package com.xly.tool;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.xly.agent.AgentIdentity;
import com.xly.service.ErpClient;
import com.xly.service.FormResolverService;
import com.xly.service.OpService;
import dev.langchain4j.agent.tool.P;
import dev.langchain4j.agent.tool.Tool;
import org.springframework.jdbc.core.JdbcTemplate;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * ProposeWrite 工具（写操作，人在环）。
 *
 * <p>**只提议并暂存，绝不立即执行**：把「改某条记录的某字段」解析成具体的 表/记录id/列/新值，
 * 写一条 draft 到 ai_op_queue，返回一个提议。真正执行发生在用户点【确认】后的确定性端点里
 * （见 OpController），不经过 LLM。
 */
public class ProposeWriteTool {

    private final ErpClient erp;
    private final JdbcTemplate jdbc;
    private final OpService ops;
    private final ObjectMapper mapper;
    private final AgentIdentity identity;
    private final FormResolverService resolver;

    public ProposeWriteTool(ErpClient erp, JdbcTemplate jdbc, OpService ops, ObjectMapper mapper,
                            AgentIdentity identity, FormResolverService resolver) {
        this.erp = erp;
        this.jdbc = jdbc;
        this.ops = ops;
        this.mapper = mapper;
        this.identity = identity;
        this.resolver = resolver;
    }

    @Tool("提议修改某条现有记录的某个字段（写操作）。本工具**只提议并暂存、绝不立即执行**——"
            + "必须等用户在对话内点【确认】后才真正修改。用于「把某个客户/物料的某字段改成X」这类需求。"
            + "直接给出实体类型（如 客户）即可，本工具会自行定位主表，无需先 findForms。")
    public String proposeUpdate(
            @P("实体/单据类型关键词，如 客户 / 物料 / 供应商") String entityKeyword,
            @P("要修改的那条记录的名称关键词（如某个客户名）") String recordKeyword,
            @P("要修改的字段中文名（如 简称 / 备注 / 联系电话）") String fieldChinese,
            @P("修改后的新值") String newValue) {

        if (isBlank(entityKeyword) || isBlank(recordKeyword) || isBlank(fieldChinese)) {
            return err("缺少信息：需要实体类型、记录名称关键词、字段中文名、新值。");
        }

        // 1) 定位可修改的主表（该实体名下、table 类型、最常用的一张）
        Map<String, Object> form = resolveForm(entityKeyword.trim());
        if (form == null) {
            return err("找不到「" + entityKeyword + "」对应的可修改主表。");
        }
        String formId = str(form.get("sFormId"));
        String moduleId = str(form.get("sModuleId"));
        String table = str(form.get("sDataSource"));
        if (!identity.canAccessModule(moduleId)) {
            return err("你没有修改「" + entityKeyword + "」的权限。");
        }

        // 2) 字段中文名 -> 技术列名
        String field = queryOne(
                "SELECT sField FROM viw_kg_field_dict WHERE sTable=? AND sChinese=? ORDER BY iFormUses DESC LIMIT 1",
                table, fieldChinese.trim());
        if (field == null) {
            field = queryOne(
                    "SELECT sField FROM viw_kg_field_dict WHERE sTable=? AND sChinese LIKE ? ORDER BY iFormUses DESC LIMIT 1",
                    table, "%" + fieldChinese.trim() + "%");
        }
        if (field == null) {
            return err("在该表单里找不到叫「" + fieldChinese + "」的字段，请换个字段名或先查看该表单有哪些字段。");
        }

        // 3) 定位唯一记录 + 旧值（用名称字段过滤）
        String nameField = queryOne(
                "SELECT sField FROM viw_kg_field_dict WHERE sTable=? AND sField LIKE '%Name' AND sField NOT LIKE '%NameId' " +
                        "ORDER BY iFormUses DESC LIMIT 1", table);
        JsonNode root;
        try {
            root = erp.readForm(identity.token(), formId.trim(), moduleId.trim(), 1, 5, nameField, recordKeyword.trim());
        } catch (Exception e) {
            return err("定位记录时读取失败：" + e.getMessage());
        }
        if (root.path("code").asInt(0) < 0) {
            return err("定位记录失败：" + root.path("msg").asText("未知错误"));
        }
        JsonNode rows = root.path("dataset").path("rows");
        JsonNode data = (rows.isArray() && rows.size() > 0) ? rows.get(0).path("dataSet") : null;
        int n = (data != null && data.isArray()) ? data.size() : 0;
        if (n == 0) {
            return err("没有找到名称含「" + recordKeyword + "」的记录，无法修改。");
        }
        if (n > 1) {
            StringBuilder names = new StringBuilder();
            for (int i = 0; i < data.size() && i < 5; i++) {
                if (i > 0) names.append("、");
                names.append(data.get(i).path(nameField == null ? "" : nameField).asText(""));
            }
            return err("匹配到多条记录（" + names + "），请提供更精确的名称，只改其中一条。");
        }

        JsonNode rec = data.get(0);
        String billId = rec.path("sId").asText(null);
        if (isBlank(billId)) {
            return err("定位到的记录缺少主键 sId，无法安全修改。");
        }
        String oldValue = rec.path(field).asText("");
        String recordName = nameField == null ? recordKeyword : rec.path(nameField).asText(recordKeyword);

        // 4) 暂存 draft（不执行）
        String description = "将【" + recordName + "】的【" + fieldChinese + "】"
                + (oldValue.isBlank() ? "" : ("由「" + oldValue + "」")) + "改为「" + newValue + "」";
        String opId = ops.createDraft(identity.userId(), "update", formId.trim(), moduleId.trim(), table, billId,
                field, fieldChinese, oldValue, newValue, description);

        Map<String, Object> out = new LinkedHashMap<>();
        out.put("opId", opId);
        out.put("summary", description);
        out.put("message", "已为你生成一条待确认的修改，请在下方点【确认】执行、或【取消】。");
        return toJson(out);
    }

    @Tool("提议**删除**某条现有记录（写操作）。本工具只提议并暂存、绝不立即执行——必须等用户点【确认】后才真正删除。"
            + "删除不可恢复，请慎用。直接给出实体类型与记录名即可。")
    public String proposeDelete(
            @P("实体类型，如 客户 / 物料 / 供应商") String entityKeyword,
            @P("要删除的记录的名称关键词") String recordKeyword) {

        if (isBlank(entityKeyword) || isBlank(recordKeyword)) {
            return err("缺少实体类型或记录名称。");
        }
        Map<String, Object> form = resolveForm(entityKeyword.trim());
        if (form == null) {
            return err("找不到「" + entityKeyword + "」对应的可操作主表。");
        }
        String formId = str(form.get("sFormId"));
        String moduleId = str(form.get("sModuleId"));
        String table = str(form.get("sDataSource"));
        if (!identity.canAccessModule(moduleId)) {
            return err("你没有操作「" + entityKeyword + "」的权限。");
        }
        String nameField = queryOne(
                "SELECT sField FROM viw_kg_field_dict WHERE sTable=? AND sField LIKE '%Name' AND sField NOT LIKE '%NameId' " +
                        "ORDER BY iFormUses DESC LIMIT 1", table);
        JsonNode root;
        try {
            root = erp.readForm(identity.token(), formId, moduleId, 1, 5, nameField, recordKeyword.trim());
        } catch (Exception e) {
            return err("定位记录失败：" + e.getMessage());
        }
        if (root.path("code").asInt(0) < 0) {
            return err("定位记录失败：" + root.path("msg").asText("未知错误"));
        }
        JsonNode rows = root.path("dataset").path("rows");
        JsonNode data = (rows.isArray() && rows.size() > 0) ? rows.get(0).path("dataSet") : null;
        int n = (data != null && data.isArray()) ? data.size() : 0;
        if (n == 0) {
            return err("没有找到名称含「" + recordKeyword + "」的记录。");
        }
        if (n > 1) {
            StringBuilder names = new StringBuilder();
            for (int i = 0; i < data.size() && i < 5; i++) {
                if (i > 0) names.append("、");
                names.append(nameField == null ? "" : data.get(i).path(nameField).asText(""));
            }
            return err("匹配到多条记录（" + names + "），请提供更精确的名称，只删其中一条。");
        }
        JsonNode rec = data.get(0);
        String billId = rec.path("sId").asText(null);
        if (isBlank(billId)) {
            return err("定位到的记录缺少主键 sId，无法安全删除。");
        }
        String recordName = nameField == null ? recordKeyword : rec.path(nameField).asText(recordKeyword);
        String description = "删除【" + recordName + "】（" + entityKeyword + "）";
        String opId = ops.createDraft(identity.userId(), "delete", formId, moduleId, table, billId,
                null, null, recordName, null, description);

        Map<String, Object> out = new LinkedHashMap<>();
        out.put("opId", opId);
        out.put("summary", description);
        out.put("message", "已为你生成一条待确认的删除，请在下方点【确认】执行、或【取消】。删除不可恢复，请谨慎。");
        return toJson(out);
    }

    @Tool("提议**新增**一条记录（写操作）。只提议并暂存、绝不立即执行——用户点确认后才真正新增。"
            + "给出实体类型 + 已知字段（JSON：字段中文名->值）；主键与必填字段会自动补齐。")
    public String proposeCreate(
            @P("实体类型，如 客户 / 物料") String entityKeyword,
            @P("已知字段的 JSON，键=字段中文名、值=字段值，例如 {\"客户名称\":\"常州测试公司\",\"客户简称\":\"常测\"}") String fieldsJson) {

        if (isBlank(entityKeyword)) {
            return err("缺少实体类型。");
        }
        Map<String, Object> form = resolveForm(entityKeyword.trim());
        if (form == null) {
            return err("找不到「" + entityKeyword + "」对应的可新增主表。");
        }
        String formId = str(form.get("sFormId"));
        String moduleId = str(form.get("sModuleId"));
        String table = str(form.get("sDataSource"));
        if (!identity.canAccessModule(moduleId)) {
            return err("你没有新增「" + entityKeyword + "」的权限。");
        }

        // 报价是跨表主-从单据 → 走多表创建（主表 + 印刷/部件从表 + 多数量）
        if ("quoquotationmaster".equalsIgnoreCase(table)) {
            return proposeQuote(fieldsJson, formId, moduleId, table);
        }

        Map<String, String> types = resolver.columnTypes(table);
        // 权威 label -> {col, fk} 映射（与 collectForm 同源：策展/字段字典），保证前端标签能被正确回映射
        Map<String, Map<String, Object>> labelMap = new LinkedHashMap<>();
        for (Map<String, Object> bfm : resolver.businessFields(table, 40)) {
            labelMap.put(String.valueOf(bfm.get("label")), bfm);
        }
        Map<String, Object> col = new LinkedHashMap<>();
        List<String> descParts = new ArrayList<>();
        try {
            if (!isBlank(fieldsJson)) {
                JsonNode fj = mapper.readTree(fieldsJson.trim());
                Iterator<Map.Entry<String, JsonNode>> it = fj.fields();
                while (it.hasNext()) {
                    Map.Entry<String, JsonNode> e = it.next();
                    String zh = e.getKey();
                    String v = e.getValue().asText("");
                    if (isBlank(v)) {
                        continue;
                    }
                    Map<String, Object> fm = labelMap.get(zh);
                    if (fm == null) {
                        fm = resolveColumn(table, zh); // 回退字段字典
                    }
                    if (fm == null) {
                        continue; // 该实体没有这个字段，忽略
                    }
                    String colName = str(fm.get("col"));
                    // 别让 LLM/用户直填系统列（制单人/单据日期/租户/单号…），交给 ERP 与下方系统列处理
                    if (resolver.isSystemColumn(colName)) {
                        continue;
                    }
                    String fk = str(fm.get("fk"));
                    if (fk != null && !fk.isBlank()) {
                        String id = resolver.resolveFk(fk, v); // 外键：名称 -> id
                        if (id == null) {
                            return err("找不到名为「" + v + "」的" + zh + "，请确认该" + zh + "是否已存在。");
                        }
                        col.put(colName, id);
                    } else {
                        Object cv = resolver.coerce(types.get(colName), v); // 按列类型强转
                        if (cv != null) {
                            col.put(colName, cv);
                        }
                    }
                    descParts.add(zh + "=" + v);
                }
            }
        } catch (Exception ex) {
            return err("字段解析失败：" + ex.getMessage());
        }
        if (descParts.isEmpty()) {
            return err("请至少提供一个有效字段（如客户名称）。");
        }

        // 自动补齐 NOT-NULL 无默认列（系统列跳过；其余按类型给默认 0/''）
        for (String rc : requiredCols(table)) {
            if (col.containsKey(rc) || resolver.isSystemColumn(rc)) {
                continue;
            }
            col.put(rc, resolver.typeDefault(rc, types.get(rc)));
        }
        // 系统列：主键 + 表单id + 单号（租户/制单人/日期由 ERP 注入，不填）
        col.put("sId", erp.newUuid(identity.token()));
        col.put("sFormId", formId);
        String billNo = resolver.nextBillNo(table, identity.brandsId());
        if (billNo != null) {
            col.put("sBillNo", billNo);
        }

        String payload;
        try {
            payload = mapper.writeValueAsString(col);
        } catch (Exception e) {
            return err("内部错误：" + e.getMessage());
        }
        String description = "新增【" + entityKeyword + "】：" + String.join("，", descParts);
        String opId = ops.createDraftPayload(identity.userId(), "create", formId, moduleId, table, payload, description);

        Map<String, Object> out = new LinkedHashMap<>();
        out.put("opId", opId);
        out.put("summary", description);
        out.put("message", "已为你生成一条待确认的新增，请在下方点【确认】执行、或【取消】。");
        return toJson(out);
    }

    @Tool("提议**审核/过账**某条单据（写操作）。只提议并暂存、绝不立即执行——用户点确认后才真正审核。"
            + "用于「审核 / 过账某张单据」这类需求；审核有业务后果，请谨慎。给出单据类型与单号/名称即可。")
    public String proposeExamine(
            @P("单据类型，如 销售订单 / 采购订单 / 报价") String entityKeyword,
            @P("要审核的单据编号或名称关键词") String recordKeyword) {

        if (isBlank(entityKeyword) || isBlank(recordKeyword)) {
            return err("缺少单据类型或单号/名称。");
        }
        Map<String, Object> form = resolveForm(entityKeyword.trim());
        if (form == null) {
            return err("找不到「" + entityKeyword + "」对应的可审核单据主表。");
        }
        String formId = str(form.get("sFormId"));
        String moduleId = str(form.get("sModuleId"));
        String table = str(form.get("sDataSource"));
        if (!identity.canAccessModule(moduleId)) {
            return err("你没有审核「" + entityKeyword + "」的权限。");
        }
        String nameField = queryOne(
                "SELECT sField FROM viw_kg_field_dict WHERE sTable=? AND sField LIKE '%Name' AND sField NOT LIKE '%NameId' " +
                        "ORDER BY iFormUses DESC LIMIT 1", table);
        JsonNode root;
        try {
            root = erp.readForm(identity.token(), formId, moduleId, 1, 5, nameField, recordKeyword.trim());
        } catch (Exception e) {
            return err("定位单据失败：" + e.getMessage());
        }
        if (root.path("code").asInt(0) < 0) {
            return err("定位单据失败：" + root.path("msg").asText("未知错误"));
        }
        JsonNode rows = root.path("dataset").path("rows");
        JsonNode data = (rows.isArray() && rows.size() > 0) ? rows.get(0).path("dataSet") : null;
        int n = (data != null && data.isArray()) ? data.size() : 0;
        if (n == 0) {
            return err("没有找到含「" + recordKeyword + "」的单据。");
        }
        if (n > 1) {
            StringBuilder names = new StringBuilder();
            for (int i = 0; i < data.size() && i < 5; i++) {
                if (i > 0) names.append("、");
                names.append(nameField == null ? "" : data.get(i).path(nameField).asText(""));
            }
            return err("匹配到多条单据（" + names + "），请提供更精确的单号，只审核其中一条。");
        }
        JsonNode rec = data.get(0);
        String billId = rec.path("sId").asText(null);
        if (isBlank(billId)) {
            return err("定位到的单据缺少主键 sId，无法审核。");
        }
        String recordName = nameField == null ? recordKeyword : rec.path(nameField).asText(recordKeyword);
        String description = "审核【" + recordName + "】（" + entityKeyword + "）";
        // examine：sNewValue 存 iFlag（1=审核）；执行走 ERP doExamine（存储过程驱动）
        String opId = ops.createDraft(identity.userId(), "examine", formId, moduleId, table, billId,
                null, null, null, "1", description);

        Map<String, Object> out = new LinkedHashMap<>();
        out.put("opId", opId);
        out.put("summary", description);
        out.put("message", "已为你生成一条待确认的审核，请在下方点【确认】执行、或【取消】。审核有业务后果，请谨慎。");
        return toJson(out);
    }

    /**
     * 报价多表创建：主表(quoquotationmaster) + 印刷/部件从表(quoquotationslave) + 多数量(quoquotationmanyqtys)。
     * 字段按策展的 target 表分流；印刷/颜色/单双面无独立列 → 合进从表 sMaterialsMemo；多数量按逗号拆多行。
     * 价格由 ERP【核价】计算，本工具只落主-从明细。生成 __tables__ 结构化 payload，确认端点做多表写入。
     */
    private String proposeQuote(String fieldsJson, String formId, String moduleId, String table) {
        Map<String, String> masterTypes = resolver.columnTypes(table);
        Map<String, String> slaveTypes = resolver.columnTypes("quoquotationslave");
        Map<String, Map<String, Object>> labelMap = new LinkedHashMap<>();
        for (Map<String, Object> bfm : resolver.businessFields(table, 40)) {
            labelMap.put(String.valueOf(bfm.get("label")), bfm);
        }

        Map<String, Object> masterCol = new LinkedHashMap<>();
        Map<String, Object> slaveCol = new LinkedHashMap<>();
        List<String> notes = new ArrayList<>();
        List<String> manyQtys = new ArrayList<>();
        List<String> descParts = new ArrayList<>();
        String custId = null;
        try {
            if (!isBlank(fieldsJson)) {
                JsonNode fj = mapper.readTree(fieldsJson.trim());
                Iterator<Map.Entry<String, JsonNode>> it = fj.fields();
                while (it.hasNext()) {
                    Map.Entry<String, JsonNode> e = it.next();
                    String zh = e.getKey();
                    String v = e.getValue().asText("");
                    if (isBlank(v)) {
                        continue;
                    }
                    Map<String, Object> fm = labelMap.get(zh);
                    if (fm == null) {
                        continue;
                    }
                    String colName = str(fm.get("col"));
                    String tgt = fm.get("table") == null ? "master" : str(fm.get("table"));
                    String fk = str(fm.get("fk"));
                    if ("note".equals(tgt)) {
                        notes.add(zh + "=" + v);
                        descParts.add(zh + "=" + v);
                        continue;
                    }
                    if ("manyqtys".equals(tgt)) {
                        for (String q : v.split("[,，、\\s]+")) {
                            String n = q.replaceAll("[^0-9.]", "");
                            if (!n.isEmpty()) {
                                manyQtys.add(n);
                            }
                        }
                        descParts.add(zh + "=" + v);
                        continue;
                    }
                    Object value;
                    if (fk != null && !fk.isBlank()) {
                        String id = resolver.resolveFk(fk, v);
                        if (id == null) {
                            return err("找不到名为「" + v + "」的" + zh + "，请确认是否已存在。");
                        }
                        value = id;
                        if ("sCustomerId".equals(colName)) {
                            custId = id;
                        }
                    } else {
                        String dt = "slave".equals(tgt) ? slaveTypes.get(colName) : masterTypes.get(colName);
                        value = resolver.coerce(dt, v);
                    }
                    if (value != null) {
                        if ("slave".equals(tgt)) {
                            slaveCol.put(colName, value);
                        } else {
                            masterCol.put(colName, value);
                        }
                    }
                    descParts.add(zh + "=" + v);
                }
            }
        } catch (Exception ex) {
            return err("字段解析失败：" + ex.getMessage());
        }
        if (descParts.isEmpty()) {
            return err("请至少填写一个字段（如客户名称/产品名称/数量）。");
        }

        // 主表：补必填(非系统) + 主键 + 表单id + 单号
        for (String rc : requiredCols(table)) {
            if (masterCol.containsKey(rc) || resolver.isSystemColumn(rc)) {
                continue;
            }
            masterCol.put(rc, resolver.typeDefault(rc, masterTypes.get(rc)));
        }
        String masterId = erp.newUuid(identity.token());
        masterCol.put("sId", masterId);
        masterCol.put("sFormId", formId);
        String billNo = resolver.nextBillNo(table, identity.brandsId());
        if (billNo != null) {
            masterCol.put("sBillNo", billNo);
        }

        List<Map<String, Object>> tables = new ArrayList<>();
        tables.add(tableItem("quoquotationmaster", "master", masterCol));

        // 印刷/部件从表：有从表字段或印刷备注就建一行（sCustomerId 从表 NOT-NULL）
        if (!slaveCol.isEmpty() || !notes.isEmpty()) {
            if (!notes.isEmpty()) {
                String memo = String.join("；", notes);
                Object exist = slaveCol.get("sMaterialsMemo");
                slaveCol.put("sMaterialsMemo", exist == null ? memo : (exist + "；" + memo));
            }
            slaveCol.put("sId", erp.newUuid(identity.token()));
            slaveCol.put("sParentId", masterId);
            slaveCol.put("sCustomerId", custId == null ? "" : custId);
            tables.add(tableItem("quoquotationslave", "slave", slaveCol));
        }
        // 多数量报价：每个数量一行
        for (String q : manyQtys) {
            Map<String, Object> mq = new LinkedHashMap<>();
            mq.put("sId", erp.newUuid(identity.token()));
            mq.put("sParentId", masterId);
            mq.put("dManyQty", q);
            tables.add(tableItem("quoquotationmanyqtys", "slave", mq));
        }

        Map<String, Object> wrap = new LinkedHashMap<>();
        wrap.put("__tables__", tables);
        String payload;
        try {
            payload = mapper.writeValueAsString(wrap);
        } catch (Exception e) {
            return err("内部错误：" + e.getMessage());
        }
        String description = "新增【报价】：" + String.join("，", descParts)
                + "（含印刷/多数量明细；价格请在 ERP 点【核价】计算）";
        String opId = ops.createDraftPayload(identity.userId(), "create", formId, moduleId, table, payload, description);

        Map<String, Object> out = new LinkedHashMap<>();
        out.put("opId", opId);
        out.put("summary", description);
        out.put("message", "已为你生成一条待确认的报价新增（主表+印刷明细+多数量），请点【确认】执行、或【取消】。价格在 ERP 里点【核价】计算。");
        return toJson(out);
    }

    private Map<String, Object> tableItem(String sTable, String name, Map<String, Object> column) {
        Map<String, Object> m = new LinkedHashMap<>();
        m.put("sTable", sTable);
        m.put("name", name);
        m.put("column", column);
        return m;
    }

    /** 中文名 -> {col, fk}（字段字典，先精确合并模糊，取使用度最高的一列）。 */
    private Map<String, Object> resolveColumn(String table, String zh) {
        try {
            List<Map<String, Object>> r = jdbc.queryForList(
                    "SELECT sField col, MAX(sFkTable) fk FROM viw_kg_field_dict " +
                            "WHERE sTable=? AND (sChinese=? OR sChinese LIKE ?) " +
                            "GROUP BY sField ORDER BY SUM(iFormUses) DESC LIMIT 1",
                    table, zh, "%" + zh + "%");
            return r.isEmpty() ? null : r.get(0);
        } catch (Exception e) {
            return null;
        }
    }

    /** 目标表的 NOT-NULL 无默认列（排除 ERP 会自动注入的租户/制单人）。 */
    private List<String> requiredCols(String table) {
        List<String> out = new ArrayList<>();
        try {
            List<Map<String, Object>> rows = jdbc.queryForList(
                    "SELECT COLUMN_NAME FROM information_schema.COLUMNS WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME=? " +
                            "AND IS_NULLABLE='NO' AND COLUMN_DEFAULT IS NULL AND EXTRA NOT LIKE '%auto_increment%'", table);
            Set<String> skip = Set.of("sBrandsId", "sSubsidiaryId", "sMakePerson");
            for (Map<String, Object> r : rows) {
                String c = str(r.get("COLUMN_NAME"));
                if (c != null && !skip.contains(c)) {
                    out.add(c);
                }
            }
        } catch (Exception ignore) {
        }
        return out;
    }

    /** 外键兜底：该列现有的最常见非空值。列名来自 KG/info_schema（可信）。 */
    private String commonValue(String table, String col) {
        try {
            return queryOne("SELECT `" + col + "` FROM `" + table + "` WHERE `" + col + "` IS NOT NULL AND `" + col +
                    "`<>'' GROUP BY `" + col + "` ORDER BY COUNT(*) DESC LIMIT 1");
        } catch (Exception e) {
            return null;
        }
    }

    /** 定位实体的可写主表——统一走 FormResolverService（与 collectForm 同源，含从属/参数表排除）。 */
    private Map<String, Object> resolveForm(String entityKeyword) {
        return resolver.resolveMasterForm(entityKeyword);
    }

    private static String str(Object o) {
        return o == null ? null : o.toString();
    }

    private String queryOne(String sql, Object... args) {
        try {
            List<Map<String, Object>> r = jdbc.queryForList(sql, args);
            if (!r.isEmpty()) {
                Object v = r.get(0).values().iterator().next();
                return v == null ? null : v.toString();
            }
        } catch (Exception ignore) {
        }
        return null;
    }

    private static boolean isBlank(String s) {
        return s == null || s.isBlank();
    }

    private String err(String msg) {
        Map<String, Object> m = new LinkedHashMap<>();
        m.put("error", msg);
        return toJson(m);
    }

    private String toJson(Map<String, Object> m) {
        try {
            return mapper.writeValueAsString(m);
        } catch (Exception e) {
            return "{\"error\":\"内部错误\"}";
        }
    }
}