Plan service and weekly plan API (#114)

Co-authored-by: orchestrator-agent <20+orchestrator-agent@code.cubecraftcreations.com>

internal/plan/draft.go

@@ -0,0 +1,212 @@
+package plan
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"time"
+
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/ai/harness"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/ai/skills"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/db"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/dinners"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/household"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/jobs"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/store"
+)
+
+// DraftJob is the KindDraftWeek payload: the week to draft, and whether
+// the household confirmed drafting over a synced or changed plan.
+type DraftJob struct {
+	WeekStart string `json:"week_start"`
+	Confirm   bool   `json:"confirm"`
+}
+
+// draftResult is the KindDraftWeek result: the week drafted and its plan.
+type draftResult struct {
+	WeekStart string `json:"week_start"`
+	PlanID    string `json:"plan_id"`
+}
+
+func (r draftResult) PublicJSON() ([]byte, error) { return json.Marshal(r) }
+
+// runDraft drafts the week p.WeekStart: draft_week plans it from the
+// Regulars and the Quest log dinners no other current or later plan has,
+// given the household context and last week's dinners, and the draft is
+// stored as the week's plan if the plan is still as it was before
+// draft_week ran. A pool under seven dinners fails with
+// ReasonNotEnoughDinners and draft_week failing with ReasonAIFailed; no
+// week is made up instead.
+func (s *Service) runDraft(ctx context.Context, p DraftJob, _ func(draftResult) error) (draftResult, error) {
+	weekStart, err := ParseWeekStart(p.WeekStart)
+	if err != nil {
+		return draftResult{}, fmt.Errorf("plan: draft: %w", err)
+	}
+	base, err := s.revision(ctx, weekStart)
+	if err != nil {
+		return draftResult{}, err
+	}
+	in, err := s.request(ctx, weekStart)
+	if err != nil {
+		return draftResult{}, err
+	}
+	week, err := s.draft(ctx, household.PeriodKey(weekStart), in)
+	if err != nil {
+		if ctx.Err() != nil {
+			return draftResult{}, ctx.Err()
+		}
+		var few *skills.NotEnoughDinnersError
+		if errors.As(err, &few) {
+			return draftResult{}, &jobs.Failure{Code: ReasonNotEnoughDinners}
+		}
+		// Only the code is logged: the error may quote a model's response.
+		s.logger.InfoContext(ctx, "week draft failed", "week_start", p.WeekStart, "reason", ReasonAIFailed)
+		return draftResult{}, &jobs.Failure{Code: ReasonAIFailed}
+	}
+	for _, w := range week.Warnings {
+		s.logger.InfoContext(ctx, "week draft warning", "week_start", p.WeekStart, "warning", w)
+	}
+	planID, err := s.storeDraft(ctx, weekStart, p.Confirm, base, week)
+	if err != nil {
+		return draftResult{}, err
+	}
+	return draftResult{WeekStart: p.WeekStart, PlanID: planID}, nil
+}
+
+// noPlan is the revision of a week with no plan.
+const noPlan = -1
+
+// revision returns the revision of the plan of the week starting
+// weekStart, or noPlan when the week has none.
+func (s *Service) revision(ctx context.Context, weekStart store.LocalDate) (int64, error) {
+	cur, err := db.New(s.st.Reader).GetWeekPlan(ctx, weekStart.String())
+	if errors.Is(err, sql.ErrNoRows) {
+		return noPlan, nil
+	}
+	if err != nil {
+		return 0, fmt.Errorf("plan: read week %s: %w", weekStart, err)
+	}
+	return cur.Revision, nil
+}
+
+// request reads what draft_week is given for the week starting weekStart:
+// the household context, the pool, last week's dinners and the dinner
+// time.
+func (s *Service) request(ctx context.Context, weekStart store.LocalDate) (skills.WeekRequest, error) {
+	hctx, err := harness.BuildContext(ctx, s.st, time.Now(), ContextBudget)
+	if err != nil {
+		return skills.WeekRequest{}, fmt.Errorf("plan: %w", err)
+	}
+	q := db.New(s.st.Reader)
+	settings, err := q.GetHouseholdSettings(ctx)
+	if err != nil {
+		return skills.WeekRequest{}, fmt.Errorf("plan: read household settings: %w", err)
+	}
+	thisWeek := household.WeekStart(hctx.Today)
+	rows, err := q.ListDraftPool(ctx, db.ListDraftPoolParams{FromWeekStart: thisWeek.String(), WeekStart: weekStart.String()})
+	if err != nil {
+		return skills.WeekRequest{}, fmt.Errorf("plan: list draft pool: %w", err)
+	}
+	pool := make([]skills.Candidate, len(rows))
+	for i, d := range rows {
+		kind := skills.KindRegular
+		if d.Status == dinners.StatusQuestLog {
+			kind = skills.KindQuestLog
+		}
+		pool[i] = skills.Candidate{ID: d.ID, Name: d.Name, Kind: kind, Method: d.Method.String, Minutes: int(d.MinutesTotal.Int64)}
+	}
+	last, err := q.ListWeekPlanDinnerIDs(ctx, addDays(weekStart, -7).String())
+	if err != nil {
+		return skills.WeekRequest{}, fmt.Errorf("plan: list last week's dinners: %w", err)
+	}
+	lastWeek := []string{}
+	for _, id := range last {
+		lastWeek = append(lastWeek, id.String)
+	}
+	return skills.WeekRequest{
+		Context:    hctx,
+		WeekStart:  weekStart,
+		Pool:       pool,
+		LastWeek:   lastWeek,
+		DinnerTime: settings.DinnerTime,
+	}, nil
+}
+
+// storeDraft stores week as the plan of the week starting weekStart in one
+// transaction and returns the plan's id. A new plan is draft. A draft
+// replaces the days of an existing plan, keeping each day's calendar
+// event id; a draft plan stays draft and a synced or changed one becomes
+// changed, since Calendar no longer shows it. A plan synced since the
+// draft was asked for without confirm is left as it is, failing with
+// ReasonConfirmRequired, and so is a plan no longer at revision base (the
+// revision before draft_week ran, or noPlan), failing with
+// ReasonPlanChanged.
+func (s *Service) storeDraft(ctx context.Context, weekStart store.LocalDate, confirm bool, base int64, week skills.Week) (string, error) {
+	var planID string
+	err := s.st.WithTx(ctx, func(tx *sql.Tx) error {
+		q := db.New(tx)
+		now := store.Now().String()
+		note := sql.NullString{String: week.Note, Valid: week.Note != ""}
+		cur, err := q.GetWeekPlan(ctx, weekStart.String())
+		switch {
+		case errors.Is(err, sql.ErrNoRows) && base != noPlan:
+			return &jobs.Failure{Code: ReasonPlanChanged}
+		case errors.Is(err, sql.ErrNoRows):
+			planID = store.NewID()
+			if err := q.CreateWeekPlan(ctx, db.CreateWeekPlanParams{
+				ID:        planID,
+				WeekStart: weekStart.String(),
+				AiNote:    note,
+				CreatedAt: now,
+				UpdatedAt: now,
+			}); err != nil {
+				return fmt.Errorf("plan: create week %s: %w", weekStart, err)
+			}
+		case err != nil:
+			return fmt.Errorf("plan: read week %s: %w", weekStart, err)
+		case cur.Status != StatusDraft && !confirm:
+			return &jobs.Failure{Code: ReasonConfirmRequired}
+		case cur.Revision != base:
+			return &jobs.Failure{Code: ReasonPlanChanged}
+		default:
+			planID = cur.ID
+			status := StatusDraft
+			if cur.Status != StatusDraft {
+				status = StatusChanged
+			}
+			if err := q.RedraftWeekPlan(ctx, db.RedraftWeekPlanParams{Status: status, AiNote: note, UpdatedAt: now, ID: cur.ID}); err != nil {
+				return fmt.Errorf("plan: redraft %s: %w", cur.ID, err)
+			}
+		}
+		for _, d := range week.Days {
+			isNew := int64(0)
+			if d.IsNew {
+				isNew = 1
+			}
+			if err := q.PutPlanDay(ctx, db.PutPlanDayParams{
+				ID:        store.NewID(),
+				PlanID:    planID,
+				Date:      d.Date,
+				DinnerID:  sql.NullString{String: d.DinnerID, Valid: true},
+				IsNew:     isNew,
+				CreatedAt: now,
+				UpdatedAt: now,
+			}); err != nil {
+				return fmt.Errorf("plan: put %s of %s: %w", d.Date, planID, err)
+			}
+		}
+		return nil
+	})
+	if err != nil {
+		return "", err
+	}
+	return planID, nil
+}
+
+// addDays returns d plus n days.
+func addDays(d store.LocalDate, n int) store.LocalDate {
+	y, m, day := d.Date()
+	return store.LocalDateOf(time.Date(y, m, day+n, 0, 0, 0, 0, time.UTC))
+}

internal/plan/plan.go

@@ -0,0 +1,424 @@
+// Package plan keeps the household's weekly plans: the Draft board the AI
+// drafts from the Regulars and the Quest log, and the swaps the household
+// makes on it. A draft runs as a job: draft_week plans seven dinners, one
+// a day from Monday to Sunday, and the job stores them as the week's plan,
+// replacing any draft before it unless the household edited the plan
+// while draft_week ran. A plan is draft until Push to Calendar
+// syncs it (Feature 16); an edit of a synced plan makes it changed.
+package plan
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+	"log/slog"
+	"slices"
+	"time"
+
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/ai/skills"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/db"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/dinners"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/household"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/jobs"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/store"
+)
+
+// KindDraftWeek is the job that drafts a week's plan.
+const KindDraftWeek = "draft_week"
+
+// Plan statuses (the week_plans.status column).
+const (
+	StatusDraft   = "draft"
+	StatusSynced  = "synced"
+	StatusChanged = "changed"
+)
+
+// Reasons a draft failed, stored as the KindDraftWeek job's failure code.
+// Any other failure, such as the database's, is the runner's
+// internal_error.
+const (
+	// ReasonNotEnoughDinners: the Regulars and Quest log hold fewer than
+	// seven dinners to draft from.
+	ReasonNotEnoughDinners = "not_enough_dinners"
+	// ReasonAIFailed: draft_week failed; no week is made up instead.
+	ReasonAIFailed = "ai_failed"
+	// ReasonConfirmRequired: the plan was synced after the draft was
+	// asked for without confirm, so the draft does not replace it.
+	ReasonConfirmRequired = "confirm_required"
+	// ReasonPlanChanged: the plan was edited while draft_week ran, so the
+	// draft does not replace the edit.
+	ReasonPlanChanged = "plan_changed"
+)
+
+// Reasons are every draft failure reason.
+var Reasons = []string{ReasonNotEnoughDinners, ReasonAIFailed, ReasonConfirmRequired, ReasonPlanChanged}
+
+// ContextBudget is the character budget of the household context
+// draft_week is given (see harness.BuildContext).
+const ContextBudget = 16000
+
+// plannable are the dinner statuses a day may be swapped to.
+var plannable = []string{dinners.StatusRegular, dinners.StatusQuestLog}
+
+// ErrNotFound is returned for a week with no plan.
+var ErrNotFound = errors.New("plan not found")
+
+// ErrDinnerNotFound is a swap to an unknown dinner.
+var ErrDinnerNotFound = errors.New("dinner not found")
+
+// ErrConfirmRequired is a draft over a synced or changed plan asked for
+// without confirm.
+var ErrConfirmRequired = errors.New("the plan was pushed to Calendar; drafting over it needs confirm")
+
+// ErrDraftRunning is a confirmed draft asked for while a draft of the week
+// asked for without confirm is queued or running.
+var ErrDraftRunning = errors.New("a draft of the week without confirm is already running; ask again when it finishes")
+
+// InvalidWeekError is a week start that is not a Monday date.
+type InvalidWeekError struct {
+	Value string
+}
+
+func (e *InvalidWeekError) Error() string {
+	return fmt.Sprintf("week start %q is not a Monday date (YYYY-MM-DD)", e.Value)
+}
+
+// InvalidDayError is a swap of a date outside the plan's week.
+type InvalidDayError struct {
+	Value string
+}
+
+func (e *InvalidDayError) Error() string {
+	return fmt.Sprintf("date %q is not a day of the week (YYYY-MM-DD)", e.Value)
+}
+
+// DinnerNotPlannableError is a swap to a dinner that is neither a Regular
+// nor in the Quest log.
+type DinnerNotPlannableError struct {
+	Status string
+}
+
+func (e *DinnerNotPlannableError) Error() string {
+	return fmt.Sprintf("the dinner is %s; only Regulars and Quest log dinners can be planned", e.Status)
+}
+
+// ParseWeekStart parses s, a household-local Monday as YYYY-MM-DD.
+func ParseWeekStart(s string) (store.LocalDate, error) {
+	d, err := store.ParseLocalDate(s)
+	if err != nil {
+		return store.LocalDate{}, &InvalidWeekError{Value: s}
+	}
+	if _, err := household.WeekDays(d); err != nil {
+		return store.LocalDate{}, &InvalidWeekError{Value: s}
+	}
+	return d, nil
+}
+
+// Drafter runs draft_week on in; scope names the week. In production it is
+// skills.DraftWeek with the household's harness.Config.
+type Drafter func(ctx context.Context, scope string, in skills.WeekRequest) (skills.Week, error)
+
+// Service drafts, reads and edits weekly plans.
+type Service struct {
+	st       *store.Store
+	draft    Drafter
+	logger   *slog.Logger
+	draftJob *jobs.Kind[DraftJob]
+}
+
+// NewService returns a service over st that drafts with draft and
+// registers the KindDraftWeek job on runner, which must not have started
+// yet. The kind is service-only: StartDraft, which keeps one draft in
+// flight per week, is the only way to enqueue it.
+func NewService(st *store.Store, draft Drafter, runner *jobs.Runner, logger *slog.Logger) (*Service, error) {
+	switch {
+	case st == nil:
+		return nil, errors.New("plan: nil store")
+	case draft == nil:
+		return nil, errors.New("plan: nil drafter")
+	case runner == nil:
+		return nil, errors.New("plan: nil job runner")
+	case logger == nil:
+		return nil, errors.New("plan: nil logger")
+	}
+	s := &Service{st: st, draft: draft, logger: logger}
+	kind, err := jobs.Register(runner, KindDraftWeek, s.runDraft, Reasons...)
+	if err != nil {
+		return nil, err
+	}
+	if err := kind.ServiceOnly(); err != nil {
+		return nil, err
+	}
+	s.draftJob = kind
+	return s, nil
+}
+
+// Plan is a week's plan as the API shows it.
+type Plan struct {
+	ID        string `json:"id"`
+	WeekStart string `json:"week_start"`
+	// WeekLabel is e.g. "Week 41 · Oct 5 – 11".
+	WeekLabel        string  `json:"week_label"`
+	Status           string  `json:"status"`
+	AINote           *string `json:"ai_note"`
+	CalendarSyncedAt *string `json:"calendar_synced_at"`
+	Days             []Day   `json:"days"`
+	UpdatedAt        string  `json:"updated_at"`
+}
+
+// Day is one day of a plan.
+type Day struct {
+	// Date is household-local, YYYY-MM-DD.
+	Date   string `json:"date"`
+	Dinner Dinner `json:"dinner"`
+	// IsNew is true for a dinner planned from the Quest log.
+	IsNew bool `json:"is_new"`
+	// StartBy is when a crock-pot dinner must start to be ready at the
+	// household's dinner time; null for any other dinner and for a
+	// crock-pot dinner whose minutes are unknown.
+	StartBy *time.Time `json:"start_by"`
+}
+
+// Dinner is a planned dinner as a plan day shows it.
+type Dinner struct {
+	ID      string  `json:"id"`
+	Name    string  `json:"name"`
+	Photo   *string `json:"photo"`
+	Minutes *int64  `json:"minutes"`
+	Method  *string `json:"method"`
+	Origin  string  `json:"origin"`
+}
+
+// Get returns the plan of the week starting weekStart, or ErrNotFound.
+// The plan and the household settings come from one read transaction.
+func (s *Service) Get(ctx context.Context, weekStart store.LocalDate) (p Plan, err error) {
+	tx, err := s.st.Reader.BeginTx(ctx, nil)
+	if err != nil {
+		return Plan{}, fmt.Errorf("plan: begin read: %w", err)
+	}
+	defer func() {
+		err = errors.Join(err, tx.Rollback())
+	}()
+	return readPlan(ctx, db.New(tx), weekStart)
+}
+
+// readPlan reads the plan of the week starting weekStart through q, with
+// each day's start_by from the household's dinner time and zone.
+func readPlan(ctx context.Context, q *db.Queries, weekStart store.LocalDate) (Plan, error) {
+	label, err := household.WeekLabel(weekStart)
+	if err != nil {
+		return Plan{}, fmt.Errorf("plan: %w", err)
+	}
+	row, err := q.GetWeekPlan(ctx, weekStart.String())
+	if errors.Is(err, sql.ErrNoRows) {
+		return Plan{}, ErrNotFound
+	}
+	if err != nil {
+		return Plan{}, fmt.Errorf("plan: read week %s: %w", weekStart, err)
+	}
+	settings, err := q.GetHouseholdSettings(ctx)
+	if err != nil {
+		return Plan{}, fmt.Errorf("plan: read household settings: %w", err)
+	}
+	zone, err := household.LoadZone(settings.Timezone)
+	if err != nil {
+		return Plan{}, fmt.Errorf("plan: household settings: %w", err)
+	}
+	rows, err := q.ListPlanDays(ctx, row.ID)
+	if err != nil {
+		return Plan{}, fmt.Errorf("plan: read days of %s: %w", row.ID, err)
+	}
+	dates, err := household.WeekDays(weekStart)
+	if err != nil {
+		return Plan{}, fmt.Errorf("plan: %w", err)
+	}
+	if len(rows) != len(dates) {
+		return Plan{}, fmt.Errorf("plan: week %s has %d planned days, want %d", weekStart, len(rows), len(dates))
+	}
+	p := Plan{
+		ID:               row.ID,
+		WeekStart:        row.WeekStart,
+		WeekLabel:        label,
+		Status:           row.Status,
+		AINote:           nullString(row.AiNote),
+		CalendarSyncedAt: nullString(row.CalendarSyncedAt),
+		Days:             make([]Day, len(rows)),
+		UpdatedAt:        row.UpdatedAt,
+	}
+	for i, r := range rows {
+		if r.Date != dates[i].String() {
+			return Plan{}, fmt.Errorf("plan: week %s day %d is %s, want %s", weekStart, i+1, r.Date, dates[i])
+		}
+		startBy, err := startBy(zone, dates[i], settings.DinnerTime, r.Dinner)
+		if err != nil {
+			return Plan{}, fmt.Errorf("plan: start by of %s: %w", r.Date, err)
+		}
+		p.Days[i] = Day{Date: r.Date, Dinner: fromDinner(r.Dinner), IsNew: r.IsNew == 1, StartBy: startBy}
+	}
+	return p, nil
+}
+
+// startBy returns when crock-pot dinner d must start on date to be ready at
+// dinnerTime in zone, or nil for any other dinner and for a crock-pot
+// dinner whose minutes are unknown.
+func startBy(zone *time.Location, date store.LocalDate, dinnerTime string, d db.Dinner) (*time.Time, error) {
+	if !d.Method.Valid || d.Method.String != "crockpot" || !d.MinutesTotal.Valid || d.MinutesTotal.Int64 <= 0 {
+		return nil, nil
+	}
+	at, err := household.LocalTime(zone, date, dinnerTime)
+	if err != nil {
+		return nil, err
+	}
+	at = at.Add(-time.Duration(d.MinutesTotal.Int64) * time.Minute)
+	return &at, nil
+}
+
+// Draft is a draft asked for: the job drafting the week, and whether this
+// call enqueued it rather than found one already queued or running.
+type Draft struct {
+	JobID   string `json:"jobId"`
+	Created bool   `json:"-"`
+}
+
+// StartDraft enqueues the KindDraftWeek job drafting the week starting
+// weekStart, unless one is already queued or running for it, which it
+// returns instead with Created false, so a week has at most one draft in
+// flight. A confirmed draft joins only a confirmed job: while the week's
+// job was asked for without confirm, it fails with ErrDraftRunning and
+// enqueues nothing. Drafting over a synced or changed plan needs confirm,
+// else it fails with ErrConfirmRequired and enqueues nothing.
+func (s *Service) StartDraft(ctx context.Context, weekStart store.LocalDate, confirm bool) (Draft, error) {
+	if _, err := household.WeekDays(weekStart); err != nil {
+		return Draft{}, &InvalidWeekError{Value: weekStart.String()}
+	}
+	var d Draft
+	err := s.st.WithTx(ctx, func(tx *sql.Tx) error {
+		q := db.New(tx)
+		cur, err := q.GetWeekPlan(ctx, weekStart.String())
+		switch {
+		case errors.Is(err, sql.ErrNoRows):
+		case err != nil:
+			return fmt.Errorf("plan: read week %s: %w", weekStart, err)
+		case cur.Status != StatusDraft && !confirm:
+			return ErrConfirmRequired
+		}
+		active, err := q.GetActiveDraftJob(ctx, db.GetActiveDraftJobParams{Kind: KindDraftWeek, WeekStart: weekStart.String()})
+		switch {
+		case errors.Is(err, sql.ErrNoRows):
+		case err != nil:
+			return fmt.Errorf("plan: read draft job of %s: %w", weekStart, err)
+		case confirm && active.Confirmed != 1:
+			return ErrDraftRunning
+		default:
+			d = Draft{JobID: active.ID}
+			return nil
+		}
+		id, err := s.draftJob.EnqueueTx(ctx, tx, DraftJob{WeekStart: weekStart.String(), Confirm: confirm})
+		if err != nil {
+			return fmt.Errorf("plan: enqueue draft of %s: %w", weekStart, err)
+		}
+		d = Draft{JobID: id, Created: true}
+		return nil
+	})
+	if err != nil {
+		return Draft{}, err
+	}
+	if d.Created {
+		s.draftJob.Wake()
+	}
+	return d, nil
+}
+
+// Swap plans dinnerID on date of the week starting weekStart, marking the
+// day new when the dinner is in the Quest log. Swapping a synced plan
+// makes it changed. The week must have a plan (else ErrNotFound), date
+// must be one of its days (else *InvalidDayError), and the dinner must be
+// a Regular or in the Quest log (else ErrDinnerNotFound or
+// *DinnerNotPlannableError). It returns the plan as swapped.
+func (s *Service) Swap(ctx context.Context, weekStart store.LocalDate, date, dinnerID string) (Plan, error) {
+	dates, err := household.WeekDays(weekStart)
+	if err != nil {
+		return Plan{}, &InvalidWeekError{Value: weekStart.String()}
+	}
+	day, err := store.ParseLocalDate(date)
+	if err != nil || !slices.Contains(dates[:], day) {
+		return Plan{}, &InvalidDayError{Value: date}
+	}
+	var p Plan
+	err = s.st.WithTx(ctx, func(tx *sql.Tx) error {
+		q := db.New(tx)
+		cur, err := q.GetWeekPlan(ctx, weekStart.String())
+		if errors.Is(err, sql.ErrNoRows) {
+			return ErrNotFound
+		}
+		if err != nil {
+			return fmt.Errorf("plan: read week %s: %w", weekStart, err)
+		}
+		d, err := q.GetDinner(ctx, dinnerID)
+		if errors.Is(err, sql.ErrNoRows) {
+			return ErrDinnerNotFound
+		}
+		if err != nil {
+			return fmt.Errorf("plan: read dinner %s: %w", dinnerID, err)
+		}
+		if !slices.Contains(plannable, d.Status) {
+			return &DinnerNotPlannableError{Status: d.Status}
+		}
+		now := store.Now().String()
+		n, err := q.SwapPlanDay(ctx, db.SwapPlanDayParams{
+			DinnerID:  sql.NullString{String: d.ID, Valid: true},
+			IsNew:     isNew(d.Status),
+			UpdatedAt: now,
+			PlanID:    cur.ID,
+			Date:      day.String(),
+		})
+		if err != nil {
+			return fmt.Errorf("plan: swap %s of %s: %w", day, cur.ID, err)
+		}
+		if n != 1 {
+			return fmt.Errorf("plan: %s has no day %s", cur.ID, day)
+		}
+		if err := q.MarkWeekPlanEdited(ctx, db.MarkWeekPlanEditedParams{UpdatedAt: now, ID: cur.ID}); err != nil {
+			return fmt.Errorf("plan: mark %s edited: %w", cur.ID, err)
+		}
+		p, err = readPlan(ctx, q, weekStart)
+		return err
+	})
+	if err != nil {
+		return Plan{}, err
+	}
+	return p, nil
+}
+
+// isNew is plan_days.is_new for a dinner with status: 1 for the Quest log.
+func isNew(status string) int64 {
+	if status == dinners.StatusQuestLog {
+		return 1
+	}
+	return 0
+}
+
+func fromDinner(d db.Dinner) Dinner {
+	out := Dinner{
+		ID:     d.ID,
+		Name:   d.Name,
+		Method: nullString(d.Method),
+		Origin: d.Origin,
+	}
+	if d.MinutesTotal.Valid {
+		out.Minutes = &d.MinutesTotal.Int64
+	}
+	if d.PhotoID.Valid {
+		u := dinners.PhotoURL(d.PhotoID.String)
+		out.Photo = &u
+	}
+	return out
+}
+
+func nullString(s sql.NullString) *string {
+	if !s.Valid {
+		return nil
+	}
+	return &s.String
+}

internal/plan/plan_test.go

@@ -0,0 +1,872 @@
+package plan_test
+
+import (
+	"context"
+	"database/sql"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"slices"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/ai/harness"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/ai/llm"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/ai/skills"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/db"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/household"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/jobs"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/plan"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/store"
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/migrations"
+)
+
+// week is the Monday the tests draft, and weekDates its days.
+var (
+	week      = mustDate("2026-10-12")
+	weekDates = []string{"2026-10-12", "2026-10-13", "2026-10-14", "2026-10-15", "2026-10-16", "2026-10-17", "2026-10-18"}
+)
+
+func mustDate(s string) store.LocalDate {
+	d, err := store.ParseLocalDate(s)
+	if err != nil {
+		panic(err)
+	}
+	return d
+}
+
+type env struct {
+	svc    *plan.Service
+	st     *store.Store
+	runner *jobs.Runner
+	model  *llm.Fake
+	// ids are the seeded dinners' ids by name.
+	ids map[string]string
+
+	mu     sync.Mutex
+	inputs []skills.WeekRequest
+}
+
+// newEnv returns a plan service over a migrated store in zone
+// America/New_York with dinner time 17:30, the Regulars below and Quest
+// log dinners Pad Thai and Shawarma Bowls, and an unstarted job runner
+// with two workers. It drafts through the real harness and draft_week with
+// the scripted e.model.
+func newEnv(t *testing.T) *env {
+	t.Helper()
+	ctx := t.Context()
+	st, err := store.Open(ctx, t.TempDir())
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() {
+		if err := st.Close(); err != nil {
+			t.Error(err)
+		}
+	})
+	if err := store.Migrate(ctx, st.Writer, migrations.FS); err != nil {
+		t.Fatal(err)
+	}
+	if err := household.SeedSettings(ctx, st, "America/New_York"); err != nil {
+		t.Fatal(err)
+	}
+	e := &env{st: st, model: &llm.Fake{}, ids: map[string]string{}}
+	for _, d := range []struct {
+		name, status, method string
+		minutes              int64
+	}{
+		{"Beef Chili", "regular", "crockpot", 240},
+		{"Pot Roast", "regular", "crockpot", 0},
+		{"Chicken Fajitas", "regular", "stovetop", 30},
+		{"Spaghetti Bolognese", "regular", "stovetop", 45},
+		{"Sheet Pan Salmon", "regular", "oven", 35},
+		{"Pad Thai", "quest_log", "stovetop", 35},
+		{"Shawarma Bowls", "quest_log", "oven", 40},
+	} {
+		e.ids[d.name] = e.dinner(t, d.name, d.status, d.method, d.minutes)
+	}
+	guard, err := harness.NewGuard(harness.DefaultMaxCalls)
+	if err != nil {
+		t.Fatal(err)
+	}
+	cfg := harness.Config{
+		Settings:    llm.Settings{Provider: "anthropic", Model: "claude-test", Temperature: 0.7},
+		NewProvider: func(llm.Settings, string) (llm.Provider, error) { return e.model, nil },
+		Store:       st,
+		Guard:       guard,
+	}
+	drafter := func(ctx context.Context, scope string, in skills.WeekRequest) (skills.Week, error) {
+		e.mu.Lock()
+		e.inputs = append(e.inputs, in)
+		e.mu.Unlock()
+		return skills.DraftWeek(ctx, cfg, scope, in)
+	}
+	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
+	// Two workers, as cmd/server runs, so drafts of a week could overlap.
+	e.runner, err = jobs.NewRunner(st, logger, 2)
+	if err != nil {
+		t.Fatal(err)
+	}
+	e.svc, err = plan.NewService(st, drafter, e.runner, logger)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return e
+}
+
+// input returns the request of the ith draft_week run.
+func (e *env) input(i int) skills.WeekRequest {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+	return e.inputs[i]
+}
+
+// start starts the env's job runner, stopping it when the test ends.
+func (e *env) start(t *testing.T) {
+	t.Helper()
+	ctx, cancel := context.WithCancel(context.Background())
+	if err := e.runner.Start(ctx); err != nil {
+		cancel()
+		t.Fatal(err)
+	}
+	t.Cleanup(func() {
+		cancel()
+		e.runner.Wait()
+	})
+}
+
+// dinner stores a dinner and returns its id; minutes 0 is unknown.
+func (e *env) dinner(t *testing.T, name, status, method string, minutes int64) string {
+	t.Helper()
+	now := store.Now().String()
+	origin := "regular"
+	if status != "regular" {
+		origin = "side_quest"
+	}
+	d, err := db.New(e.st.Writer).CreateDinner(t.Context(), db.CreateDinnerParams{
+		ID:              store.NewID(),
+		Name:            name,
+		NormalizedName:  harness.Normalize(name),
+		Status:          status,
+		Origin:          origin,
+		Method:          sql.NullString{String: method, Valid: method != ""},
+		MinutesTotal:    sql.NullInt64{Int64: minutes, Valid: minutes > 0},
+		GroundingStatus: "manual",
+		CreatedAt:       now,
+		UpdatedAt:       now,
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return d.ID
+}
+
+// reply scripts one draft_week reply planning the dinners named names on
+// weekDates, in order.
+func (e *env) reply(note string, names ...string) {
+	e.model.QueueGenerate(e.weekReply(note, names...))
+}
+
+// weekReply is the draft_week reply planning the dinners named names on
+// weekDates, in order.
+func (e *env) weekReply(note string, names ...string) llm.GenerateResult {
+	var days []string
+	for i, name := range names {
+		days = append(days, fmt.Sprintf(`{"date":%q,"dinner_id":%q}`, weekDates[i], e.ids[name]))
+	}
+	js := fmt.Sprintf(`{"days":[%s],"note":%q}`, strings.Join(days, ","), note)
+	return llm.GenerateResult{Response: llm.Response{Text: js, JSON: json.RawMessage(js)}}
+}
+
+// fullWeek plans every seeded dinner, Beef Chili on Monday and Pot Roast
+// on Tuesday.
+var fullWeek = []string{"Beef Chili", "Pot Roast", "Pad Thai", "Chicken Fajitas", "Shawarma Bowls", "Spaghetti Bolognese", "Sheet Pan Salmon"}
+
+// waitJob waits for job id to finish and returns it.
+func (e *env) waitJob(t *testing.T, id string) jobs.Job {
+	t.Helper()
+	deadline := time.Now().Add(10 * time.Second)
+	for {
+		job, err := e.runner.Get(t.Context(), id)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if job.Status == jobs.StatusSucceeded || job.Status == jobs.StatusFailed {
+			return job
+		}
+		if time.Now().After(deadline) {
+			t.Fatalf("job %s still %s", id, job.Status)
+		}
+		time.Sleep(5 * time.Millisecond)
+	}
+}
+
+// draft asks for a draft of week with confirm and waits for its job.
+func (e *env) draft(t *testing.T, confirm bool) jobs.Job {
+	t.Helper()
+	d, err := e.svc.StartDraft(t.Context(), week, confirm)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !d.Created {
+		t.Fatalf("draft job %s was already queued", d.JobID)
+	}
+	return e.waitJob(t, d.JobID)
+}
+
+// mustDraft drafts week with confirm, requiring the job to succeed, and
+// returns the plan.
+func (e *env) mustDraft(t *testing.T, confirm bool) plan.Plan {
+	t.Helper()
+	job := e.draft(t, confirm)
+	if job.Status != jobs.StatusSucceeded {
+		t.Fatalf("draft job %s, error %v", job.Status, *job.Error)
+	}
+	p, err := e.svc.Get(t.Context(), week)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var res struct {
+		WeekStart string `json:"week_start"`
+		PlanID    string `json:"plan_id"`
+	}
+	if err := json.Unmarshal(job.Result, &res); err != nil {
+		t.Fatal(err)
+	}
+	if res.WeekStart != week.String() || res.PlanID != p.ID {
+		t.Fatalf("draft result = %+v, want week %s plan %s", res, week, p.ID)
+	}
+	return p
+}
+
+// setStatus sets the plan of week to status, as Push to Calendar would.
+func (e *env) setStatus(t *testing.T, status string) {
+	t.Helper()
+	if _, err := e.st.Writer.ExecContext(t.Context(), `UPDATE week_plans SET status = ?, calendar_synced_at = ? WHERE week_start = ?`,
+		status, store.Now().String(), week.String()); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func dayNames(p plan.Plan) []string {
+	var names []string
+	for _, d := range p.Days {
+		names = append(names, d.Dinner.Name)
+	}
+	return names
+}
+
+func TestDraftCreatesPlan(t *testing.T) {
+	e := newEnv(t)
+	e.start(t)
+	e.reply("Five Regulars and two from your Quest log.", fullWeek...)
+
+	p := e.mustDraft(t, false)
+
+	if p.Status != plan.StatusDraft || p.WeekStart != "2026-10-12" || p.WeekLabel != "Week 42 · Oct 12 – 18" {
+		t.Errorf("plan = %s %s %q, want draft 2026-10-12 \"Week 42 · Oct 12 – 18\"", p.Status, p.WeekStart, p.WeekLabel)
+	}
+	if p.AINote == nil || *p.AINote != "Five Regulars and two from your Quest log." {
+		t.Errorf("ai_note = %v", p.AINote)
+	}
+	if p.CalendarSyncedAt != nil {
+		t.Errorf("calendar_synced_at = %v, want null", *p.CalendarSyncedAt)
+	}
+	if got := dayNames(p); !slices.Equal(got, fullWeek) {
+		t.Errorf("days = %v, want %v", got, fullWeek)
+	}
+	for i, d := range p.Days {
+		if d.Date != weekDates[i] {
+			t.Errorf("day %d date = %s, want %s", i, d.Date, weekDates[i])
+		}
+		wantNew := d.Dinner.Name == "Pad Thai" || d.Dinner.Name == "Shawarma Bowls"
+		if d.IsNew != wantNew {
+			t.Errorf("%s is_new = %v, want %v", d.Dinner.Name, d.IsNew, wantNew)
+		}
+		if d.Dinner.ID != e.ids[d.Dinner.Name] {
+			t.Errorf("%s id = %s", d.Dinner.Name, d.Dinner.ID)
+		}
+	}
+	chili := p.Days[0]
+	if chili.Dinner.Method == nil || *chili.Dinner.Method != "crockpot" || chili.Dinner.Minutes == nil || *chili.Dinner.Minutes != 240 || chili.Dinner.Origin != "regular" {
+		t.Errorf("Beef Chili dinner = %+v", chili.Dinner)
+	}
+
+	// The pool is every Regular and Quest log dinner; last week has no
+	// plan.
+	in := e.input(0)
+	var pool []string
+	for _, c := range in.Pool {
+		pool = append(pool, c.Name+"/"+c.Kind)
+	}
+	slices.Sort(pool)
+	want := []string{"Beef Chili/regular", "Chicken Fajitas/regular", "Pad Thai/quest_log", "Pot Roast/regular",
+		"Shawarma Bowls/quest_log", "Sheet Pan Salmon/regular", "Spaghetti Bolognese/regular"}
+	if !slices.Equal(pool, want) {
+		t.Errorf("pool = %v, want %v", pool, want)
+	}
+	if in.WeekStart != week || in.DinnerTime != "17:30" || len(in.LastWeek) != 0 {
+		t.Errorf("request week %s dinner time %s last week %v", in.WeekStart, in.DinnerTime, in.LastWeek)
+	}
+}
+
+func TestStartByIsDinnerTimeMinusMinutesForCrockPot(t *testing.T) {
+	e := newEnv(t)
+	e.start(t)
+	e.reply("", fullWeek...)
+	p := e.mustDraft(t, false)
+
+	newYork, err := time.LoadLocation("America/New_York")
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Beef Chili: crock pot, 240 minutes, dinner at 17:30 EDT.
+	if got, want := p.Days[0].StartBy, time.Date(2026, 10, 12, 13, 30, 0, 0, newYork); got == nil || !got.Equal(want) {
+		t.Errorf("Beef Chili start_by = %v, want %v", got, want)
+	}
+	// Pot Roast is a crock-pot dinner with no minutes; the rest are not
+	// crock-pot dinners.
+	for _, d := range p.Days[1:] {
+		if d.StartBy != nil {
+			t.Errorf("%s start_by = %v, want null", d.Dinner.Name, *d.StartBy)
+		}
+	}
+	if p.AINote != nil {
+		t.Errorf("ai_note = %q, want null for an empty note", *p.AINote)
+	}
+
+	// start_by follows the household's dinner time.
+	dinnerTime := "18:45"
+	if _, err := household.NewSettingsService(e.st).Update(t.Context(), household.SettingsPatch{DinnerTime: &dinnerTime}, "member-1"); err != nil {
+		t.Fatal(err)
+	}
+	p, err = e.svc.Get(t.Context(), week)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got, want := p.Days[0].StartBy, time.Date(2026, 10, 12, 14, 45, 0, 0, newYork); got == nil || !got.Equal(want) {
+		t.Errorf("Beef Chili start_by = %v, want %v", got, want)
+	}
+	if b, err := json.Marshal(p.Days[0]); err != nil || !strings.Contains(string(b), `"start_by":"2026-10-12T14:45:00-04:00"`) {
+		t.Errorf("day JSON = %s, %v; want start_by in the household zone", b, err)
+	}
+}
+
+func TestStartByAcrossDaylightSavingTimeEnd(t *testing.T) {
+	e := newEnv(t)
+	// New York leaves daylight saving time at 02:00 on Sunday 2026-11-01.
+	// Beef Chili (240 minutes) is planned Monday to Saturday and a 20-hour
+	// crock-pot dinner on Sunday, so its start crosses the change.
+	stew := e.dinner(t, "Overnight Stew", "regular", "crockpot", 1200)
+	q := db.New(e.st.Writer)
+	now := store.Now().String()
+	id := store.NewID()
+	dst := mustDate("2026-10-26")
+	if err := q.CreateWeekPlan(t.Context(), db.CreateWeekPlanParams{ID: id, WeekStart: dst.String(), CreatedAt: now, UpdatedAt: now}); err != nil {
+		t.Fatal(err)
+	}
+	dates := []string{"2026-10-26", "2026-10-27", "2026-10-28", "2026-10-29", "2026-10-30", "2026-10-31", "2026-11-01"}
+	for i, date := range dates {
+		dinner := e.ids["Beef Chili"]
+		if i == 6 {
+			dinner = stew
+		}
+		if err := q.PutPlanDay(t.Context(), db.PutPlanDayParams{ID: store.NewID(), PlanID: id, Date: date,
+			DinnerID: sql.NullString{String: dinner, Valid: true}, CreatedAt: now, UpdatedAt: now}); err != nil {
+			t.Fatal(err)
+		}
+	}
+	p, err := e.svc.Get(t.Context(), dst)
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Saturday's dinner is 17:30 EDT; Sunday's is 17:30 EST, 22:30 UTC, and
+	// twenty hours before it is 22:30 EDT on Saturday.
+	for _, tc := range []struct {
+		day  int
+		want string
+	}{
+		{5, `"2026-10-31T13:30:00-04:00"`},
+		{6, `"2026-10-31T22:30:00-04:00"`},
+	} {
+		b, err := json.Marshal(p.Days[tc.day].StartBy)
+		if err != nil || string(b) != tc.want {
+			t.Errorf("%s start_by = %s, %v; want %s", dates[tc.day], b, err, tc.want)
+		}
+	}
+	// Swapped to Beef Chili, Sunday starts at 13:30 EST.
+	if _, err := e.svc.Swap(t.Context(), dst, "2026-11-01", e.ids["Beef Chili"]); err != nil {
+		t.Fatal(err)
+	}
+	if p, err = e.svc.Get(t.Context(), dst); err != nil {
+		t.Fatal(err)
+	}
+	if b, err := json.Marshal(p.Days[6].StartBy); err != nil || string(b) != `"2026-11-01T13:30:00-05:00"` {
+		t.Errorf("Sunday Beef Chili start_by = %s, %v; want 13:30 EST", b, err)
+	}
+}
+
+func TestDraftGivesLastWeek(t *testing.T) {
+	e := newEnv(t)
+	e.start(t)
+	last := mustDate("2026-10-05")
+	q := db.New(e.st.Writer)
+	now := store.Now().String()
+	id := store.NewID()
+	if err := q.CreateWeekPlan(t.Context(), db.CreateWeekPlanParams{ID: id, WeekStart: last.String(), CreatedAt: now, UpdatedAt: now}); err != nil {
+		t.Fatal(err)
+	}
+	if err := q.PutPlanDay(t.Context(), db.PutPlanDayParams{ID: store.NewID(), PlanID: id, Date: "2026-10-06",
+		DinnerID: sql.NullString{String: e.ids["Chicken Fajitas"], Valid: true}, CreatedAt: now, UpdatedAt: now}); err != nil {
+		t.Fatal(err)
+	}
+	e.reply("", fullWeek...)
+	e.mustDraft(t, false)
+	if got := e.input(0).LastWeek; !slices.Equal(got, []string{e.ids["Chicken Fajitas"]}) {
+		t.Errorf("last week = %v, want Chicken Fajitas", got)
+	}
+}
+
+func TestDraftPoolLeavesOutQuestLogPlannedOnAnotherWeek(t *testing.T) {
+	e := newEnv(t)
+	e.start(t)
+	// Pad Thai is on a later week's plan, so the Quest log no longer
+	// offers it; an eighth dinner keeps the pool at seven.
+	q := db.New(e.st.Writer)
+	now := store.Now().String()
+	later := store.NewID()
+	if err := q.CreateWeekPlan(t.Context(), db.CreateWeekPlanParams{ID: later, WeekStart: "2099-01-05", CreatedAt: now, UpdatedAt: now}); err != nil {
+		t.Fatal(err)
+	}
+	if err := q.PutPlanDay(t.Context(), db.PutPlanDayParams{ID: store.NewID(), PlanID: later, Date: "2099-01-05",
+		DinnerID: sql.NullString{String: e.ids["Pad Thai"], Valid: true}, IsNew: 1, CreatedAt: now, UpdatedAt: now}); err != nil {
+		t.Fatal(err)
+	}
+	e.ids["Fish Tacos"] = e.dinner(t, "Fish Tacos", "regular", "", 0)
+	names := []string{"Beef Chili", "Pot Roast", "Fish Tacos", "Chicken Fajitas", "Shawarma Bowls", "Spaghetti Bolognese", "Sheet Pan Salmon"}
+	e.reply("", names...)
+	p := e.mustDraft(t, false)
+	if got := dayNames(p); !slices.Equal(got, names) {
+		t.Errorf("days = %v", got)
+	}
+	for _, c := range e.input(0).Pool {
+		if c.Name == "Pad Thai" {
+			t.Errorf("pool has Pad Thai, planned on a later week")
+		}
+	}
+	// A redraft of the week keeps offering its own Quest log dinners.
+	e.reply("", names...)
+	e.mustDraft(t, false)
+	if !slices.ContainsFunc(e.input(1).Pool, func(c skills.Candidate) bool { return c.Name == "Shawarma Bowls" }) {
+		t.Errorf("redraft pool left out Shawarma Bowls, planned on this week")
+	}
+}
+
+func TestDraftFailsWithNotEnoughDinners(t *testing.T) {
+	e := newEnv(t)
+	e.start(t)
+	if _, err := e.st.Writer.ExecContext(t.Context(), `UPDATE dinners SET status = 'archived' WHERE id = ?`, e.ids["Pad Thai"]); err != nil {
+		t.Fatal(err)
+	}
+	job := e.draft(t, false)
+	if job.Status != jobs.StatusFailed || *job.Error != plan.ReasonNotEnoughDinners {
+		t.Fatalf("job %s %v, want failed %s", job.Status, job.Error, plan.ReasonNotEnoughDinners)
+	}
+	if n := len(e.model.Requests()); n != 0 {
+		t.Errorf("model called %d times", n)
+	}
+	if _, err := e.svc.Get(t.Context(), week); !errors.Is(err, plan.ErrNotFound) {
+		t.Errorf("Get = %v, want ErrNotFound", err)
+	}
+}
+
+func TestDraftFailsWhenAIFails(t *testing.T) {
+	e := newEnv(t)
+	e.start(t)
+	e.model.QueueGenerate(llm.GenerateResult{Err: errors.New("provider down")})
+	job := e.draft(t, false)
+	if job.Status != jobs.StatusFailed || *job.Error != plan.ReasonAIFailed {
+		t.Fatalf("job %s %v, want failed %s", job.Status, job.Error, plan.ReasonAIFailed)
+	}
+	if _, err := e.svc.Get(t.Context(), week); !errors.Is(err, plan.ErrNotFound) {
+		t.Errorf("Get = %v, want ErrNotFound", err)
+	}
+}
+
+func TestStartDraftIsSingleFlight(t *testing.T) {
+	e := newEnv(t)
+	first, err := e.svc.StartDraft(t.Context(), week, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	again, err := e.svc.StartDraft(t.Context(), week, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !first.Created || again.Created || again.JobID != first.JobID {
+		t.Fatalf("drafts = %+v then %+v, want the second to join the first", first, again)
+	}
+	other, err := e.svc.StartDraft(t.Context(), mustDate("2026-10-19"), false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !other.Created || other.JobID == first.JobID {
+		t.Errorf("another week's draft = %+v, want its own job", other)
+	}
+}
+
+func TestSimultaneousStartDraftsShareOneJob(t *testing.T) {
+	for _, confirmFirst := range []bool{false, true} {
+		t.Run(fmt.Sprintf("first confirm %v", confirmFirst), func(t *testing.T) {
+			e := newEnv(t)
+			first, err := e.svc.StartDraft(t.Context(), week, confirmFirst)
+			if err != nil {
+				t.Fatal(err)
+			}
+			// Twenty simultaneous drafts, half of them confirmed: every
+			// one joins the queued job, except a confirmed one while the
+			// job is unconfirmed, which is refused.
+			const n = 20
+			drafts := make([]plan.Draft, n)
+			errs := make([]error, n)
+			var wg sync.WaitGroup
+			for i := range n {
+				wg.Go(func() {
+					drafts[i], errs[i] = e.svc.StartDraft(context.Background(), week, i%2 == 1)
+				})
+			}
+			wg.Wait()
+			for i, d := range drafts {
+				if i%2 == 1 && !confirmFirst {
+					if !errors.Is(errs[i], plan.ErrDraftRunning) {
+						t.Errorf("confirmed draft %d = %+v, %v, want ErrDraftRunning", i, d, errs[i])
+					}
+					continue
+				}
+				if errs[i] != nil || d.JobID != first.JobID || d.Created {
+					t.Errorf("draft %d = %+v, %v, want it to join %s", i, d, errs[i], first.JobID)
+				}
+			}
+			var queued int
+			if err := e.st.Reader.QueryRowContext(t.Context(), `SELECT COUNT(*) FROM jobs WHERE kind = ?`, plan.KindDraftWeek).Scan(&queued); err != nil {
+				t.Fatal(err)
+			}
+			if queued != 1 {
+				t.Errorf("%d draft jobs, want 1", queued)
+			}
+		})
+	}
+}
+
+func TestConfirmedDraftWhileUnconfirmedDraftRuns(t *testing.T) {
+	e := newEnv(t)
+	e.start(t)
+	e.reply("first", fullWeek...)
+	e.mustDraft(t, false)
+
+	// An unconfirmed redraft is running when the plan is synced; the
+	// household then confirms a redraft. With a second worker idle, a
+	// second job would draft alongside the first, so the confirmed draft
+	// is refused and only the first job runs draft_week.
+	reversed := slices.Clone(fullWeek)
+	slices.Reverse(reversed)
+	started, release := make(chan struct{}), make(chan struct{})
+	r := e.weekReply("unconfirmed", fullWeek...)
+	r.Started, r.Release = started, release
+	e.model.QueueGenerate(r)
+	e.reply("concurrent", reversed...)
+	unconfirmed, err := e.svc.StartDraft(t.Context(), week, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	<-started
+	e.setStatus(t, plan.StatusSynced)
+	if d, err := e.svc.StartDraft(t.Context(), week, true); !errors.Is(err, plan.ErrDraftRunning) {
+		t.Fatalf("confirmed draft = %+v, %v, want ErrDraftRunning", d, err)
+	}
+	close(release)
+	if job := e.waitJob(t, unconfirmed.JobID); job.Status != jobs.StatusFailed || *job.Error != plan.ReasonConfirmRequired {
+		t.Errorf("unconfirmed job %s %v, want failed %s", job.Status, job.Error, plan.ReasonConfirmRequired)
+	}
+	var queued int
+	if err := e.st.Reader.QueryRowContext(t.Context(), `SELECT COUNT(*) FROM jobs WHERE kind = ?`, plan.KindDraftWeek).Scan(&queued); err != nil {
+		t.Fatal(err)
+	}
+	if queued != 2 {
+		t.Errorf("%d draft jobs, want the first and the unconfirmed redraft", queued)
+	}
+	p, err := e.svc.Get(t.Context(), week)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if p.Status != plan.StatusSynced || *p.AINote != "first" || !slices.Equal(dayNames(p), fullWeek) {
+		t.Errorf("plan = %s %q %v, want the synced first draft", p.Status, *p.AINote, dayNames(p))
+	}
+
+	// Asked again once the unconfirmed job has finished, the confirmed
+	// draft replaces the plan.
+	if p := e.mustDraft(t, true); p.Status != plan.StatusChanged || *p.AINote != "concurrent" || !slices.Equal(dayNames(p), reversed) {
+		t.Errorf("plan = %s %q %v, want the confirmed draft, changed", p.Status, *p.AINote, dayNames(p))
+	}
+}
+
+func TestDraftFailsWhenPlanSwappedWhileDrafting(t *testing.T) {
+	e := newEnv(t)
+	e.start(t)
+	e.reply("first", fullWeek...)
+	e.mustDraft(t, false)
+
+	// The household swaps Wednesday while draft_week runs; the draft must
+	// not erase the swap.
+	reversed := slices.Clone(fullWeek)
+	slices.Reverse(reversed)
+	started, release := make(chan struct{}), make(chan struct{})
+	r := e.weekReply("second", reversed...)
+	r.Started, r.Release = started, release
+	e.model.QueueGenerate(r)
+	d, err := e.svc.StartDraft(t.Context(), week, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	<-started
+	if _, err := e.svc.Swap(t.Context(), week, "2026-10-14", e.ids["Sheet Pan Salmon"]); err != nil {
+		t.Fatal(err)
+	}
+	close(release)
+	job := e.waitJob(t, d.JobID)
+	if job.Status != jobs.StatusFailed || *job.Error != plan.ReasonPlanChanged {
+		t.Fatalf("job %s %v, want failed %s", job.Status, job.Error, plan.ReasonPlanChanged)
+	}
+	p, err := e.svc.Get(t.Context(), week)
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := slices.Clone(fullWeek)
+	want[2] = "Sheet Pan Salmon"
+	if *p.AINote != "first" || !slices.Equal(dayNames(p), want) {
+		t.Errorf("plan = %q %v, want the first draft with the swap %v", *p.AINote, dayNames(p), want)
+	}
+
+	// A draft after the swap replaces the plan.
+	e.reply("third", reversed...)
+	if p := e.mustDraft(t, false); *p.AINote != "third" || !slices.Equal(dayNames(p), reversed) {
+		t.Errorf("redraft after the swap = %q %v, want the third draft", *p.AINote, dayNames(p))
+	}
+}
+
+func TestRedraftOverDraftNeedsNoConfirm(t *testing.T) {
+	e := newEnv(t)
+	e.start(t)
+	e.reply("first", fullWeek...)
+	first := e.mustDraft(t, false)
+	reversed := slices.Clone(fullWeek)
+	slices.Reverse(reversed)
+	e.reply("second", reversed...)
+	second := e.mustDraft(t, false)
+	if second.ID != first.ID || second.Status != plan.StatusDraft || *second.AINote != "second" {
+		t.Errorf("redraft = %s %s %v, want plan %s draft \"second\"", second.ID, second.Status, *second.AINote, first.ID)
+	}
+	if got := dayNames(second); !slices.Equal(got, reversed) {
+		t.Errorf("days = %v, want %v", got, reversed)
+	}
+}
+
+func TestDraftOverSyncedOrChangedPlanNeedsConfirm(t *testing.T) {
+	for _, status := range []string{plan.StatusSynced, plan.StatusChanged} {
+		t.Run(status, func(t *testing.T) {
+			e := newEnv(t)
+			e.start(t)
+			e.reply("first", fullWeek...)
+			first := e.mustDraft(t, false)
+			e.setStatus(t, status)
+			// Push to Calendar records each day's event id.
+			if _, err := e.st.Writer.ExecContext(t.Context(), `UPDATE plan_days SET calendar_event_id = 'ev-' || date`); err != nil {
+				t.Fatal(err)
+			}
+
+			if _, err := e.svc.StartDraft(t.Context(), week, false); !errors.Is(err, plan.ErrConfirmRequired) {
+				t.Fatalf("StartDraft without confirm = %v, want ErrConfirmRequired", err)
+			}
+			var queued int
+			if err := e.st.Reader.QueryRowContext(t.Context(), `SELECT COUNT(*) FROM jobs WHERE kind = ?`, plan.KindDraftWeek).Scan(&queued); err != nil {
+				t.Fatal(err)
+			}
+			if queued != 1 {
+				t.Errorf("%d draft jobs, want only the first", queued)
+			}
+
+			reversed := slices.Clone(fullWeek)
+			slices.Reverse(reversed)
+			e.reply("second", reversed...)
+			p := e.mustDraft(t, true)
+			if p.ID != first.ID || p.Status != plan.StatusChanged || p.CalendarSyncedAt == nil {
+				t.Errorf("confirmed redraft = %s %s synced %v, want plan %s changed, still synced once", p.ID, p.Status, p.CalendarSyncedAt, first.ID)
+			}
+			if got := dayNames(p); !slices.Equal(got, reversed) {
+				t.Errorf("days = %v, want %v", got, reversed)
+			}
+			var events int
+			if err := e.st.Reader.QueryRowContext(t.Context(), `SELECT COUNT(*) FROM plan_days WHERE calendar_event_id = 'ev-' || date`).Scan(&events); err != nil {
+				t.Fatal(err)
+			}
+			if events != 7 {
+				t.Errorf("%d days kept their calendar event id, want 7", events)
+			}
+		})
+	}
+}
+
+func TestDraftFailsWhenPlanSyncedAfterAskingWithoutConfirm(t *testing.T) {
+	e := newEnv(t)
+	e.start(t)
+	e.reply("first", fullWeek...)
+	e.mustDraft(t, false)
+
+	// The redraft is asked for while the plan is draft; the plan is synced
+	// while draft_week runs, so the draft must not replace it.
+	reversed := slices.Clone(fullWeek)
+	slices.Reverse(reversed)
+	started, release := make(chan struct{}), make(chan struct{})
+	r := e.weekReply("second", reversed...)
+	r.Started, r.Release = started, release
+	e.model.QueueGenerate(r)
+	d, err := e.svc.StartDraft(t.Context(), week, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	<-started
+	e.setStatus(t, plan.StatusSynced)
+	close(release)
+	job := e.waitJob(t, d.JobID)
+	if job.Status != jobs.StatusFailed || *job.Error != plan.ReasonConfirmRequired {
+		t.Fatalf("job %s %v, want failed %s", job.Status, job.Error, plan.ReasonConfirmRequired)
+	}
+	p, err := e.svc.Get(t.Context(), week)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if p.Status != plan.StatusSynced || *p.AINote != "first" || !slices.Equal(dayNames(p), fullWeek) {
+		t.Errorf("plan = %s %q %v, want the synced first draft", p.Status, *p.AINote, dayNames(p))
+	}
+}
+
+func TestParseWeekStart(t *testing.T) {
+	if d, err := plan.ParseWeekStart("2026-10-12"); err != nil || d != week {
+		t.Errorf("ParseWeekStart(Monday) = %v, %v", d, err)
+	}
+	// 2026-02-30 and 2027-02-29 would be Mondays were they dates.
+	for _, s := range []string{"2026-10-13", "2026-10-18", "2026-10-5", "2026-02-30", "2027-02-29", "2026-13-05", "next-week", ""} {
+		var invalid *plan.InvalidWeekError
+		if _, err := plan.ParseWeekStart(s); !errors.As(err, &invalid) {
+			t.Errorf("ParseWeekStart(%q) = %v, want *InvalidWeekError", s, err)
+		}
+	}
+}
+
+func TestSwapDay(t *testing.T) {
+	e := newEnv(t)
+	e.start(t)
+	e.reply("", fullWeek...)
+	e.mustDraft(t, false)
+	e.ids["Fish Tacos"] = e.dinner(t, "Fish Tacos", "regular", "stovetop", 25)
+	e.ids["Ramen"] = e.dinner(t, "Ramen", "quest_log", "crockpot", 300)
+
+	// A Quest log dinner is new, and a crock-pot one gets its start_by.
+	p, err := e.svc.Swap(t.Context(), week, "2026-10-14", e.ids["Ramen"])
+	if err != nil {
+		t.Fatal(err)
+	}
+	day := p.Days[2]
+	if day.Dinner.Name != "Ramen" || !day.IsNew || day.StartBy == nil || day.StartBy.Format("15:04") != "12:30" {
+		t.Errorf("Wednesday = %+v, want Ramen, new, start by 12:30", day)
+	}
+	if p.Status != plan.StatusDraft {
+		t.Errorf("status = %s, want a swapped draft to stay draft", p.Status)
+	}
+
+	// A Regular in place of a Quest log dinner is not new.
+	p, err = e.svc.Swap(t.Context(), week, "2026-10-14", e.ids["Fish Tacos"])
+	if err != nil {
+		t.Fatal(err)
+	}
+	if day := p.Days[2]; day.Dinner.Name != "Fish Tacos" || day.IsNew || day.StartBy != nil {
+		t.Errorf("Wednesday = %+v, want Fish Tacos, not new, no start_by", day)
+	}
+	want := slices.Clone(fullWeek)
+	want[2] = "Fish Tacos"
+	if got := dayNames(p); !slices.Equal(got, want) {
+		t.Errorf("days = %v, want %v", got, want)
+	}
+	got, err := e.svc.Get(t.Context(), week)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !slices.Equal(dayNames(got), want) {
+		t.Errorf("Get days = %v, want %v", dayNames(got), want)
+	}
+}
+
+func TestSwapStatusTransitions(t *testing.T) {
+	for _, tc := range []struct{ from, want string }{
+		{plan.StatusDraft, plan.StatusDraft},
+		{plan.StatusSynced, plan.StatusChanged},
+		{plan.StatusChanged, plan.StatusChanged},
+	} {
+		t.Run(tc.from, func(t *testing.T) {
+			e := newEnv(t)
+			e.start(t)
+			e.reply("", fullWeek...)
+			e.mustDraft(t, false)
+			e.setStatus(t, tc.from)
+			p, err := e.svc.Swap(t.Context(), week, "2026-10-12", e.ids["Pad Thai"])
+			if err != nil {
+				t.Fatal(err)
+			}
+			if p.Status != tc.want {
+				t.Errorf("status after swap = %s, want %s", p.Status, tc.want)
+			}
+		})
+	}
+}
+
+func TestSwapRefusals(t *testing.T) {
+	e := newEnv(t)
+	e.start(t)
+	e.reply("", fullWeek...)
+	e.mustDraft(t, false)
+	e.setStatus(t, plan.StatusSynced)
+	suggested := e.dinner(t, "Laksa", "suggested", "stovetop", 30)
+	archived := e.dinner(t, "Old Stew", "archived", "", 0)
+
+	var notPlannable *plan.DinnerNotPlannableError
+	var badDay *plan.InvalidDayError
+	for _, tc := range []struct {
+		name      string
+		week      store.LocalDate
+		date, id  string
+		wantError func(error) bool
+	}{
+		{"no plan", mustDate("2026-10-19"), "2026-10-19", e.ids["Pad Thai"], func(err error) bool { return errors.Is(err, plan.ErrNotFound) }},
+		{"unknown dinner", week, "2026-10-12", "no-such-dinner", func(err error) bool { return errors.Is(err, plan.ErrDinnerNotFound) }},
+		{"suggested dinner", week, "2026-10-12", suggested, func(err error) bool { return errors.As(err, &notPlannable) }},
+		{"archived dinner", week, "2026-10-12", archived, func(err error) bool { return errors.As(err, &notPlannable) }},
+		{"day of another week", week, "2026-10-19", e.ids["Pad Thai"], func(err error) bool { return errors.As(err, &badDay) }},
+		{"not a date", week, "monday", e.ids["Pad Thai"], func(err error) bool { return errors.As(err, &badDay) }},
+		{"impossible date", week, "2026-10-32", e.ids["Pad Thai"], func(err error) bool { return errors.As(err, &badDay) }},
+	} {
+		if _, err := e.svc.Swap(t.Context(), tc.week, tc.date, tc.id); !tc.wantError(err) {
+			t.Errorf("%s: Swap = %v", tc.name, err)
+		}
+	}
+	p, err := e.svc.Get(t.Context(), week)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if p.Status != plan.StatusSynced || !slices.Equal(dayNames(p), fullWeek) {
+		t.Errorf("plan = %s %v, want it unchanged by refused swaps", p.Status, dayNames(p))
+	}
+}