// Compile with: gcc OffsetKML.c -Wall -Werror -lm -o OffsetKML
#include <stdio.h>
#include <string.h>
#include <math.h>

struct offset_s
{
    double from_x;
    double from_y;
    double to_x;
    double to_y;
    double offset_x;
    double offset_y;
};

struct offset_s offsets[100];
int nr_offsets = 0;

double dist(double dx, double dy) { return sqrt(dx*dx + dy*dy); }

int main(int argc, char *argv[])
{
    FILE *f = fopen("diffs.kml", "r");
    if (f == NULL)
    {
        printf("Failed to open diffs.kml\n");
        return 1;
    }

    char buffer[4000];

    while (fgets(buffer, 3999, f))
    {
        //printf("Read: %s", buffer);
        if (strstr(buffer, "<coordinates>") != 0)
        {
            //printf("%s", buffer);
            for (;;)
            {
                fgets(buffer, 3999, f);
                if (strstr(buffer, "</coordinates>") != 0)
                    break;
                double z;
                sscanf(buffer, "%lf,%lf,%lf %lf,%lf,0",
                    &offsets[nr_offsets].from_x, &offsets[nr_offsets].from_y, &z,
                    &offsets[nr_offsets].to_x, &offsets[nr_offsets].to_y);
                offsets[nr_offsets].offset_x = offsets[nr_offsets].to_x - offsets[nr_offsets].from_x;
                offsets[nr_offsets].offset_y = offsets[nr_offsets].to_y - offsets[nr_offsets].from_y;
                fprintf(stderr, "Offset %lf,%lf\n", offsets[nr_offsets].offset_x, offsets[nr_offsets].offset_y);
                nr_offsets++;
            }
        }
        //printf("%s", buffer);
    }
    fclose(f);
    fprintf(stderr, "nr offsets: %d\n", nr_offsets);
    
    while (fgets(buffer, 3999, stdin))
    {
        if (strstr(buffer, "<coordinates>") != 0)
        {
            printf("%s", buffer);
            for (;;)
            {
                fgets(buffer, 3999, stdin);
                if (strstr(buffer, "</coordinates>") != 0)
                    break;
                double x, y;
                sscanf(buffer, "%lf,%lf", &x, &y);
                double offset_x = 0;
                double offset_y = 0;
                double weight = 0;
                for (int i = 0; i < nr_offsets; i++)
                {
                    double d = dist(offsets[i].from_x - x, offsets[i].from_y - y);
                    if (d < 0.00000001)
                        d = 0.00000001;
                    double rev_d = 1/d;
                    offset_x += rev_d * offsets[i].offset_x;
                    offset_y += rev_d * offsets[i].offset_y;
                    weight += rev_d;
                }
                printf("          %lf,%lf,0\n", x + offset_x / weight, y + offset_y / weight);
            }
        }
        printf("%s", buffer);
    }
    
    return 0;
}