plomlompom.com Git - plomtask/blob - plomtask/processes.py

   1 """Collecting Processes and Process-related items."""
   2 from __future__ import annotations
   3 from sqlite3 import Row
   4 from datetime import datetime
   5 from plomtask.db import DatabaseConnection
   6 from plomtask.misc import HandledException
   7
   8
   9 class Process:
  10     """Template for, and metadata for, Todos, and their arrangements."""
  11
  12     def __init__(self, id_: int | None) -> None:
  13         self.id_ = id_ if id_ != 0 else None  # to avoid DB-confusing rowid=0
  14         self.title = VersionedAttribute(self, 'title', 'UNNAMED')
  15         self.description = VersionedAttribute(self, 'description', '')
  16         self.effort = VersionedAttribute(self, 'effort', 1.0)
  17
  18     @classmethod
  19     def from_table_row(cls, row: Row) -> Process:
  20         """Make Process from database row, with empty VersionedAttributes."""
  21         return cls(row[0])
  22
  23     @classmethod
  24     def all(cls, db_conn: DatabaseConnection) -> list[Process]:
  25         """Collect all Processes and their connected VersionedAttributes."""
  26         processes = {}
  27         for row in db_conn.exec('SELECT * FROM processes'):
  28             process = cls.from_table_row(row)
  29             processes[process.id_] = process
  30         for row in db_conn.exec('SELECT * FROM process_titles'):
  31             processes[row[0]].title.history[row[1]] = row[2]
  32         for row in db_conn.exec('SELECT * FROM process_descriptions'):
  33             processes[row[0]].description.history[row[1]] = row[2]
  34         for row in db_conn.exec('SELECT * FROM process_efforts'):
  35             processes[row[0]].effort.history[row[1]] = row[2]
  36         return list(processes.values())
  37
  38     @classmethod
  39     def by_id(cls, db_conn: DatabaseConnection, id_: int | None,
  40               create: bool = False) -> Process:
  41         """Collect all Processes and their connected VersionedAttributes."""
  42         process = None
  43         for row in db_conn.exec('SELECT * FROM processes '
  44                                 'WHERE id = ?', (id_,)):
  45             process = cls(row[0])
  46             break
  47         if not process:
  48             if not create:
  49                 raise HandledException(f'Process not found of id: {id_}')
  50             process = Process(id_)
  51         if process:
  52             for row in db_conn.exec('SELECT * FROM process_titles '
  53                                     'WHERE process_id = ?', (process.id_,)):
  54                 process.title.history[row[1]] = row[2]
  55             for row in db_conn.exec('SELECT * FROM process_descriptions '
  56                                     'WHERE process_id = ?', (process.id_,)):
  57                 process.description.history[row[1]] = row[2]
  58             for row in db_conn.exec('SELECT * FROM process_efforts '
  59                                     'WHERE process_id = ?', (process.id_,)):
  60                 process.effort.history[row[1]] = row[2]
  61         return process
  62
  63     def save(self, db_conn: DatabaseConnection) -> None:
  64         """Add (or re-write) self and connected VersionedAttributes to DB."""
  65         cursor = db_conn.exec('REPLACE INTO processes VALUES (?)', (self.id_,))
  66         self.id_ = cursor.lastrowid
  67         self.title.save(db_conn)
  68         self.description.save(db_conn)
  69         self.effort.save(db_conn)
  70
  71
  72 class VersionedAttribute:
  73     """Attributes whose values are recorded as a timestamped history."""
  74
  75     def __init__(self,
  76                  parent: Process, name: str, default: str | float) -> None:
  77         self.parent = parent
  78         self.name = name
  79         self.default = default
  80         self.history: dict[str, str | float] = {}
  81
  82     @property
  83     def _newest_timestamp(self) -> str:
  84         """Return most recent timestamp."""
  85         return sorted(self.history.keys())[-1]
  86
  87     @property
  88     def newest(self) -> str | float:
  89         """Return most recent value, or self.default if self.history empty."""
  90         if 0 == len(self.history):
  91             return self.default
  92         return self.history[self._newest_timestamp]
  93
  94     def set(self, value: str | float) -> None:
  95         """Add to self.history if and only if not same value as newest one."""
  96         if 0 == len(self.history) \
  97                 or value != self.history[self._newest_timestamp]:
  98             self.history[datetime.now().strftime('%Y-%m-%d %H:%M:%S')] = value
  99
 100     def at(self, queried_time: str) -> str | float:
 101         """Retrieve value of timestamp nearest queried_time from the past."""
 102         sorted_timestamps = sorted(self.history.keys())
 103         if 0 == len(sorted_timestamps):
 104             return self.default
 105         selected_timestamp = sorted_timestamps[0]
 106         for timestamp in sorted_timestamps[1:]:
 107             if timestamp > queried_time:
 108                 break
 109             selected_timestamp = timestamp
 110         return self.history[selected_timestamp]
 111
 112     def save(self, db_conn: DatabaseConnection) -> None:
 113         """Save as self.history entries, but first wipe old ones."""
 114         db_conn.exec(f'DELETE FROM process_{self.name}s WHERE process_id = ?',
 115                      (self.parent.id_,))
 116         for timestamp, value in self.history.items():
 117             db_conn.exec(f'INSERT INTO process_{self.name}s VALUES (?, ?, ?)',
 118                          (self.parent.id_, timestamp, value))