# Copyright 2013 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import os.path
import its.caps
import its.device
import its.image
import its.objects
import its.target

NAME = os.path.basename(__file__).split('.')[0]
GRADIENT_DELTA = 0.1
Y_RELATIVE_DELTA_FLASH = 0.1  # 10%
Y_RELATIVE_DELTA_TORCH = 0.05  # 5%


def main():
    """Test that the android.flash.mode parameter is applied."""

    with its.device.ItsSession() as cam:
        props = cam.get_camera_properties()
        its.caps.skip_unless(its.caps.compute_target_exposure(props) and
                             its.caps.flash(props))
        sync_latency = its.caps.sync_latency(props)

        flash_modes_reported = []
        flash_states_reported = []
        means = []
        grads = []

        # Manually set the exposure to be a little on the dark side, so that
        # it should be obvious whether the flash fired or not, and use a
        # linear tonemap.
        debug = its.caps.debug_mode()
        largest_yuv = its.objects.get_largest_yuv_format(props)
        if debug:
            fmt = largest_yuv
        else:
            match_ar = (largest_yuv['width'], largest_yuv['height'])
            fmt = its.objects.get_smallest_yuv_format(props, match_ar=match_ar)

        e, s = its.target.get_target_exposure_combos(cam)['midExposureTime']
        e /= 2
        req = its.objects.manual_capture_request(s, e, 0.0, True, props)

        for f in [0, 1, 2]:
            req['android.flash.mode'] = f
            cap = its.device.do_capture_with_latency(
                    cam, req, sync_latency, fmt)
            flash_modes_reported.append(cap['metadata']['android.flash.mode'])
            flash_states_reported.append(cap['metadata']['android.flash.state'])
            y, _, _ = its.image.convert_capture_to_planes(cap, props)
            its.image.write_image(y, '%s_%d.jpg' % (NAME, f))
            tile = its.image.get_image_patch(y, 0.375, 0.375, 0.25, 0.25)
            its.image.write_image(tile, '%s_%d_tile.jpg' % (NAME, f))
            means.append(its.image.compute_image_means(tile)[0])
            grads.append(its.image.compute_image_max_gradients(tile)[0])

        assert flash_modes_reported == [0, 1, 2]
        assert flash_states_reported[0] not in [3, 4]
        assert flash_states_reported[1] in [3, 4]
        assert flash_states_reported[2] in [3, 4]

        print 'Brightnesses:', means
        print 'Max gradients: ', grads
        assert (grads[1]-grads[0] > GRADIENT_DELTA or
                (means[1]-means[0]) / means[0] > Y_RELATIVE_DELTA_FLASH)
        assert (grads[2]-grads[0] > GRADIENT_DELTA or
                (means[2]-means[0]) / means[0] > Y_RELATIVE_DELTA_TORCH)

if __name__ == '__main__':
    main()