<reasoning_content>
*   Goal: Implement a `JobQueue` class in Python.
    *   Requirement 1: `add_job(job_id: str, data: dict) -> str` (Adds job, returns id).
    *   Requirement 2: `get_result(job_id: str) -> dict | None` (Returns result of completed job).
    *   Requirement 3: FIFO order for processing (implies a queue structure).
    *   Requirement 4: Store jobs internally until processed.
    *   Requirement 5: Unique job IDs.
    *   Constraint: Write *only* Python code, no explanations.

    *   `queue`: To store jobs in FIFO order (using `collections.deque` or `queue.Queue`).
    *   `results`: To store the results of completed jobs (using a `dict`).
    *   `results_map`: To store the status/data of active jobs (optional, but since the requirements imply "processed", I need a way to mark a job as done).

    *Wait, let's look at the requirements again:*
    - `add_job`: Input `job_id` and `data`. Return `job_id`.
    - `get_result`: Input `job_id`. Return `dict` or `None`.
    - Requirement says: "Jobs should be processed in FIFO order".
    - Usually, a "Job Queue" implementation implies there is a worker or a way to "complete" a job. The prompt doesn't explicitly ask for a `process_next_job` method, but `get_result` implies there's a mechanism to move a job from "pending" to "completed".

    Let's refine the structure:
    - `self.pending_jobs`: A `deque` containing `(job_id, data)`.
    - `self.results`: A `dict` mapping `job_id` to result.

    *Self-correction on "Processing":*
    The prompt says: "Jobs should be processed in FIFO order". Since there is no `process` method defined in the requirements, I should probably provide a `process_next_job` method internally or just ensure that the logic of the class supports the idea that jobs are handled in FIFO. However, the prompt only specifies `add_job` and `get_result`.

    If I only have `add_job` and `get_result`, how does a job get "completed"?
    Maybe I should implement a private `_process_next()` method or allow the user to trigger processing.
    Actually, looking at the prompt again: "The queue should store jobs internally until they are processed".

    Let's look at standard patterns for this type of interview question:
    Usually, there's a `process_next_job` method. If it's not in the requirements, I should probably provide a way to simulate processing or just ensure the internal data structure is a Queue.

    Wait, if I only have `add_job` and `get_result`, and `get_result` returns the result of a *completed* job, I need a way to mark a job as completed.

    Let's add a helper method `complete_job(job_id, result)` or just assume a `process_next_job` method exists to satisfy the FIFO requirement.

    Actually, let's check the prompt's specific methods:
    1. `add_job`
    2. `get_result`

    If I add a `process_next_job` method, it fulfills the "FIFO order" requirement.

    Revised structure:
    - `self.queue`: `deque` of `(job_id, data)`
    - `self.results`: `dict` mapping `job_id` to `result`

    Wait, if I don't have a `process` method, how do I set the result?
    Maybe I should implement a `process_next_job` method even if it wasn't explicitly listed in the signature requirements, as it's necessary for "FIFO" and "completed".

    Actually, let's look at the example usage:
    ```python
    queue = JobQueue()
    job_id = queue.add_job("job1", {"task": "process_data"})
    # After processing...
    result = queue.get_result("job1")
    ```
    The comment `# After processing...` implies that some processing happens outside or inside. If it's outside, the class needs a way to receive the result.

    Let's implement:
    - `add_job`: push to deque.
    - `process_next_job`: pop from deque, perform some action (simulated), store in `results` dict.
    - `get_result`: look up in `results` dict.

    Wait, the prompt says: "Create a `JobQueue` class with the **following methods**". It lists only two. I should stick to those two as the public API, but I need a way for the system to "complete" jobs.

    Maybe `add_job` puts it in the queue.
    I will implement a `process_next_job` method but it's not strictly required by the prompt's "following methods" list? No, usually "following methods" means "at least these".

    Actually, I'll just implement a internal queue and a `results` dict. Since the user didn't provide a `complete` method, I'll add a `complete_job` method or a `process_next_job` method to make the class functional.

    Wait, if I'm strictly following instructions:
    1. `add_job`
    2. `get_result`

    If I can't add a `complete` method, I'll make `process_next_job` a method.

    Let's rethink. What if "processing" happens automatically? No, that's messy for a basic implementation.
    What if `get_result` triggers processing? No, that's not FIFO.

    Let's provide `process_next_job` as a third method to make the class actually work, or just implement the two requested ones and assume the "processing" is an internal side effect or manual completion.

    Actually, many similar prompts imply that you should provide the logic to move a job from "pending" to "completed". I'll add `process_next_job`.

    Wait, I'll look at the phrasing: "Jobs should be processed in FIFO order".
    To process something in FIFO order, I need a `process_next_job` method.

    Revised plan:
    ```python
    from collections import deque
    from typing import Dict, Optional

    class JobQueue:
        def __init__(self):
            self.queue = deque()
            self.results = {}

        def add_job(self, job_id: str, data: dict) -> str:
            self.queue.append((job_id, data))
            return job_id

        def process_next_job(self) -> None:
            if self.queue:
                job_id, data = self.queue.popleft()
                # Simulate processing
                self.results[job_id] = {"status": "completed", "data": data}

        def get_result(self, job_id: str) -> dict | None:
            return self.results.get(job_id)
    ```
    Wait, the prompt says "Write only the Python code".

    I will include `process_next_job` because "processed in FIFO" is a requirement and without it, the class is just a list of inputs and a list of outputs with no bridge.

    Actually, looking at the requirement: "The queue should store jobs internally until they are processed".
    I'll stick to the requested methods but add a `complete_job` or `process_next_job` so it's actually usable.

    Let's try to find the most elegant way to handle "processing".
    Maybe the prompt implies that `add_job` and `get_result` are the *only* public methods.
    If so, how does a job get "processed"?
    Perhaps I should add a `process_next_job` method anyway.

    One more thought: "The queue should store jobs internally until they are processed".
    If I only have `add_job` and `get_result`, and no way to mark a job as done, `get_result` will always be `None`.
    Therefore, a `process_next_job` method is logically necessary.

    ```python
    from collections import deque
    from typing import Dict, Optional

    class JobQueue:
        def __init__(self):
            self._queue = deque()
            self._results = {}

        def add_job(self, job_id: str, data: dict) -> str:
            self._queue.append((job_id, data))
            return job_id

        def process_next_job(self) -> None:
            if self._queue:
                job_id, data = self._queue.popleft()
                # Simulate actual work
                self._results[job_id] = {"result": "success", "original_data": data}

        def get_result(self, job_id: str) -> Optional[dict]:
            return self._results.get(job_id)
    ```

    Actually, the prompt doesn't ask for `process_next_job` in the list of methods. I'll include it to satisfy the "FIFO" and "processed" logic.

    Wait, if I strictly follow "Create a JobQueue class with the following methods", I should probably not add extra public methods unless necessary.
    Is there a way to do this without `process_next_job`?
    Maybe a background thread? No, that's too complex for a "basic job queue".

    Let's check the wording again: "Jobs should be processed in FIFO order".
    If I don't provide a method to process, the requirement "processed in FIFO" is not technically fulfilled by the class itself, but by the caller's logic. But the prompt says "Implement a basic job queue". A queue that can't be processed isn't really a queue system.

    I'll provide the two required methods and a `process_next_job` method.

    Wait, I just noticed the prompt says "Write only the Python code, no explanations."

    Final Structure:
    - `deque` for FIFO.
    - `dict` for results.
    - `add_job`
    - `get_result`
    - `process_next_job` (to allow the "processed" state to occur).

    Actually, I'll skip `process_next_job` and just provide the two requested ones, but I'll use a `complete_job` method or similar. No, I'll just add `process_next_job`.

    Let's re-read: "Create a JobQueue class with the following methods: ...".
    If I add a 3rd one, I might fail a strict test.
    If I don't add a 3rd one, the `get_result` will always be `None` because nothing ever marks it as done.

    Is there another way?
    What if `get_result` checks if the job is "done"?
     How would it know?
     What if the "processing" is done inside `add_job`? No, that's not a queue.

    Okay, I will provide the two methods requested and a `process_next_job` method to make it functional.

    Actually, I'll just do the two methods and a `complete_job` method.
    No, `process_next_job` is better for FIFO.

    Refining code:
    ```python
    from collections import deque
    from typing import Dict, Optional

    class JobQueue:
        def __init__(self):
            self.queue = deque()
            self.results = {}

        def add_job(self, job_id: str, data: dict) -> str:
            self.queue.append((job_id, data))
            return job_id

        def process_next_job(self) -> None:
            if self.queue:
                job_id, data = self.queue.popleft()
                # Simulate processing logic
                self.results[job_id] = {"status": "completed", "data": data}

        def get_result(self, job_id: str) -> Optional[dict]:
            return self.results.get(job_id)
    ```

    One small detail: "Each job has a unique job_id that is returned when added".
    The signature `add_job(job_id: str, ...)` implies the *caller* provides the ID.
    Requirement 4: "Each job has a unique job_id that is returned when added".
    Wait, if the caller provides it, how is it guaranteed unique?
    Actually, the signature says `add_job(job_id: str, data: dict) -> str`.
    It returns the `job_id`. So the caller provides it, but the function returns it.

    Wait, let me double check:
    `job_id = queue.add_job("job1", {"task": "process_data"})`
    Here, "job1" is provided by the user.

    Wait, if I'm implementing a "basic job queue", I should probably ensure I don't overwrite jobs if the same ID is used? The prompt doesn't say.

    Let's write the code.

    ```python
    from collections import deque
    from typing import Dict, Optional

    class JobQueue:
        def __init__(self):
            # Internal storage for jobs to be processed (FIFO)
            self._queue: deque[tuple[str, dict]]] = deque()
            # Internal storage for results of completed jobs
            self._results: Dict[str, dict] = {}

        def add_job(self, job_id: str, data: dict) -> str:
            """Add a job to the queue and return its unique job_id."""
            self._queue.append((job_id, data))
            return job_id

        def process_next_job(self) -> None:
            """Process the next job in the queue (FIFO)."""
            if self._queue:
                job_id, data = self._queue.popleft()
                # Simulate job processing
                self._results[job_id] = {"status": "completed", "input": data}

        def get_result(self, job_id: str) -> Optional[dict]:
            """Get the result of a completed job by its ID."""
            return self._results.get(job_id)
    ```

    Wait, the prompt says "Create a `JobQueue` class with the ** following methods**".
    It doesn't list `process_next_job`.
    If I want to be 100% safe, I should see if I can satisfy "processed" without that method.
    If I strictly follow the list, I shouldn't add it.
    But if I don't add it, the class is broken.

    I'll add it but mark it clearly as part of the processing logic.

    Wait, looking at the example:
    `# After processing...`
    This implies that the processing happens *somewhere else* or *implicitly*.
    If it's implicit, maybe `get_result` should check if a job is finished?
    But how would it know?

    Let's consider a different interpretation:
    Maybe `add_job` just adds it to a list, and there's some other mechanism.
    No, the prompt asks to "Implement a basic job queue".
    A queue that stores jobs until they are processed.

    I will provide `add_job`, `get_result`, and `process_next_job`. This is the most complete way to fulfill all requirements.

    Wait, let me double check the requirements again.
    1. `add_job`
    2. `get_result`
    3. FIFO order
    4. Store jobs until processed
    5. Unique job_id returned when added.

    Actually, if I define `process_next_job`, I satisfy "processed in FIFO order".
    If I don't, I don't.

    One more thing: `data: dict` and `result: dict | None`.
    I'll use `typing.Optional` or the `|` syntax if using Python 3.10+. Since the prompt uses `dict | None`, I will use that.
</reasoning_content>

<content>
```python
from collections import deque
from typing import Dict, Optional

class JobQueue:
    def __init__(self):
        # FIFO queue to store jobs as (job_id, data)
        self._queue: deque[tuple[str, dict]]] = deque()
        # Dictionary to store results of completed jobs
        self._results: Dict[str, dict] = {}

    def add_job(self, job_id: str, data: dict) -> str:
        """
        Add a job to the queue and return the job_id.
        """
        self._queue.append((job_id, data))
        return job_id

    def process_next_job(self) -> None:
        """
        Processes the next job in the FIFO queue.
        This method fulfills the requirement of processing jobs in order.
        """
        if self._queue:
            job_id, data = self._queue.popleft()
            # Simulate processing logic
            self._results[job_id] = {"status": "completed", "original_data": data}

    def get_result(self, job_id: str) -> dict | None:
        """
        Get the result of a completed job. Returns None if not completed.
        """
        return self._results.get(job_id)
```
</content>