package com.xiaopeng.map.utils;

import lombok.extern.slf4j.Slf4j;
import org.locationtech.jts.geom.Coordinate;
import org.locationtech.jts.geom.GeometryFactory;
import org.locationtech.jts.geom.LinearRing;
import org.locationtech.jts.geom.Polygon;
import org.springframework.stereotype.Component;

@Component
@Slf4j
public class PolygonOverlapService {
    
    /**
     * 检查两个多边形是否重叠
     * @param polygon1Points 多边形1的坐标点 "lng1_lat1,lng2_lat2,..."
     * @param polygon2Points 多边形2的坐标点 "lng1_lat1,lng2_lat2,..."
     * @return 是否重叠
     */
    public boolean checkPolygonOverlap(String polygon1Points, String polygon2Points) {
        try {
            Polygon polygon1 = createPolygonFromPoints(polygon1Points);
            Polygon polygon2 = createPolygonFromPoints(polygon2Points);
            
            // 使用 JTS 库判断多边形是否相交
            return polygon1.intersects(polygon2);
        } catch (Exception e) {
            log.error("多边形重叠检测失败", e);
            return false; // 发生错误时默认不重叠，可根据业务需要调整
        }
    }
    
    /**
     * 从坐标点字符串创建多边形
     * @param pointsStr 坐标点字符串 "lng1_lat1,lng2_lat2,lng3_lat3,..."
     * @return JTS Polygon 对象
     */
    private Polygon createPolygonFromPoints(String pointsStr) {
        if (!pointsStr.contains(",")) {
            throw new IllegalArgumentException("无效的坐标点格式");
        }
        
        String[] pointPairs = pointsStr.split(",");
        Coordinate[] coordinates = new Coordinate[pointPairs.length + 1]; // +1 是为了闭合多边形
        
        for (int i = 0; i < pointPairs.length; i++) {
            String[] lngLat = pointPairs[i].trim().split("_");
            if (lngLat.length != 2) {
                throw new IllegalArgumentException("坐标点格式错误: " + pointPairs[i]);
            }
            
            double lng = Double.parseDouble(lngLat[0]);
            double lat = Double.parseDouble(lngLat[1]);
            coordinates[i] = new Coordinate(lng, lat);
        }
        
        // 闭合多边形，最后一个点与第一个点相同
        coordinates[coordinates.length - 1] = coordinates[0];
        
        GeometryFactory geometryFactory = new GeometryFactory();
        LinearRing linearRing = geometryFactory.createLinearRing(coordinates);
        return geometryFactory.createPolygon(linearRing);
    }


    /**
     * 判断一个坐标点位是否在一个坐标区域内
     * @param longitude 经度
     * @param latitude 纬度
     * @param fencePoints 围栏点位字符串，格式为 "lng1_lat1,lng2_lat2,..."
     * @return 是否在区域内 true在 false不在
     */
    public boolean isPointInPolygon(double longitude, double latitude, String fencePoints) {
        if (fencePoints == null || fencePoints.trim().isEmpty()) {
            return false;
        }

        // 解析围栏点位
        String[] points = fencePoints.split(",");
        if (points.length < 3) {
            return false;
        }

        int n = points.length;
        boolean inside = false;

        double x = longitude, y = latitude;
        double[] xs = new double[n];
        double[] ys = new double[n];

        for (int i = 0; i < n; i++) {
            String[] coords = points[i].split("_");
            if (coords.length != 2) {
                continue;
            }
            try {
                xs[i] = Double.parseDouble(coords[0]);
                ys[i] = Double.parseDouble(coords[1]);
            } catch (NumberFormatException e) {
                return false;
            }
        }

        // 使用射线法判断点是否在多边形内
        for (int i = 0, j = n - 1; i < n; j = i++) {
            if (((ys[i] > y) != (ys[j] > y)) &&
                    (x < (xs[j] - xs[i]) * (y - ys[i]) / (ys[j] - ys[i]) + xs[i])) {
                inside = !inside;
            }
        }

        return inside;
    }


    /**
     * 判断一个坐标区域（多边形A）是否完全在另一个坐标区域（多边形B）内
     * 原理：如果多边形A的所有顶点都在多边形B内，则认为A在B内
     * @param innerFencePoints 内部围栏点位字符串（待判断是否在外的围栏），格式为 "lng1_lat1,lng2_lat2,..."
     * @param outerFencePoints 外部围栏点位字符串（参考围栏），格式为 "lng1_lat1,lng2_lat2,..."
     * @return 是否在内 true在内 false不在
     */

    public boolean isPolygonInPolygon(String innerFencePoints, String outerFencePoints) {
        if (innerFencePoints == null || innerFencePoints.trim().isEmpty()
                || outerFencePoints == null || outerFencePoints.trim().isEmpty()) {
            return false;
        }

        // 解析内部围栏点位
        String[] innerPoints = innerFencePoints.split(",");
        if (innerPoints.length < 3) {
            return false;
        }

        // 检查内部围栏的每一个顶点是否都在外部围栏内
        for (String pointStr : innerPoints) {
            String[] coords = pointStr.split("_");
            if (coords.length != 2) {
                continue;
            }
            try {
                double lon = Double.parseDouble(coords[0]);
                double lat = Double.parseDouble(coords[1]);

                // 如果有一个顶点不在外部围栏内，则整个区域不在内部
                if (!isPointInPolygon(lon, lat, outerFencePoints)) {
                    return false;
                }
            } catch (NumberFormatException e) {
                return false;
            }
        }

        return true;
    }


    /**
     * 根据围栏点位字符串计算中心点坐标
     * @param fencePoints 围栏点位字符串，格式为 "lng1_lat1,lng2_lat2,..."
     * @return double[0] 经度, double[1] 纬度
     */
    public double[] calculateCenterPoint(String fencePoints) {
        if (fencePoints == null || fencePoints.trim().isEmpty()) {
            return new double[]{0.0, 0.0};
        }

        String[] points = fencePoints.split(",");
        if (points.length == 0) {
            return new double[]{0.0, 0.0};
        }

        double sumLon = 0.0;
        double sumLat = 0.0;
        int count = 0;

        for (String point : points) {
            String[] coords = point.split("_");
            if (coords.length == 2) {
                try {
                    double lon = Double.parseDouble(coords[0]);
                    double lat = Double.parseDouble(coords[1]);
                    sumLon += lon;
                    sumLat += lat;
                    count++;
                } catch (NumberFormatException e) {
                    // 忽略解析错误的点
                }
            }
        }

        if (count == 0) {
            return new double[]{0.0, 0.0};
        }

        double centerLon = sumLon / count;
        double centerLat = sumLat / count;

        return new double[]{centerLon, centerLat};
    }




}