# go-nc-files

Shared Go library for Nextcloud ExApp Services: a User Files seam (local disk and WebDAV), Saved Default path storage, and Visit-scoped Working Folder resolution.

Import: `gitea.neitzel.de/konrad/go-nc-files`

Depends on [go-nc-exapp](https://gitea.neitzel.de/konrad/go-nc-exapp) for AppAPI credentials on WebDAV.

## v1 scope

**Included**

- **Files seam** — `Root` and `Folder` interfaces with `OpenFolder`, `EnsureFolder`, `List`, `Read`, `Write`, `Exists`
- **Local** — filesystem-backed User Files Root for tests and local `go run`
- **WebDAVRoot** — Nextcloud Files at `/remote.php/dav/files/{user}/` using `gonexapp.Credentials`
- **CleanRel** — rejects `..`, URLs, and numeric file IDs
- **RequireBasename** — shared basename rules for child file names
- **DefaultPathStore** — `GetDefault` / `SetDefault` for Saved Default paths; `FileStore` (JSON) and `Memory` implementations
- **Visit** — `Open` resolves Working Folder from Saved Default (app-icon) or visit-only path (Files view); fail-closed on missing/forbidden visit paths
- Sentinel errors: `ErrNotExist`, `ErrForbidden`, `ErrNotDir`

**Excluded from v1**

- ExApp lifecycle HTTP routes and HaRP bootstrap (see **go-nc-exapp**)
- AppAPI preference OCS wiring (ExApp adapts `gonexapp.AppAPIPreferences` to `DefaultPathStore`)
- Catalog, DNS, or product-specific file semantics
- Recursive tree walks and Nextcloud numeric file IDs

## Usage

```go
import (
    goncfiles "gitea.neitzel.de/konrad/go-nc-files"
    gonexapp "gitea.neitzel.de/konrad/go-nc-exapp"
)

// Local mode
visit, err := goncfiles.OpenLocal("/data/files", "/data/settings.json", "myapp", "")

// WebDAV + ExApp preferences (adapter in your ExApp)
cred := gonexapp.Credentials{ /* ... */ }
root := goncfiles.WebDAVRoot{Cred: cred}
prefs := gonexapp.NewAppAPIPreferences(cred, "myexapp", "savedDefault")
store := myAppAPIPathStore{prefs} // implement DefaultPathStore
visit, err := goncfiles.Open(root, store, "myapp", visitRelative)
```

Each ExApp chooses its Saved Default preference key and initial folder name; this library stays key-agnostic.

## Domain language

See [CONTEXT.md](./CONTEXT.md) for User Files Root, Working Folder, Saved Default, Visit, and Files seam terminology.

## Related

- **go-nc-exapp** — AppAPI credentials and OCS preferences
- Workspace ADR 0013 — extraction from CheckDNS