var helpers = require('../ParseHelpers');

module.exports = EntityParser;

function EntityParser() {}

EntityParser.ForEntityName = '3DFACE';

EntityParser.prototype.parseEntity = function(scanner, curr) {

    var entity = { type: curr.value, vertices: [] };
    curr = scanner.next();
    while (curr !== 'EOF') {
        if (curr.code === 0) break;
        switch (curr.code) {
            case 70: // 1 = Closed shape, 128 = plinegen?, 0 = default
                entity.shape = ((curr.value & 1) === 1);
                entity.hasContinuousLinetypePattern = ((curr.value & 128) === 128);
                break;
            case 10: // X coordinate of point
                entity.vertices = parse3dFaceVertices(scanner, curr);
                curr = scanner.lastReadGroup;
                break;
            default:
                helpers.checkCommonEntityProperties(entity, curr);
                break;
        }
        curr = scanner.next();
    }
    return entity;
};

function parse3dFaceVertices(scanner, curr) {
    var vertices = [],
        i;
    var vertexIsStarted = false;
    var vertexIsFinished = false;
    var verticesPer3dFace = 4; // there can be up to four vertices per face, although 3 is most used for TIN
    
    for (i = 0; i <= verticesPer3dFace; i++) {
        var vertex = {};
        while (curr !== 'EOF') {
            if (curr.code === 0 || vertexIsFinished) break;

            switch (curr.code) {
                case 10: // X0
                case 11: // X1
                case 12: // X2
                case 13: // X3
                    if (vertexIsStarted) {
                        vertexIsFinished = true;
                        continue;
                    }
                    vertex.x = curr.value;
                    vertexIsStarted = true;
                    break;
                case 20: // Y
                case 21:
                case 22:
                case 23:
                    vertex.y = curr.value;
                    break;
                case 30: // Z
                case 31:
                case 32:
                case 33:
                    vertex.z = curr.value;
                    break;
                default:
                    // it is possible to have entity codes after the vertices.  
                    // So if code is not accounted for return to entity parser where it might be accounted for
                    return vertices;
                    continue;
            }
            curr = scanner.next();
        }
        // See https://groups.google.com/forum/#!topic/comp.cad.autocad/9gn8s5O_w6E
        vertices.push(vertex);
        vertexIsStarted = false;
        vertexIsFinished = false;
    }
    scanner.rewind();
    return vertices;
};