/* voronoi.c
 *
 * Created by Rory Healy (healyr@student.unimelb.edu.au)
 * Created on 12th August 2021
 * Last modified 11th September 2021
 *
 * Contains functions involving the generation of the Voronoi diagram, and 
 * running each stage of the assignment.
 * 
 */

#ifndef COMMON_HEADER
#include "common.h"
#endif

#ifndef VORONOI_HEADER
#include "voronoi.h"
#endif

vertex_t **readPoints(vertex_t **points, FILE *pointsFile, int *numPoints) {
    /* Initial size of buffer is 1 as getline() reallocs as needed */
    size_t lineBufferSize = 1;

    /* Stores the current line from the points file */
    char *lineBuffer = malloc(lineBufferSize * sizeof(*lineBuffer));
    checkNullPointer(lineBuffer);

    /* Assuming that pointsFile is valid, there must be at least two points */
    int maxSizePoints = 2;

    while (getline(&lineBuffer, &lineBufferSize, pointsFile) > 0) {
        /* Check if there is enough space in the points array */
        if (*numPoints == maxSizePoints) {
            maxSizePoints *= 2;
            vertex_t **temp = realloc(points, maxSizePoints * sizeof(*points));
            checkNullPointer(temp);
            points = temp;
        }

        double xCoordinateA, yCoordinateA, xCoordinateB, yCoordinateB;
        sscanf(lineBuffer, "%lf %lf %lf %lf", &xCoordinateA, &yCoordinateA, \
            &xCoordinateB, &yCoordinateB);
        
        points[*numPoints] = malloc(sizeof(*points[*numPoints]));
        points[*numPoints]->x = xCoordinateA;
        points[*numPoints]->y = yCoordinateA;
        *numPoints += 1;

        points[*numPoints] = malloc(sizeof(*points[*numPoints]));
        points[*numPoints]->x = xCoordinateB;
        points[*numPoints]->y = yCoordinateB;
        *numPoints += 1;
    }

    free(lineBuffer);
    return points;
}

void stage1PrintBisector(bisector_t *bisector, FILE *outputFile) {
    if (bisector->isSlopeInfinite) {
        /* Cannot print infinite slope, so print only x-intercept */
        fprintf(outputFile, "x = %lf\n", bisector->midX);
    } else {
        fprintf(outputFile, "y = %lf * (x - %lf) + %lf\n", \
            bisector->slope, bisector->midX,  bisector->midY);
    }
}

void freePoints(vertex_t **points, int numPoints) {
    for (int i = 0; i < numPoints; i++) {
        free(points[i]);
    }
    free(points);
}

void stage1(char *pointsFileName, char *outputFileName) {
    FILE *pointsFile = NULL, *outputFile = NULL;
    pointsFile = safeFileOpen(&pointsFile, pointsFileName, "r");
    outputFile = safeFileOpen(&outputFile, outputFileName, "w");
    
    /* Points are given as pairs, so initialise 2 points */
    vertex_t **points = malloc(sizeof(*points) * 2);
    checkNullPointer(points);
    int numPoints = 0;
    points = readPoints(points, pointsFile, &numPoints);

    /* For each pair, calculate and print the bisector to outputFile */
    for (int i = 0; i < numPoints; i += 2) {
        bisector_t *currBisector = getBisector(points[i], points[i + 1]);
        stage1PrintBisector(currBisector, outputFile);
        free(currBisector);
    }

    /* Clean up */
    freePoints(points, numPoints);
    fclose(pointsFile);
    fclose(outputFile);
}

void stage2(char *pointsFileName, char *polygonFileName, char *outputFileName) {
    FILE *pointsFile = NULL, *polygonFile = NULL, *outputFile = NULL;
    pointsFile = safeFileOpen(&pointsFile, pointsFileName, "r");
    polygonFile = safeFileOpen(&polygonFile, polygonFileName, "r");
    outputFile = safeFileOpen(&outputFile, outputFileName, "w");

    /* Points are given as pairs, so initialise 2 points */
    vertex_t **points = malloc(sizeof(*points) * 2);
    checkNullPointer(points);
    int numPoints = 0;
    points = readPoints(points, pointsFile, &numPoints);

    /* Construct the DCEL from the polygon file */
    DCEL_t *dcel = readPolygonFile(polygonFileName);

    /* Calculate and print intersections to the output file */
    

    /* Clean up */
    freePoints(points, numPoints);
    freeDCEL(dcel);
    fclose(pointsFile);
    fclose(polygonFile);
    fclose(outputFile);
}

void stage3(char *dataFileName, char *polygonFileName, char *outputFileName) {
    FILE *dataFile = NULL, *polygonFile = NULL, *outputFile = NULL;
    dataFile = safeFileOpen(&dataFile, dataFileName, "r");
    polygonFile = safeFileOpen(&polygonFile, polygonFileName, "r");
    outputFile = safeFileOpen(&outputFile, outputFileName, "w");



    /* Clean up */
    fclose(dataFile);
    fclose(polygonFile);
    fclose(outputFile);
}

void stage4(char *dataFileName, char *polygonFileName, char *outputFileName) {
    FILE *dataFile = NULL, *polygonFile = NULL, *outputFile = NULL;
    dataFile = safeFileOpen(&dataFile, dataFileName, "r");
    polygonFile = safeFileOpen(&polygonFile, polygonFileName, "r");
    outputFile = safeFileOpen(&outputFile, outputFileName, "w");



    /* Clean up */
    fclose(dataFile);
    fclose(polygonFile);
    fclose(outputFile);
}