GeoNearRandomTest = function(name) {
    this.name = name;
    this.t = db[name];
    this.nPts = 0;

    // reset state
    this.t.drop();
    Random.srand(1234);

    print("starting test: " + name);
};

GeoNearRandomTest.prototype.mkPt = function mkPt(scale, indexBounds) {
    if (!indexBounds) {
        scale = scale || 1;  // scale is good for staying away from edges
        return [((Random.rand() * 359.8) - 179.9) * scale, ((Random.rand() * 180) - 90) * scale];
    } else {
        var range = indexBounds.max - indexBounds.min;
        var eps = Math.pow(2, -40);
        // Go very close to the borders but not quite there.
        return [
            (Random.rand() * (range - eps) + eps) + indexBounds.min,
            (Random.rand() * (range - eps) + eps) + indexBounds.min
        ];
    }

};

GeoNearRandomTest.prototype.insertPts = function(nPts, indexBounds, scale) {
    assert.eq(this.nPts, 0, "insertPoints already called");
    this.nPts = nPts;

    var bulk = this.t.initializeUnorderedBulkOp();
    for (var i = 0; i < nPts; i++) {
        bulk.insert({_id: i, loc: this.mkPt(scale, indexBounds)});
    }
    assert.writeOK(bulk.execute());

    if (!indexBounds)
        this.t.ensureIndex({loc: '2d'});
    else
        this.t.ensureIndex({loc: '2d'}, indexBounds);
};

GeoNearRandomTest.prototype.assertIsPrefix = function(short, long) {
    for (var i = 0; i < short.length; i++) {
        var xS = short[i].obj ? short[i].obj.loc[0] : short[i].loc[0];
        var yS = short[i].obj ? short[i].obj.loc[1] : short[i].loc[1];
        var dS = short[i].obj ? short[i].dis : 1;

        var xL = long[i].obj ? long[i].obj.loc[0] : long[i].loc[0];
        var yL = long[i].obj ? long[i].obj.loc[1] : long[i].loc[1];
        var dL = long[i].obj ? long[i].dis : 1;

        assert.eq([xS, yS, dS], [xL, yL, dL]);
    }
};

GeoNearRandomTest.prototype.testPt = function(pt, opts) {
    assert.neq(this.nPts, 0, "insertPoints not yet called");

    opts = opts || {};
    opts['sphere'] = opts['sphere'] || 0;
    opts['nToTest'] = opts['nToTest'] || this.nPts;  // be careful, test is O( N^2 )

    print("testing point: " + tojson(pt) + " opts: " + tojson(opts));

    var cmd = {geoNear: this.t.getName(), near: pt, num: 1, spherical: opts.sphere};

    var last = db.runCommand(cmd).results;
    for (var i = 2; i <= opts.nToTest; i++) {
        // print(i); // uncomment to watch status
        cmd.num = i;
        var ret = db.runCommand(cmd).results;

        try {
            this.assertIsPrefix(last, ret);
        } catch (e) {
            print("*** failed while compairing " + (i - 1) + " and " + i);
            printjson(cmd);
            throw e;  // rethrow
        }

        // Make sure distances are in increasing order
        assert.gte(ret[ret.length - 1].dis, last[last.length - 1].dis);

        last = ret;
    }

    last = last.map(function(x) {
        return x.obj;
    });

    var query = {loc: {}};
    query.loc[opts.sphere ? '$nearSphere' : '$near'] = pt;
    var near = this.t.find(query).limit(opts.nToTest).toArray();

    // Test that a query using $near/$nearSphere with a limit of 'nToTest' returns the same points
    // (in order) as the geoNear command with num=nToTest.
    assert.eq(last, near);
};