package com.ruoyi.ai.tools;

import com.alibaba.fastjson2.JSON;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.ruoyi.ai.context.AiSessionUserContext;
import com.ruoyi.common.utils.SecurityUtils;
import com.ruoyi.framework.security.LoginUser;
import com.ruoyi.purchase.mapper.InvoicePurchaseMapper;
import com.ruoyi.purchase.mapper.PaymentRegistrationMapper;
import com.ruoyi.purchase.mapper.PurchaseLedgerMapper;
import com.ruoyi.purchase.mapper.PurchaseReturnOrdersMapper;
import com.ruoyi.purchase.pojo.InvoicePurchase;
import com.ruoyi.purchase.pojo.PaymentRegistration;
import com.ruoyi.purchase.pojo.PurchaseLedger;
import com.ruoyi.purchase.pojo.PurchaseReturnOrders;
import dev.langchain4j.agent.tool.P;
import dev.langchain4j.agent.tool.Tool;
import dev.langchain4j.agent.tool.ToolMemoryId;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;

import java.math.BigDecimal;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.Date;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.stream.Collectors;

@Component
public class PurchaseAgentTools {

    private static final DateTimeFormatter DATE_FMT = DateTimeFormatter.ofPattern("yyyy-MM-dd");
    private static final int DEFAULT_LIMIT = 10;
    private static final int MAX_LIMIT = 30;

    private final PurchaseLedgerMapper purchaseLedgerMapper;
    private final PaymentRegistrationMapper paymentRegistrationMapper;
    private final InvoicePurchaseMapper invoicePurchaseMapper;
    private final PurchaseReturnOrdersMapper purchaseReturnOrdersMapper;
    private final AiSessionUserContext aiSessionUserContext;

    public PurchaseAgentTools(PurchaseLedgerMapper purchaseLedgerMapper,
                              PaymentRegistrationMapper paymentRegistrationMapper,
                              InvoicePurchaseMapper invoicePurchaseMapper,
                              PurchaseReturnOrdersMapper purchaseReturnOrdersMapper,
                              AiSessionUserContext aiSessionUserContext) {
        this.purchaseLedgerMapper = purchaseLedgerMapper;
        this.paymentRegistrationMapper = paymentRegistrationMapper;
        this.invoicePurchaseMapper = invoicePurchaseMapper;
        this.purchaseReturnOrdersMapper = purchaseReturnOrdersMapper;
        this.aiSessionUserContext = aiSessionUserContext;
    }

    @Tool(name = "查询采购台账列表", value = "按关键字和时间范围查询采购台账，支持返回最近N条")
    public String listPurchaseLedgers(@ToolMemoryId String memoryId,
                                      @P(value = "关键字，可匹配采购合同号/供应商/项目名", required = false) String keyword,
                                      @P(value = "开始日期 yyyy-MM-dd", required = false) String startDate,
                                      @P(value = "结束日期 yyyy-MM-dd", required = false) String endDate,
                                      @P(value = "返回条数，默认10，最大30", required = false) Integer limit) {
        LoginUser loginUser = currentLoginUser(memoryId);
        LocalDate start = parseLocalDate(startDate);
        LocalDate end = parseLocalDate(endDate);
        int finalLimit = normalizeLimit(limit);

        LambdaQueryWrapper<PurchaseLedger> wrapper = new LambdaQueryWrapper<>();
        applyTenantFilter(wrapper, loginUser.getTenantId(), PurchaseLedger::getTenantId);
        if (StringUtils.hasText(keyword)) {
            wrapper.and(w -> w.like(PurchaseLedger::getPurchaseContractNumber, keyword)
                    .or().like(PurchaseLedger::getSupplierName, keyword)
                    .or().like(PurchaseLedger::getProjectName, keyword));
        }
        if (start != null) {
            wrapper.ge(PurchaseLedger::getEntryDate, toDate(start));
        }
        if (end != null) {
            wrapper.le(PurchaseLedger::getEntryDate, toDate(end));
        }
        wrapper.orderByDesc(PurchaseLedger::getEntryDate, PurchaseLedger::getId).last("limit " + finalLimit);

        List<PurchaseLedger> rows = defaultList(purchaseLedgerMapper.selectList(wrapper));
        List<Map<String, Object>> items = rows.stream().map(this::toLedgerItem).collect(Collectors.toList());
        return jsonResponse(true, "purchase_ledger_list", "已返回采购台账列表",
                Map.of("count", items.size(), "limit", finalLimit, "keyword", safe(keyword)),
                Map.of("items", items), Map.of());
    }

    @Tool(name = "查询采购台账详情", value = "按采购台账ID查询详情")
    public String getPurchaseLedgerDetail(@ToolMemoryId String memoryId, @P("采购台账ID") Long ledgerId) {
        if (ledgerId == null) {
            return jsonResponse(false, "purchase_ledger_detail", "采购台账ID不能为空", Map.of(), Map.of(), Map.of());
        }
        LoginUser loginUser = currentLoginUser(memoryId);
        PurchaseLedger ledger = purchaseLedgerMapper.selectById(ledgerId);
        if (ledger == null || !tenantMatched(ledger.getTenantId(), loginUser.getTenantId())) {
            return jsonResponse(false, "purchase_ledger_detail", "未找到该采购台账或无权限访问", Map.of("ledgerId", ledgerId), Map.of(), Map.of());
        }
        return jsonResponse(true, "purchase_ledger_detail", "已返回采购台账详情",
                Map.of("ledgerId", ledgerId),
                Map.of("detail", toLedgerItem(ledger)),
                Map.of());
    }

    @Tool(name = "统计采购数据", value = "统计时间范围内采购合同数、合同金额、付款金额、发票金额、退货金额")
    public String getPurchaseStats(@ToolMemoryId String memoryId,
                                   @P(value = "开始日期 yyyy-MM-dd", required = false) String startDate,
                                   @P(value = "结束日期 yyyy-MM-dd", required = false) String endDate,
                                   @P(value = "时间范围描述，例如今年、本月、近30天", required = false) String timeRange) {
        LoginUser loginUser = currentLoginUser(memoryId);
        DateRange range = resolveDateRange(startDate, endDate, timeRange);

        List<PurchaseLedger> ledgers = queryLedgers(loginUser, range);
        List<PaymentRegistration> payments = queryPayments(loginUser, range);
        List<InvoicePurchase> invoices = queryInvoices(loginUser, range);
        List<PurchaseReturnOrders> returns = queryReturns(loginUser, range);

        BigDecimal contractAmount = ledgers.stream()
                .map(PurchaseLedger::getContractAmount)
                .filter(Objects::nonNull)
                .reduce(BigDecimal.ZERO, BigDecimal::add);
        BigDecimal paymentAmount = payments.stream()
                .map(PaymentRegistration::getCurrentPaymentAmount)
                .filter(Objects::nonNull)
                .reduce(BigDecimal.ZERO, BigDecimal::add);
        BigDecimal invoiceAmount = invoices.stream()
                .map(InvoicePurchase::getInvoiceAmount)
                .filter(Objects::nonNull)
                .reduce(BigDecimal.ZERO, BigDecimal::add);
        BigDecimal returnAmount = returns.stream()
                .map(PurchaseReturnOrders::getTotalAmount)
                .filter(Objects::nonNull)
                .reduce(BigDecimal.ZERO, BigDecimal::add);

        Map<String, Object> summary = new LinkedHashMap<>();
        summary.put("timeRange", range.label());
        summary.put("startDate", range.start().toString());
        summary.put("endDate", range.end().toString());
        summary.put("ledgerCount", ledgers.size());
        summary.put("paymentCount", payments.size());
        summary.put("invoiceCount", invoices.size());
        summary.put("returnCount", returns.size());
        summary.put("contractAmount", contractAmount);
        summary.put("paymentAmount", paymentAmount);
        summary.put("invoiceAmount", invoiceAmount);
        summary.put("returnAmount", returnAmount);

        return jsonResponse(true, "purchase_stats", "已返回采购统计数据", summary, Map.of(), Map.of());
    }

    private List<PurchaseLedger> queryLedgers(LoginUser loginUser, DateRange range) {
        LambdaQueryWrapper<PurchaseLedger> wrapper = new LambdaQueryWrapper<>();
        applyTenantFilter(wrapper, loginUser.getTenantId(), PurchaseLedger::getTenantId);
        wrapper.ge(PurchaseLedger::getEntryDate, toDate(range.start()))
                .le(PurchaseLedger::getEntryDate, toDate(range.end()));
        return defaultList(purchaseLedgerMapper.selectList(wrapper));
    }

    private List<PaymentRegistration> queryPayments(LoginUser loginUser, DateRange range) {
        LambdaQueryWrapper<PaymentRegistration> wrapper = new LambdaQueryWrapper<>();
        applyTenantFilter(wrapper, loginUser.getTenantId(), PaymentRegistration::getTenantId);
        wrapper.ge(PaymentRegistration::getPaymentDate, toDate(range.start()))
                .le(PaymentRegistration::getPaymentDate, toDate(range.end()));
        return defaultList(paymentRegistrationMapper.selectList(wrapper));
    }

    private List<InvoicePurchase> queryInvoices(LoginUser loginUser, DateRange range) {
        LambdaQueryWrapper<InvoicePurchase> wrapper = new LambdaQueryWrapper<>();
        applyTenantFilter(wrapper, loginUser.getTenantId(), InvoicePurchase::getTenantId);
        wrapper.ge(InvoicePurchase::getIssueDate, range.start())
                .le(InvoicePurchase::getIssueDate, range.end());
        return defaultList(invoicePurchaseMapper.selectList(wrapper));
    }

    private List<PurchaseReturnOrders> queryReturns(LoginUser loginUser, DateRange range) {
        LambdaQueryWrapper<PurchaseReturnOrders> wrapper = new LambdaQueryWrapper<>();
        applyDeptFilter(wrapper, loginUser.getCurrentDeptId(), PurchaseReturnOrders::getDeptId);
        wrapper.ge(PurchaseReturnOrders::getPreparedAt, range.start())
                .le(PurchaseReturnOrders::getPreparedAt, range.end());
        return defaultList(purchaseReturnOrdersMapper.selectList(wrapper));
    }

    private Map<String, Object> toLedgerItem(PurchaseLedger item) {
        Map<String, Object> map = new LinkedHashMap<>();
        map.put("id", item.getId());
        map.put("purchaseContractNumber", safe(item.getPurchaseContractNumber()));
        map.put("supplierName", safe(item.getSupplierName()));
        map.put("projectName", safe(item.getProjectName()));
        map.put("entryDate", formatDate(item.getEntryDate()));
        map.put("contractAmount", item.getContractAmount());
        map.put("approvalStatus", item.getApprovalStatus());
        map.put("paymentMethod", safe(item.getPaymentMethod()));
        return map;
    }

    private DateRange resolveDateRange(String startDate, String endDate, String timeRange) {
        LocalDate today = LocalDate.now();
        LocalDate start = parseLocalDate(startDate);
        LocalDate end = parseLocalDate(endDate);
        if (start != null || end != null) {
            LocalDate s = start != null ? start : end;
            LocalDate e = end != null ? end : start;
            if (s.isAfter(e)) {
                LocalDate temp = s;
                s = e;
                e = temp;
            }
            return new DateRange(s, e, s + "至" + e);
        }
        if (!StringUtils.hasText(timeRange)) {
            return new DateRange(today.minusDays(29), today, "近30天");
        }
        String text = timeRange.trim();
        if (text.contains("今年") || text.contains("本年")) {
            return new DateRange(today.withDayOfYear(1), today, "今年");
        }
        if (text.contains("本月")) {
            return new DateRange(today.withDayOfMonth(1), today, "本月");
        }
        if (text.contains("上月")) {
            LocalDate first = today.minusMonths(1).withDayOfMonth(1);
            LocalDate last = first.withDayOfMonth(first.lengthOfMonth());
            return new DateRange(first, last, "上月");
        }
        if (text.contains("近半年") || text.contains("最近半年")) {
            return new DateRange(today.minusMonths(6).plusDays(1), today, "近半年");
        }
        if (text.contains("近半个月") || text.contains("最近半个月") || text.contains("半个月")) {
            return new DateRange(today.minusDays(14), today, "近半个月");
        }
        return new DateRange(today.minusDays(29), today, "近30天");
    }

    private LocalDate parseLocalDate(String text) {
        if (!StringUtils.hasText(text)) {
            return null;
        }
        return LocalDate.parse(text.trim(), DATE_FMT);
    }

    private Date toDate(LocalDate localDate) {
        return Date.from(localDate.atStartOfDay(ZoneId.systemDefault()).toInstant());
    }

    private String formatDate(Date date) {
        if (date == null) {
            return "";
        }
        return DATE_FMT.format(date.toInstant().atZone(ZoneId.systemDefault()).toLocalDate());
    }

    private boolean tenantMatched(Long dataTenantId, Long userTenantId) {
        if (userTenantId == null) {
            return true;
        }
        return Objects.equals(dataTenantId, userTenantId);
    }

    private <T> void applyTenantFilter(LambdaQueryWrapper<T> wrapper, Long tenantId, com.baomidou.mybatisplus.core.toolkit.support.SFunction<T, Long> field) {
        if (tenantId != null) {
            wrapper.eq(field, tenantId);
        }
    }

    private <T> void applyDeptFilter(LambdaQueryWrapper<T> wrapper, Long deptId, com.baomidou.mybatisplus.core.toolkit.support.SFunction<T, Long> field) {
        if (deptId != null) {
            wrapper.eq(field, deptId);
        }
    }

    private LoginUser currentLoginUser(String memoryId) {
        LoginUser loginUser = aiSessionUserContext.get(memoryId);
        if (loginUser != null) {
            return loginUser;
        }
        return SecurityUtils.getLoginUser();
    }

    private int normalizeLimit(Integer limit) {
        if (limit == null || limit <= 0) {
            return DEFAULT_LIMIT;
        }
        return Math.min(limit, MAX_LIMIT);
    }

    private String safe(Object value) {
        return value == null ? "" : String.valueOf(value).replace('\n', ' ').replace('\r', ' ');
    }

    private <T> List<T> defaultList(List<T> list) {
        return list == null ? List.of() : list;
    }

    private String jsonResponse(boolean success,
                                String type,
                                String description,
                                Map<String, Object> summary,
                                Map<String, Object> data,
                                Map<String, Object> charts) {
        Map<String, Object> result = new LinkedHashMap<>();
        result.put("success", success);
        result.put("type", type);
        result.put("description", description);
        result.put("summary", summary == null ? Map.of() : summary);
        result.put("data", data == null ? Map.of() : data);
        result.put("charts", charts == null ? Map.of() : charts);
        return JSON.toJSONString(result);
    }

    private record DateRange(LocalDate start, LocalDate end, String label) {
    }
}