package com.vincent.rsf.server.ai.service;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.vincent.rsf.server.ai.model.AiPromptContext;
import com.vincent.rsf.server.manager.entity.Loc;
import com.vincent.rsf.server.manager.entity.LocItem;
import com.vincent.rsf.server.manager.mapper.LocItemMapper;
import com.vincent.rsf.server.manager.mapper.LocMapper;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.math.BigDecimal;
import java.util.*;

@Service
public class AiWarehouseSummaryService implements AiPromptContextProvider {

    private static final Map<String, String> LOC_STATUS_LABELS = new LinkedHashMap<>();

    static {
        LOC_STATUS_LABELS.put("O", "空库");
        LOC_STATUS_LABELS.put("D", "空板");
        LOC_STATUS_LABELS.put("R", "预约出库");
        LOC_STATUS_LABELS.put("S", "预约入库");
        LOC_STATUS_LABELS.put("X", "禁用");
        LOC_STATUS_LABELS.put("F", "在库");
    }

    @Resource
    private LocMapper locMapper;
    @Resource
    private LocItemMapper locItemMapper;

    @Override
    public boolean supports(AiPromptContext context) {
        return context != null && shouldSummarize(context.getQuestion());
    }

    @Override
    public String buildContext(AiPromptContext context) {
        if (!supports(context)) {
            return "";
        }

        List<Loc> activeLocs = locMapper.selectList(new LambdaQueryWrapper<Loc>()
                .select(Loc::getUseStatus)
                .eq(Loc::getStatus, 1));
        long totalLoc = activeLocs.size();

        List<LocItem> activeLocItems = locItemMapper.selectList(new LambdaQueryWrapper<LocItem>()
                .select(LocItem::getLocCode, LocItem::getMatnrCode, LocItem::getMaktx, LocItem::getAnfme)
                .eq(LocItem::getStatus, 1));

        Map<String, Long> locStatusCounters = new LinkedHashMap<>();
        for (Loc loc : activeLocs) {
            String useStatus = loc.getUseStatus();
            locStatusCounters.put(useStatus, locStatusCounters.getOrDefault(useStatus, 0L) + 1);
        }

        long itemRows = activeLocItems.size();
        Set<String> locCodes = new HashSet<>();
        Set<String> materialCodes = new HashSet<>();
        BigDecimal totalQty = BigDecimal.ZERO;
        Map<String, LocAggregate> locAggregates = new LinkedHashMap<>();
        Map<String, MaterialAggregate> materialAggregates = new LinkedHashMap<>();
        for (LocItem item : activeLocItems) {
            if (item.getLocCode() != null && !item.getLocCode().trim().isEmpty()) {
                locCodes.add(item.getLocCode());
            }
            if (item.getMatnrCode() != null && !item.getMatnrCode().trim().isEmpty()) {
                materialCodes.add(item.getMatnrCode());
            }
            totalQty = totalQty.add(toDecimal(item.getAnfme()));

            String locKey = item.getLocCode();
            if (locKey != null && !locKey.trim().isEmpty()) {
                LocAggregate locAggregate = locAggregates.computeIfAbsent(locKey, key -> new LocAggregate());
                locAggregate.totalQty = locAggregate.totalQty.add(toDecimal(item.getAnfme()));
                if (item.getMatnrCode() != null && !item.getMatnrCode().trim().isEmpty()) {
                    locAggregate.materialCodes.add(item.getMatnrCode());
                }
            }

            String materialKey = item.getMatnrCode();
            if (materialKey != null && !materialKey.trim().isEmpty()) {
                MaterialAggregate materialAggregate = materialAggregates.computeIfAbsent(materialKey, key -> new MaterialAggregate());
                materialAggregate.matnrCode = materialKey;
                materialAggregate.maktx = item.getMaktx();
                materialAggregate.totalQty = materialAggregate.totalQty.add(toDecimal(item.getAnfme()));
                if (item.getLocCode() != null && !item.getLocCode().trim().isEmpty()) {
                    materialAggregate.locCodes.add(item.getLocCode());
                }
            }
        }

        List<Map.Entry<String, LocAggregate>> topLocRows = new ArrayList<>(locAggregates.entrySet());
        topLocRows.sort((left, right) -> right.getValue().totalQty.compareTo(left.getValue().totalQty));
        if (topLocRows.size() > 5) {
            topLocRows = topLocRows.subList(0, 5);
        }

        List<MaterialAggregate> topMaterialRows = new ArrayList<>(materialAggregates.values());
        topMaterialRows.sort((left, right) -> right.totalQty.compareTo(left.totalQty));
        if (topMaterialRows.size() > 5) {
            topMaterialRows = topMaterialRows.subList(0, 5);
        }

        StringBuilder summary = new StringBuilder();
        summary.append("以下是基于 man_loc 和 man_loc_item 的实时汇总，请优先依据这些数据回答；如果超出这两张表可推断的范围，请明确说明。");
        summary.append("\n库位概况：总库位 ")
                .append(totalLoc)
                .append(" 个；状态分布：")
                .append(formatLocStatuses(locStatusCounters))
                .append("。");
        summary.append("\n库存概况：库存记录 ")
                .append(itemRows)
                .append(" 条，覆盖库位 ")
                .append(locCodes.size())
                .append(" 个，涉及物料 ")
                .append(materialCodes.size())
                .append(" 种，总数量 ")
                .append(formatDecimal(totalQty))
                .append("。");
        if (!topLocRows.isEmpty()) {
            summary.append("\n库存最多的库位 TOP5：")
                    .append(formatTopLocs(topLocRows))
                    .append("。");
        }
        if (!topMaterialRows.isEmpty()) {
            summary.append("\n库存最多的物料 TOP5：")
                    .append(formatTopMaterials(topMaterialRows))
                    .append("。");
        }
        return summary.toString();
    }

    private boolean shouldSummarize(String question) {
        if (question == null || question.trim().isEmpty()) {
            return false;
        }
        String normalized = question.toLowerCase(Locale.ROOT);
        return normalized.contains("loc")
                || normalized.contains("库位")
                || normalized.contains("货位")
                || normalized.contains("库区")
                || normalized.contains("库存")
                || normalized.contains("物料")
                || normalized.contains("巷道")
                || normalized.contains("储位");
    }

    private String formatLocStatuses(Map<String, Long> counters) {
        if (counters == null || counters.isEmpty()) {
            return "暂无数据";
        }
        List<String> parts = new ArrayList<>();
        for (Map.Entry<String, String> entry : LOC_STATUS_LABELS.entrySet()) {
            parts.add(entry.getValue() + " " + counters.getOrDefault(entry.getKey(), 0L) + " 个");
        }
        return String.join("，", parts);
    }

    private String formatTopLocs(List<Map.Entry<String, LocAggregate>> rows) {
        List<String> parts = new ArrayList<>();
        for (Map.Entry<String, LocAggregate> row : rows) {
            parts.add(row.getKey()
                    + "（数量 " + formatDecimal(row.getValue().totalQty)
                    + "，物料 " + row.getValue().materialCodes.size() + " 种）");
        }
        return String.join("；", parts);
    }

    private String formatTopMaterials(List<MaterialAggregate> rows) {
        List<String> parts = new ArrayList<>();
        for (MaterialAggregate row : rows) {
            String matnrCode = row.matnrCode;
            String maktx = Objects.toString(row.maktx, "");
            String title = maktx == null || maktx.trim().isEmpty() ? matnrCode : matnrCode + "/" + maktx;
            parts.add(title
                    + "（数量 " + formatDecimal(row.totalQty)
                    + "，分布库位 " + row.locCodes.size() + " 个）");
        }
        return String.join("；", parts);
    }

    private String formatDecimal(Object value) {
        BigDecimal decimal = toDecimal(value);
        return decimal.stripTrailingZeros().toPlainString();
    }

    private BigDecimal toDecimal(Object value) {
        if (value == null) {
            return BigDecimal.ZERO;
        }
        if (value instanceof BigDecimal) {
            return (BigDecimal) value;
        }
        if (value instanceof Number) {
            return BigDecimal.valueOf(((Number) value).doubleValue());
        }
        return new BigDecimal(String.valueOf(value));
    }

    private static class LocAggregate {
        private BigDecimal totalQty = BigDecimal.ZERO;
        private final Set<String> materialCodes = new HashSet<>();
    }

    private static class MaterialAggregate {
        private String matnrCode;
        private String maktx;
        private BigDecimal totalQty = BigDecimal.ZERO;
        private final Set<String> locCodes = new HashSet<>();
    }
}