# `SferaDoc.Template`
[🔗](https://github.com/sfera-lab/sfera-doc/blob/v0.1.0/lib/sfera_doc/template.ex#L1)

The domain struct representing a versioned Liquid template.

This is the canonical type used throughout the library regardless of which
storage backend is configured. Adapters convert their internal representation
(Ecto schema record, ETS tuple, Redis JSON) into this struct.

## Fields

- `:id`: internal identifier (UUID string for Ecto, integer for ETS, string for Redis)
- `:name`: human-readable identifier used in the public API (e.g. `"invoice"`)
- `:body`: Liquid template source string
- `:version`: monotonically increasing integer per name; starts at 1
- `:is_active`: `true` for the currently active version of a given name
- `:variables_schema`: optional map declaring required/optional variables:
  `%{"required" => ["name", "date"], "optional" => ["footer"]}`
- `:inserted_at` / `:updated_at`: timestamps

## Variable Validation

Use `validate_variables/2` before rendering to ensure all required variables are present in the assigns map.

# `t`

```elixir
@type t() :: %SferaDoc.Template{
  body: String.t(),
  id: String.t() | integer() | nil,
  inserted_at: DateTime.t() | nil,
  is_active: boolean() | nil,
  name: String.t(),
  updated_at: DateTime.t() | nil,
  variables_schema: %{optional(String.t()) => [String.t()]} | nil,
  version: pos_integer() | nil
}
```

# `validate_variables`

```elixir
@spec validate_variables(t(), term()) ::
  :ok
  | {:error, {:missing_variables, [String.t()]}}
  | {:error, :assigns_must_be_map}
```

Validates that all required variables from `variables_schema` are present in the `assigns` map.

Returns `:ok` when:
- no `variables_schema` is set, or
- `variables_schema` has no `"required"` key, or
- all required keys are present in `assigns`

Returns `{:error, {:missing_variables, [String.t()]}}` listing missing keys.

Returns `{:error, :assigns_must_be_map}` when `assigns` is not a map.

## Examples

    iex> t = %SferaDoc.Template{name: "t", body: "x", variables_schema: %{"required" => ["name"]}}
    iex> SferaDoc.Template.validate_variables(t, %{"name" => "Alice"})
    :ok

    iex> SferaDoc.Template.validate_variables(t, %{})
    {:error, {:missing_variables, ["name"]}}

---

*Consult [api-reference.md](api-reference.md) for complete listing*