# Report Template Internals

`internal/reporttemplate` embeds and renders the repository's native Markdown
templates and exposes their companion generated-text schemas. The current asset
IDs are `daily`, `today`, `tomorrow`, and `hourly`. The template files, partials,
and complete render-context field reference are maintained in
[report templates](../templates.md).

## Assets and lookup

The package embeds top-level templates, shared partials, and JSON schemas from
its asset directories. `Template` and `Schema` return the requested embedded
asset and fail with the requested ID when it is unknown or unreadable.

Generated-text catalog handlers obtain schema bytes and template source through
these APIs. Prompt source files are repository assets for prompt registration;
they are not reporttemplate lookup assets. Report definitions select IDs, while
[generated-text internals](generatedtext.md) verifies the supported
schema/template pairing.

## Rendering

`Render` loads the top-level template, creates a `text/template` with helper
functions and `missingkey=error`, parses the template, parses every shared
partial, and executes the result against the typed render context. This makes
missing context fields, bad template syntax, unreadable partials, and execution
failures actionable with template or partial context.

Top-level templates decide which shared partials they invoke. The current
partials cover daypart forecast variants, alert digest, and precipitation
timing. Template code receives curated typed contexts rather than raw data
packages, and it must not reimplement weather selection or generated-text
validation.

## Boundaries and verification

This package does not collect weather data, build modules, validate generated
text, construct contexts, resolve report definitions, write state, execute
Scriptorium, or upload reports. It produces Markdown bytes for application
orchestration to persist.

Focused tests cover asset lookup, schema availability, rendering, partial
behavior, missing keys, and malformed context:

```sh
go test ./internal/reporttemplate
```

Embedded assets stay as separate files, shared fragments stay under the partial
directory, and generated-text schemas describe prose slots rather than
deterministic weather facts.