decomposer: generate deliverable files for Define the service contract and project architecture for the FastAPI endpoint monitoring service.; Implement the typed monitor CRUD API and concurrency-safe in-memory state according to the service design.; Implement secure on-demand endpoint checks with status updates, latency measurement, robust error handling, and redacted structured logs.; Add operational API endpoints and environment-driven runtime configuration to the monitoring service.; Create automated tests for the monitoring service.; Package the service with Docker and developer documentation.; Validate the complete project.

app/models.py

@@ -1,41 +1,56 @@
-from datetime import UTC, datetime
+from datetime import datetime, timezone
 from enum import StrEnum
-from uuid import UUID, uuid4
+from uuid import UUID
 
 from pydantic import AnyHttpUrl, BaseModel, ConfigDict, Field
 
 
-class State(StrEnum):
-    UNKNOWN = "unknown"
-    UP = "up"
-    DOWN = "down"
-    ERROR = "error"
+def utc_now() -> datetime:
+    return datetime.now(timezone.utc)
+
+
+class HealthState(StrEnum):
+    unknown = "unknown"
+    up = "up"
+    down = "down"
 
 
 class MonitorCreate(BaseModel):
-    name: str = Field(min_length=1, max_length=100)
+    name: str = Field(min_length=1, max_length=120)
     url: AnyHttpUrl
 
 
-class MonitorUpdate(BaseModel):
-    name: str | None = Field(default=None, min_length=1, max_length=100)
-    url: AnyHttpUrl | None = None
+class MonitorUpdate(MonitorCreate):
+    pass
 
 
 class CurrentStatus(BaseModel):
-    state: State = State.UNKNOWN
-    checked_at: datetime | None = None
-    status_code: int | None = None
-    latency_ms: float | None = Field(default=None, ge=0)
-    error: str | None = None
+    state: HealthState
+    checked_at: datetime
+    latency_ms: float = Field(ge=0)
+    http_status: int | None = None
+    error_code: str | None = None
+    error_message: str | None = None
 
 
 class Monitor(BaseModel):
-    model_config = ConfigDict(from_attributes=True)
+    model_config = ConfigDict(frozen=True)
 
-    id: UUID = Field(default_factory=uuid4)
+    id: UUID
     name: str
     url: AnyHttpUrl
-    created_at: datetime = Field(default_factory=lambda: datetime.now(UTC))
-    updated_at: datetime = Field(default_factory=lambda: datetime.now(UTC))
-    current_status: CurrentStatus = Field(default_factory=CurrentStatus)
+    created_at: datetime
+    updated_at: datetime
+    revision: int
+    current_status: CurrentStatus | None = None
+
+
+class CheckResponse(BaseModel):
+    monitor_id: UUID
+    status: CurrentStatus
+    applied: bool
+
+
+class ErrorDetail(BaseModel):
+    code: str
+    message: str