"""Explore/Explore ratio module."""

"""
This program is free software: you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program. If not, see <https://www.gnu.org/licenses/>.
"""

__author__ = "Théo de la Hogue"
__credits__ = []
__copyright__ = "Copyright 2023, Ecole Nationale de l'Aviation Civile (ENAC)"
__license__ = "GPLv3"

from argaze import GazeFeatures, DataFeatures

import numpy

class ScanPathAnalyzer(GazeFeatures.ScanPathAnalyzer):
    """Implementation of explore vs exploit ratio algorithm as described in:

        **Dehais F., Peysakhovich V., Scannella S., Fongue J., Gateau T. (2015).**  
        *Automation surprise in aviation: Real-time solutions.*  
        Proceedings of the 33rd annual ACM conference on Human Factors in Computing Systems (2525–2534).  
        [https://doi.org/10.1145/2702123.2702521](https://doi.org/10.1145/2702123.2702521)
    """

    @DataFeatures.PipelineStepInit
    def __init__(self, **kwargs):

        # Init ScanPathAnalyzer class
        super().__init__()

        self.__short_fixation_duration_threshold = 0.
        self.__explore_exploit_ratio = 0.

    @property
    def short_fixation_duration_threshold(self) -> float:
        """Time below which a fixation is considered to be short and so as exploratory."""
        return self.__short_fixation_duration_threshold

    @short_fixation_duration_threshold.setter
    def short_fixation_duration_threshold(self, short_fixation_duration_threshold: float):

        self.__short_fixation_duration_threshold = short_fixation_duration_threshold

    @DataFeatures.PipelineStepMethod
    def analyze(self, scan_path: GazeFeatures.ScanPath):

        assert(len(scan_path) > 1)

        short_fixations_durations = []
        long_fixations_durations = []
        saccades_durations = []

        for scan_step in scan_path:

            if scan_step.first_fixation.duration > self.short_fixation_duration_threshold:

                long_fixations_durations.append(scan_step.first_fixation.duration)

            else:

                short_fixations_durations.append(scan_step.first_fixation.duration)

            saccades_durations.append(scan_step.last_saccade.duration)

        short_fixations_duration = numpy.array(short_fixations_durations).sum()
        long_fixations_duration = numpy.array(long_fixations_durations).sum()
        saccades_duration = numpy.array(saccades_durations).sum()

        assert(long_fixations_duration > 0)

        self.__explore_exploit_ratio =  (saccades_duration + short_fixations_duration) / long_fixations_duration

    @property
    def explore_exploit_ratio(self) -> float:
        """Explore/Exploit ratio."""
        
        return self.__explore_exploit_ratio