"use strict";

// Cleans the scene and spawns an instance of a cube (also updates
// the cubies map).
function buildCube(data)
{
    clearCubies(scene);
    cubies.clear();

    // Solved configuration
    cubies.set(0, new Cubie(0,0,[{ key: 0, value: data[0][0] },{ key: 2, value: data[0][1] },{ key: 4, value: data[0][2] }]));
    cubies.set(1, new Cubie(1,1,[{ key: 0, value: data[1][0] },{ key: 2, value: data[1][1] },{ key: 5, value: data[1][2] }]));
    cubies.set(2, new Cubie(2,2,[{ key: 1, value: data[2][0] },{ key: 2, value: data[2][1] },{ key: 5, value: data[2][2] }]));
    cubies.set(3, new Cubie(3,3,[{ key: 1, value: data[3][0] },{ key: 2, value: data[3][1] },{ key: 4, value: data[3][2] }]));
    cubies.set(4, new Cubie(4,4,[{ key: 0, value: data[4][0] },{ key: 3, value: data[4][1] },{ key: 4, value: data[4][2] }]));
    cubies.set(5, new Cubie(5,5,[{ key: 0, value: data[5][0] },{ key: 3, value: data[5][1] },{ key: 5, value: data[5][2] }]));
    cubies.set(6, new Cubie(6,6,[{ key: 1, value: data[6][0] },{ key: 3, value: data[6][1] },{ key: 5, value: data[6][2] }]));
    cubies.set(7, new Cubie(7,7,[{ key: 1, value: data[7][0] },{ key: 3, value: data[7][1] },{ key: 4, value: data[7][2] }]));

    // Adding cubies to scene
    for (var i = 0; i < cubies.size; i++)
    {
        scene.add(cubies.get(i).mesh);
    }

    needsRender = true;
}

var solvedConfig = [
                   ["white", "green", "red"],
                   ["white", "green", "orange"],
                   ["yellow", "green", "orange"],
                   ["yellow", "green", "red"],
                   ["white", "blue", "red"],
                   ["white", "blue", "orange"],
                   ["yellow", "blue", "orange"],
                   ["yellow", "blue", "red"],
                   ];

function solvedCube()
{
    buildCube(solvedConfig);
}

function scramble()
{
    var moves = [];
    var rotations = ["pitchA", "pitchB", "rollA", "rollB", "yawA", "yawB"];

    for(var i = 0; i < Math.random()*10+10; i++)
    {
        moves.push({ move: rotations[Math.floor(Math.random() * rotations.length)], dir: (Math.random() < 0.5) ? 1 : -1 });
    }

    if (! animator)
    {
        scramb = true;
        animator = new Animator(moves);
        animator.goOn();
    }
}


function clearCubies(node)
{
    cubies.forEach(function(value)
    { 
        node.remove(value.mesh);
    });
}

// Get the contents of the file "fname".
// Returns an object with two attributes:
//  - succeeded: true if the function was able to retrieve the file.
//  - contents: the contents retrieved or an empty string.
function getFileContents(fname) {
    /*
    // Request file content via HTTP's GET request
    var xmlhttp = new XMLHttpRequest();
    xmlhttp.responseType = "text/plain";    // Content is not XML!

    xmlhttp.open("GET", "file:\\\\" + fname, false);

    // NOTE: This can take some time if the server is remote
    //       which means the UI might freeze for some time...
    xmlhttp.send();

    var status = true;
    var contents = "";

    if (xmlhttp.status != 200) {
        status = false;
    }
    else
    {
        contents = xmlhttp.responseText;
    }

    return {succeeded: status, contents: contents};
    */
}

function loadShaders()
{
    var tmp,vs,fs;

    tmp = getFileContents("vs.glsl");
    if (!tmp.succeeded)
    {
        window.alert('Failed to load Blinn-Phong vertex shader: vs.glsl');
    }
    vs = tmp.contents;

    tmp = getFileContents("fs.glsl");
    if (!tmp.succeeded)
    {
        window.alert('Failed to load Blinn-Phong fragment shader: fs.glsl');
    }
    fs = tmp.contents;

    return { vertex: vs, fragment: fs };
}

// Updates position after a complete animation.
// Don't touch it, if you can't understand it!
function updatePositions()
{
    scene.remove(face);

    var temp = cubies.get(current_animation.cubies[0]);
    for(var i = 0; Math.abs(i) < 4; i += current_animation.dir)
    {
        var keys, colors;
        var c_new, c_old = temp;
        switch (current_animation.cubies[mod(i+current_animation.dir,4)]) 
        {
            case 0: keys = [0,2,4]; break; 
            case 1: keys = [0,2,5]; break;
            case 2: keys = [1,2,5]; break;
            case 3: keys = [1,2,4]; break;
            case 4: keys = [0,3,4]; break;
            case 5: keys = [0,3,5]; break;
            case 6: keys = [1,3,5]; break;
            case 7: keys = [1,3,4]; break;
        }
        switch (current_animation.name)
        {
            case "pitch": colors = [0,2,1]; break;
            case "roll":  colors = [1,0,2]; break;
            case "yaw":   colors = [2,1,0]; break;
        }
        c_new = new Cubie(c_old.key,
                          current_animation.cubies[mod(i+current_animation.dir,4)],
                          [{ key: keys[0], value: c_old.colors[colors[0]].value },
                           { key: keys[1], value: c_old.colors[colors[1]].value },
                           { key: keys[2], value: c_old.colors[colors[2]].value }
                          ]);
        temp = cubies.get(current_animation.cubies[mod(i+current_animation.dir,4)]);
        cubies.set(current_animation.cubies[mod(i+current_animation.dir,4)], c_new);
        scene.add(c_new.mesh);
    }

    needsRender = true
}

// Right module operator.
// Beware the Javascript module! (it doesn't work with negative integers)
function mod(n, m)
{
        return ((n % m) + m) % m;
}

// Open a local file.
function selectFile(loop)
{
    var element = document.createElement('div');
    element.innerHTML = '<input type="file">';
    var fileInput = element.firstChild;
    
    fileInput.addEventListener('change', function() {
        var file = fileInput.files[0];
        if (file.name.match(/\.(txt)$/))
        {
            var reader = new FileReader();
            reader.onload = function() {
                var data = parseData(reader.result);
                buildCube(data.cube);
                if (data.solutions[0].length > 0) {
                    animator = new Animator(data.solutions[0]);
                    animator.goOn();
                }
            };
            reader.readAsText(file);    
        } else {
            alert("File not supported, .txt files only");
        }
    });

    fileInput.click();
}

function saveToFile(filename, content) {
    var elem = document.createElement('a');
    elem.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(content));
    elem.setAttribute('download', filename);

    document.body.appendChild(elem);
    elem.click();
    document.body.removeChild(elem);
}

// Parse a local file
function parseData(text)
{
    var data = [], instance;
    var moves = [], predicates;
    var i = -1,  pred;
    var lines = text.split("\n");

    instance = new Array(8);

    // Look for the first line with an answer
    while(lines[++i].search(/Answer:/g) !== 0) { }
    // Parse answers
    while(i < lines.length && lines[i++].search(/Answer:/g) === 0)
    {
        predicates = lines[i++].split(" ");

        pred = predicates[predicates.length-1];
        if (pred.search(/solved/i) === 0) {
            moves = new Array(parseInt(pred.substring(pred.indexOf("(") + 1,pred.indexOf(")"))));
        }

        for(var j = 0; j < predicates.length; j++)
        {
            pred = predicates[j].split(",");

            if(predicates[j].search(/move/i) === 0)
            {
                switch (pred[1])
                {
                    case "pitch": var move = (parseInt(pred[2]) == 0) ? "pitchA" : "pitchB"; break;
                    case "roll":  var move = (parseInt(pred[2]) == 0) ? "rollA" : "rollB"; break;
                    case "yaw":   var move = (parseInt(pred[2]) == 0) ? "yawA" : "yawB"; break;
                }

                var ind = parseInt(pred[0].substring(pred[0].indexOf("(")+1));
                if(ind < moves.length)
                {
                    moves[ind] =
                    { 
                        move:   move,
                        dir:    parseInt(pred[3].substr(0,pred[3].length-1))
                    };
                }

            } else if(predicates[j].search(/is/i) === 0) {

                if(parseInt(pred[0].substring(pred[0].indexOf("(")+1)) === 0)
                {
                    instance[parseInt(pred[1])] = [
                        pred[2],
                        pred[3],
                        pred[4].substr(0,pred[4].length-1)
                    ];
                }
            }

        }

        data.push(moves);
    }

    return { cube: instance, solutions: data };
}