/*************************************************************************************************************************
File:       rail.js
Purpose:    This file contains the class definition for a rail to be used in the view.  The main reason to use this
            class instead of just using a raw object gleaned from a JSON string from the server is that this class
            implements a Draw function that is capable of displaying the rail to the view by calling a single line in
            sketch.js.

References: Daniel Shiffman - The Coding Train - "Classes in JavaScript with ES6":
            https://www.youtube.com/watch?v=T-HGdc8L-7w

            P5.JS Reference - https://p5js.org/reference/

Written by John McGorey - Spring 2019 - Using Microsoft visual Studio Code 2019
For use in the St. Norbert College CSCI460 Senior Capstone Experience
**************************************************************************************************************************/
class Rail {

    // Constructor
    constructor(rail_obj) {
        /***************************************************************************************
        Function:  constructor
        Purpose:   Takes a rail object from the server & converts it into this Rail object
                   so that its Draw() function can be used.

        Input:     rail_obj - An object containing the information for the rail that is
                   sent as a JSON string from the server.  It is marshalled into an object from
                   the string before being passed to this constructor.
        ****************************************************************************************/
        // Copy over the information from the rail object
        this.id = rail_obj.rail_id;
        this.x = rail_obj.x;
        this.y = rail_obj.y;
        this.orientation = rail_obj.orientation;
    }

    Draw() {
        /***************************************************************************************
        Function:   Draw
        Purpose:    Draws the rail to the canvas according to its properties.  The rail is
                    represented by a gray line in this case.  Each rail is bounded by a 'box' 
                    that is 50 px wide, and the x and y coordinate of the 'rail' represent where
                    the top left corner of where that box is
        ****************************************************************************************/
        // Position the rail (coordinate is in top left of 'box' the rail is on)
        let x = 30 + 50 * this.x;
        let y = 30 + 50 * this.y;

        // Draw the rail
        stroke(170, 170, 170);
        strokeWeight(1);
        
        switch (this.orientation % 4)
        {
            case 0: // Right & left
                line(x, y, x + 50, y);
                break;
            case 1: // Up Right & down left
                line(x, y + 50, x + 50, y);
                break;
            case 2: // Up & down
                line(x, y, x, y + 50);
                break;
            case 3: // Up Left & down right
                line(x, y, x + 50, y + 50);
                break;
        }
        if (this.orientation == 0) // Right
        {
            strokeCap(SQUARE);
            line(x, y, x + 50, y);
        }
        
    }

} // end class