Write log file

#94 (closed)

sohstationviewer/model/reftek_data/reftek.py

 """
 RT130 object to hold and process RefTek data
 """
+import datetime
 from pathlib import Path
 from typing import Union, List, Tuple, Dict
 import traceback
 import numpy as np
+from obspy import UTCDateTime
 from obspy.core import Stream
 
 from sohstationviewer.conf import constants
+from sohstationviewer.conf.constants import SOFTWARE_VERSION
 from sohstationviewer.model.reftek_data.reftek_reader.log_file_reader import (
     LogFileReader, process_mass_poss_line,
 )
@@ -26,6 +29,24 @@ from sohstationviewer.model.reftek_data.reftek_reader import core, soh_packet
 from sohstationviewer.model.reftek_data.log_info import LogInfo
 
 
+def format_timestamp_as_mass_pos_time(timestamp: float) -> str:
+    """
+    Format a UTC timestamp in the format of a mass-position time in SOH
+    messages.
+    :param timestamp: the UTC timestamp to format
+    :return: the formatted time string
+    """
+    # We trim the last three character because the %f format character has a
+    # millisecond precision (6 characters), while the time format we use only
+    # has a microsecond precision (3 characters).
+    return UTCDateTime(timestamp).strftime('%Y:%j:%H:%M:%S.%f')[:-3]
+
+
+format_timestamp_as_mass_pos_time = np.vectorize(
+    format_timestamp_as_mass_pos_time, otypes=[str]
+)
+
+
 class RT130(GeneralData):
     """
     read and process reftek file into object with properties can be used to
@@ -114,6 +135,41 @@ class RT130(GeneralData):
                 # this happens when there is text or ascii only in the data
                 self.data_time[key] = [self.read_start, self.read_end]
 
+        for key in self.log_data:
+            if key == 'TEXT':
+                continue
+            soh_header = ''
+            soh_footer = ''
+            soh_messages = self.log_data[key]['SOH']
+            # We want to include a log file header only when there is not
+            # already one.
+            possible_programs = ['logpeek', 'SOHStationViewer', 'rt2ms']
+            message_has_header = any(soh_messages[0].startswith(program)
+                                     for program
+                                     in possible_programs)
+            if not message_has_header:
+                current_time = datetime.datetime.now().ctime()
+                soh_header = (f'SOHStationViewer: v{SOFTWARE_VERSION} '
+                              f'Run time (UTC): {current_time}\n')
+            if self.include_masspos_in_soh_messages:
+                soh_footer += '\n\nMass-positions:\n'
+                mass_pos_lines = []
+                soh_messages = self.log_data[key]['SOH']
+                for chan in self.mass_pos_data[key]:
+                    chan_data = self.mass_pos_data[key][chan]
+                    # We combined all data into one trace above
+                    trace = chan_data['tracesInfo'][0]
+                    times = format_timestamp_as_mass_pos_time(trace['times'])
+                    data = trace['data'].astype(times.dtype)
+                    formatted_lines = [
+                        f'LPMP {time} {chan[-1]} {mass_position}'
+                        for (time, mass_position)
+                        in zip(times, data)
+                    ]
+                    mass_pos_lines.extend(formatted_lines)
+                soh_footer += '\n'.join(mass_pos_lines)
+            soh_messages[0] = soh_header + soh_messages[0] + soh_footer
+
     def read_log_files(self):
         """
         Read data from self.rt130_log_files and store it in self.log_data