//Variables------------------------------------------------------------------------------------------------------
var FPS = 60;
var framesElapsed = 0;
var c = document.getElementById("ballgame");
var ctx = c.getContext("2d");
const width = c.width;
const height = c.height;
const playerPos = [0, 0, 0, 0];
const inputDir = [0, 0];
var termOpen = false;
var termString = "help";
var command;
var cmdHistory = [""];
var historyIndex = 0;
var plrFill = getRandomColor();
var plrOutline = "000000";
var colorChangeOnBounce = false;
var splatAlpha = 0.4;
var splat = true;
var splatSizeMax = 250;
var splatSizeMin = 100;
var splatX = [];
var splatY = [];
var splatColor = [];
var splatSize = [];
var splatFrames = [];
var plrSize = 10;
var maxVel = 100;
var accel = 1;
var friction = 1;

const fontURL = "../resources/fonts/TeleSys.ttf";
const TeleSys = new FontFace("TeleSys", `url(${fontURL})`);
document.fonts.add(TeleSys);

ctx.font = "16px TeleSys";

//Functions------------------------------------------------------------------------------------------------------
function draw() {
    //draw player
    ctx.clearRect(0, 0, width, height);
    if (splat) {
        for (let i = 0; i < splatX.length; i++) {
            ctx.fillStyle = convertHexToRgbA(splatColor[i], splatAlpha);
            ctx.strokeStyle = convertHexToRgbA(splatColor[i], 0);
            ctx.beginPath();
            ctx.arc(
                splatX[i] + width / 2, //x
                splatY[i] + height / 2, //y
                splatGrow(i), //px
                0, //idk
                2 * Math.PI, //rad
            );
            ctx.fill();
            ctx.stroke();
        }
    }
    ctx.fillStyle = "#" + plrFill;
    ctx.strokeStyle = "#" + plrOutline;
    ctx.beginPath();
    ctx.arc(
        playerPos[0] + width / 2, //x
        playerPos[1] + height / 2, //y
        plrSize / 2, //px
        0, //idk
        2 * Math.PI, //rad
    );
    ctx.fill();
    ctx.stroke();

    //draw terminal
    if (termOpen) {
        ctx.fillStyle = "#000000";
        ctx.fillText("(" + historyIndex + ")> " + termString, 5, 20);
        for (let i = 0; i < cmdHistory.length; i++) {
            ctx.fillText(i + 1 + "_ " + cmdHistory[i], 5, i * 20 + 40);
        }
    }
}

function checkKeys() {
    if (!termOpen) {
        //ball mode
        function checkKeyDown(event) {
            if (event.key == "d") {
                //Right
                inputDir[0] = 1;
            }
            if (event.key == "a") {
                //Left
                inputDir[0] = -1;
            }
            if (event.key == "w") {
                //Up
                inputDir[1] = -1;
            }
            if (event.key == "s") {
                //Down
                inputDir[1] = 1;
            }
            if (event.key == "c" && !termOpen) {
                termOpen = true;
            }
        }
        function checkKeyUp(event) {
            if (event.key == "a" || event.key == "d") {
                inputDir[0] = 0;
            }
            if (event.key == "w" || event.key == "s") {
                inputDir[1] = 0;
            }
        }

        document.onkeydown = checkKeyDown;
        document.onkeyup = checkKeyUp;
    } else {
        //terminal mode
        function doTyping(event) {
            if (event.key == "c" && event.ctrlKey) {
                termString = "";
            } else if (event.key.length == 1) {
                termString = termString + event.key;
            } else {
                if (event.key == "Escape") {
                    termOpen = false;
                }
                if (event.key == "Backspace") {
                    termString = termString.substring(0, termString.length - 1);
                }
                if (
                    event.key == "ArrowUp" &&
                    historyIndex <= cmdHistory.length - 1
                ) {
                    termString = cmdHistory[historyIndex];
                    historyIndex++;
                }
                if (event.key == "ArrowDown") {
                    if (historyIndex > 1) {
                        historyIndex--;
                        termString = cmdHistory[historyIndex - 1];
                    } else {
                        historyIndex = 0;
                        termString = "";
                    }
                }
            }
            //command submission-------------------------------------!!
            if (event.key == "Enter") {
                var regexPass = false;
                command = termString;
                var cmdArray = [command];
                cmdHistory = cmdArray.concat(cmdHistory);
                termString = "";
                termOpen = false;
                //define the commands and regex here
                //color change on bounce command=================
                if (
                    !command
                        .substring(0, 5)
                        .toUpperCase()
                        .localeCompare("CCONB")
                ) {
                    if (
                        !command
                            .substring(6)
                            .toUpperCase()
                            .localeCompare("TRUE")
                    ) {
                        colorChangeOnBounce = true;
                    } else if (
                        !command
                            .substring(6)
                            .toUpperCase()
                            .localeCompare("FALSE")
                    ) {
                        colorChangeOnBounce = false;
                    } else {
                        cmdArray[0] = "CConB: Syntax error";
                        cmdHistory = cmdArray.concat(cmdHistory);
                        termOpen = true;
                    }
                    regexPass = true;
                }
                //echo command=================
                if (
                    !command.substring(0, 4).toUpperCase().localeCompare("ECHO")
                ) {
                    if (
                        !command
                            .substring(5)
                            .toUpperCase()
                            .localeCompare("SIZE")
                    ) {
                        cmdArray[0] = "// (size) Size: " + plrSize + "px";
                    }
                    if (
                        !command
                            .substring(5)
                            .toUpperCase()
                            .localeCompare("FILL")
                    ) {
                        cmdArray[0] = "// (fill) Fill color: #" + plrFill;
                    }
                    if (
                        !command
                            .substring(5)
                            .toUpperCase()
                            .localeCompare("OUTLINE")
                    ) {
                        cmdArray[0] =
                            "// (outline) Outline color: #" + plrOutline;
                    }
                    if (
                        !command
                            .substring(5, 10)
                            .toUpperCase()
                            .localeCompare("SPLAT")
                    ) {
                        if (
                            !command
                                .substring(11)
                                .toUpperCase()
                                .localeCompare("MAX")
                        ) {
                            cmdArray[0] =
                                "// (splat) Maximum splat size: " +
                                splatSizeMax +
                                "px";
                        } else if (
                            !command
                                .substring(11)
                                .toUpperCase()
                                .localeCompare("MIN")
                        ) {
                            cmdArray[0] =
                                "// (splat) Minimum splat size: " +
                                splatSizeMin +
                                "px";
                        } else if (
                            !command
                                .substring(11)
                                .toUpperCase()
                                .localeCompare("ALPHA")
                        ) {
                            cmdArray[0] =
                                "// (splat) Splat alpha value: " + splatAlpha;
                        } else {
                            cmdArray[0] = "// (splat) Splat enabled: " + splat;
                        }
                    }
                    if (
                        !command
                            .substring(5)
                            .toUpperCase()
                            .localeCompare("CCONB")
                    ) {
                        cmdArray[0] =
                            "// (CConB) Color change on bounce enabled: " +
                            colorChangeOnBounce;
                    }
                    if (
                        !command
                            .substring(5)
                            .toUpperCase()
                            .localeCompare("MAXVEL")
                    ) {
                        cmdArray[0] = "// (maxvel) Maximum velocity: " + maxVel;
                    }
                    if (
                        !command
                            .substring(5)
                            .toUpperCase()
                            .localeCompare("ACCEL")
                    ) {
                        cmdArray[0] = "// (accel) Acceleration rate: " + accel;
                    }
                    if (
                        !command
                            .substring(5)
                            .toUpperCase()
                            .localeCompare("FRICTION")
                    ) {
                        cmdArray[0] = "// (friction) Friction: " + friction;
                    }
                    if (
                        !command
                            .substring(5)
                            .toUpperCase()
                            .localeCompare("ECHO")
                    ) {
                        cmdArray[0] = "echo! echo!";
                    }
                    if (
                        !command
                            .substring(5)
                            .toUpperCase()
                            .localeCompare("CLEAR")
                    ) {
                        cmdArray[0] = "// (clear) w-. what. why";
                    }
                    if (
                        !command
                            .substring(5)
                            .toUpperCase()
                            .localeCompare("HELP")
                    ) {
                        showHelp();
                    }
                    cmdHistory = cmdArray.concat(cmdHistory);
                    termOpen = true;
                    regexPass = true;
                }
                //clear command=================
                if (
                    !command
                        .substring(0, 5)
                        .toUpperCase()
                        .localeCompare("CLEAR")
                ) {
                    cmdHistory = [""];
                    termOpen = true;
                    regexPass = true;
                }
                //acceleration command=================
                if (
                    !command
                        .substring(0, 5)
                        .toUpperCase()
                        .localeCompare("ACCEL")
                ) {
                    accel = command.substring(6);
                    regexPass = true;
                }
                //friction command=================
                if (
                    !command
                        .substring(0, 8)
                        .toUpperCase()
                        .localeCompare("FRICTION")
                ) {
                    friction = command.substring(9);
                    regexPass = true;
                }
                //velocity command=================
                if (
                    !command
                        .substring(0, 6)
                        .toUpperCase()
                        .localeCompare("MAXVEL")
                ) {
                    maxVel = command.substring(7);
                    regexPass = true;
                }
                //splat command=================
                if (
                    !command
                        .substring(0, 5)
                        .toUpperCase()
                        .localeCompare("SPLAT")
                ) {
                    if (
                        !command
                            .substring(6, 9)
                            .toUpperCase()
                            .localeCompare("MAX")
                    ) {
                        splatSizeMax = parseInt(command.substring(10), 10);
                    } else if (
                        !command
                            .substring(6, 9)
                            .toUpperCase()
                            .localeCompare("MIN")
                    ) {
                        splatSizeMin = parseInt(command.substring(10), 10);
                    } else {
                        if (
                            !command
                                .substring(6)
                                .toUpperCase()
                                .localeCompare("TRUE")
                        ) {
                            splat = true;
                        } else if (
                            !command
                                .substring(6)
                                .toUpperCase()
                                .localeCompare("FALSE")
                        ) {
                            splat = false;
                            splatX = [];
                            splatY = [];
                            splatColor = [];
                            splatSize = [];
                            splatFrames = [];
                        } else if (
                            !command
                                .substring(6, 11)
                                .toUpperCase()
                                .localeCompare("ALPHA")
                        ) {
                            splatAlpha = Number(command.substring(12));
                        } else {
                            cmdArray[0] = "Splat: Syntax error";
                            cmdHistory = cmdArray.concat(cmdHistory);
                            termOpen = true;
                        }
                    }
                    regexPass = true;
                }
                //outline color command=================
                if (
                    !command
                        .substring(0, 7)
                        .toUpperCase()
                        .localeCompare("OUTLINE")
                ) {
                    if (!command.substring(8, 9).localeCompare("#")) {
                        plrOutline = command.substring(9, 15).toUpperCase();
                        regexPass = true;
                    } else {
                        plrOutline = command.substring(8, 14).toUpperCase();
                        regexPass = true;
                    }
                }
                //fill color command=================
                if (
                    !command.substring(0, 4).toUpperCase().localeCompare("FILL")
                ) {
                    if (!command.substring(5, 6).localeCompare("#")) {
                        plrFill = command.substring(6, 12).toUpperCase();
                        regexPass = true;
                    } else {
                        plrFill = command.substring(5, 11).toUpperCase();
                        regexPass = true;
                    }
                }
                //size command=================
                if (
                    !command.substring(0, 4).toUpperCase().localeCompare("SIZE")
                ) {
                    plrSize = command.substring(5);
                    regexPass = true;
                }
                //help command=================
                if (
                    !command.substring(0, 4).toUpperCase().localeCompare("HELP")
                ) {
                    showHelp(command.substring());
                    termOpen = true;
                    regexPass = true;
                }
                //regex checker=================
                if (command == "" || command.substring(0, 2) == "//") {
                    regexPass = true;
                }
                //regex fail handler=================
                if (!regexPass) {
                    cmdArray[0] = "Command not recognized";
                    termString = "";
                    cmdHistory = cmdArray.concat(cmdHistory);
                    termOpen = true;
                }
                //reset historyIndex
                historyIndex = 0;
            }
        }
        document.onkeydown = doTyping;
    }
}

function doPlayerPhys() {
    //change x velocity
    if (inputDir[0] != 0) {
        //increase velocity
        playerPos[2] = playerPos[2] + (inputDir[0] / 10) * accel;
    } else {
        //decrease velocity
        playerPos[2] = playerPos[2] * (1 - 0.005 * friction);
    }
    //change y velocity
    if (inputDir[1] != 0) {
        //increase velocity
        playerPos[3] = playerPos[3] + (inputDir[1] / 10) * accel;
    } else {
        //decrease velocity
        playerPos[3] = playerPos[3] * (1 - 0.005 * friction);
    }

    //clamp velocity
    playerPos[2] = playerPos[2].clamp(maxVel * -1, maxVel);
    playerPos[3] = playerPos[3].clamp(maxVel * -1, maxVel);

    //bounce check
    if (playerPos[0] > width / 2 - plrSize / 2) {
        playerPos[2] = Math.abs(playerPos[2]) * -1;
        doSplat();
        if (colorChangeOnBounce) {
            plrFill = getRandomColor();
        }
    } else if (playerPos[0] < width / -2 + plrSize / 2) {
        playerPos[2] = Math.abs(playerPos[2]);
        doSplat();
        if (colorChangeOnBounce) {
            plrFill = getRandomColor();
        }
    }
    if (playerPos[1] > height / 2 - plrSize / 2) {
        playerPos[3] = Math.abs(playerPos[3]) * -1;
        doSplat();
        if (colorChangeOnBounce) {
            plrFill = getRandomColor();
        }
    } else if (playerPos[1] < height / -2 + plrSize / 2) {
        playerPos[3] = Math.abs(playerPos[3]);
        doSplat();
        if (colorChangeOnBounce) {
            plrFill = getRandomColor();
        }
    }

    //apply motion
    playerPos[0] = playerPos[0] + playerPos[2];
    playerPos[1] = playerPos[1] + playerPos[3];
}

//adds function examplevar.clamp(min, max)
Number.prototype.clamp = function (min, max) {
    return Math.min(Math.max(this, min), max);
};

function showHelp(cmd) {
    var cmdArray = [];
    if (!cmd.substring(5).toUpperCase().localeCompare("SPLAT")) {
        cmdArray[0] = "// SPLAT HELP:";
        cmdArray[1] = "// splat (true/false) -- Enable or disable splatting";
        cmdArray[2] =
            "// splat max (#) -- Change max splat size (default: 250)";
        cmdArray[3] =
            "// splat min (#) -- Change min splat size (default: 100)";
        cmdArray[4] =
            "// splat alpha (#) -- Set splat alpha from 0-1 (default: 0.4)";
        cmdHistory = cmdArray.concat(cmdHistory);
        cmdArray = [];
    } else {
        cmdArray[0] = "// COMMAND HELP:";
        cmdArray[1] = "// help -- Show these lines";
        cmdArray[2] = "// size (px) -- Change ball size (default: 10)";
        cmdArray[3] = "// fill (hex) -- Change ball fill color";
        cmdArray[4] = "// outline (hex) -- Change ball outline color";
        cmdArray[5] = "// splat (true/false) -- Do 'help splat' for more info";
        cmdArray[6] =
            "// CConB (true/false) -- Enable or disable fill color change on bounce";
        cmdArray[7] = "// maxvel (#) -- Set max velocity (default: 100)";
        cmdArray[8] = "// accel (#) -- Set acceleration speed (default: 1)";
        cmdArray[9] =
            "// friction (#) -- Set speed at which ball slows (default: 1)";
        cmdArray[10] = "// echo (cmd) -- Check the value of a command";
        cmdArray[11] =
            "// (up arrow, down arrow) -- Cycle through command history";
        cmdArray[12] = "// clear -- Clear command history";
        cmdArray[13] = "// (ctrl + c) -- Clear current command line input";
        cmdHistory = cmdArray.concat(cmdHistory);
        cmdArray = [];
    }
}

function doSplat() {
    splatX.push(playerPos[0]);
    splatY.push(playerPos[1]);
    splatColor.push(plrFill);
    var randSize = (splatSizeMax - splatSizeMin) * Math.random();
    splatSize.push(randSize + splatSizeMin);
    splatFrames.push(framesElapsed);
}

function splatGrow(i) {
    if (framesElapsed - splatFrames[i] <= 180) {
        var x = (framesElapsed - splatFrames[i]) / 60;
        return (
            splatSize[i] -
            Math.abs((splatSize[i] / 2) * -(Math.pow(10, -x) + 1))
        );
    } else {
        return splatSize[i] / 2;
    }
}

function getRandomColor() {
    var letters = "0123456789ABCDEF";
    var color = "";
    for (var i = 0; i < 6; i++) {
        color += letters[Math.floor(Math.random() * 16)];
    }
    return color;
}

function convertHexToRgbA(val, alpha) {
    var hexVal = "#" + val;
    let ret;

    // If the hex value is valid.
    if (/^#([A-Fa-f0-9]{3}){1,2}$/.test(hexVal)) {
        // Getting the content after '#',
        // eg. 'ffffff' in case of '#ffffff'
        ret = hexVal.slice(1);

        // Splitting each character
        ret = ret.split("");

        // Checking if the length is 3
        // then make that 6
        if (ret.length == 3) {
            let ar = [];
            ar.push(ret[0]);
            ar.push(ret[0]);
            ar.push(ret[1]);
            ar.push(ret[1]);
            ar.push(ret[2]);
            ar.push(ret[2]);
            ret = ar;
        }

        // Starts with '0x'(in hexadecimal)
        ret = "0x" + ret.join("");

        // Converting the first 2 characters
        // from hexadecimal to r value
        let r = (ret >> 16) & 255;

        // Converting the second 2 characters
        // to hexadecimal to g value
        let g = (ret >> 8) & 255;

        // Converting the last 2 characters
        // to hexadecimal to b value
        let b = ret & 255;

        // Appending all of them to make
        // the RGBA value
        return "rgba(" + [r, g, b].join(",") + "," + alpha + ")";
    }
}

//Loop------------------------------------------------------------------------------------------------------
setInterval(function () {
    framesElapsed++;
    checkKeys();
    if (!termOpen) {
        doPlayerPhys();
    }
    draw();
}, 1000 / FPS);