Add report registry and valid periods

docs/cli.md

@@ -1,7 +1,8 @@
 # Weatherreporter CLI
 
-`weatherreporter` currently resolves configuration and command requests, then
-returns a not-implemented error for report generation and scheduled runs.
+`weatherreporter` currently resolves configuration, command requests, report
+definitions, and valid periods, then returns a not-implemented error for report
+generation and scheduled runs.
 
 ## Shortest Useful Command
 
@@ -9,8 +10,8 @@ returns a not-implemented error for report generation and scheduled runs.
 weatherreporter generate daily --date 2026-05-29 --out ./daily.md
 ```
 
-The command parses flags, loads configuration, resolves the request, and then
-stops before weather data fetching or report rendering.
+The command parses flags, loads configuration, resolves report identity and the
+valid period, and then stops before weather data fetching or report rendering.
 
 ## Command Overview
 

docs/internal/report-registry.md

@@ -0,0 +1,63 @@
+# Report Registry Internals
+
+This document describes the implemented report identity and valid-period
+boundary.
+
+## Purpose
+
+`internal/report` centralizes report IDs, prompt IDs, comparison strategies,
+valid-period resolution, report metadata, and scheduled batch membership.
+
+## Inputs and Outputs
+
+Inputs:
+
+- report ID or batch name
+- generation time
+- configured timezone
+- optional Daily date override
+- optional manual storm start and end times
+
+Outputs:
+
+- `report.Resolved` values with definition metadata and half-open valid periods
+- `report.Metadata` values suitable for later persisted run metadata
+
+## Boundaries
+
+- This package defines report identity and time coverage only.
+- It does not fetch weather data, build briefings, compare snapshots, write
+  state, or call `scriptorium`.
+
+## Behavior
+
+- Daily Today covers one configured local civil day.
+- Daily Tomorrow covers the next configured local civil day.
+- 3-Day Outlook covers generation time through local midnight after the second
+  following local civil day.
+- Weekend Outlook covers Saturday 00:00 to Monday 00:00 Monday through
+  Thursday; Friday and Saturday cover the remaining weekend from Friday 18:00
+  or generation time, whichever is later.
+- Manual Storm Report uses explicit start and end times.
+- Morning batch resolves Daily Today and 3-Day Outlook, plus Weekend Outlook
+  except on Sunday.
+- Evening batch resolves Daily Tomorrow.
+
+## Failure Behavior
+
+- Unknown report and batch names return actionable errors.
+- Sunday Weekend Outlook resolution returns an error.
+- Storm windows require start and end, with end after start.
+
+## Tests
+
+Inspect:
+
+- `internal/report/period_test.go`
+- `internal/app/app_test.go`
+
+## Invariants
+
+- Report selection goes through the registry.
+- Valid periods are independent of rendered report text.
+- Prompt IDs and comparison strategies are declared with report definitions.

internal/app/app.go

@@ -9,6 +9,8 @@ import (
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/adapters/weatherapi"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/config"
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/forecast"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
 )
 
 type ReportKind string
@@ -49,16 +51,81 @@ type FetchBundleRequest struct {
 
 func Generate(ctx context.Context, req GenerateRequest) error {
 	_ = ctx
-	_ = req
+	if _, err := ResolveGenerate(req, time.Now()); err != nil {
+		return err
+	}
 	return fmt.Errorf("generate is not implemented")
 }
 
 func RunBatch(ctx context.Context, req BatchRequest) error {
 	_ = ctx
-	_ = req
+	if _, err := ResolveBatch(req, time.Now()); err != nil {
+		return err
+	}
 	return fmt.Errorf("run is not implemented")
 }
 
+func ResolveGenerate(req GenerateRequest, now time.Time) (report.Resolved, error) {
+	location, err := timeutil.LoadLocation(req.Config.WeatherAPI.Timezone)
+	if err != nil {
+		return report.Resolved{}, err
+	}
+	id, err := reportIDForCommand(req.Report)
+	if err != nil {
+		return report.Resolved{}, err
+	}
+	return report.DefaultRegistry().Resolve(id, report.ResolveRequest{
+		Now:        now,
+		Location:   location,
+		Date:       req.Date,
+		StormStart: req.StormStart,
+		StormEnd:   req.StormEnd,
+	})
+}
+
+func ResolveBatch(req BatchRequest, now time.Time) ([]report.Resolved, error) {
+	location, err := timeutil.LoadLocation(req.Config.WeatherAPI.Timezone)
+	if err != nil {
+		return nil, err
+	}
+	batch, err := reportBatchForCommand(req.Batch)
+	if err != nil {
+		return nil, err
+	}
+	return report.DefaultRegistry().BatchReports(batch, report.ResolveRequest{
+		Now:      now,
+		Location: location,
+	})
+}
+
+func reportIDForCommand(kind ReportKind) (report.ID, error) {
+	switch kind {
+	case ReportDaily:
+		return report.DailyToday, nil
+	case ReportTomorrow:
+		return report.DailyTomorrow, nil
+	case ReportThreeDay:
+		return report.ThreeDay, nil
+	case ReportWeekend:
+		return report.Weekend, nil
+	case ReportStorm:
+		return report.Storm, nil
+	default:
+		return "", fmt.Errorf("unknown report command %q", kind)
+	}
+}
+
+func reportBatchForCommand(kind BatchKind) (report.Batch, error) {
+	switch kind {
+	case BatchMorning:
+		return report.Morning, nil
+	case BatchEvening:
+		return report.Evening, nil
+	default:
+		return "", fmt.Errorf("unknown batch command %q", kind)
+	}
+}
+
 func FetchBundle(ctx context.Context, req FetchBundleRequest) (*forecast.Bundle, error) {
 	client, err := weatherapi.New(req.Config)
 	if err != nil {

internal/app/app_test.go

@@ -8,8 +8,10 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+	"time"
 
 	"gitea.maximumdirect.net/eric/weatherreporter/internal/config"
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/report"
 )
 
 func TestFetchAndSaveBundle(t *testing.T) {
@@ -62,3 +64,77 @@ func TestFetchAndSaveBundleRequiresOutputPath(t *testing.T) {
 		t.Fatalf("error = %q, want output path context", err.Error())
 	}
 }
+
+func TestResolveGenerateMapsCommandToReportDefinition(t *testing.T) {
+	cfg := config.Defaults()
+	cfg.WeatherAPI.Timezone = "America/Chicago"
+	now := mustParse("2026-05-29T18:00:00-05:00")
+
+	resolved, err := ResolveGenerate(GenerateRequest{
+		Config: cfg,
+		Report: ReportTomorrow,
+	}, now)
+	if err != nil {
+		t.Fatalf("ResolveGenerate() error = %v", err)
+	}
+	if resolved.Definition.ID != report.DailyTomorrow {
+		t.Fatalf("ID = %q, want daily_tomorrow", resolved.Definition.ID)
+	}
+	if resolved.Definition.PromptID != "weather.daily_report" {
+		t.Fatalf("PromptID = %q, want weather.daily_report", resolved.Definition.PromptID)
+	}
+	if got := resolved.ValidPeriod.Start.Format("2006-01-02"); got != "2026-05-30" {
+		t.Fatalf("valid start date = %s, want 2026-05-30", got)
+	}
+}
+
+func TestResolveGenerateStorm(t *testing.T) {
+	cfg := config.Defaults()
+	cfg.WeatherAPI.Timezone = "America/Chicago"
+	now := mustParse("2026-05-29T12:00:00-05:00")
+	start := mustParse("2026-05-29T18:00:00-05:00")
+	end := mustParse("2026-05-30T06:00:00-05:00")
+
+	resolved, err := ResolveGenerate(GenerateRequest{
+		Config:     cfg,
+		Report:     ReportStorm,
+		StormStart: start,
+		StormEnd:   end,
+	}, now)
+	if err != nil {
+		t.Fatalf("ResolveGenerate() error = %v", err)
+	}
+	if resolved.Definition.ID != report.Storm {
+		t.Fatalf("ID = %q, want storm", resolved.Definition.ID)
+	}
+	if !resolved.ValidPeriod.Start.Equal(start) || !resolved.ValidPeriod.End.Equal(end) {
+		t.Fatalf("period = %#v, want storm window", resolved.ValidPeriod)
+	}
+}
+
+func TestResolveBatchMorningSkipsWeekendOnSunday(t *testing.T) {
+	cfg := config.Defaults()
+	cfg.WeatherAPI.Timezone = "America/Chicago"
+	now := mustParse("2026-05-31T06:00:00-05:00")
+
+	resolved, err := ResolveBatch(BatchRequest{Config: cfg, Batch: BatchMorning}, now)
+	if err != nil {
+		t.Fatalf("ResolveBatch() error = %v", err)
+	}
+	if len(resolved) != 2 {
+		t.Fatalf("resolved length = %d, want 2", len(resolved))
+	}
+	for _, item := range resolved {
+		if item.Definition.ID == report.Weekend {
+			t.Fatal("morning batch included weekend on Sunday")
+		}
+	}
+}
+
+func mustParse(value string) time.Time {
+	parsed, err := time.Parse(time.RFC3339, value)
+	if err != nil {
+		panic(err)
+	}
+	return parsed
+}

internal/report/definition.go

@@ -0,0 +1,87 @@
+// Package report defines report identities, registry metadata, and valid periods.
+package report
+
+import (
+	"fmt"
+	"time"
+
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
+)
+
+type ID string
+
+const (
+	DailyToday    ID = "daily_today"
+	DailyTomorrow ID = "daily_tomorrow"
+	ThreeDay      ID = "three_day"
+	Weekend       ID = "weekend"
+	Storm         ID = "storm"
+)
+
+type ComparisonStrategy string
+
+const (
+	CompareSameValidDate  ComparisonStrategy = "same_valid_date"
+	CompareWeekendWindow  ComparisonStrategy = "same_weekend_window"
+	CompareExplicitWindow ComparisonStrategy = "explicit_event_window"
+)
+
+type Batch string
+
+const (
+	Morning Batch = "morning"
+	Evening Batch = "evening"
+)
+
+type Definition struct {
+	ID                 ID
+	Name               string
+	PromptID           string
+	ComparisonStrategy ComparisonStrategy
+	DefaultOutputName  string
+	Morning            bool
+	Evening            bool
+	resolve            func(ResolveRequest) (timeutil.Period, error)
+}
+
+func (d Definition) ResolvePeriod(req ResolveRequest) (timeutil.Period, error) {
+	if d.resolve == nil {
+		return timeutil.Period{}, fmt.Errorf("report %q has no valid-period resolver", d.ID)
+	}
+	return d.resolve(req)
+}
+
+type ResolveRequest struct {
+	Now        time.Time
+	Location   *time.Location
+	Date       time.Time
+	StormStart time.Time
+	StormEnd   time.Time
+}
+
+type Resolved struct {
+	Definition  Definition
+	GeneratedAt time.Time
+	Timezone    string
+	ValidPeriod timeutil.Period
+}
+
+type Metadata struct {
+	RunID       string          `json:"runId"`
+	ReportID    ID              `json:"reportId"`
+	PromptID    string          `json:"promptId"`
+	GeneratedAt time.Time       `json:"generatedAt"`
+	Timezone    string          `json:"timezone"`
+	ValidPeriod timeutil.Period `json:"validPeriod"`
+}
+
+func (r Resolved) Metadata() Metadata {
+	return Metadata{
+		RunID:       r.GeneratedAt.UTC().Format("20060102T150405Z") + "_" + string(r.Definition.ID),
+		ReportID:    r.Definition.ID,
+		PromptID:    r.Definition.PromptID,
+		GeneratedAt: r.GeneratedAt,
+		Timezone:    r.Timezone,
+		ValidPeriod: r.ValidPeriod,
+	}
+}

internal/report/period.go

@@ -0,0 +1,144 @@
+package report
+
+import (
+	"fmt"
+	"time"
+
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
+)
+
+func Resolve(id ID, req ResolveRequest) (Resolved, error) {
+	return DefaultRegistry().Resolve(id, req)
+}
+
+func (r Registry) Resolve(id ID, req ResolveRequest) (Resolved, error) {
+	definition, err := r.Lookup(id)
+	if err != nil {
+		return Resolved{}, err
+	}
+	return r.resolveDefinition(definition, req)
+}
+
+func (r Registry) BatchReports(batch Batch, req ResolveRequest) ([]Resolved, error) {
+	if req.Location == nil {
+		req.Location = time.UTC
+	}
+	if req.Now.IsZero() {
+		req.Now = time.Now()
+	}
+	switch batch {
+	case Morning:
+		ids := []ID{DailyToday, ThreeDay}
+		if req.Now.In(req.Location).Weekday() != time.Sunday {
+			ids = append(ids, Weekend)
+		}
+		return r.resolveIDs(ids, req)
+	case Evening:
+		return r.resolveIDs([]ID{DailyTomorrow}, req)
+	default:
+		return nil, fmt.Errorf("unknown batch %q", batch)
+	}
+}
+
+func (r Registry) resolveIDs(ids []ID, req ResolveRequest) ([]Resolved, error) {
+	resolved := make([]Resolved, 0, len(ids))
+	for _, id := range ids {
+		item, err := r.Resolve(id, req)
+		if err != nil {
+			return nil, err
+		}
+		resolved = append(resolved, item)
+	}
+	return resolved, nil
+}
+
+func (r Registry) resolveDefinition(definition Definition, req ResolveRequest) (Resolved, error) {
+	if req.Location == nil {
+		req.Location = time.UTC
+	}
+	if req.Now.IsZero() {
+		req.Now = time.Now()
+	}
+	period, err := definition.ResolvePeriod(req)
+	if err != nil {
+		return Resolved{}, err
+	}
+	return Resolved{
+		Definition:  definition,
+		GeneratedAt: req.Now,
+		Timezone:    req.Location.String(),
+		ValidPeriod: period,
+	}, nil
+}
+
+func resolveDailyToday(req ResolveRequest) (timeutil.Period, error) {
+	if !req.Date.IsZero() {
+		return timeutil.CivilDay(req.Date, req.Location), nil
+	}
+	return timeutil.CivilDay(req.Now, req.Location), nil
+}
+
+func ParseStormPeriod(start string, end string, location *time.Location) (timeutil.Period, error) {
+	if location == nil {
+		location = time.UTC
+	}
+	startTime, err := timeutil.ParseStormTime(start, location)
+	if err != nil {
+		return timeutil.Period{}, err
+	}
+	endTime, err := timeutil.ParseStormTime(end, location)
+	if err != nil {
+		return timeutil.Period{}, err
+	}
+	period := timeutil.Period{Start: startTime, End: endTime}
+	if !period.IsValid() {
+		return timeutil.Period{}, fmt.Errorf("storm report requires end time after start time")
+	}
+	return period, nil
+}
+
+func resolveDailyTomorrow(req ResolveRequest) (timeutil.Period, error) {
+	return timeutil.CivilDay(req.Now.In(req.Location).AddDate(0, 0, 1), req.Location), nil
+}
+
+func resolveThreeDay(req ResolveRequest) (timeutil.Period, error) {
+	localNow := req.Now.In(req.Location)
+	endDate := localNow.AddDate(0, 0, 3)
+	end := time.Date(endDate.Year(), endDate.Month(), endDate.Day(), 0, 0, 0, 0, req.Location)
+	return timeutil.Period{Start: localNow, End: end}, nil
+}
+
+func resolveWeekend(req ResolveRequest) (timeutil.Period, error) {
+	localNow := req.Now.In(req.Location)
+	weekday := localNow.Weekday()
+	if weekday == time.Sunday {
+		return timeutil.Period{}, fmt.Errorf("weekend outlook is not scheduled on Sunday morning")
+	}
+
+	daysUntilSaturday := (int(time.Saturday) - int(weekday) + 7) % 7
+	saturday := localNow.AddDate(0, 0, daysUntilSaturday)
+	start := time.Date(saturday.Year(), saturday.Month(), saturday.Day(), 0, 0, 0, 0, req.Location)
+	if weekday == time.Friday || weekday == time.Saturday {
+		friday := start.AddDate(0, 0, -1)
+		fridayEvening := time.Date(friday.Year(), friday.Month(), friday.Day(), 18, 0, 0, 0, req.Location)
+		start = fridayEvening
+		if localNow.After(start) {
+			start = localNow
+		}
+	}
+	end := time.Date(saturday.Year(), saturday.Month(), saturday.Day(), 0, 0, 0, 0, req.Location).AddDate(0, 0, 2)
+	return timeutil.Period{Start: start, End: end}, nil
+}
+
+func resolveStorm(req ResolveRequest) (timeutil.Period, error) {
+	if req.StormStart.IsZero() {
+		return timeutil.Period{}, fmt.Errorf("storm report requires a start time")
+	}
+	if req.StormEnd.IsZero() {
+		return timeutil.Period{}, fmt.Errorf("storm report requires an end time")
+	}
+	if !req.StormEnd.After(req.StormStart) {
+		return timeutil.Period{}, fmt.Errorf("storm report requires end time after start time")
+	}
+	return timeutil.Period{Start: req.StormStart, End: req.StormEnd}, nil
+}

internal/report/period_test.go

@@ -0,0 +1,231 @@
+package report
+
+import (
+	"strings"
+	"testing"
+	"time"
+
+	"gitea.maximumdirect.net/eric/weatherreporter/internal/timeutil"
+)
+
+func TestDailyValidPeriod(t *testing.T) {
+	location := mustLoadLocation(t)
+	now := mustParse("2026-05-29T17:45:00-05:00")
+
+	resolved, err := Resolve(DailyToday, ResolveRequest{Now: now, Location: location})
+	if err != nil {
+		t.Fatalf("Resolve() error = %v", err)
+	}
+	assertPeriod(t, resolved.ValidPeriod, "2026-05-29T00:00:00-05:00", "2026-05-30T00:00:00-05:00")
+}
+
+func TestDailyValidPeriodCanUseExplicitDate(t *testing.T) {
+	location := mustLoadLocation(t)
+	now := mustParse("2026-05-29T17:45:00-05:00")
+	date := mustParse("2026-05-31T12:00:00-05:00")
+
+	resolved, err := Resolve(DailyToday, ResolveRequest{Now: now, Location: location, Date: date})
+	if err != nil {
+		t.Fatalf("Resolve() error = %v", err)
+	}
+	assertPeriod(t, resolved.ValidPeriod, "2026-05-31T00:00:00-05:00", "2026-06-01T00:00:00-05:00")
+}
+
+func TestTomorrowValidPeriodFromEveningGeneration(t *testing.T) {
+	location := mustLoadLocation(t)
+	now := mustParse("2026-05-29T20:00:00-05:00")
+
+	resolved, err := Resolve(DailyTomorrow, ResolveRequest{Now: now, Location: location})
+	if err != nil {
+		t.Fatalf("Resolve() error = %v", err)
+	}
+	assertPeriod(t, resolved.ValidPeriod, "2026-05-30T00:00:00-05:00", "2026-05-31T00:00:00-05:00")
+	if resolved.Definition.PromptID != "weather.daily_report" {
+		t.Fatalf("PromptID = %q, want weather.daily_report", resolved.Definition.PromptID)
+	}
+}
+
+func TestThreeDayPeriodCalculation(t *testing.T) {
+	location := mustLoadLocation(t)
+	now := mustParse("2026-05-29T05:00:00-05:00")
+
+	resolved, err := Resolve(ThreeDay, ResolveRequest{Now: now, Location: location})
+	if err != nil {
+		t.Fatalf("Resolve() error = %v", err)
+	}
+	assertPeriod(t, resolved.ValidPeriod, "2026-05-29T05:00:00-05:00", "2026-06-01T00:00:00-05:00")
+}
+
+func TestWeekendPeriodCalculation(t *testing.T) {
+	location := mustLoadLocation(t)
+	tests := []struct {
+		name  string
+		now   string
+		start string
+		end   string
+	}{
+		{name: "monday", now: "2026-05-25T05:00:00-05:00", start: "2026-05-30T00:00:00-05:00", end: "2026-06-01T00:00:00-05:00"},
+		{name: "friday before evening", now: "2026-05-29T05:00:00-05:00", start: "2026-05-29T18:00:00-05:00", end: "2026-06-01T00:00:00-05:00"},
+		{name: "friday after evening", now: "2026-05-29T19:30:00-05:00", start: "2026-05-29T19:30:00-05:00", end: "2026-06-01T00:00:00-05:00"},
+		{name: "saturday", now: "2026-05-30T08:00:00-05:00", start: "2026-05-30T08:00:00-05:00", end: "2026-06-01T00:00:00-05:00"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			resolved, err := Resolve(Weekend, ResolveRequest{Now: mustParse(tt.now), Location: location})
+			if err != nil {
+				t.Fatalf("Resolve() error = %v", err)
+			}
+			assertPeriod(t, resolved.ValidPeriod, tt.start, tt.end)
+		})
+	}
+}
+
+func TestWeekendSundayErrors(t *testing.T) {
+	location := mustLoadLocation(t)
+	_, err := Resolve(Weekend, ResolveRequest{Now: mustParse("2026-05-31T08:00:00-05:00"), Location: location})
+	if err == nil {
+		t.Fatal("Resolve() error = nil, want Sunday weekend error")
+	}
+	if !strings.Contains(err.Error(), "Sunday") {
+		t.Fatalf("error = %q, want Sunday context", err.Error())
+	}
+}
+
+func TestStormManualPeriodParsingAndValidation(t *testing.T) {
+	location := mustLoadLocation(t)
+	period, err := ParseStormPeriod("2026-05-29T18:00", "2026-05-30T06:00:00-05:00", location)
+	if err != nil {
+		t.Fatalf("ParseStormPeriod() error = %v", err)
+	}
+	assertPeriod(t, period, "2026-05-29T18:00:00-05:00", "2026-05-30T06:00:00-05:00")
+
+	_, err = ParseStormPeriod("2026-05-30T06:00", "2026-05-29T18:00", location)
+	if err == nil {
+		t.Fatal("ParseStormPeriod() error = nil, want invalid period error")
+	}
+}
+
+func TestStormResolve(t *testing.T) {
+	location := mustLoadLocation(t)
+	resolved, err := Resolve(Storm, ResolveRequest{
+		Now:        mustParse("2026-05-29T12:00:00-05:00"),
+		Location:   location,
+		StormStart: mustParse("2026-05-29T18:00:00-05:00"),
+		StormEnd:   mustParse("2026-05-30T06:00:00-05:00"),
+	})
+	if err != nil {
+		t.Fatalf("Resolve() error = %v", err)
+	}
+	assertPeriod(t, resolved.ValidPeriod, "2026-05-29T18:00:00-05:00", "2026-05-30T06:00:00-05:00")
+	if resolved.Definition.ComparisonStrategy != CompareExplicitWindow {
+		t.Fatalf("ComparisonStrategy = %q, want explicit event window", resolved.Definition.ComparisonStrategy)
+	}
+}
+
+func TestMorningBatchSkipsWeekendOnSunday(t *testing.T) {
+	location := mustLoadLocation(t)
+	resolved, err := DefaultRegistry().BatchReports(Morning, ResolveRequest{
+		Now:      mustParse("2026-05-31T06:00:00-05:00"),
+		Location: location,
+	})
+	if err != nil {
+		t.Fatalf("BatchReports() error = %v", err)
+	}
+	ids := resolvedIDs(resolved)
+	if strings.Join(ids, ",") != "daily_today,three_day" {
+		t.Fatalf("ids = %v, want daily_today and three_day", ids)
+	}
+}
+
+func TestEveningBatchIncludesTomorrow(t *testing.T) {
+	location := mustLoadLocation(t)
+	resolved, err := DefaultRegistry().BatchReports(Evening, ResolveRequest{
+		Now:      mustParse("2026-05-29T18:00:00-05:00"),
+		Location: location,
+	})
+	if err != nil {
+		t.Fatalf("BatchReports() error = %v", err)
+	}
+	ids := resolvedIDs(resolved)
+	if strings.Join(ids, ",") != "daily_tomorrow" {
+		t.Fatalf("ids = %v, want daily_tomorrow", ids)
+	}
+}
+
+func TestRegistryLookupErrorIsActionable(t *testing.T) {
+	_, err := DefaultRegistry().Lookup(ID("unknown"))
+	if err == nil {
+		t.Fatal("Lookup() error = nil, want unknown report error")
+	}
+	if !strings.Contains(err.Error(), `unknown report "unknown"`) {
+		t.Fatalf("error = %q, want unknown report context", err.Error())
+	}
+}
+
+func TestRegistryDefinitionsHavePromptIDsAndComparisonStrategies(t *testing.T) {
+	for _, definition := range DefaultRegistry().All() {
+		if definition.PromptID == "" {
+			t.Fatalf("%s PromptID is empty", definition.ID)
+		}
+		if definition.ComparisonStrategy == "" {
+			t.Fatalf("%s ComparisonStrategy is empty", definition.ID)
+		}
+	}
+}
+
+func TestResolvedMetadata(t *testing.T) {
+	location := mustLoadLocation(t)
+	resolved, err := Resolve(DailyToday, ResolveRequest{Now: mustParse("2026-05-29T05:00:00-05:00"), Location: location})
+	if err != nil {
+		t.Fatalf("Resolve() error = %v", err)
+	}
+	metadata := resolved.Metadata()
+	if metadata.ReportID != DailyToday {
+		t.Fatalf("ReportID = %q, want daily_today", metadata.ReportID)
+	}
+	if metadata.PromptID != "weather.daily_report" {
+		t.Fatalf("PromptID = %q, want weather.daily_report", metadata.PromptID)
+	}
+	if !strings.Contains(metadata.RunID, "daily_today") {
+		t.Fatalf("RunID = %q, want report id", metadata.RunID)
+	}
+}
+
+func assertPeriod(t *testing.T, period timeutil.Period, wantStart string, wantEnd string) {
+	t.Helper()
+	if !period.IsValid() {
+		t.Fatalf("period = %#v, want valid", period)
+	}
+	if period.Start.Format(time.RFC3339) != wantStart {
+		t.Fatalf("Start = %s, want %s", period.Start.Format(time.RFC3339), wantStart)
+	}
+	if period.End.Format(time.RFC3339) != wantEnd {
+		t.Fatalf("End = %s, want %s", period.End.Format(time.RFC3339), wantEnd)
+	}
+}
+
+func resolvedIDs(resolved []Resolved) []string {
+	ids := make([]string, 0, len(resolved))
+	for _, item := range resolved {
+		ids = append(ids, string(item.Definition.ID))
+	}
+	return ids
+}
+
+func mustLoadLocation(t *testing.T) *time.Location {
+	t.Helper()
+	location, err := time.LoadLocation("America/Chicago")
+	if err != nil {
+		t.Fatalf("load location: %v", err)
+	}
+	return location
+}
+
+func mustParse(value string) time.Time {
+	parsed, err := time.Parse(time.RFC3339, value)
+	if err != nil {
+		panic(err)
+	}
+	return parsed
+}

internal/report/registry.go

@@ -0,0 +1,88 @@
+package report
+
+import "fmt"
+
+type Registry struct {
+	definitions map[ID]Definition
+}
+
+func DefaultRegistry() Registry {
+	definitions := []Definition{
+		{
+			ID:                 DailyToday,
+			Name:               "Daily Report",
+			PromptID:           "weather.daily_report",
+			ComparisonStrategy: CompareSameValidDate,
+			DefaultOutputName:  "daily.md",
+			Morning:            true,
+			resolve:            resolveDailyToday,
+		},
+		{
+			ID:                 DailyTomorrow,
+			Name:               "Tomorrow Planning Brief",
+			PromptID:           "weather.daily_report",
+			ComparisonStrategy: CompareSameValidDate,
+			DefaultOutputName:  "tomorrow.md",
+			Evening:            true,
+			resolve:            resolveDailyTomorrow,
+		},
+		{
+			ID:                 ThreeDay,
+			Name:               "3-Day Outlook",
+			PromptID:           "weather.three_day_outlook",
+			ComparisonStrategy: CompareSameValidDate,
+			DefaultOutputName:  "three_day.md",
+			Morning:            true,
+			resolve:            resolveThreeDay,
+		},
+		{
+			ID:                 Weekend,
+			Name:               "Weekend Outlook",
+			PromptID:           "weather.weekend_outlook",
+			ComparisonStrategy: CompareWeekendWindow,
+			DefaultOutputName:  "weekend.md",
+			Morning:            true,
+			resolve:            resolveWeekend,
+		},
+		{
+			ID:                 Storm,
+			Name:               "Storm Report",
+			PromptID:           "weather.storm_report",
+			ComparisonStrategy: CompareExplicitWindow,
+			DefaultOutputName:  "storm.md",
+			resolve:            resolveStorm,
+		},
+	}
+	registry := Registry{definitions: map[ID]Definition{}}
+	for _, definition := range definitions {
+		registry.definitions[definition.ID] = definition
+	}
+	return registry
+}
+
+func (r Registry) Lookup(id ID) (Definition, error) {
+	definition, ok := r.definitions[id]
+	if !ok {
+		return Definition{}, fmt.Errorf("unknown report %q", id)
+	}
+	return definition, nil
+}
+
+func (r Registry) MustLookup(id ID) Definition {
+	definition, err := r.Lookup(id)
+	if err != nil {
+		panic(err)
+	}
+	return definition
+}
+
+func (r Registry) All() []Definition {
+	ids := []ID{DailyToday, DailyTomorrow, ThreeDay, Weekend, Storm}
+	out := make([]Definition, 0, len(ids))
+	for _, id := range ids {
+		if definition, ok := r.definitions[id]; ok {
+			out = append(out, definition)
+		}
+	}
+	return out
+}