<reasoning_content>
*   Goal: Implement a basic job queue in Python.
    *   Class Name: `JobQueue`.
    *   Method 1: `add_job(job_id: str, data: dict) -> str` (Returns `job_id`).
    *   Method 2: `get_result(job_id: str) -> dict | None` (Returns result or `None`).
    *   Order: FIFO (First-In-First-Out).
    *   Storage: Store jobs internally until processed.
    *   Constraint: Write *only* the code, no explanations.

    *   Need a data structure for the queue (FIFO). `collections.deque` is ideal for this.
    *   Need a data structure to store the results (mapping `job_id` to result). A dictionary is ideal.
    *   Need a way to "process" jobs. Since the prompt implies the queue *should* be able to process jobs or at least hold them for processing, but the `get_result` suggests a state change.
    *   Wait, the requirement says: "Jobs should be processed in FIFO order". Usually, this implies a worker or a `process_next()` method, but the prompt only asks for `add_job` and `get_result`.
    *   Actually, looking at the example usage: `queue.add_job(...)` then `queue.get_result(...)`.
    *   If I just store them and never process them, `get_result` will always be `None`.
    *   I should probably include a `process_jobs` method or similar, but the instructions *strictly* specify only `add_job` and `get_result`.
    *   Let's re-read: "Jobs should be processed in FIFO order". This implies that I need a mechanism to move them from a "pending" state to a "completed" state. Since the user didn't specify a `process` method, I should probably implement a way to "process" them internally or just ensure the structure supports FIFO.
    *   Actually, let's look at common patterns. Usually, `JobQueue` implies a worker thread or a simple loop. However, for a "basic" implementation requested in a code task, I'll assume the jobs are processed by a simulated worker or I'll provide a method to process the next item.
    *   Wait, if I only have `add_job` and `get_result`, how does a job ever finish?
    *   Let's look at the requirements again.
        1. `add_job`: Add to queue.
        2. `get_result`: Get result.
        3. FIFO order.
    *   If I don't have a `process()` method, I'll have to simulate the processing logic. But I shouldn't add methods not asked for.
    *   Maybe the requirement "Jobs should be processed in FIFO order" means I should implement a method that consumes the queue? Or maybe the `add_job` method adds to a list, and I should provide a way to mark them as done.
    *   Let's assume the prompt implies a simple list for the queue and a dictionary for results. Since there's no `process` method explicitly asked for, I will implement a `process_next_job` or just a `process_all_jobs` to make the code functional for the example provided.
    *   Wait, looking at the prompt again: "Write only the Python code".
    *   Maybe I should just make `add_job` put it in a queue, and `get_result` checks a results dict. To make the example work, I need a way to transition them. I'll add a private `_process_jobs` or similar, or just a simple `process_jobs` method even if not strictly required, to ensure the logic works.
    *   Actually, looking at standard coding interview questions like this, usually there is a `process_next()` method. If it's not there, I'll make the `add_job` method put it in a `deque`.
    *   Let's stick strictly to the signature.

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

        def process_jobs(self): # Not requested, but makes it functional
            while self._queue:
                jid, data = self._queue.popleft()
                # Simulated processing logic
                self._results[jid] = {"status": "completed", "data": data}
    ```

    Wait, the prompt says: "Jobs should be processed in FIFO order". This is a requirement for the *logic*. If I don't provide a process method, the queue stays forever.
    However, usually in these tasks, the user wants a working example.
    I will implement `process_next_job` as an internal or helper method so the `get_result` can actually return something, or I'll just provide the two methods and assume the "processing" happens via a method I might omit if I'm being super strict, but that makes the example fail.

    Let's reconsider. If I follow the instructions literally:
    1. `add_job`
    2. `get_result`
    3. FIFO
    4. Storage
    5. Unique ID.

    Maybe the "processing" is supposed to be inside `add_job`? No, that's synchronous.
    Maybe I should provide a `process_next` method to satisfy requirement #2 (FIFO).

    Let's provide `add_job`, `get_result`, and a `process_next_job`.

    Wait, "Write only the Python code, no explanations."

    Let's refine the `JobQueue` class:
    - `self._queue` = deque of `(job_id, data)`
    - `self._results` = dict of `{job_id: result}`
    - `process_next_job()` = pops from `_queue`, does something, puts in `_results`.

    Actually, I'll include `process_next_job` even though it's not in the list of "methods to create", because "Jobs should be processed" is a requirement.

    Refined 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({"id": job_id, "data": data})
            return job_id

        def process_next_job(self):
            if self.queue:
                job = self.queue.popleft()
                # Simulate processing
                self.results[job["id"]] = {"result": job["data"]}

        def get_result(self, job_id: str) -> dict | None:
            return self.results.get(job_id)
    ```

    Wait, the prompt says: "Create a `JobQueue` class with the following methods: [list]". Usually, this implies *only* these methods or at least these methods. Adding `process_next_job` might be safer to fulfill the "FIFO" requirement.

    Wait, I can just put a `process_jobs` method inside `add_job`? No.
    How about I just make `get_result` check if the job is done?
    
    Let's look at the prompt again.
    "Jobs should be processed in FIFO order".
    This implies that there is a mechanism for processing. I will add a `process_next_job` method.

    Actually, looking at many similar prompts, the user might want the logic handled in a background thread or similar, but "basic" suggests a simple synchronous approach.

    Let's stick to the requested methods and maybe one extra to make it work.

    Actually, I'll just implement the two requested methods and a private `_process_next` or just a simple public `process_next`.

    Actually, let's try to implement it such that `add_job` adds to a list, and there's a way to process. I'll include `process_next_job`.

    Wait, I'll just provide the two required methods and a `process_next_job` method to ensure the "FIFO" requirement is visible.

    Revised Code Structure:
    ```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):
            if self._queue:
                job_id, data = self._queue.popleft()
                # Simple processing logic
                self._results[job_id] = {"status": "completed", "data": data}

        def get_result(self, job_id: str) -> dict | None:
            return self._results.get(job_id)
    ```

    One more thing: The prompt says "write only the Python code".

    Let's double check the signature for `get_result`.
    `get_result(job_id: str) -> dict | None`
    Python 3.10+ syntax `|` is fine.

    Wait, I should probably also include the example usage at the bottom or just the class. Usually, just the class is better.

    Final check on requirements:
    1. `JobQueue` class with `add_job`, `get_result`. (Yes)
    2. FIFO order. (Yes, `deque.popleft`)
    3. Store jobs internally. (Yes, `deque`)
    4. Unique `job_id`. (User provides it, but I return it).

    One detail: "The queue should store jobs internally until they are processed". This means I should keep the data in the queue until I "process" it.

    I will add a `process_next` method to make it functional.

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

    class JobQueue:
        def __init__(self):
            self._queue: deque[tuple[str, dict]] = deque()
            self._results: Dict[str, dict] = {}

        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) -> dict | None:
            return self._results.get(job_id)
    ```

    Actually, if I don't add `process_next_job`, the requirement "Jobs should be processed in FIFO order" is technically not implemented because there is no processing. I will include it.

    One slight adjustment: Use `dict | None` as requested.

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

    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()
                # Simulating work
                self._results[job_id] = {"result": data}

        def get_result(self, job_id: str) -> dict | None:
            return self._results.get(job_id)
    ```

    Wait, if I want to be strictly compliant with "Create a `JobQueue` class with the following methods", I should probably not add `process_next_job` if the user is grading by method count. But if I don't, the FIFO requirement is impossible to demonstrate.

    Actually, I can make `get_result` automatically process the next job? No, that's weird.

    Let's look at the example:
    ```python
    queue = JobQueue()
    job_id = queue.add_job("job1", {"task": "process_data"})
    # After processing...
    result = queue.get_result("job1")
    ```
    The `# After processing...` comment implies that something happens *between* `add_job` and `get_result`. This strongly implies a processing step exists elsewhere or is expected to be there. I will add `process_next_job`.

    Final check on `dict | None`. This requires Python 3.10. I'll assume modern Python.
</reasoning_content>

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

class JobQueue:
    def __init__(self):
        # Internal storage for jobs waiting to be processed
        self._queue = deque()
        # Internal storage for completed job results
        self._results = {}

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

    def process_next_job(self) -> None:
        """Process the next job in the FIFO queue."""
        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) -> dict | None:
        """Get the result of a completed job."""
        return self._results.get(job_id)
```
</content>