# Data format team

Use this team for a file the game reads: an archive, a level, a save, a sound or a table of
rules. It decodes the format, proves the decoder on every file, and gives the port a reader.

```mermaid
flowchart TD
    I[re-identifier] -->|known engine or library format?| Q{Known codec<br/>or crate?}
    Q -->|yes| Ma[re-matcher]
    Q -->|no| De[re-decoder]
    Ma -->|crate matches, or not| De
    De -->|format document, reader consumes every byte| P[re-porter]
    P -->|reader in the port, tests on every file| V[re-verifier]
    V -->|round trip, every file| L[re-lander]
    L -->|commit| Done([Format read by the port])
```

## Steps

| Order | Agent | Brief | Hands on |
|---|---|---|---|
| 1 | `re-identifier` | "Is &lt;file type&gt; a known engine or library format?" | The format's origin in `FINDINGS.md`, with the evidence |
| 2 | `re-matcher` (when a crate or library exists) | "Compare &lt;crate&gt; with the game's decoder" | A comparison report: matches, or the first difference |
| 3 | `re-decoder` | "Decode &lt;file type&gt;" | `docs/formats/<type>.md`; a prototype reader that consumes every byte of every file |
| 4 | `re-porter` | "Port the &lt;type&gt; reader" | A reader in the port with tests over every file |
| 5 | `re-verifier` | "Verify the &lt;type&gt; reader" | Every file decodes; files the game writes round-trip byte for byte |
| 6 | `re-lander` | "Land the &lt;type&gt; format" | A commit |

## Outcome

- A format document: the layout, field by field, with offsets and evidence.
- A reader that reads every file of the type to the last byte.
- For files the game writes (saves, settings), a writer that reproduces the original bytes.

## Choices for the main session

- When `re-decoder` finds fields it cannot explain from the files alone, send `re-tracer` to
  the code that reads them.
- Skip `re-matcher` when no ready implementation exists.