A mock OpenAPI server

task_api_server.py

from fastapi import FastAPI, HTTPException, Query, Path
from pydantic import BaseModel, Field
from typing import Optional
from datetime import datetime
from enum import Enum
import uuid
import uvicorn

app = FastAPI(
    title="Task Manager API",
    version="1.0.0",
    servers=[{"url": "http://localhost:3000", "description": "Local development server"}]
)


class TaskStatus(str, Enum):
    pending = "pending"
    in_progress = "in-progress"
    completed = "completed"


class NewTask(BaseModel):
    title: str
    description: Optional[str] = None
    status: TaskStatus


class Task(BaseModel):
    id: str = Field(default_factory=lambda: str(uuid.uuid4()))
    title: str
    description: Optional[str] = None
    status: TaskStatus
    createdAt: datetime = Field(default_factory=datetime.utcnow)
    updatedAt: Optional[datetime] = None


class Error(BaseModel):
    code: int
    message: str


# In-memory task storage with some mock data
tasks_db: dict[str, Task] = {}

# Add some initial mock tasks
def init_mock_data():
    mock_tasks = [
        Task(
            id="550e8400-e29b-41d4-a716-446655440001",
            title="Review pull request",
            description="Review the new feature PR from the team",
            status=TaskStatus.in_progress,
            createdAt=datetime(2026, 2, 14, 10, 0, 0),
        ),
        Task(
            id="550e8400-e29b-41d4-a716-446655440002",
            title="Write documentation",
            description="Document the API endpoints",
            status=TaskStatus.pending,
            createdAt=datetime(2026, 2, 13, 9, 0, 0),
        ),
        Task(
            id="550e8400-e29b-41d4-a716-446655440003",
            title="Fix login bug",
            description="Users unable to login with special characters in password",
            status=TaskStatus.completed,
            createdAt=datetime(2026, 2, 12, 14, 30, 0),
            updatedAt=datetime(2026, 2, 14, 16, 0, 0),
        ),
        Task(
            id="550e8400-e29b-41d4-a716-446655440004",
            title="Deploy to staging",
            description="Deploy the latest build to staging environment",
            status=TaskStatus.in_progress,
            createdAt=datetime(2026, 2, 15, 8, 0, 0),
        ),
    ]
    for task in mock_tasks:
        tasks_db[task.id] = task

init_mock_data()


@app.get("/api/tasks", response_model=list[Task])
async def list_tasks(
    status: Optional[TaskStatus] = Query(None, description="Filter tasks by status"),
    limit: Optional[int] = Query(None, ge=1, le=100, description="Maximum number of tasks to return"),
):
    """Get all tasks, optionally filtered by status."""
    result = list(tasks_db.values())
    
    if status:
        result = [t for t in result if t.status == status]
    
    if limit:
        result = result[:limit]
    
    return result


@app.post("/api/tasks", response_model=Task, status_code=201)
async def create_task(new_task: NewTask):
    """Create a new task."""
    task = Task(
        title=new_task.title,
        description=new_task.description,
        status=new_task.status,
    )
    tasks_db[task.id] = task
    return task


@app.get("/api/tasks/{taskId}", response_model=Task)
async def get_task_by_id(
    taskId: str = Path(..., description="Unique identifier of the task"),
):
    """Get a task by ID."""
    if taskId not in tasks_db:
        raise HTTPException(status_code=404, detail="Task not found")
    return tasks_db[taskId]


@app.put("/api/tasks/{taskId}", response_model=Task)
async def update_task_by_id(
    taskId: str = Path(..., description="Unique identifier of the task"),
    updated_task: NewTask = ...,
):
    """Update a task by ID."""
    if taskId not in tasks_db:
        raise HTTPException(status_code=404, detail="Task not found")
    
    existing = tasks_db[taskId]
    existing.title = updated_task.title
    existing.description = updated_task.description
    existing.status = updated_task.status
    existing.updatedAt = datetime.utcnow()
    
    return existing


@app.delete("/api/tasks/{taskId}", status_code=204)
async def delete_task_by_id(
    taskId: str = Path(..., description="Unique identifier of the task"),
):
    """Delete a task by ID."""
    if taskId not in tasks_db:
        raise HTTPException(status_code=404, detail="Task not found")
    del tasks_db[taskId]
    return None


if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=3000)