFile $csv): \Generator
    {
        $path = $csv->getRealPath();
        if ($path === false) return;

        $fh = fopen($path, 'rb');
        if (!$fh) return;

        try {
            while (($row = fgetcsv($fh)) !== false) {
                if ($row === [null] || $row === false) continue;

                // encoding normalize
                $out = [];
                foreach ($row as $cell) {
                    $cell = (string)$cell;
                    $out[] = $this->toUtf8($cell);
                }
                yield $out;
            }
        } finally {
            fclose($fh);
        }
    }

    private function toUtf8(string $s): string
    {
        // BOM 제거
        $s = preg_replace('/^\xEF\xBB\xBF/', '', $s) ?? $s;

        // 이미 UTF-8이면 그대로
        if (mb_check_encoding($s, 'UTF-8')) return $s;

        // CP949/EUC-KR 가능성
        $converted = @mb_convert_encoding($s, 'UTF-8', 'CP949,EUC-KR,ISO-8859-1');
        return is_string($converted) ? $converted : $s;
    }
}