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