# Report Registry Internals

This document describes report identity, valid-period resolution, batch
membership, output naming, artifact grouping, and comparison declarations in
`internal/report`.

## Purpose

`internal/report` is the canonical source for report definitions. App, state,
briefing, and CLI wiring consume resolved definitions instead of owning report
identity policy themselves.

## Definition Fields

Each report definition declares:

- report ID and display name
- Scriptorium prompt ID
- valid-period resolver
- comparison strategy
- managed artifact group
- batch output copy filename
- generated-report eligibility
- prior-report compatibility list
- morning or evening batch membership

## Implemented Reports

| Report | ID | Prompt | Artifact group | Batch copy | Prior compatibility |
| --- | --- | --- | --- | --- | --- |
| Daily Today | `daily_today` | `weather.daily_report` | `daily` | `daily.md` | Daily Today, Daily Tomorrow |
| Daily Tomorrow | `daily_tomorrow` | `weather.daily_report` | `daily` | `tomorrow.md` | Daily Today, Daily Tomorrow |
| 3-Day Outlook | `three_day` | `weather.three_day_outlook` | `three-day` | `three-day.md` | 3-Day Outlook |
| Weekend Outlook | `weekend` | `weather.weekend_outlook` | `weekend` | `weekend.md` | Weekend Outlook |
| Storm Report | `storm` | `weather.storm_report` | `storm` | `storm.md` | Storm Report |

All implemented report definitions are eligible for generation.

## Valid Periods

- Daily Today covers the selected local civil day, or the current local civil
  day when no date override is supplied.
- Daily Tomorrow covers the next local civil day from generation time.
- 3-Day Outlook covers the interval from generation time through local midnight
  three days later.
- Weekend Outlook covers the upcoming weekend window and is not scheduled for
  Sunday morning batch resolution.
- Storm Report covers an explicit event window supplied by the caller.

Storm event windows can be parsed from local `YYYY-MM-DDTHH:MM` timestamps in
the configured timezone or RFC3339 timestamps with explicit offsets. End time
must be after start time.

## Boundaries

`internal/report` defines report metadata and time coverage. It does not fetch
weather data, build briefings, compare briefing contents, write state, parse CLI
flags, or invoke Scriptorium.

The CLI owns public command names. The app maps those command names to report
IDs, then uses the registry for report policy.

## Config Fields Used

The app supplies `weather_api.timezone` as a loaded `time.Location`. Batch
output path copying uses batch output names from report definitions.

## State And App Usage

- State paths use `ArtifactGroup`.
- Batch output copies use `BatchOutputName`.
- Generation checks `Generated`.
- Prior lookup checks `CompatiblePriorIDs` and the comparison strategy.
- RunIDs include the resolved report ID.

## Failure Behavior

- Unknown report IDs and batch names return actionable errors.
- Weekend Outlook resolution returns an error when resolved directly on Sunday.
- Storm Report resolution requires start and end, with end after start.

## Tests

Inspect:

- `internal/report/period_test.go`
- `internal/app/app_test.go`
- `internal/cli/root_test.go`

## Invariants

- Report selection goes through the registry.
- Daily Today and Daily Tomorrow both use `weather.daily_report`.
- Valid periods are half-open intervals independent of rendered report text.
- Artifact grouping, batch output filenames, generated-report eligibility,
  comparison compatibility, and comparison strategy are declared by report
  definition.