feat(core): Add slash command /spend for ticket and ticket comments

ref: #284 closes #286

app/core/lib/slash_commands/__init__.py

@@ -0,0 +1,37 @@
+import re
+
+from core.lib.slash_commands.duration import Duration
+
+
+class SlashCommands(
+    Duration
+):
+    """Slash Commands Base Class
+    
+    This class in intended to be included in the following models:
+    
+    - Ticket
+    
+    - TicketComment
+    """
+
+
+    def slash_command(self, markdown:str) -> str:
+        """ Slash Commands Processor
+
+        Markdown text that contains a slash command is passed to this function and on the processing
+        of any valid slash command, the slash command will be removed from the markdown.
+
+        If any error occurs when attempting to process the slash command, it will not be removed from
+        the markdown. This is by design so that the "errored" slash command can be inspected.
+
+        Args:
+            markdown (str): un-processed Markdown
+
+        Returns:
+            str: Markdown without the slash command text.
+        """
+
+        markdown = re.sub(self.time_spent, self.command_duration, markdown)
+
+        return markdown

app/core/lib/slash_commands/duration.py

@@ -0,0 +1,91 @@
+import re
+
+
+class Duration:
+    """Duration Slash Command
+
+    The command keyword is `spend` and you can also use `spent`. The formatting for the time
+    after the command, is <digit> then either `h`, `m`, `s` for hours, minutes and seconds respectively.
+    
+    Valid commands are as follows:
+
+    - /spend 1h1ms
+
+    - /spend 1h 1m 1s
+
+    For this command to process the following conditions must be met:
+
+    - There is either a `<new line>` (`\n`) or a `<space>` char immediatly before the slash `/`
+
+    - There is a `<space>` char after the command keyword, i.e. `/spend<space>1h`
+
+    - _Optional_ `<space>` char between the time blocks.
+    """
+
+
+    time_spent: str = r'[\s|\n]\/(?P<command>[spend|spent]+)\s(?P<time>(?P<hours>\d+h)?\s?(?P<minutes>[\d]{1,2}m)?\s?(?P<seconds>\d+[s])?)[\s|\n]?'
+
+
+    def command_duration(self, match) -> str:
+        """/spend, /spent processor
+
+        Slash command usage within a ticket description will add an action comment with the
+        time spent. For a ticket comment, it's duration field is set to the duration valuee calculated.
+
+        Args:
+            match (re.Match): Grouped matches
+
+        Returns:
+            str: The matched string if the duration calculation is `0`
+            None: On successfully processing the command
+        """
+
+        a = 'a'
+
+        command = match.group('command')
+        time:str =  str(match.group('time')).replace(' ', '')
+        hours =  match.group('hours')
+        minutes =  match.group('minutes')
+        seconds =  match.group('seconds')
+
+        duration: int = 0
+
+        if hours is not None:
+
+            duration += int(hours[:-1])*60*60
+
+        if minutes is not None:
+
+            duration += int(minutes[:-1])*60
+
+        if seconds is not None:
+
+            duration += int(seconds[:-1])
+
+        if duration > 0:
+
+            if str(self._meta.verbose_name).lower() == 'ticket':
+
+                from core.models.ticket.ticket_comment import TicketComment
+
+                comment_text = f'added {time} of time spent'
+
+                TicketComment.objects.create(
+                    ticket = self,
+                    comment_type = TicketComment.CommentType.ACTION,
+                    body = comment_text,
+                    duration = duration,
+                    user = self.opened_by,
+                )
+
+            if str(self._meta.verbose_name).lower() == 'comment':
+
+                self.duration = duration
+
+        else:
+
+            #ToDo: Add logging that the slash command could not be processed.
+
+            return str(match.string[match.start():match.end()])
+
+        return None