Files
lda-wf/src/wf_core/analysis/context_scopes.py
T

436 lines
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Python

from __future__ import annotations
from collections.abc import Mapping
from copy import deepcopy
from dataclasses import dataclass
from typing import Literal
from wf_core.analysis.control_regions import (
ControlRegionAnalysis,
ForeachOwnerStack,
analyze_control_regions,
)
from wf_core.context_contracts import (
FOREACH_CONTEXT_KEY,
LOOP_INDEX_CONTEXT_KEY,
LOOP_ITEM_CONTEXT_KEY,
RESERVED_CONTEXT_KEYS,
STANDARD_CONTEXT_FIELDS,
ContextFieldContract,
ContextSchema,
foreach_context_fields,
foreach_entry_schema,
structured_foreach_contract,
)
from wf_core.models.steps import ForeachNode
from wf_core.models.workflow import Edge, Workflow
from wf_core.schema_navigation import SchemaNavigator
from wf_core.tokens import END
type ContextAvailability = Literal["available", "conditional"]
@dataclass(frozen=True, slots=True)
class ContextFieldAvailability:
"""One context contract plus whether it is guaranteed at a graph node."""
contract: ContextFieldContract
availability: ContextAvailability
reason: str | None = None
@property
def name(self) -> str:
return self.contract.name
@property
def schema(self) -> ContextSchema:
return self.contract.schema
@property
def description(self) -> str:
return self.contract.description
@dataclass(slots=True)
class _ContextAnalysis:
fields_by_node: dict[str, tuple[ContextFieldAvailability, ...]]
warnings: tuple[str, ...]
class _Warnings:
def __init__(self) -> None:
self.values: list[str] = []
self.seen: set[str] = set()
def add(self, value: str) -> None:
if value not in self.seen:
self.seen.add(value)
self.values.append(value)
def context_fields_by_node(
workflow: Workflow,
*,
control_regions: ControlRegionAnalysis | None = None,
) -> dict[str, tuple[ContextFieldAvailability, ...]]:
"""Return runtime context contracts for every reachable graph node.
This is an abstract execution-frame analysis keyed by static control
region: each node use belongs to exactly one foreach-owner stack, and
that stack decides which foreach entries the node exposes. A node
reachable under two stacks is a region conflict and receives no foreach
fields. The traversal still memoizes node id and owner stack so cyclic
graphs terminate.
"""
return _analyze(workflow, control_regions=control_regions).fields_by_node
def context_analysis_warnings(workflow: Workflow) -> tuple[str, ...]:
"""Return bounded warnings found while analyzing workflow frame scopes."""
return _analyze(workflow).warnings
def context_schemas_by_node(
workflow: Workflow,
*,
control_regions: ControlRegionAnalysis | None = None,
) -> dict[str, ContextSchema]:
"""Return schemas for all unambiguous, reachable program locations.
A conflicted or unreachable node has no generated per-node schema;
callers treat that absence as invalid, not as root context. Schemas are
composed from the same owner-stack analysis as field contracts, not from
a second graph traversal.
"""
analysis = control_regions or analyze_control_regions(workflow)
foreach_nodes = {
node.id: node for node in workflow.nodes if isinstance(node, ForeachNode)
}
schemas: dict[str, ContextSchema] = {}
for node_id, stack in analysis.owner_stack_by_node.items():
# Conflicted nodes are already dropped from owner_stack_by_node by the
# control-region analysis, so every entry here is unambiguous.
schemas[node_id] = _context_schema_for_stack(
workflow, foreach_nodes, analysis.owner_stack_by_node, stack
)
return schemas
def context_schema_for_node(workflow: Workflow, node_id: str) -> ContextSchema:
"""Return the complete graph-visible context object schema at one node."""
schemas = context_schemas_by_node(workflow)
try:
return schemas[node_id]
except KeyError as exc:
raise KeyError(f"no context schema for node {node_id!r}") from exc
def root_context_schema() -> ContextSchema:
"""Return standard fields plus an empty structured foreach map."""
properties: dict[str, ContextSchema] = {
field.name: deepcopy(field.schema) for field in STANDARD_CONTEXT_FIELDS
}
properties[FOREACH_CONTEXT_KEY] = {
"type": "object",
"properties": {},
"required": [],
"additionalProperties": False,
}
return {
"type": "object",
"properties": properties,
"required": sorted(properties),
"additionalProperties": False,
}
def _analyze(
workflow: Workflow,
*,
control_regions: ControlRegionAnalysis | None = None,
) -> _ContextAnalysis:
"""Derive context contracts from static foreach control regions.
Each unambiguous node use has exactly one owner stack; all active entries
in that stack are exposed. A canonical return edge pops the stack, so the
controller itself stays in the outer context. Conflicted nodes receive no
foreach fields.
"""
nodes = {node.id: node for node in workflow.nodes}
foreach_nodes = {
node.id: node for node in workflow.nodes if isinstance(node, ForeachNode)
}
edges_by_node: dict[str, list[Edge]] = {}
warnings = _Warnings()
for edge in workflow.edges:
edges_by_node.setdefault(edge.from_, []).append(edge)
if edge.from_ not in nodes:
warnings.add(f"edge source {edge.from_!r} is not a workflow node")
if edge.to != END and edge.to not in nodes:
warnings.add(f"edge from {edge.from_!r} targets missing node {edge.to!r}")
for foreach in foreach_nodes.values():
if not any(
edge.outcome == "loop" for edge in edges_by_node.get(foreach.id, [])
):
warnings.add(
f"foreach node {foreach.id!r} has no loop route; "
"no scoped alias is guaranteed"
)
if workflow.start not in nodes:
warnings.add(f"workflow start targets missing node {workflow.start!r}")
return _ContextAnalysis({}, tuple(warnings.values))
analysis = control_regions or analyze_control_regions(workflow)
for issue in analysis.issues:
warnings.add(
f"control region {issue.kind.value} at {issue.path}: {issue.message}"
)
fields_by_node: dict[str, tuple[ContextFieldAvailability, ...]] = {}
for node_id, stack in analysis.owner_stack_by_node.items():
fields_by_node[node_id] = _available_fields(
workflow,
foreach_nodes,
analysis.owner_stack_by_node,
stack,
)
return _ContextAnalysis(fields_by_node, tuple(warnings.values))
def _available_fields(
workflow: Workflow,
foreach_nodes: Mapping[str, ForeachNode],
owner_stack_by_node: Mapping[str, ForeachOwnerStack],
stack: ForeachOwnerStack,
) -> tuple[ContextFieldAvailability, ...]:
"""Return contracts for one static owner stack; all are guaranteed.
A single node use has one control region, so foreach fields are either
present (inside bodies) or absent (outside). Every owner in the stack
contributes one required ``foreach.<id>`` entry, every active configured
alias, and ``loop_item``/``loop_index`` from the final owner only.
Conditional availability is not used to represent multiple owner stacks:
a node reached under two stacks is a region conflict and receives no
foreach fields at all.
"""
contracts = list(STANDARD_CONTEXT_FIELDS)
if not stack:
# The empty foreach map stays readable at root, matching
# ``root_context_schema`` and the validation pass.
contracts.append(structured_foreach_contract({}))
return tuple(
ContextFieldAvailability(
contract=ContextFieldContract(
contract.name,
deepcopy(contract.schema),
contract.description,
),
availability="available",
)
for contract in contracts
)
entry_schemas: dict[str, ContextSchema] = {}
for owner_id in stack:
foreach = foreach_nodes.get(owner_id)
if foreach is None:
continue
entry_schemas[owner_id] = foreach_entry_schema(
owner_id,
_foreach_item_schema(
workflow,
foreach,
foreach_nodes,
owner_stack_by_node,
),
)
if entry_schemas:
contracts.append(structured_foreach_contract(entry_schemas))
# Aliases for every active owner, plus innermost loop keys.
for owner_id in stack:
foreach = foreach_nodes.get(owner_id)
if foreach is None:
continue
item_schema = _foreach_item_schema(
workflow, foreach, foreach_nodes, owner_stack_by_node
)
# Only the innermost owner contributes loop_item/loop_index; every
# owner contributes its configured alias when unambiguous. Alias
# collision handling is a validation concern; here we expose what the
# stack declares.
if owner_id == stack[-1]:
contracts.extend(foreach_context_fields(foreach.as_, item_schema))
elif foreach.as_:
# Outer aliases are exposed without re-emitting loop keys.
outer_fields = foreach_context_fields(foreach.as_, item_schema)
for field in outer_fields:
if field.name not in (LOOP_ITEM_CONTEXT_KEY, LOOP_INDEX_CONTEXT_KEY):
contracts.append(field)
return tuple(
ContextFieldAvailability(
contract=ContextFieldContract(
contract.name,
deepcopy(contract.schema),
contract.description,
),
availability="available",
)
for contract in contracts
)
def _context_schema_for_stack(
workflow: Workflow,
foreach_nodes: Mapping[str, ForeachNode],
owner_stack_by_node: Mapping[str, ForeachOwnerStack],
stack: ForeachOwnerStack,
) -> ContextSchema:
"""Build the complete graph-visible context object schema for one stack."""
properties: dict[str, ContextSchema] = {
field.name: deepcopy(field.schema) for field in STANDARD_CONTEXT_FIELDS
}
entry_schemas: dict[str, ContextSchema] = {}
for owner_id in stack:
foreach = foreach_nodes.get(owner_id)
if foreach is None:
continue
entry_schemas[owner_id] = foreach_entry_schema(
owner_id,
_foreach_item_schema(workflow, foreach, foreach_nodes, owner_stack_by_node),
)
properties[FOREACH_CONTEXT_KEY] = {
"type": "object",
"properties": entry_schemas,
"required": sorted(entry_schemas),
"additionalProperties": False,
}
required: list[str] = [field.name for field in STANDARD_CONTEXT_FIELDS] + [
FOREACH_CONTEXT_KEY
]
if stack:
innermost = foreach_nodes.get(stack[-1])
if innermost is not None:
inner_item = _foreach_item_schema(
workflow, innermost, foreach_nodes, owner_stack_by_node
)
properties[LOOP_ITEM_CONTEXT_KEY] = deepcopy(inner_item)
properties[LOOP_INDEX_CONTEXT_KEY] = {"type": "integer"}
required.extend([LOOP_ITEM_CONTEXT_KEY, LOOP_INDEX_CONTEXT_KEY])
for owner_id in stack:
foreach = foreach_nodes.get(owner_id)
if (
foreach is not None
and foreach.as_
and foreach.as_ not in RESERVED_CONTEXT_KEYS
):
properties[foreach.as_] = deepcopy(
_foreach_item_schema(
workflow, foreach, foreach_nodes, owner_stack_by_node
)
)
required.append(foreach.as_)
# Deduplicate while preserving order; aliases could theoretically repeat
# a standard name, but validation rejects those collisions.
seen: set[str] = set()
deduped_required: list[str] = []
for name in required:
if name not in seen:
seen.add(name)
deduped_required.append(name)
return {
"type": "object",
"properties": properties,
"required": sorted(deduped_required),
"additionalProperties": False,
}
def _foreach_item_schema(
workflow: Workflow,
foreach: ForeachNode,
foreach_nodes: Mapping[str, ForeachNode],
owner_stack_by_node: Mapping[str, ForeachOwnerStack],
) -> ContextSchema:
"""Resolve one controller's item schema in its own static context.
An inner foreach may declare ``over="context.foreach.outer.item.children"``;
the lookup uses the controller's own owner stack, not the inner body stack.
"""
controller_stack = owner_stack_by_node.get(foreach.id)
if controller_stack is None:
return {}
document = _schema_document(
workflow,
foreach.over.root,
stack=controller_stack,
foreach_nodes=foreach_nodes,
owner_stack_by_node=owner_stack_by_node,
)
source = SchemaNavigator(document).at_path(foreach.over.parts)
if source is None:
return {}
items = source.array_items()
if items is None:
return {}
return items.standalone_schema()
def _schema_document(
workflow: Workflow,
root: str,
*,
stack: ForeachOwnerStack | None = None,
foreach_nodes: Mapping[str, ForeachNode] | None = None,
owner_stack_by_node: Mapping[str, ForeachOwnerStack] | None = None,
) -> Mapping[str, object]:
if root == "input":
return workflow.input_schema.model_dump(mode="json", exclude_none=True)
if root == "state":
return workflow.state_schema.model_dump(mode="json", exclude_none=True)
if root == "context":
resolved_stack: ForeachOwnerStack = stack or ()
current: dict[str, object] = {
field.name: field.schema for field in STANDARD_CONTEXT_FIELDS
}
if foreach_nodes is not None and owner_stack_by_node is not None:
entry_schemas: dict[str, object] = {}
for owner_id in resolved_stack:
foreach = foreach_nodes.get(owner_id)
if foreach is not None:
entry_schemas[owner_id] = foreach_entry_schema(
owner_id,
_foreach_item_schema(
workflow,
foreach,
foreach_nodes,
owner_stack_by_node,
),
)
current[FOREACH_CONTEXT_KEY] = {
"type": "object",
"properties": entry_schemas,
"required": sorted(entry_schemas),
"additionalProperties": False,
}
for owner_id in resolved_stack:
foreach = foreach_nodes.get(owner_id)
if foreach is not None:
item_schema = _foreach_item_schema(
workflow,
foreach,
foreach_nodes,
owner_stack_by_node,
)
for field in foreach_context_fields(foreach.as_, item_schema):
# Innermost loop keys win; outer aliases accumulate.
# Validation owns collision diagnostics.
is_innermost = (
bool(resolved_stack) and owner_id == resolved_stack[-1]
)
if field.name not in current or is_innermost:
current[field.name] = field.schema
return {"type": "object", "properties": current}
return {}