felicity-lims/backend/felicity_lims/felicity/apps/audit/models.py

import json
import logging

from sqlalchemy import Column, Integer, String, UnicodeText

from felicity.apps import DBModel

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)


class AuditLog(DBModel):
    """Model an audit log of user actions"""
    user_id = Column(Integer, doc="The ID of the user who made the change")
    target_type = Column(String(100), nullable=False, doc="The table name of the altered object")
    target_id = Column(Integer, doc="The ID of the altered object")
    action = Column(Integer, doc="Create (1), update (2), or delete (3)")
    state_before = Column(UnicodeText, doc="Stores a JSON string representation of a dict containing the altered "
                                           "column names and original values")
    state_after = Column(UnicodeText, doc="Stores a JSON string representation of a dict containing the altered "
                                          "column names and new values")

    def __init__(self, target_type, target_id, action, state_before, state_after):

        self.state_after = state_after
        self.target_type = target_type
        self.target_id = target_id
        self.action = action
        self.state_before = state_before

        if isinstance(state_after, str):
            state_after = json.loads(state_after)

        try:
            updated_by_uid = state_after['updated_by_uid']
        except KeyError:
            updated_by_uid = None

        self.user_id = updated_by_uid  # current user id

    def __repr__(self):
        return '<AuditLog %r: %r -> %r>' % (self.user_id, self.target_type, self.action)

    def save(self, connection):

        state_after = self.state_after
        if isinstance(state_after, str):
            state_after = json.loads(state_after)

        state_before = self.state_before
        if isinstance(state_before, str):
            state_before = json.loads(state_before)

        to_delete = []
        for key in state_after.keys():
            if state_after[key] == state_before[key]:
                to_delete.append(key)

        for _key in to_delete:
            del state_after[_key]
            del state_before[_key]

        state_after = json.dumps(state_after)
        state_before = json.dumps(state_before)

        connection.execute(
            self.__table__.insert(),
            user_id=self.user_id,
            target_type=self.target_type,
            target_id=self.target_id,
            action=self.action,
            state_before=state_before,
            state_after=state_after
        )