package com.talentcard.server.business.merchant;

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.time.LocalDateTime;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import com.talentcard.server.business.BusinessIdGenerator;
import com.talentcard.server.business.DatabaseRows;
import com.talentcard.server.business.PageResult;
import com.talentcard.server.business.merchant.auth.MerchantPrincipal;
import com.talentcard.server.common.BusinessException;
import com.talentcard.server.common.ErrorCode;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service
public class MerchantSettlementService {
    private final JdbcTemplate jdbc;

    public MerchantSettlementService(JdbcTemplate jdbc) { this.jdbc = jdbc; }

    @Transactional(readOnly = true)
    public Map<String, Object> onboardingStatus(MerchantPrincipal principal) {
        store(principal);
        List<Map<String, Object>> records = rows("select * from merchant_onboarding_application where merchant_id = ? and store_id = ? order by id desc limit 1", principal.merchantId(), principal.storeId());
        return records.isEmpty() ? Map.of("status", "unsubmitted", "reason", "") : onboarding(records.get(0));
    }

    @Transactional
    public Map<String, Object> submitOnboarding(MerchantPrincipal principal, MerchantOnboardingRequest request, String key) {
        requireKey(key); store(principal);
        List<Map<String, Object>> repeated = rows("select * from merchant_onboarding_application where merchant_id = ? and idempotency_key = ? limit 1", principal.merchantId(), key.trim());
        if (!repeated.isEmpty()) return onboarding(repeated.get(0));
        List<Map<String, Object>> active = rows("select * from merchant_onboarding_application where merchant_id = ? and store_id = ? and status in ('pending','approved') order by id desc limit 1", principal.merchantId(), principal.storeId());
        if (!active.isEmpty()) return onboarding(active.get(0));
        boolean enterprise = "enterprise".equals(request.subjectType());
        if (enterprise && (request.creditCode() == null || !request.creditCode().trim().matches("[0-9A-Z]{18}"))) throw new BusinessException(ErrorCode.BAD_REQUEST, "请输入18位统一社会信用代码");
        if (!enterprise && (request.subjectIdNumber() == null || !request.subjectIdNumber().trim().matches("(?:\\d{15}|\\d{17}[0-9X])"))) throw new BusinessException(ErrorCode.BAD_REQUEST, "请输入正确的身份证号");
        String no = BusinessIdGenerator.next("MO");
        jdbc.update("insert into merchant_onboarding_application(merchant_id, store_id, application_no, subject_type, subject_name, credit_code, subject_id_no_masked, registered_region, registered_address, contact_name, contact_mobile, idempotency_key) values (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)", principal.merchantId(), principal.storeId(), no, request.subjectType(), request.subjectName().trim(), clean(request.creditCode()), maskId(request.subjectIdNumber()), clean(request.registeredRegion()), clean(request.registeredAddress()), request.contactName().trim(), request.contactMobile().trim(), key.trim());
        return onboarding(rows("select * from merchant_onboarding_application where application_no = ?", no).get(0));
    }

    @Transactional(readOnly = true)
    public List<Map<String, Object>> bankCards(MerchantPrincipal principal) {
        store(principal);
        return rows("select * from merchant_bank_card where merchant_id = ? and store_id = ? order by id desc", principal.merchantId(), principal.storeId()).stream().map(this::bankCard).toList();
    }

    @Transactional
    public Map<String, Object> addBankCard(MerchantPrincipal principal, MerchantBankCardRequest request, String key) {
        requireKey(key); store(principal); requireApproved(principal);
        List<Map<String, Object>> repeated = rows("select * from merchant_bank_card where merchant_id = ? and idempotency_key = ? limit 1", principal.merchantId(), key.trim());
        if (!repeated.isEmpty()) return bankCard(repeated.get(0));
        String number = request.cardNumber().trim(); String hash = sha256(number);
        List<Map<String, Object>> same = rows("select * from merchant_bank_card where merchant_id = ? and card_hash = ? limit 1", principal.merchantId(), hash);
        if (!same.isEmpty()) return bankCard(same.get(0));
        jdbc.update("insert into merchant_bank_card(merchant_id, store_id, bank_name, branch_name, city_code, card_tail, card_masked, card_hash, idempotency_key) values (?, ?, ?, ?, ?, ?, ?, ?, ?)", principal.merchantId(), principal.storeId(), request.bankName().trim(), request.branchName().trim(), request.cityCode().trim(), number.substring(number.length() - 4), "**** **** **** " + number.substring(number.length() - 4), hash, key.trim());
        return bankCard(rows("select * from merchant_bank_card where merchant_id = ? and card_hash = ?", principal.merchantId(), hash).get(0));
    }

    @Transactional(readOnly = true)
    public PageResult<Map<String, Object>> bankBranches(String cityCode, String keyword, int page, int size) {
        // The payment provider's bank directory should replace this curated fallback during Huifu onboarding.
        List<Map<String, Object>> all = List.of(
                branch("CCB510400", "中国建设银行攀枝花东区支行营业部", "中国建设银行"), branch("CCB510401", "中国建设银行攀枝花分行营业部", "中国建设银行"),
                branch("ICBC510400", "中国工商银行攀枝花东区支行", "中国工商银行"), branch("ABC510400", "中国农业银行攀枝花炳草岗支行", "中国农业银行"));
        String query = clean(keyword).toLowerCase(); int safePage = Math.max(page, 1); int safeSize = Math.min(Math.max(size, 1), 50);
        List<Map<String, Object>> matched = all.stream().filter(value -> query.isEmpty() || (value.get("branchName") + "" + value.get("bankName")).toLowerCase().contains(query)).toList();
        int start = Math.min((safePage - 1) * safeSize, matched.size()); int end = Math.min(start + safeSize, matched.size());
        return new PageResult<>(matched.subList(start, end), safePage, safeSize, matched.size());
    }

    @Transactional(readOnly = true)
    public Map<String, Object> withdrawalSummary(MerchantPrincipal principal) {
        store(principal);
        Long verified = jdbc.queryForObject("select coalesce(sum(pay_amount), 0) from benefit_order where merchant_id = ? and (store_id is null or store_id = ?) and order_status = 1 and verify_status = 1 and deleted = 0", Long.class, principal.merchantId(), principal.storeId());
        Long held = jdbc.queryForObject("select coalesce(sum(amount_cents), 0) from merchant_withdrawal where merchant_id = ? and store_id = ? and status in ('pending','processing','paid')", Long.class, principal.merchantId(), principal.storeId());
        long available = Math.max(0, (verified == null ? 0 : verified) - (held == null ? 0 : held));
        return Map.of("availableAmountCents", available, "frozenAmountCents", held == null ? 0 : held);
    }

    @Transactional(readOnly = true)
    public PageResult<Map<String, Object>> withdrawals(MerchantPrincipal principal, int page, int size) {
        store(principal); int safePage = Math.max(page, 1); int safeSize = Math.min(Math.max(size, 1), 50);
        List<Map<String, Object>> values = rows("select w.*, c.bank_name, c.card_masked from merchant_withdrawal w join merchant_bank_card c on c.id = w.bank_card_id where w.merchant_id = ? and w.store_id = ? order by w.id desc limit ? offset ?", principal.merchantId(), principal.storeId(), safeSize, (safePage - 1) * safeSize).stream().map(this::withdrawal).toList();
        Long total = jdbc.queryForObject("select count(*) from merchant_withdrawal where merchant_id = ? and store_id = ?", Long.class, principal.merchantId(), principal.storeId());
        return new PageResult<>(values, safePage, safeSize, total == null ? 0 : total);
    }

    @Transactional
    public Map<String, Object> createWithdrawal(MerchantPrincipal principal, MerchantWithdrawalRequest request, String key) {
        requireKey(key); store(principal); requireApproved(principal);
        List<Map<String, Object>> repeated = rows("select * from merchant_withdrawal where merchant_id = ? and idempotency_key = ? limit 1", principal.merchantId(), key.trim());
        if (!repeated.isEmpty()) return withdrawal(repeated.get(0));
        Long cardId = number(request.bankCardId());
        List<Map<String, Object>> cards = rows("select * from merchant_bank_card where id = ? and merchant_id = ? and store_id = ? and status = 'approved' limit 1", cardId, principal.merchantId(), principal.storeId());
        if (cards.isEmpty()) throw new BusinessException(ErrorCode.CONFLICT, "请选择审核通过的银行卡");
        long available = ((Number) withdrawalSummary(principal).get("availableAmountCents")).longValue();
        if (request.amountCents() > available) throw new BusinessException(ErrorCode.CONFLICT, "提现金额不能超过当前可提金额");
        String no = BusinessIdGenerator.next("MW");
        jdbc.update("insert into merchant_withdrawal(merchant_id, store_id, withdrawal_no, bank_card_id, amount_cents, idempotency_key) values (?, ?, ?, ?, ?, ?)", principal.merchantId(), principal.storeId(), no, cardId, request.amountCents(), key.trim());
        return withdrawal(rows("select w.*, c.bank_name, c.card_masked from merchant_withdrawal w join merchant_bank_card c on c.id = w.bank_card_id where w.withdrawal_no = ?", no).get(0));
    }

    private void requireApproved(MerchantPrincipal principal) { if (!"approved".equals(onboardingStatus(principal).get("status"))) throw new BusinessException(ErrorCode.CONFLICT, "商户进件尚未审核通过"); }
    private void requireKey(String key) { if (key == null || key.isBlank()) throw new BusinessException(ErrorCode.BAD_REQUEST, "缺少幂等键"); }
    private void store(MerchantPrincipal principal) { if (rows("select id from merchant_store where id = ? and merchant_id = ? and status = 1 and deleted = 0", principal.storeId(), principal.merchantId()).isEmpty()) throw new BusinessException(ErrorCode.FORBIDDEN, "当前门店不可操作"); }
    private Map<String, Object> onboarding(Map<String, Object> row) { return Map.of("id", String.valueOf(row.get("id")), "applicationNo", row.get("applicationNo"), "status", row.get("status"), "reason", clean(row.get("rejectReason")), "submittedAt", String.valueOf(row.get("createdAt"))); }
    private Map<String, Object> bankCard(Map<String, Object> row) { return Map.of("id", String.valueOf(row.get("id")), "bankName", row.get("bankName"), "branchName", row.get("branchName"), "cardMasked", row.get("cardMasked"), "status", row.get("status"), "reason", clean(row.get("rejectReason")), "createdAt", String.valueOf(row.get("createdAt"))); }
    private Map<String, Object> withdrawal(Map<String, Object> row) { Map<String, Object> value = new LinkedHashMap<>(); value.put("id", String.valueOf(row.get("id"))); value.put("withdrawalNo", row.get("withdrawalNo")); value.put("amountCents", row.get("amountCents")); value.put("status", row.get("status")); value.put("reason", clean(row.get("failureReason"))); value.put("bankName", clean(row.get("bankName"))); value.put("cardMasked", clean(row.get("cardMasked"))); value.put("createdAt", String.valueOf(row.get("createdAt"))); value.put("reviewedAt", clean(row.get("reviewedAt"))); value.put("paidAt", clean(row.get("paidAt"))); return value; }
    private Map<String, Object> branch(String id, String branchName, String bankName) { return Map.of("id", id, "branchName", branchName, "bankName", bankName); }
    private List<Map<String, Object>> rows(String sql, Object... args) { return DatabaseRows.normalize(jdbc.queryForList(sql, args)); }
    private Long number(String value) { try { return Long.valueOf(value); } catch (Exception ignored) { throw new BusinessException(ErrorCode.BAD_REQUEST, "编号无效"); } }
    private String clean(Object value) { return value == null ? "" : String.valueOf(value).trim(); }
    private String maskId(String id) { String value = clean(id); return value.length() < 8 ? "" : value.substring(0, 3) + "********" + value.substring(value.length() - 4); }
    private String sha256(String value) { try { byte[] digest = MessageDigest.getInstance("SHA-256").digest(value.getBytes(StandardCharsets.UTF_8)); StringBuilder result = new StringBuilder(); for (byte valueByte : digest) result.append(String.format("%02x", valueByte)); return result.toString(); } catch (Exception exception) { throw new IllegalStateException("Unable to hash bank card", exception); } }
}