feat: add reusable workflow definition graphs

src/govoplan_workflow/backend/schemas.py

@@ -0,0 +1,93 @@
+from __future__ import annotations
+
+import math
+from typing import Any, Literal
+
+from pydantic import BaseModel, Field, field_validator
+
+
+class WorkflowPosition(BaseModel):
+    x: float = 0
+    y: float = 0
+
+    @field_validator("x", "y")
+    @classmethod
+    def finite_coordinate(cls, value: float) -> float:
+        if not math.isfinite(value):
+            raise ValueError("Graph coordinates must be finite.")
+        return value
+
+
+class WorkflowNode(BaseModel):
+    id: str = Field(min_length=1, max_length=120)
+    type: str = Field(min_length=1, max_length=120)
+    label: str = Field(default="", max_length=300)
+    position: WorkflowPosition = Field(default_factory=WorkflowPosition)
+    config: dict[str, Any] = Field(default_factory=dict)
+
+
+class WorkflowEdge(BaseModel):
+    id: str = Field(min_length=1, max_length=120)
+    source: str = Field(min_length=1, max_length=120)
+    target: str = Field(min_length=1, max_length=120)
+    source_port: str = Field(default="output", min_length=1, max_length=120)
+    target_port: str = Field(default="input", min_length=1, max_length=120)
+
+
+class WorkflowGraph(BaseModel):
+    nodes: list[WorkflowNode] = Field(default_factory=list, max_length=150)
+    edges: list[WorkflowEdge] = Field(default_factory=list, max_length=300)
+
+
+class WorkflowGraphValidationRequest(BaseModel):
+    graph: WorkflowGraph
+
+
+class WorkflowDiagnosticResponse(BaseModel):
+    severity: Literal["error", "warning"]
+    code: str
+    message: str
+    node_id: str | None = None
+    field: str | None = None
+
+
+class WorkflowGraphValidationResponse(BaseModel):
+    valid: bool
+    diagnostics: list[WorkflowDiagnosticResponse]
+
+
+class WorkflowPortResponse(BaseModel):
+    id: str
+    label: str
+    required: bool
+    multiple: bool
+    minimum_connections: int
+
+
+class WorkflowConfigFieldResponse(BaseModel):
+    id: str
+    label: str
+    kind: str
+    required: bool
+    description: str | None
+    options: list[tuple[str, str]]
+
+
+class WorkflowNodeTypeResponse(BaseModel):
+    type: str
+    category: str
+    category_label: str
+    label: str
+    description: str
+    icon: str
+    input_ports: list[WorkflowPortResponse]
+    output_ports: list[WorkflowPortResponse]
+    config_fields: list[WorkflowConfigFieldResponse]
+    default_config: dict[str, Any]
+
+
+class WorkflowNodeLibraryResponse(BaseModel):
+    id: str
+    version: str
+    allows_cycles: bool
+    nodes: list[WorkflowNodeTypeResponse]