# Source code for logger

    """ Module for logging Velocity data form the Gramophone into HDF5 files. """

    import os.path
    import time
    from abc import ABC, abstractmethod

    import h5py
    import numpy as np
    import xlsxwriter
    import GramophoneTools

    class VelocityLog(object):
        """ A container object for velocity recordins. Handles
            saving records to HDF5 files. """

        def __init__(self):
            self.filename = None
            self.records = []
            self.deleted = []
            self.log_file = None

        @classmethod
        def from_file(cls, filename):
            loaded_log = cls()
            try:
                loaded_log.filename = filename
                loaded_log.log_file = h5py.File(loaded_log.filename, "a")
                for key in sorted(loaded_log.log_file.keys(), key=lambda key: loaded_log.log_file[key].attrs['start_time']):
                    loaded_log.records.append(FileRecord(loaded_log.log_file[key]))
            except OSError as err:
                print(err)

            return loaded_log

        def open_log_file(self, filename, mode='a'):
            self.filename = filename
            self.log_file = h5py.File(self.filename, mode)

        def save(self):
            """ Saves all records from this log to file. """
            for rec_id, record in enumerate(self.records):
                print('Saved:', record)
                self.records[rec_id] = record.save(self.log_file)

            for record in self.deleted:
                if isinstance(record, FileRecord):
                    del self.log_file[record.unique_id]
            self.deleted = []

        def close_log_file(self):
            if self.log_file is not None:
                self.log_file.close()
                self.log_file = None

        def xls_export(self, filename):
            if self.records:
                counter = 0
                workbook = xlsxwriter.Workbook(filename)
                data_sheet = workbook.add_worksheet('Data')
                metadata_sheet = workbook.add_worksheet('Metadata')
                for record in self.records:
                    # Data sheet
                    data_sheet.merge_range(0, counter, 0, counter+1, record.unique_id)

                    comment = 'ID:{}\nDate: {}\nStart: {}\nFinish:{}\nLength: {}\nMean velocity: {}\nComment: {}'.format(
                        record.rec_id, record.date_hr, record.start_time_hr, record.finish_time_hr, record.length_hr, record.mean_vel, record.comment
                    )
                    data_sheet.write_comment(0,counter, comment, {'x_scale': 1.5, 'y_scale': 1.5})
                    data_sheet.write(1,counter, 'time')
                    data_sheet.write(1,counter+1, 'velocity')

                    for t_id, t in enumerate(record.times):
                        data_sheet.write(t_id+2, counter, t)

                    for v_id, v in enumerate(record.velocities):
                        data_sheet.write(v_id+2, counter+1, v)

                    # Metadata sheet
                    metadata_sheet.write(1, 0, 'ID')
                    metadata_sheet.write(2, 0, 'Date')
                    metadata_sheet.write(3, 0, 'Start')
                    metadata_sheet.write(4, 0, 'Finish')
                    metadata_sheet.write(5, 0, 'Length')
                    metadata_sheet.write(6, 0, 'Mean velocity')
                    metadata_sheet.write(7, 0, 'Comment')
                    metadata_sheet.write(8, 0, 'Device serial')
                    metadata_sheet.write(9, 0, 'Software version')

                    metadata_sheet.write(0, (counter+2)//2, record.unique_id)
                    metadata_sheet.write(1, (counter+2)//2, record.rec_id)
                    metadata_sheet.write(2, (counter+2)//2, record.date_hr)
                    metadata_sheet.write(3, (counter+2)//2, record.start_time_hr)
                    metadata_sheet.write(4, (counter+2)//2, record.finish_time_hr)
                    metadata_sheet.write(5, (counter+2)//2, record.length_hr)
                    metadata_sheet.write(6, (counter+2)//2, record.mean_vel)
                    metadata_sheet.write(7, (counter+2)//2, record.comment)
                    metadata_sheet.write(8, (counter+2)//2, record.device_serial)
                    metadata_sheet.write(9, (counter+2)//2, record.software_version)

                    counter += 2

                # Formatting
                cell_format_center = workbook.add_format({'align': 'center'})
                cell_format_bold = workbook.add_format({'bold': True})
                cell_format_center_bold = workbook.add_format({'bold': True, 'align': 'center', 'valign': 'vcenter'})

                metadata_sheet.set_column(0, 0, 15, cell_format_bold)
                metadata_sheet.set_column(1, (counter+2)//2-1, 20, cell_format_center)

                metadata_sheet.set_row(0, 20, cell_format_center_bold)

            workbook.close()

    class Record(ABC):
        """ Abstract class for velocity records. """
        date_format = '%Y.%m.%d.'
        time_format = '%H:%M:%S'
        length_format = '%M:%S'

        @abstractmethod
        def __init__(self):
            pass

        # Subclass should implement these
        times = NotImplemented
        velocities = NotImplemented
        rec_id = NotImplemented
        start_time = NotImplemented
        finish_time = NotImplemented
        comment = NotImplemented
        sampling_freq = NotImplemented
        device_serial = NotImplemented
        software_version = GramophoneTools.__version__

        @property
        def unique_id(self):
            """ A property that stores a unique id based on the start time
                of this record. Used for naming folders in the HDF5 file. """
            return '%08X' % hash(self.start_time)

        @property
        def mean_vel(self):
            """ A property that holds the mean of the recorded velocities. """
            return np.mean(self.velocities)

        @property
        def length(self):
            """ A property that holds the length of this recording in seconds. """
            return self.finish_time-self.start_time

        @property
        def date_hr(self):
            """ A property that holds the starting date in a human readable format
                defined by the data_format class variable. """
            return time.strftime(self.date_format, time.localtime(self.start_time))

        @property
        def start_time_hr(self):
            """ A property that holds the starting time in a human readable format
                defined by the time_format class variable. """
            return time.strftime(self.time_format, time.localtime(self.start_time))

        @property
        def finish_time_hr(self):
            """ A property that holds the finishing time in a human readable format
                defined by the time_format class variable. """
            return time.strftime(self.time_format, time.localtime(self.finish_time))

        @property
        def length_hr(self):
            """ A property that holds the length of the recording in a human readable
                format defined by the length_format class variable. """
            return time.strftime(self.length_format, time.localtime(self.length))

        def save(self, log_file):
            '''
            Saves this record into a file and returns a FileRecord that can replace it.

            :param log_file: An opened HDF5 file
            :type log_file: h5py.File
            '''

            log_file.create_group(self.unique_id)
            log_file[self.unique_id].attrs['id'] = self.rec_id
            log_file[self.unique_id].attrs['comment'] = self.comment
            log_file[self.unique_id].attrs['date_hr'] = self.date_hr
            log_file[self.unique_id].attrs['start_time'] = self.start_time
            log_file[self.unique_id].attrs['start_time_hr'] = self.start_time_hr
            log_file[self.unique_id].attrs['finish_time'] = self.finish_time
            log_file[self.unique_id].attrs['finish_time_hr'] = self.finish_time_hr
            log_file[self.unique_id].attrs['length'] = self.length
            log_file[self.unique_id].attrs['length_hr'] = self.length_hr
            log_file[self.unique_id].attrs['mean_velocity'] = self.mean_vel
            log_file[self.unique_id].attrs['sampling_freq'] = self.sampling_freq
            log_file[self.unique_id].attrs['device_serial'] = self.device_serial
            log_file[self.unique_id].attrs['software_version'] = self.software_version

            log_file[self.unique_id+'/time'] = self.times
            log_file[self.unique_id+'/velocity'] = self.velocities

            return FileRecord(log_file[self.unique_id])

    class MemoryRecord(Record):
        """ A velocity record that is in memory ie. not saved yet. """

        def __init__(self, rec_id, sampling_freq, device_serial):
            super().__init__()

            # Data
            self.times = []
            self.velocities = []

            # Metadata
            self.rec_id = rec_id
            self.sampling_freq = float(sampling_freq)
            self.device_serial = device_serial
            self.start_time = None
            self.finish_time = None
            self.comment = ''

        def start(self):
            """ Called when recording to this record is started.
                Saves the current time as the start time. """
            self.start_time = time.time()

        def append(self, gtime, vel, rec):
            """ Appends this record with the given time and velocity
                if the recording state is 1. """
            if bool(rec):
                self.times.append(gtime)
                self.velocities.append(vel)

        def finish(self):
            """ Called then the recording to this record is finished.
                Saves the current time as the finish time. """
            self.finish_time = time.time()
            self.times = np.array(self.times, dtype=np.uint64)
            self.times -= self.times[0] # start time at 0
            self.velocities = np.array(self.velocities, dtype=float)

    class FileRecord(Record):
        """ A velocity record that is saved in a HDF5 file. """

        def __init__(self, file_group):
            super().__init__()
            self.file_group = file_group
            self.m_rec_id = None
            self.m_comment = None

        @property
        def times(self):
            """ Returns the time data form file """
            return self.file_group['time'][...]

        @property
        def velocities(self):
            """ Returns the velocity data form file """
            return self.file_group['velocity'][...]

        @property
        def start_time(self):
            """ Returns the start time form file """
            return self.file_group.attrs['start_time']

        @property
        def finish_time(self):
            """ Returns the finish time form file """
            return self.file_group.attrs['finish_time']

        @property
        def rec_id(self):
            """ Returns the record's ID form file """
            if self.m_rec_id is None:
                return int(self.file_group.attrs['id'])
            else:
                return self.m_rec_id

        @rec_id.setter
        def rec_id(self, value):
            """ Sets the record's ID in the file """
            self.m_rec_id = value

        @property
        def comment(self):
            """ Returns the record's comment form file """
            if self.m_comment is None:
                return self.file_group.attrs['comment']
            else:
                return self.m_comment

        @comment.setter
        def comment(self, value):
            """ Sets the record's comment in the file """
            self.m_comment = value

        @property
        def mean_vel(self):
            """ Returns the record's mean velocity form file """
            return self.file_group.attrs['mean_velocity']

        @property
        def sampling_freq(self):
            """ Returns the record's mean velocity form file """
            return self.file_group.attrs['sampling_freq']

        @property
        def device_serial(self):
            """ Returns the record's device id form file """
            return self.file_group.attrs['device_serial']

        @property
        def software_version(self):
            """ Returns the record's device id form file """
            return self.file_group.attrs['software_version']

        def save(self, log_file):
            """ Saves the modified fields and returns itself. """
            if self.unique_id not in log_file:
                return super().save(log_file)
            else:
                if self.m_rec_id is not None:
                    log_file[self.unique_id].attrs['id'] = self.m_rec_id
                    self.m_rec_id = None

                if self.m_comment is not None:
                    log_file[self.unique_id].attrs['comment'] = self.m_comment
                    self.m_comment = None

                return self

    class DummyRecord(Record):
        """ A record with random data insted of recorded velocity. Can be used for
            testing purposes. """

        def __init__(self):
            from random import randint
            from scipy.interpolate import interp1d
            super().__init__()
            self.rec_id = randint(1, 999)
            self.sampling_freq = 100.0
            self.device_serial = 42
            self.start_time = time.time()
            self.finish_time = time.time()+10
            self.times = np.linspace(0, 10_000, num=1001, dtype=np.uint64)
            vel_f = interp1d(np.linspace(0, 10_000, num=11),
                             np.random.rand(11)*50_000, kind='cubic', )
            self.velocities = vel_f(self.times).astype(float)
            self.comment = 'Fake data'