Added stage moving endpoints

#!/usr/bin/env python

"""

TODO: Implement stage control methods

TODO: Reimplement capture methods

TODO: Implement API route to cleanly shut down server

TODO: Implement microscope function API routes (autofocus etc)

    Flask, render_template, Response,

    redirect, request, jsonify, send_file)

import numpy as np

from openflexure_microscope.api.utilities import parse_payload, gen

from openflexure_stage import OpenFlexureStage

import logging, sys

logging.basicConfig(stream=sys.stderr, level=logging.INFO)

logging.basicConfig(stream=sys.stderr, level=logging.DEBUG)

# Create the microscope object globally (common to all spawned server threads)

@app.route(uri('/position'), methods=['GET', 'POST', 'PUT'])

def position():

    """Return JSONified microscope state"""

    """Set and get the microscope stage position"""

    global microscope

    if request.method == 'POST' or request.method == 'PUT':

        logging.debug("TODO: Move stage.")

        # Get payload

        state = parse_payload(request)

        logging.debug(state)

        # Construct position array

        position = [0, 0, 0]

        # Handle absolute positioning

        if 'absolute' in state and state['absolute'] is True:

            # Get coordinates from payload

            for axis, key in enumerate(['x', 'y', 'z']):

                if key in state:

                    position[axis] = int(state[key]-microscope.stage.position[axis])

        else:

            # Get coordinates from payload

            for axis, key in enumerate(['x', 'y', 'z']):

                if key in state:

                    position[axis] = int(state[key])

        logging.debug(position)

        # Safeguard to prevent moving to an absolute position beyond a fixed limit

        if not 'force' in state or state['force'] is False:  # Allow for override

            # TODO: Make travel_limit a property of the stage or microscope

            # TODO: Make travel_limit a 3-axis list

            travel_limit = 2000 

            for axis, pos in enumerate(position):

                if abs(pos) > travel_limit:

                    # Respond with 400 Bad Request

                    response = {'error': 'Cannot move to absolute position beyond the safeguard limit.'}

                    return jsonify(response), 400

        microscope.stage.move_rel(position)

    return jsonify(microscope.state['position'])