package tqq9.lc123.cloud.app.api.utils;

import com.fasterxml.jackson.databind.JsonNode;
import tqq9.lc123.cloud.app.api.utils.mapping.GyDeliveryMapping;

import java.util.*;

/**
 * 把 delivery 节点全部拍扁
 */
public final class GyDeliverySyncMappingUtil {

    /* 1. 缓存：key = 全路径，value = 值或List<Map> */
    private static final Map<String, Object> CACHE = new HashMap<>();

    /* 2. 入口 */
    public static void parse(JsonNode delivery) {
        CACHE.clear();
        flatten(null, delivery);
    }

    /* 3. 统一取值 */
    public static Object get(String outerKey) {
        String path = GyDeliveryMapping.FIELD_MAP.get(outerKey);
        if (path == null) return null;

        /* 3.1 整段数组或对象 */
        if (isWholeBlock(path)) return CACHE.get(path);

        /* 3.2 数组模板：details[].field 或 details[1].field */
        if (path.contains("[") && path.contains("].")) {
            return handleArrayTemplate(path);
        }

        /* 3.3 普通根字段 */
        return CACHE.get(path);
    }

    /* 4. 拍扁：对象展开；数组既存整段，又明细到 CACHE */
    private static void flatten(String parent, JsonNode node) {
        if (node.isObject()) {
            Iterator<Map.Entry<String, JsonNode>> it = node.fields();
            while (it.hasNext()) {
                Map.Entry<String, JsonNode> e = it.next();
                flatten(join(parent, e.getKey()), e.getValue());
            }
        } else if (node.isArray()) {
            List<Map<String, Object>> list = new ArrayList<>();
            for (int i = 0; i < node.size(); i++) {
                JsonNode child = node.get(i);
                Map<String, Object> row = new LinkedHashMap<>();
                Iterator<Map.Entry<String, JsonNode>> it = child.fields();
                while (it.hasNext()) {
                    Map.Entry<String, JsonNode> f = it.next();
                    String key = f.getKey();
                    Object val = convert(f.getValue());
                    row.put(key, val);

                    /* 字段别名：item_code -> material */
                    String alias = GyDeliveryMapping.ALIAS_MAP.get(key);
                    if (alias != null) row.put(alias, val);
                }
                list.add(row);

                /* 明细拍扁：details[0].xxx */
                String idxKey = parent + "[" + i + "]";
                for (Map.Entry<String, Object> entry : row.entrySet()) {
                    CACHE.put(idxKey + "." + entry.getKey(), entry.getValue());
                }
            }
            CACHE.put(parent, list);   // 整段也保留
        } else {
            CACHE.put(parent, convert(node));
        }
    }

    /* 5. 数组模板处理 */
    private static Object handleArrayTemplate(String path) {
        int dot = path.indexOf("].");
        String listPart = path.substring(0, dot + 1);
        String field = path.substring(dot + 2);

        String listKey = listPart.substring(0, listPart.indexOf("["));
        Object block = CACHE.get(listKey);
        if (!(block instanceof List)) return null;
        List<Map<String, Object>> list = (List<Map<String, Object>>) block;

        String idxPart = listPart.substring(listPart.indexOf("[") + 1, listPart.length() - 1);

        /* 5.1 通配：details[].field */
        if (idxPart.isEmpty()) {
            List<Object> res = new ArrayList<>(list.size());
            for (Map<String, Object> row : list) {
                res.add(row.get(field));
            }
            return res;
        }

        /* 5.2 单条：details[1].field */
        int i = Integer.parseInt(idxPart);
        return i < 0 || i >= list.size() ? null : list.get(i).get(field);
    }

    /* 6. 工具方法 */
    private static boolean isWholeBlock(String path) {
        return path.equals("details") || path.equals("payments")
                || path.equals("invoices") || path.equals("tags")
                || path.equals("stock_location")
                || path.equals("delivery_statusInfo")
                || path.equals("store_info");
    }

    private static String join(String parent, String key) {
        return parent == null ? key : parent + "." + key;
    }

    private static Object convert(JsonNode n) {
        if (n.isTextual()) return n.asText();
        if (n.isNumber()) return n.isFloatingPointNumber() ? n.asDouble() : n.asLong();
        if (n.isBoolean()) return n.asBoolean();
        return n.asText();
    }
}