# Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
#
# 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.

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import logging
import numpy as np

import paddle.fluid as fluid

__all__ = ['parse_fetches', 'eval_run', 'eval_results']

logger = logging.getLogger(__name__)


def parse_fetches(fetches, prog=None, extra_keys=None):
    """
    Parse fetch variable infos from model fetches,
    values for fetch_list and keys for stat
    """
    keys, values = [], []
    cls = []
    for k, v in fetches.items():
        if hasattr(v, 'name'):
            keys.append(k)
            v.persistable = True
            values.append(v.name)
        else:
            cls.append(v)

    if prog is not None and extra_keys is not None:
        for k in extra_keys:
            try:
                v = fluid.framework._get_var(k, prog)
                v.persistable = True
                keys.append(k)
                values.append(v.name)
            except Exception:
                pass

    return keys, values, cls


def eval_run(exe, compile_program, pyreader, keys, values, cls):
    """
    Run evaluation program, return program outputs.
    """
    iter_id = 0
    results = []
    if len(cls) != 0:
        values = []
        for i in range(len(cls)):
            _, accum_map = cls[i].get_map_var()
            cls[i].reset(exe)
            values.append(accum_map)

    try:
        pyreader.start()
        while True:
            outs = exe.run(compile_program,
                           fetch_list=values,
                           return_numpy=False)
            res = {
                k: (np.array(v), v.recursive_sequence_lengths())
                for k, v in zip(keys, outs)
            }
            results.append(res)
            if iter_id % 100 == 0:
                logger.info('Test iter {}'.format(iter_id))
            iter_id += 1
    except (StopIteration, fluid.core.EOFException):
        pyreader.reset()
    logger.info('Test finish iter {}'.format(iter_id))

    return results


def eval_results(results, feed, metric, resolution=None, output_file=None):
    """Evaluation for evaluation program results"""
    if metric == 'COCO':
        from ppdet.utils.coco_eval import proposal_eval, bbox_eval, mask_eval
        anno_file = getattr(feed.dataset, 'annotation', None)
        with_background = getattr(feed, 'with_background', True)
        if 'proposal' in results[0]:
            output = 'proposal.json'
            if output_file:
                output = '{}_proposal.json'.format(output_file)
            proposal_eval(results, anno_file, output)
        if 'bbox' in results[0]:
            output = 'bbox.json'
            if output_file:
                output = '{}_bbox.json'.format(output_file)
            bbox_eval(results, anno_file, output, with_background)
        if 'mask' in results[0]:
            output = 'mask.json'
            if output_file:
                output = '{}_mask.json'.format(output_file)
            mask_eval(results, anno_file, output, resolution)
    else:
        res = np.mean(results[-1]['accum_map'][0])
        logger.info('Test mAP: {}'.format(res))