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