package com.ruoyi.production.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.ruoyi.common.exception.ServiceException;
import com.ruoyi.common.exception.base.BaseException;
import com.ruoyi.common.utils.StringUtils;
import com.ruoyi.common.utils.bean.BeanUtils;
import com.ruoyi.common.utils.poi.ExcelUtil;
import com.ruoyi.production.bean.dto.ProductionPlanDto;
import com.ruoyi.production.bean.dto.ProductionPlanImportDto;
import com.ruoyi.production.bean.vo.ProductionPlanVo;
import com.ruoyi.production.mapper.ProductionOrderMapper;
import com.ruoyi.production.mapper.ProductionPlanMapper;
import com.ruoyi.production.pojo.ProductionOrder;
import com.ruoyi.production.pojo.ProductionPlan;
import com.ruoyi.production.service.ProductionOrderService;
import com.ruoyi.production.service.ProductionPlanService;
import jakarta.servlet.http.HttpServletResponse;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.multipart.MultipartFile;

import java.math.BigDecimal;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.*;
import java.util.stream.Collectors;

@Service
@RequiredArgsConstructor
public class ProductionPlanServiceImpl extends ServiceImpl<ProductionPlanMapper, ProductionPlan> implements ProductionPlanService {

    private static final int PLAN_STATUS_WAIT = 0;
    private static final int PLAN_STATUS_PARTIAL = 1;
    private static final int PLAN_STATUS_ISSUED = 2;

    private final ProductionPlanMapper productionPlanMapper;
    private final ProductionOrderMapper productionOrderMapper;
    private final ProductionOrderService productionOrderService;

    @Override
    public IPage<ProductionPlanVo> listPage(Page<ProductionPlanDto> page, ProductionPlanDto productionPlanDto) {
        return productionPlanMapper.listPage(page, productionPlanDto);
    }

    /**
     * 合并生产计划并下发生产订单。
     * 业务约束：
     * 1. 仅允许同一产品型号的计划合并；
     * 2. 已下发或部分下发的计划禁止再次合并；
     * 3. 下发数量不能大于所选计划需求总量；
     * 4. 订单创建统一复用 ProductionOrderService.saveProductionOrder，确保工艺/BOM/领料主单等后续逻辑一致。
     */
    @Override
    @Transactional(rollbackFor = Exception.class)
    public boolean combine(ProductionPlanDto productionPlanDto) {
        if (productionPlanDto == null || productionPlanDto.getIds() == null || productionPlanDto.getIds().isEmpty()) {
            return false;
        }

        List<Long> planIds = productionPlanDto.getIds().stream()
                .filter(Objects::nonNull)
                .distinct()
                .collect(Collectors.toList());
        if (planIds.isEmpty()) {
            throw new ServiceException("下发失败，未选择生产计划");
        }

        List<ProductionPlanDto> planLists = productionPlanMapper.selectWithMaterialByIds(planIds);
        if (planLists == null || planLists.isEmpty() || planLists.size() != planIds.size()) {
            throw new ServiceException("下发失败，生产计划不存在或已被删除");
        }

        ProductionPlanDto firstPlan = planLists.getFirst();
        if (firstPlan.getProductModelId() == null) {
            throw new ServiceException("下发失败，生产计划缺少产品型号");
        }

        boolean hasDifferentModel = planLists.stream()
                .anyMatch(item -> !Objects.equals(item.getProductModelId(), firstPlan.getProductModelId()));
        if (hasDifferentModel) {
            throw new BaseException("合并失败，所选生产计划的产品型号不一致");
        }

        boolean hasIssuedPlan = planLists.stream()
                .anyMatch(item -> item.getStatus() != null && item.getStatus() == PLAN_STATUS_ISSUED);
        if (hasIssuedPlan) {
            throw new BaseException("合并失败，所选生产计划存在已下发或部分下发数据");
        }

        BigDecimal totalRequiredQuantity = planLists.stream()
                .map(this::resolveRemainingQuantity)
                .reduce(BigDecimal.ZERO, BigDecimal::add);
        if (totalRequiredQuantity.compareTo(BigDecimal.ZERO) <= 0) {
            throw new ServiceException("下发失败，所选生产计划需求总量必须大于0");
        }

        BigDecimal assignedQuantity = productionPlanDto.getTotalAssignedQuantity();
        if (assignedQuantity == null || assignedQuantity.compareTo(BigDecimal.ZERO) <= 0) {
            throw new ServiceException("下发失败，下发数量必须大于0");
        }
        if (assignedQuantity.compareTo(totalRequiredQuantity) > 0) {
            throw new ServiceException("下发失败，下发数量不能大于计划需求总量");
        }

        BigDecimal remainingForOrderBind = assignedQuantity;
        List<Long> issuedPlanIds = new ArrayList<>();
        for (ProductionPlanDto plan : planLists) {
            BigDecimal remainingQuantity = resolveRemainingQuantity(plan);
            if (remainingForOrderBind.compareTo(BigDecimal.ZERO) <= 0 || remainingQuantity.compareTo(BigDecimal.ZERO) <= 0) {
                continue;
            }
            BigDecimal issueForThisPlan = remainingForOrderBind.min(remainingQuantity);
            remainingForOrderBind = remainingForOrderBind.subtract(issueForThisPlan);
            if (issueForThisPlan.compareTo(BigDecimal.ZERO) > 0) {
                issuedPlanIds.add(plan.getId());
            }
        }
        if (issuedPlanIds.isEmpty()) {
            throw new ServiceException("Issue failed, no quantity available for dispatch");
        }

        ProductionOrder productionOrder = new ProductionOrder();
        productionOrder.setProductionPlanIds(formatPlanIds(issuedPlanIds));
        productionOrder.setProductModelId(firstPlan.getProductModelId());
        productionOrder.setQuantity(assignedQuantity);
        productionOrder.setPlanCompleteTime(productionPlanDto.getPlanCompleteTime());

        boolean saved = productionOrderService.saveProductionOrder(productionOrder);
        if (!saved) {
            throw new ServiceException("下发失败，生产订单保存失败");
        }

        //已下发数量
        BigDecimal remainingAssignedQuantity = assignedQuantity;
        List<ProductionPlan> updates = new ArrayList<>();
        for (ProductionPlanDto plan : planLists) {
            BigDecimal requiredQuantity = Optional.ofNullable(plan.getQtyRequired()).orElse(BigDecimal.ZERO);
            if (requiredQuantity.compareTo(BigDecimal.ZERO) < 0) {
                requiredQuantity = BigDecimal.ZERO;
            }
            BigDecimal remainingQuantity = resolveRemainingQuantity(plan);
            BigDecimal historicalIssuedQuantity = requiredQuantity.subtract(remainingQuantity);
            BigDecimal issuedQuantity = BigDecimal.ZERO;
            if (remainingAssignedQuantity.compareTo(BigDecimal.ZERO) > 0 && remainingQuantity.compareTo(BigDecimal.ZERO) > 0) {
                issuedQuantity = remainingAssignedQuantity.min(remainingQuantity);
                remainingAssignedQuantity = remainingAssignedQuantity.subtract(issuedQuantity);
            }

            BigDecimal totalIssuedQuantity = historicalIssuedQuantity.add(issuedQuantity);
            int planStatus = resolvePlanStatus(requiredQuantity, totalIssuedQuantity);
            ProductionPlan update = new ProductionPlan();
            update.setId(plan.getId());
            update.setStatus(planStatus);
            update.setQuantityIssued(totalIssuedQuantity);
            updates.add(update);
        }
        if (!updates.isEmpty()) {
            this.updateBatchById(updates);
        }
        return true;
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public boolean add(ProductionPlanDto dto) {
        if (StringUtils.isBlank(dto.getMpsNo())) {
            dto.setMpsNo(generateNextPlanNo(LocalDate.now().format(DateTimeFormatter.ofPattern("yyyyMMdd"))));
        }else checkMpsNoUnique(dto.getMpsNo(), null);
        dto.setStatus(PLAN_STATUS_WAIT);
        dto.setSource("内部");
        return productionPlanMapper.insert(dto) > 0;
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public boolean update(ProductionPlanDto dto) {
        if (dto == null || dto.getId() == null) {
            throw new ServiceException("编辑失败，数据不能为空");
        }

        ProductionPlan old = getById(dto.getId());
        if (old == null) {
            throw new ServiceException("编辑失败，生产计划不存在");
        }

        if (old.getStatus() != PLAN_STATUS_WAIT) {
            throw new BaseException("编辑失败，该生产计划已下发或部分下发，禁止编辑");
        }

        if (StringUtils.isNotBlank(dto.getMpsNo()) && !dto.getMpsNo().equals(old.getMpsNo())) {
            checkMpsNoUnique(dto.getMpsNo(), dto.getId());
        }

        return productionPlanMapper.updateById(dto) > 0;
    }

    private void checkMpsNoUnique(String mpsNo, Long excludeId) {
        LambdaQueryWrapper<ProductionPlan> wrapper = Wrappers.lambdaQuery();
        wrapper.eq(ProductionPlan::getMpsNo, mpsNo);
        if (excludeId != null) {
            wrapper.ne(ProductionPlan::getId, excludeId);
        }
        if (productionPlanMapper.selectCount(wrapper) > 0) {
            throw new ServiceException("生产计划号 " + mpsNo + " 已存在");
        }
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public boolean delete(List<Long> ids) {
        if (productionPlanMapper.selectList(Wrappers.<ProductionPlan>lambdaQuery().in(ProductionPlan::getId, ids))
                .stream()
                .anyMatch(p -> p.getStatus() == PLAN_STATUS_PARTIAL || p.getStatus() == PLAN_STATUS_ISSUED)) {
            throw new BaseException("删除失败，存在已下发或部分下发的计划");
        }

        if (productionOrderMapper.selectList(Wrappers.<ProductionOrder>lambdaQuery().in(ProductionOrder::getProductionPlanIds, ids))
                .stream()
                .anyMatch(p -> p.getId() != null)) {
            throw new BaseException("删除失败，存在关联生产订单");
        }

        return productionPlanMapper.deleteBatchIds(ids) > 0;
    }

    @Override
    @Transactional(rollbackFor = Exception.class)
    public void importProdData(MultipartFile file) {
        if (file == null || file.isEmpty()) {
            throw new ServiceException("导入数据不能为空");
        }
        ExcelUtil<ProductionPlanImportDto> excelUtil = new ExcelUtil<>(ProductionPlanImportDto.class);
        List<ProductionPlanImportDto> list;
        try {
            list = excelUtil.importExcel(file.getInputStream());
        } catch (Exception e) {
            throw new ServiceException("Excel解析失败");
        }
        if (list == null || list.isEmpty()) {
            throw new ServiceException("Excel没有数据");
        }
        Set<String> mpsNos = new HashSet<>();
        for (int i = 0; i < list.size(); i++) {
            ProductionPlanImportDto dto = list.get(i);
            String mpsNo = dto.getMpsNo();
            if (StringUtils.isEmpty(mpsNo)) {
                generateNextPlanNo(LocalDate.now().format(DateTimeFormatter.ofPattern("yyyyMMdd")));
            }
            if (!mpsNos.add(mpsNo)) {
                throw new ServiceException("导入失败：Excel 中存在重复的申请单编号 " + mpsNo);
            }
        }
        Long existApplyNoCount = baseMapper.selectCount(Wrappers.<ProductionPlan>lambdaQuery()
                .in(ProductionPlan::getMpsNo, mpsNos));
        if (existApplyNoCount > 0) {
            List<String> existMpsNos = baseMapper.selectList(Wrappers.<ProductionPlan>lambdaQuery()
                            .in(ProductionPlan::getMpsNo, mpsNos))
                    .stream()
                    .map(ProductionPlan::getMpsNo)
                    .collect(Collectors.toList());
            throw new ServiceException("导入失败，生产计划号已存在: " + String.join(", ", existMpsNos));
        }
        LocalDateTime now = LocalDateTime.now();
        List<ProductionPlan> entityList = list.stream().map(dto -> {
            ProductionPlan entity = new ProductionPlan();
            BeanUtils.copyProperties(dto, entity);
            entity.setStatus(PLAN_STATUS_WAIT);
            entity.setSource("内部");
            entity.setCreateTime(now);
            entity.setUpdateTime(now);
            return entity;
        }).collect(Collectors.toList());
        this.saveBatch(entityList);
    }

    @Override
    public void exportProdData(HttpServletResponse response, List<Long> ids) {
        List<ProductionPlanDto> list = productionPlanMapper.selectWithMaterialByIds(ids);
        List<ProductionPlanImportDto> exportList = new ArrayList<>();
        for (ProductionPlanDto entity : list) {
            ProductionPlanImportDto dto = new ProductionPlanImportDto();
            BeanUtils.copyProperties(entity, dto);
            exportList.add(dto);
        }
        ExcelUtil<ProductionPlanImportDto> util = new ExcelUtil<>(ProductionPlanImportDto.class);
        util.exportExcel(response, exportList, "主生产计划");
    }

    private BigDecimal resolveRemainingQuantity(ProductionPlan plan) {
        if (plan == null) {
            return BigDecimal.ZERO;
        }
        BigDecimal requiredQuantity = Optional.ofNullable(plan.getQtyRequired()).orElse(BigDecimal.ZERO);
        if (requiredQuantity.compareTo(BigDecimal.ZERO) <= 0) {
            return BigDecimal.ZERO;
        }
        BigDecimal issuedQuantity = Optional.ofNullable(plan.getQuantityIssued()).orElse(BigDecimal.ZERO);
        if (issuedQuantity.compareTo(BigDecimal.ZERO) <= 0) {
            return requiredQuantity;
        }
        if (issuedQuantity.compareTo(requiredQuantity) >= 0) {
            return BigDecimal.ZERO;
        }
        return requiredQuantity.subtract(issuedQuantity);
    }

    private int resolvePlanStatus(BigDecimal requiredQuantity, BigDecimal issuedQuantity) {
        if (requiredQuantity == null || requiredQuantity.compareTo(BigDecimal.ZERO) <= 0) {
            return PLAN_STATUS_WAIT;
        }
        if (issuedQuantity == null || issuedQuantity.compareTo(BigDecimal.ZERO) <= 0) {
            return PLAN_STATUS_WAIT;
        }
        return issuedQuantity.compareTo(requiredQuantity) < 0 ? PLAN_STATUS_PARTIAL : PLAN_STATUS_ISSUED;
    }

    private String formatPlanIds(List<Long> planIds) {
        return planIds.stream()
                .filter(Objects::nonNull)
                .distinct()
                .map(String::valueOf)
                .collect(Collectors.joining(",", "[", "]"));
    }

    private String generateNextPlanNo(String datePrefix) {
        QueryWrapper<ProductionPlan> queryWrapper = new QueryWrapper<>();
        queryWrapper.likeRight("mps_no", "JH" + datePrefix);
        queryWrapper.orderByDesc("mps_no");
        queryWrapper.last("LIMIT 1");
        ProductionPlan latestPlan = productionPlanMapper.selectOne(queryWrapper);
        int sequence = 1;
        if (latestPlan != null && latestPlan.getMpsNo() != null && !latestPlan.getMpsNo().isEmpty()) {
            String sequenceStr = latestPlan.getMpsNo().substring(("JH" + datePrefix).length());
            try {
                sequence = Integer.parseInt(sequenceStr) + 1;
            } catch (NumberFormatException e) {
                sequence = 1;
            }
        }
        return "JH" + datePrefix + String.format("%04d", sequence);
    }
}