# From Eiger HDF5 to CBF frames

This tutorial shows the CBF conversion path provided by `ewoksscxrd` through
`fabio.app.eiger2cbf`, with bundled `XDS.INP` generation.

## 1. Choose the bundled workflow

Use:

- `src/ewoksscxrd/workflows/demo_eiger2cbf.json`

## 2. Inspect task inputs

```bash
ewoks show src/ewoksscxrd/workflows/demo_eiger2cbf.json
```

The main runtime inputs are:

- `images`: list of Eiger or LImA HDF5 files
- `output`: CBF filename template such as `frame_{index}.cbf`

Useful optional inputs include `offset`, `mask`, `pilatus`, `energy` or
`wavelength`, `distance`, `beam`, goniometer angles, and the image transform
flags (`rotation`, `transpose`, `flip_ud`, `flip_lr`).

Because the workflow also runs `CreateXDSInp`, you must also provide the XDS
geometry inputs such as `detector`, `nx`, `ny`, `qx`, `qy`, `data_range`,
and `oscillation_range`. Provide `starting_angle` only if you want
`STARTING_ANGLE` and `STARTING_FRAME` written into `XDS.INP`.

## 3. Execute the workflow from Python

```python
import json
from pathlib import Path

from ewoks import execute_graph

workflow_path = Path("src/ewoksscxrd/workflows/demo_eiger2cbf.json")
workflow = json.loads(workflow_path.read_text())

inputs = [
    {
        "name": "images",
        "value": ["/data/.../scan0001/eiger_0000.h5"],
        "task_identifier": "ewoksscxrd.tasks.eiger2cbf.Eiger2CBF",
    },
    {
        "name": "output",
        "value": "/data/.../scan0001/cbf/frame_{index:04d}.cbf",
        "task_identifier": "ewoksscxrd.tasks.eiger2cbf.Eiger2CBF",
    },
    {
        "name": "offset",
        "value": 1,
        "task_identifier": "ewoksscxrd.tasks.eiger2cbf.Eiger2CBF",
    },
    {
        "name": "wavelength",
        "value": 0.2846,
        "task_identifier": "ewoksscxrd.tasks.eiger2cbf.Eiger2CBF",
    },
    {
        "name": "distance",
        "value": 0.1518,
        "task_identifier": "ewoksscxrd.tasks.eiger2cbf.Eiger2CBF",
    },
    {
        "name": "beam",
        "value": [1052, 1102],
        "task_identifier": "ewoksscxrd.tasks.eiger2cbf.Eiger2CBF",
    },
    {
        "name": "rotation",
        "value": 180,
        "task_identifier": "ewoksscxrd.tasks.eiger2cbf.Eiger2CBF",
    },
    {
        "name": "flip_lr",
        "value": True,
        "task_identifier": "ewoksscxrd.tasks.eiger2cbf.Eiger2CBF",
    },
    {
        "name": "omega",
        "value": "-36.000000-index*-0.500000",
        "task_identifier": "ewoksscxrd.tasks.eiger2cbf.Eiger2CBF",
    },
]

execute_graph(
    workflow,
    inputs=inputs,
    convert_destination="executed_demo_eiger2cbf.json",
    merge_outputs=False,
)
```

## 4. Execute the script

```bash
python run_eiger2cbf.py
```

## 5. Validate produced files

The conversion creates one `.cbf` file per frame under the directory selected
by the `output` template.