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Add Conditions for Todos/Processes to be met or undone by other Todos.
[plomtask] / plomtask / processes.py
index 03fecb2fee3f570f0595ab785f096fef15cdee85..dc0613f8dbb2b01f941603203f57cbddb3766693 100644 (file)
@@ -1,51 +1,59 @@
 """Collecting Processes and Process-related items."""
 from __future__ import annotations
 from sqlite3 import Row
-from datetime import datetime
 from typing import Any, Set
 from plomtask.db import DatabaseConnection
+from plomtask.misc import VersionedAttribute
+from plomtask.conditions import Condition
 from plomtask.exceptions import NotFoundException, BadFormatException
 
 
 class Process:
     """Template for, and metadata for, Todos, and their arrangements."""
 
+    # pylint: disable=too-many-instance-attributes
+
     def __init__(self, id_: int | None) -> None:
         if (id_ is not None) and id_ < 1:
             raise BadFormatException(f'illegal Process ID, must be >=1: {id_}')
         self.id_ = id_
-        self.title = VersionedAttribute(self, 'title', 'UNNAMED')
-        self.description = VersionedAttribute(self, 'description', '')
-        self.effort = VersionedAttribute(self, 'effort', 1.0)
+        self.title = VersionedAttribute(self, 'process_titles', 'UNNAMED')
+        self.description = VersionedAttribute(self, 'process_descriptions', '')
+        self.effort = VersionedAttribute(self, 'process_efforts', 1.0)
         self.explicit_steps: list[ProcessStep] = []
-
-    def __eq__(self, other: object) -> bool:
-        return isinstance(other, self.__class__) and self.id_ == other.id_
+        self.conditions: list[Condition] = []
+        self.fulfills: list[Condition] = []
+        self.undoes: list[Condition] = []
 
     @classmethod
-    def from_table_row(cls, row: Row) -> Process:
+    def from_table_row(cls, db_conn: DatabaseConnection, row: Row) -> Process:
         """Make Process from database row, with empty VersionedAttributes."""
-        return cls(row[0])
+        process = cls(row[0])
+        assert process.id_ is not None
+        db_conn.cached_processes[process.id_] = process
+        return process
 
     @classmethod
     def all(cls, db_conn: DatabaseConnection) -> list[Process]:
         """Collect all Processes and their connected VersionedAttributes."""
         processes = {}
-        for row in db_conn.exec('SELECT * FROM processes'):
-            process = cls.from_table_row(row)
-            processes[process.id_] = process
-        for row in db_conn.exec('SELECT * FROM process_titles'):
-            processes[row[0]].title.history[row[1]] = row[2]
-        for row in db_conn.exec('SELECT * FROM process_descriptions'):
-            processes[row[0]].description.history[row[1]] = row[2]
-        for row in db_conn.exec('SELECT * FROM process_efforts'):
-            processes[row[0]].effort.history[row[1]] = row[2]
+        for id_, process in db_conn.cached_processes.items():
+            processes[id_] = process
+        already_recorded = processes.keys()
+        for row in db_conn.exec('SELECT id FROM processes'):
+            if row[0] not in already_recorded:
+                process = cls.by_id(db_conn, row[0])
+                processes[process.id_] = process
         return list(processes.values())
 
     @classmethod
     def by_id(cls, db_conn: DatabaseConnection, id_: int | None,
               create: bool = False) -> Process:
         """Collect Process, its VersionedAttributes, and its child IDs."""
+        if id_ in db_conn.cached_processes.keys():
+            process = db_conn.cached_processes[id_]
+            assert isinstance(process, Process)
+            return process
         process = None
         for row in db_conn.exec('SELECT * FROM processes '
                                 'WHERE id = ?', (id_,)):
@@ -55,19 +63,29 @@ class Process:
             if not create:
                 raise NotFoundException(f'Process not found of id: {id_}')
             process = Process(id_)
-        if process:
-            for row in db_conn.exec('SELECT * FROM process_titles '
-                                    'WHERE process_id = ?', (process.id_,)):
-                process.title.history[row[1]] = row[2]
-            for row in db_conn.exec('SELECT * FROM process_descriptions '
-                                    'WHERE process_id = ?', (process.id_,)):
-                process.description.history[row[1]] = row[2]
-            for row in db_conn.exec('SELECT * FROM process_efforts '
-                                    'WHERE process_id = ?', (process.id_,)):
-                process.effort.history[row[1]] = row[2]
-            for row in db_conn.exec('SELECT * FROM process_steps '
-                                    'WHERE owner_id = ?', (process.id_,)):
-                process.explicit_steps += [ProcessStep.from_table_row(row)]
+        for row in db_conn.exec('SELECT * FROM process_titles '
+                                'WHERE parent_id = ?', (process.id_,)):
+            process.title.history[row[1]] = row[2]
+        for row in db_conn.exec('SELECT * FROM process_descriptions '
+                                'WHERE parent_id = ?', (process.id_,)):
+            process.description.history[row[1]] = row[2]
+        for row in db_conn.exec('SELECT * FROM process_efforts '
+                                'WHERE parent_id = ?', (process.id_,)):
+            process.effort.history[row[1]] = row[2]
+        for row in db_conn.exec('SELECT * FROM process_steps '
+                                'WHERE owner_id = ?', (process.id_,)):
+            process.explicit_steps += [ProcessStep.from_table_row(db_conn,
+                                                                  row)]
+        for row in db_conn.exec('SELECT condition FROM process_conditions '
+                                'WHERE process = ?', (process.id_,)):
+            process.conditions += [Condition.by_id(db_conn, row[0])]
+        for row in db_conn.exec('SELECT condition FROM process_fulfills '
+                                'WHERE process = ?', (process.id_,)):
+            process.fulfills += [Condition.by_id(db_conn, row[0])]
+        for row in db_conn.exec('SELECT condition FROM process_undoes '
+                                'WHERE process = ?', (process.id_,)):
+            process.undoes += [Condition.by_id(db_conn, row[0])]
+        assert isinstance(process, Process)
         return process
 
     def used_as_step_by(self, db_conn: DatabaseConnection) -> list[Process]:
@@ -83,12 +101,12 @@ class Process:
         """Return tree of depended-on explicit and implicit ProcessSteps."""
 
         def make_node(step: ProcessStep) -> dict[str, object]:
-            step_process = self.__class__.by_id(db_conn, step.step_process_id)
             is_explicit = False
             if external_owner is not None:
                 is_explicit = step.owner_id == external_owner.id_
-            step_steps = step_process.get_steps(db_conn, external_owner)
-            return {'process': step_process, 'parent_id': step.parent_step_id,
+            process = self.__class__.by_id(db_conn, step.step_process_id)
+            step_steps = process.get_steps(db_conn, external_owner)
+            return {'process': process, 'parent_id': step.parent_step_id,
                     'is_explicit': is_explicit, 'steps': step_steps}
 
         def walk_steps(node_id: int, node: dict[str, Any]) -> None:
@@ -113,6 +131,24 @@ class Process:
             walk_steps(step_id, step_node)
         return steps
 
+    def set_conditions(self, db_conn: DatabaseConnection, ids: list[int],
+                       trgt: str = 'conditions') -> None:
+        """Set self.[target] to Conditions identified by ids."""
+        trgt_list = getattr(self, trgt)
+        while len(trgt_list) > 0:
+            trgt_list.pop()
+        for id_ in ids:
+            trgt_list += [Condition.by_id(db_conn, id_)]
+
+    def set_fulfills(self, db_conn: DatabaseConnection,
+                     ids: list[int]) -> None:
+        """Set self.fulfills to Conditions identified by ids."""
+        self.set_conditions(db_conn, ids, 'fulfills')
+
+    def set_undoes(self, db_conn: DatabaseConnection, ids: list[int]) -> None:
+        """Set self.undoes to Conditions identified by ids."""
+        self.set_conditions(db_conn, ids, 'undoes')
+
     def add_step(self, db_conn: DatabaseConnection, id_: int | None,
                  step_process_id: int,
                  parent_step_id: int | None) -> ProcessStep:
@@ -151,6 +187,23 @@ class Process:
         self.title.save(db_conn)
         self.description.save(db_conn)
         self.effort.save(db_conn)
+        db_conn.exec('DELETE FROM process_conditions WHERE process = ?',
+                     (self.id_,))
+        for condition in self.conditions:
+            db_conn.exec('INSERT INTO process_conditions VALUES (?,?)',
+                         (self.id_, condition.id_))
+        db_conn.exec('DELETE FROM process_fulfills WHERE process = ?',
+                     (self.id_,))
+        for condition in self.fulfills:
+            db_conn.exec('INSERT INTO process_fulfills VALUES (?,?)',
+                         (self.id_, condition.id_))
+        db_conn.exec('DELETE FROM process_undoes WHERE process = ?',
+                     (self.id_,))
+        for condition in self.undoes:
+            db_conn.exec('INSERT INTO process_undoes VALUES (?,?)',
+                         (self.id_, condition.id_))
+        assert self.id_ is not None
+        db_conn.cached_processes[self.id_] = self
 
     def fix_steps(self, db_conn: DatabaseConnection) -> None:
         """Rewrite ProcessSteps from self.explicit_steps.
@@ -184,70 +237,31 @@ class ProcessStep:
         self.parent_step_id = parent_step_id
 
     @classmethod
-    def from_table_row(cls, row: Row) -> ProcessStep:
-        """Make ProcessStep from database row."""
-        return cls(row[0], row[1], row[2], row[3])
+    def from_table_row(cls, db_conn: DatabaseConnection,
+                       row: Row) -> ProcessStep:
+        """Make ProcessStep from database row, store in DB cache."""
+        step = cls(row[0], row[1], row[2], row[3])
+        assert step.id_ is not None
+        db_conn.cached_process_steps[step.id_] = step
+        return step
 
     @classmethod
     def by_id(cls, db_conn: DatabaseConnection, id_: int) -> ProcessStep:
         """Retrieve ProcessStep by id_, or throw NotFoundException."""
+        if id_ in db_conn.cached_process_steps.keys():
+            step = db_conn.cached_process_steps[id_]
+            assert isinstance(step, ProcessStep)
+            return step
         for row in db_conn.exec('SELECT * FROM process_steps '
                                 'WHERE step_id = ?', (id_,)):
-            return cls.from_table_row(row)
+            return cls.from_table_row(db_conn, row)
         raise NotFoundException(f'found no ProcessStep of ID {id_}')
 
     def save(self, db_conn: DatabaseConnection) -> None:
-        """Save to database."""
+        """Save to database and cache."""
         cursor = db_conn.exec('REPLACE INTO process_steps VALUES (?, ?, ?, ?)',
                               (self.id_, self.owner_id, self.step_process_id,
                                self.parent_step_id))
         self.id_ = cursor.lastrowid
-
-
-class VersionedAttribute:
-    """Attributes whose values are recorded as a timestamped history."""
-
-    def __init__(self,
-                 parent: Process, name: str, default: str | float) -> None:
-        self.parent = parent
-        self.name = name
-        self.default = default
-        self.history: dict[str, str | float] = {}
-
-    @property
-    def _newest_timestamp(self) -> str:
-        """Return most recent timestamp."""
-        return sorted(self.history.keys())[-1]
-
-    @property
-    def newest(self) -> str | float:
-        """Return most recent value, or self.default if self.history empty."""
-        if 0 == len(self.history):
-            return self.default
-        return self.history[self._newest_timestamp]
-
-    def set(self, value: str | float) -> None:
-        """Add to self.history if and only if not same value as newest one."""
-        if 0 == len(self.history) \
-                or value != self.history[self._newest_timestamp]:
-            self.history[datetime.now().strftime('%Y-%m-%d %H:%M:%S')] = value
-
-    def at(self, queried_time: str) -> str | float:
-        """Retrieve value of timestamp nearest queried_time from the past."""
-        sorted_timestamps = sorted(self.history.keys())
-        if 0 == len(sorted_timestamps):
-            return self.default
-        selected_timestamp = sorted_timestamps[0]
-        for timestamp in sorted_timestamps[1:]:
-            if timestamp > queried_time:
-                break
-            selected_timestamp = timestamp
-        return self.history[selected_timestamp]
-
-    def save(self, db_conn: DatabaseConnection) -> None:
-        """Save as self.history entries, but first wipe old ones."""
-        db_conn.exec(f'DELETE FROM process_{self.name}s WHERE process_id = ?',
-                     (self.parent.id_,))
-        for timestamp, value in self.history.items():
-            db_conn.exec(f'INSERT INTO process_{self.name}s VALUES (?, ?, ?)',
-                         (self.parent.id_, timestamp, value))
+        assert self.id_ is not None
+        db_conn.cached_process_steps[self.id_] = self