galaxy-game/backend/internal/diplomail/store.go

package diplomail

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"time"

	"galaxy/backend/internal/postgres/jet/backend/model"
	"galaxy/backend/internal/postgres/jet/backend/table"

	"github.com/go-jet/jet/v2/postgres"
	"github.com/go-jet/jet/v2/qrm"
	"github.com/google/uuid"
)

// Store is the Postgres-backed query surface for the diplomail
// package. All queries are built through go-jet against the generated
// table bindings under `backend/internal/postgres/jet/backend/table`.
type Store struct {
	db *sql.DB
}

// NewStore constructs a Store wrapping db.
func NewStore(db *sql.DB) *Store { return &Store{db: db} }

// messageColumns is the canonical projection for diplomail_messages
// reads.
func messageColumns() postgres.ColumnList {
	m := table.DiplomailMessages
	return postgres.ColumnList{
		m.MessageID, m.GameID, m.GameName, m.Kind, m.SenderKind,
		m.SenderUserID, m.SenderUsername, m.SenderRaceName, m.SenderIP,
		m.Subject, m.Body, m.BodyLang, m.BroadcastScope, m.CreatedAt,
	}
}

// recipientColumns is the canonical projection for
// diplomail_recipients reads.
func recipientColumns() postgres.ColumnList {
	r := table.DiplomailRecipients
	return postgres.ColumnList{
		r.RecipientID, r.MessageID, r.GameID, r.UserID,
		r.RecipientUserName, r.RecipientRaceName, r.RecipientPreferredLanguage,
		r.AvailableAt, r.TranslationAttempts, r.NextTranslationAttemptAt,
		r.DeliveredAt, r.ReadAt, r.DeletedAt, r.NotifiedAt,
	}
}

// MessageInsert carries the immutable per-message fields. The store
// fills MessageID, sets CreatedAt to `now()` via the column default,
// and leaves recipient-side state to InsertRecipient.
type MessageInsert struct {
	MessageID      uuid.UUID
	GameID         uuid.UUID
	GameName       string
	Kind           string
	SenderKind     string
	SenderUserID   *uuid.UUID
	SenderUsername *string
	SenderRaceName *string
	SenderIP       string
	Subject        string
	Body           string
	BodyLang       string
	BroadcastScope string
}

// RecipientInsert carries the per-recipient snapshot. AvailableAt
// captures the async-delivery contract: when non-nil, the recipient
// row is materialised already-delivered (no translation needed or
// the language matches); when nil, the recipient is queued for the
// translation worker.
type RecipientInsert struct {
	RecipientID                uuid.UUID
	MessageID                  uuid.UUID
	GameID                     uuid.UUID
	UserID                     uuid.UUID
	RecipientUserName          string
	RecipientRaceName          *string
	RecipientPreferredLanguage string
	AvailableAt                *time.Time
}

// InsertMessageWithRecipients persists a Message together with one or
// more Recipient rows inside a single transaction. The function is
// the canonical write path for every send variant: Stage A passes a
// single-element slice; later stages reuse the same path for
// broadcasts.
func (s *Store) InsertMessageWithRecipients(ctx context.Context, msg MessageInsert, recipients []RecipientInsert) (Message, []Recipient, error) {
	if len(recipients) == 0 {
		return Message{}, nil, errors.New("diplomail store: at least one recipient required")
	}

	tx, err := s.db.BeginTx(ctx, nil)
	if err != nil {
		return Message{}, nil, fmt.Errorf("diplomail store: begin tx: %w", err)
	}
	defer func() { _ = tx.Rollback() }()

	m := table.DiplomailMessages
	msgStmt := m.INSERT(
		m.MessageID, m.GameID, m.GameName, m.Kind, m.SenderKind,
		m.SenderUserID, m.SenderUsername, m.SenderRaceName, m.SenderIP,
		m.Subject, m.Body, m.BodyLang, m.BroadcastScope,
	).VALUES(
		msg.MessageID,
		msg.GameID,
		msg.GameName,
		msg.Kind,
		msg.SenderKind,
		uuidPtrArg(msg.SenderUserID),
		stringPtrArg(msg.SenderUsername),
		stringPtrArg(msg.SenderRaceName),
		msg.SenderIP,
		msg.Subject,
		msg.Body,
		msg.BodyLang,
		msg.BroadcastScope,
	).RETURNING(messageColumns())

	var msgRow model.DiplomailMessages
	if err := msgStmt.QueryContext(ctx, tx, &msgRow); err != nil {
		return Message{}, nil, fmt.Errorf("diplomail store: insert message: %w", err)
	}

	r := table.DiplomailRecipients
	rcptStmt := r.INSERT(
		r.RecipientID, r.MessageID, r.GameID, r.UserID,
		r.RecipientUserName, r.RecipientRaceName,
		r.RecipientPreferredLanguage, r.AvailableAt,
	)
	for _, in := range recipients {
		rcptStmt = rcptStmt.VALUES(
			in.RecipientID,
			in.MessageID,
			in.GameID,
			in.UserID,
			in.RecipientUserName,
			stringPtrArg(in.RecipientRaceName),
			in.RecipientPreferredLanguage,
			timePtrArg(in.AvailableAt),
		)
	}
	rcptStmt = rcptStmt.RETURNING(recipientColumns())

	var rcptRows []model.DiplomailRecipients
	if err := rcptStmt.QueryContext(ctx, tx, &rcptRows); err != nil {
		return Message{}, nil, fmt.Errorf("diplomail store: insert recipients: %w", err)
	}

	if err := tx.Commit(); err != nil {
		return Message{}, nil, fmt.Errorf("diplomail store: commit: %w", err)
	}

	return messageFromModel(msgRow), recipientsFromModel(rcptRows), nil
}

// LoadMessage returns the Message row identified by messageID. The
// function is used by readers that already verified recipient
// authorisation; callers that need both the message and the
// recipient's per-user state should use LoadInboxEntry.
func (s *Store) LoadMessage(ctx context.Context, messageID uuid.UUID) (Message, error) {
	m := table.DiplomailMessages
	stmt := postgres.SELECT(messageColumns()).
		FROM(m).
		WHERE(m.MessageID.EQ(postgres.UUID(messageID))).
		LIMIT(1)
	var row model.DiplomailMessages
	if err := stmt.QueryContext(ctx, s.db, &row); err != nil {
		if errors.Is(err, qrm.ErrNoRows) {
			return Message{}, ErrNotFound
		}
		return Message{}, fmt.Errorf("diplomail store: load message %s: %w", messageID, err)
	}
	return messageFromModel(row), nil
}

// LoadInboxEntry returns a Message together with the caller's
// Recipient row, both for messageID. Returns ErrNotFound when the
// caller is not a recipient of the message — this is also how the
// service layer enforces "only recipients may read".
func (s *Store) LoadInboxEntry(ctx context.Context, messageID, userID uuid.UUID) (InboxEntry, error) {
	m := table.DiplomailMessages
	r := table.DiplomailRecipients
	cols := append(messageColumns(), recipientColumns()...)
	stmt := postgres.SELECT(cols).
		FROM(r.INNER_JOIN(m, m.MessageID.EQ(r.MessageID))).
		WHERE(
			r.MessageID.EQ(postgres.UUID(messageID)).
				AND(r.UserID.EQ(postgres.UUID(userID))),
		).
		LIMIT(1)
	var dest struct {
		model.DiplomailMessages
		Recipient model.DiplomailRecipients `alias:"diplomail_recipients"`
	}
	if err := stmt.QueryContext(ctx, s.db, &dest); err != nil {
		if errors.Is(err, qrm.ErrNoRows) {
			return InboxEntry{}, ErrNotFound
		}
		return InboxEntry{}, fmt.Errorf("diplomail store: load inbox entry %s/%s: %w", messageID, userID, err)
	}
	return InboxEntry{
		Message:   messageFromModel(dest.DiplomailMessages),
		Recipient: recipientFromModel(dest.Recipient),
	}, nil
}

// ListInbox returns the recipient view of messages addressed to
// userID in gameID, newest first. Soft-deleted rows
// (`deleted_at IS NOT NULL`) are excluded. Rows still waiting for
// the async translation worker (`available_at IS NULL`) are also
// excluded — they will appear once delivery is complete.
func (s *Store) ListInbox(ctx context.Context, gameID, userID uuid.UUID) ([]InboxEntry, error) {
	m := table.DiplomailMessages
	r := table.DiplomailRecipients
	cols := append(messageColumns(), recipientColumns()...)
	stmt := postgres.SELECT(cols).
		FROM(r.INNER_JOIN(m, m.MessageID.EQ(r.MessageID))).
		WHERE(
			r.UserID.EQ(postgres.UUID(userID)).
				AND(r.GameID.EQ(postgres.UUID(gameID))).
				AND(r.DeletedAt.IS_NULL()).
				AND(r.AvailableAt.IS_NOT_NULL()),
		).
		ORDER_BY(m.CreatedAt.DESC(), m.MessageID.DESC())
	var dest []struct {
		model.DiplomailMessages
		Recipient model.DiplomailRecipients `alias:"diplomail_recipients"`
	}
	if err := stmt.QueryContext(ctx, s.db, &dest); err != nil {
		return nil, fmt.Errorf("diplomail store: list inbox %s/%s: %w", gameID, userID, err)
	}
	out := make([]InboxEntry, 0, len(dest))
	for _, row := range dest {
		out = append(out, InboxEntry{
			Message:   messageFromModel(row.DiplomailMessages),
			Recipient: recipientFromModel(row.Recipient),
		})
	}
	return out, nil
}

// ListSent returns the sender-side view of personal messages
// authored by senderUserID in gameID, newest first. Each
// `InboxEntry` carries the message together with one of its
// recipient rows — single sends produce one entry per message;
// game broadcasts produce one entry per addressee (the in-game
// mail UI collapses broadcast entries into a single stand-alone
// item by `message_id`). Admin / system rows have
// `sender_user_id IS NULL` and are excluded by the WHERE clause.
func (s *Store) ListSent(ctx context.Context, gameID, senderUserID uuid.UUID) ([]InboxEntry, error) {
	m := table.DiplomailMessages
	r := table.DiplomailRecipients
	cols := append(messageColumns(), recipientColumns()...)
	stmt := postgres.SELECT(cols).
		FROM(m.INNER_JOIN(r, r.MessageID.EQ(m.MessageID))).
		WHERE(
			m.GameID.EQ(postgres.UUID(gameID)).
				AND(m.SenderUserID.EQ(postgres.UUID(senderUserID))),
		).
		ORDER_BY(m.CreatedAt.DESC(), m.MessageID.DESC(), r.RecipientID.ASC())
	var dest []struct {
		model.DiplomailMessages
		Recipient model.DiplomailRecipients `alias:"diplomail_recipients"`
	}
	if err := stmt.QueryContext(ctx, s.db, &dest); err != nil {
		return nil, fmt.Errorf("diplomail store: list sent %s/%s: %w", gameID, senderUserID, err)
	}
	out := make([]InboxEntry, 0, len(dest))
	for _, row := range dest {
		out = append(out, InboxEntry{
			Message:   messageFromModel(row.DiplomailMessages),
			Recipient: recipientFromModel(row.Recipient),
		})
	}
	return out, nil
}

// MarkRead sets `read_at = at` on the recipient row identified by
// (messageID, userID). Idempotent: a row that is already marked read
// is left untouched but the existing Recipient is returned.
// Returns ErrNotFound when the user is not a recipient of the message.
func (s *Store) MarkRead(ctx context.Context, messageID, userID uuid.UUID, at time.Time) (Recipient, error) {
	r := table.DiplomailRecipients
	stmt := r.UPDATE(r.ReadAt).
		SET(postgres.TimestampzT(at.UTC())).
		WHERE(
			r.MessageID.EQ(postgres.UUID(messageID)).
				AND(r.UserID.EQ(postgres.UUID(userID))).
				AND(r.ReadAt.IS_NULL()),
		).
		RETURNING(recipientColumns())
	var row model.DiplomailRecipients
	if err := stmt.QueryContext(ctx, s.db, &row); err != nil {
		if !errors.Is(err, qrm.ErrNoRows) {
			return Recipient{}, fmt.Errorf("diplomail store: mark read %s/%s: %w", messageID, userID, err)
		}
		// The row exists but read_at was already set, or the row
		// does not exist at all. Fetch to disambiguate.
		existing, loadErr := s.LoadRecipient(ctx, messageID, userID)
		if loadErr != nil {
			return Recipient{}, loadErr
		}
		return existing, nil
	}
	return recipientFromModel(row), nil
}

// SoftDelete sets `deleted_at = at` on the recipient row identified by
// (messageID, userID). The row must already have `read_at` set;
// otherwise the call returns ErrConflict so a hostile client cannot
// erase a message before opening it (item 10 of the spec).
// Returns ErrNotFound when the user is not a recipient.
func (s *Store) SoftDelete(ctx context.Context, messageID, userID uuid.UUID, at time.Time) (Recipient, error) {
	r := table.DiplomailRecipients
	stmt := r.UPDATE(r.DeletedAt).
		SET(postgres.TimestampzT(at.UTC())).
		WHERE(
			r.MessageID.EQ(postgres.UUID(messageID)).
				AND(r.UserID.EQ(postgres.UUID(userID))).
				AND(r.ReadAt.IS_NOT_NULL()).
				AND(r.DeletedAt.IS_NULL()),
		).
		RETURNING(recipientColumns())
	var row model.DiplomailRecipients
	if err := stmt.QueryContext(ctx, s.db, &row); err != nil {
		if !errors.Is(err, qrm.ErrNoRows) {
			return Recipient{}, fmt.Errorf("diplomail store: soft delete %s/%s: %w", messageID, userID, err)
		}
		existing, loadErr := s.LoadRecipient(ctx, messageID, userID)
		if loadErr != nil {
			return Recipient{}, loadErr
		}
		if existing.ReadAt == nil {
			return Recipient{}, fmt.Errorf("%w: message must be read before delete", ErrConflict)
		}
		// Already deleted: return the existing row idempotently.
		return existing, nil
	}
	return recipientFromModel(row), nil
}

// LoadRecipient fetches the Recipient row keyed on (messageID, userID).
// Returns ErrNotFound when no such recipient exists.
func (s *Store) LoadRecipient(ctx context.Context, messageID, userID uuid.UUID) (Recipient, error) {
	r := table.DiplomailRecipients
	stmt := postgres.SELECT(recipientColumns()).
		FROM(r).
		WHERE(
			r.MessageID.EQ(postgres.UUID(messageID)).
				AND(r.UserID.EQ(postgres.UUID(userID))),
		).
		LIMIT(1)
	var row model.DiplomailRecipients
	if err := stmt.QueryContext(ctx, s.db, &row); err != nil {
		if errors.Is(err, qrm.ErrNoRows) {
			return Recipient{}, ErrNotFound
		}
		return Recipient{}, fmt.Errorf("diplomail store: load recipient %s/%s: %w", messageID, userID, err)
	}
	return recipientFromModel(row), nil
}

// UnreadCountForUserGame returns the count of unread, non-deleted,
// delivered messages addressed to userID in gameID. Recipients
// still waiting for translation (`available_at IS NULL`) are
// excluded so the badge does not flicker.
func (s *Store) UnreadCountForUserGame(ctx context.Context, gameID, userID uuid.UUID) (int, error) {
	r := table.DiplomailRecipients
	stmt := postgres.SELECT(postgres.COUNT(postgres.STAR).AS("count")).
		FROM(r).
		WHERE(
			r.UserID.EQ(postgres.UUID(userID)).
				AND(r.GameID.EQ(postgres.UUID(gameID))).
				AND(r.ReadAt.IS_NULL()).
				AND(r.DeletedAt.IS_NULL()).
				AND(r.AvailableAt.IS_NOT_NULL()),
		)
	var dest struct {
		Count int64 `alias:"count"`
	}
	if err := stmt.QueryContext(ctx, s.db, &dest); err != nil {
		return 0, fmt.Errorf("diplomail store: unread count %s/%s: %w", gameID, userID, err)
	}
	return int(dest.Count), nil
}

// PendingTranslationPair carries one unit of work picked by the
// translation worker. Multiple recipients of the same message that
// share a preferred_language collapse into one pair, because the
// translation is shared via the diplomail_translations cache.
// CurrentAttempts is the highest `translation_attempts` value across
// the matching recipient rows, so the worker can decide whether the
// next attempt is the last one before falling back.
type PendingTranslationPair struct {
	MessageID       uuid.UUID
	TargetLang      string
	CurrentAttempts int32
}

// PickPendingTranslationPair returns one pair eligible for the
// translation worker, or `ok == false` when the queue is empty. The
// pair is the (message, target_lang) of any recipient where
// `available_at IS NULL` and `next_translation_attempt_at` is either
// unset or already due. The query intentionally drops the
// `FOR UPDATE` clause — the worker is single-threaded per process,
// and the optimistic UPDATE in `MarkPairDelivered` /
// `MarkPairFallback` filters by `available_at IS NULL`, so a stale
// pickup never delivers twice.
func (s *Store) PickPendingTranslationPair(ctx context.Context, now time.Time) (PendingTranslationPair, bool, error) {
	r := table.DiplomailRecipients
	stmt := postgres.SELECT(
		r.MessageID.AS("message_id"),
		r.RecipientPreferredLanguage.AS("target_lang"),
		postgres.MAX(r.TranslationAttempts).AS("attempts"),
	).
		FROM(r).
		WHERE(
			r.AvailableAt.IS_NULL().
				AND(r.RecipientPreferredLanguage.NOT_EQ(postgres.String(""))).
				AND(r.NextTranslationAttemptAt.IS_NULL().
					OR(r.NextTranslationAttemptAt.LT_EQ(postgres.TimestampzT(now.UTC())))),
		).
		GROUP_BY(r.MessageID, r.RecipientPreferredLanguage).
		ORDER_BY(r.MessageID.ASC(), r.RecipientPreferredLanguage.ASC()).
		LIMIT(1)
	var dest struct {
		MessageID  uuid.UUID `alias:"message_id"`
		TargetLang string    `alias:"target_lang"`
		Attempts   int32     `alias:"attempts"`
	}
	if err := stmt.QueryContext(ctx, s.db, &dest); err != nil {
		if errors.Is(err, qrm.ErrNoRows) {
			return PendingTranslationPair{}, false, nil
		}
		return PendingTranslationPair{}, false, fmt.Errorf("diplomail store: pick pending pair: %w", err)
	}
	if dest.MessageID == (uuid.UUID{}) {
		return PendingTranslationPair{}, false, nil
	}
	return PendingTranslationPair{
		MessageID:       dest.MessageID,
		TargetLang:      dest.TargetLang,
		CurrentAttempts: dest.Attempts,
	}, true, nil
}

// MarkPairDelivered flips every still-pending recipient of (messageID,
// targetLang) to `available_at = at`, optionally persisting the
// translation row alongside in the same transaction. Returns the
// recipients that were just delivered (used by the worker to fan out
// push events).
func (s *Store) MarkPairDelivered(ctx context.Context, messageID uuid.UUID, targetLang string, translation *Translation, at time.Time) ([]Recipient, error) {
	tx, err := s.db.BeginTx(ctx, nil)
	if err != nil {
		return nil, fmt.Errorf("diplomail store: begin deliver tx: %w", err)
	}
	defer func() { _ = tx.Rollback() }()

	if translation != nil {
		t := table.DiplomailTranslations
		ins := t.INSERT(
			t.TranslationID, t.MessageID, t.TargetLang,
			t.TranslatedSubject, t.TranslatedBody, t.Translator,
		).VALUES(
			translation.TranslationID, translation.MessageID, translation.TargetLang,
			translation.TranslatedSubject, translation.TranslatedBody, translation.Translator,
		).ON_CONFLICT(t.MessageID, t.TargetLang).DO_NOTHING()
		if _, err := ins.ExecContext(ctx, tx); err != nil {
			return nil, fmt.Errorf("diplomail store: upsert translation: %w", err)
		}
	}

	r := table.DiplomailRecipients
	upd := r.UPDATE(r.AvailableAt, r.NextTranslationAttemptAt).
		SET(postgres.TimestampzT(at.UTC()), postgres.NULL).
		WHERE(
			r.MessageID.EQ(postgres.UUID(messageID)).
				AND(r.RecipientPreferredLanguage.EQ(postgres.String(targetLang))).
				AND(r.AvailableAt.IS_NULL()),
		).
		RETURNING(recipientColumns())

	var rows []model.DiplomailRecipients
	if err := upd.QueryContext(ctx, tx, &rows); err != nil {
		return nil, fmt.Errorf("diplomail store: mark pair delivered: %w", err)
	}
	if err := tx.Commit(); err != nil {
		return nil, fmt.Errorf("diplomail store: commit deliver: %w", err)
	}
	out := make([]Recipient, 0, len(rows))
	for _, row := range rows {
		out = append(out, recipientFromModel(row))
	}
	return out, nil
}

// SchedulePairRetry bumps the attempt counter and schedules the next
// translation attempt for `next`. The recipient rows stay in the
// pending queue (`available_at IS NULL`). Returns the new attempt
// counter so the worker can decide whether to fall back to the
// original on the next pickup.
func (s *Store) SchedulePairRetry(ctx context.Context, messageID uuid.UUID, targetLang string, next time.Time) (int32, error) {
	r := table.DiplomailRecipients
	upd := r.UPDATE(r.TranslationAttempts, r.NextTranslationAttemptAt).
		SET(r.TranslationAttempts.ADD(postgres.Int(1)), postgres.TimestampzT(next.UTC())).
		WHERE(
			r.MessageID.EQ(postgres.UUID(messageID)).
				AND(r.RecipientPreferredLanguage.EQ(postgres.String(targetLang))).
				AND(r.AvailableAt.IS_NULL()),
		).
		RETURNING(r.TranslationAttempts)
	var dest []struct {
		TranslationAttempts int32 `alias:"diplomail_recipients.translation_attempts"`
	}
	if err := upd.QueryContext(ctx, s.db, &dest); err != nil {
		return 0, fmt.Errorf("diplomail store: schedule pair retry: %w", err)
	}
	if len(dest) == 0 {
		return 0, nil
	}
	max := dest[0].TranslationAttempts
	for _, d := range dest[1:] {
		if d.TranslationAttempts > max {
			max = d.TranslationAttempts
		}
	}
	return max, nil
}

// translationColumns is the canonical projection for
// diplomail_translations reads.
func translationColumns() postgres.ColumnList {
	t := table.DiplomailTranslations
	return postgres.ColumnList{
		t.TranslationID, t.MessageID, t.TargetLang,
		t.TranslatedSubject, t.TranslatedBody, t.Translator, t.TranslatedAt,
	}
}

// LoadTranslation returns the cached translation row for
// (messageID, targetLang). Returns ErrNotFound when no cache row
// exists yet — the caller decides whether to compute and persist
// one.
func (s *Store) LoadTranslation(ctx context.Context, messageID uuid.UUID, targetLang string) (Translation, error) {
	t := table.DiplomailTranslations
	stmt := postgres.SELECT(translationColumns()).
		FROM(t).
		WHERE(t.MessageID.EQ(postgres.UUID(messageID)).
			AND(t.TargetLang.EQ(postgres.String(targetLang)))).
		LIMIT(1)
	var row model.DiplomailTranslations
	if err := stmt.QueryContext(ctx, s.db, &row); err != nil {
		if errors.Is(err, qrm.ErrNoRows) {
			return Translation{}, ErrNotFound
		}
		return Translation{}, fmt.Errorf("diplomail store: load translation %s/%s: %w", messageID, targetLang, err)
	}
	return translationFromModel(row), nil
}

// InsertTranslation persists a new translation cache row. The unique
// constraint on (message_id, target_lang) prevents duplicate
// renderings. Callers that race on the same (message, lang) pair
// should be prepared for a UNIQUE violation; the second writer can
// fall back to LoadTranslation.
func (s *Store) InsertTranslation(ctx context.Context, in Translation) (Translation, error) {
	t := table.DiplomailTranslations
	stmt := t.INSERT(
		t.TranslationID, t.MessageID, t.TargetLang,
		t.TranslatedSubject, t.TranslatedBody, t.Translator,
	).VALUES(
		in.TranslationID, in.MessageID, in.TargetLang,
		in.TranslatedSubject, in.TranslatedBody, in.Translator,
	).RETURNING(translationColumns())

	var row model.DiplomailTranslations
	if err := stmt.QueryContext(ctx, s.db, &row); err != nil {
		return Translation{}, fmt.Errorf("diplomail store: insert translation %s/%s: %w", in.MessageID, in.TargetLang, err)
	}
	return translationFromModel(row), nil
}

func translationFromModel(row model.DiplomailTranslations) Translation {
	return Translation{
		TranslationID:    row.TranslationID,
		MessageID:        row.MessageID,
		TargetLang:       row.TargetLang,
		TranslatedSubject: row.TranslatedSubject,
		TranslatedBody:   row.TranslatedBody,
		Translator:       row.Translator,
		TranslatedAt:     row.TranslatedAt,
	}
}

// DeleteMessagesForGames removes every diplomail_messages row whose
// game_id falls in the supplied set. The cascade defined on the
// `diplomail_recipients` and `diplomail_translations` foreign keys
// removes the per-recipient state and the cached translations in
// the same transaction. Returns the count of messages removed.
//
// Used by the admin bulk-purge endpoint; callers are expected to
// have already filtered the input set to terminal-state games.
func (s *Store) DeleteMessagesForGames(ctx context.Context, gameIDs []uuid.UUID) (int, error) {
	if len(gameIDs) == 0 {
		return 0, nil
	}
	args := make([]postgres.Expression, 0, len(gameIDs))
	for _, id := range gameIDs {
		args = append(args, postgres.UUID(id))
	}
	m := table.DiplomailMessages
	stmt := m.DELETE().WHERE(m.GameID.IN(args...))
	res, err := stmt.ExecContext(ctx, s.db)
	if err != nil {
		return 0, fmt.Errorf("diplomail store: bulk delete messages: %w", err)
	}
	affected, err := res.RowsAffected()
	if err != nil {
		return 0, fmt.Errorf("diplomail store: rows affected: %w", err)
	}
	return int(affected), nil
}

// ListMessagesForAdmin returns a paginated slice of messages
// matching filter. The result is ordered by created_at DESC,
// message_id DESC. Total is the count without pagination so the
// caller can render a "page X of N" envelope.
func (s *Store) ListMessagesForAdmin(ctx context.Context, filter AdminMessageListing) ([]Message, int, error) {
	m := table.DiplomailMessages
	page := filter.Page
	if page < 1 {
		page = 1
	}
	pageSize := filter.PageSize
	if pageSize < 1 {
		pageSize = 50
	}

	conditions := postgres.BoolExpression(nil)
	addCondition := func(cond postgres.BoolExpression) {
		if conditions == nil {
			conditions = cond
			return
		}
		conditions = conditions.AND(cond)
	}
	if filter.GameID != nil {
		addCondition(m.GameID.EQ(postgres.UUID(*filter.GameID)))
	}
	if filter.Kind != "" {
		addCondition(m.Kind.EQ(postgres.String(filter.Kind)))
	}
	if filter.SenderKind != "" {
		addCondition(m.SenderKind.EQ(postgres.String(filter.SenderKind)))
	}

	countStmt := postgres.SELECT(postgres.COUNT(postgres.STAR).AS("count")).FROM(m)
	if conditions != nil {
		countStmt = countStmt.WHERE(conditions)
	}
	var countDest struct {
		Count int64 `alias:"count"`
	}
	if err := countStmt.QueryContext(ctx, s.db, &countDest); err != nil {
		return nil, 0, fmt.Errorf("diplomail store: count admin messages: %w", err)
	}

	listStmt := postgres.SELECT(messageColumns()).FROM(m)
	if conditions != nil {
		listStmt = listStmt.WHERE(conditions)
	}
	listStmt = listStmt.
		ORDER_BY(m.CreatedAt.DESC(), m.MessageID.DESC()).
		LIMIT(int64(pageSize)).
		OFFSET(int64((page - 1) * pageSize))

	var rows []model.DiplomailMessages
	if err := listStmt.QueryContext(ctx, s.db, &rows); err != nil {
		return nil, 0, fmt.Errorf("diplomail store: list admin messages: %w", err)
	}
	out := make([]Message, 0, len(rows))
	for _, row := range rows {
		out = append(out, messageFromModel(row))
	}
	return out, int(countDest.Count), nil
}

// UnreadCountsForUser returns a per-game breakdown of unread messages
// addressed to userID, plus the matching game names so the lobby
// badge UI can render entries even after the recipient's membership
// has been revoked. The slice is ordered by game name.
func (s *Store) UnreadCountsForUser(ctx context.Context, userID uuid.UUID) ([]UnreadCount, error) {
	r := table.DiplomailRecipients
	m := table.DiplomailMessages
	stmt := postgres.SELECT(
		r.GameID.AS("game_id"),
		postgres.MAX(m.GameName).AS("game_name"),
		postgres.COUNT(postgres.STAR).AS("count"),
	).
		FROM(r.INNER_JOIN(m, m.MessageID.EQ(r.MessageID))).
		WHERE(
			r.UserID.EQ(postgres.UUID(userID)).
				AND(r.ReadAt.IS_NULL()).
				AND(r.DeletedAt.IS_NULL()).
				AND(r.AvailableAt.IS_NOT_NULL()),
		).
		GROUP_BY(r.GameID).
		ORDER_BY(postgres.MAX(m.GameName).ASC())
	var dest []struct {
		GameID   uuid.UUID `alias:"game_id"`
		GameName string    `alias:"game_name"`
		Count    int64     `alias:"count"`
	}
	if err := stmt.QueryContext(ctx, s.db, &dest); err != nil {
		return nil, fmt.Errorf("diplomail store: unread counts %s: %w", userID, err)
	}
	out := make([]UnreadCount, 0, len(dest))
	for _, row := range dest {
		out = append(out, UnreadCount{
			GameID:   row.GameID,
			GameName: row.GameName,
			Unread:   int(row.Count),
		})
	}
	return out, nil
}

// messageFromModel converts a jet-generated row to the domain type.
func messageFromModel(row model.DiplomailMessages) Message {
	out := Message{
		MessageID:      row.MessageID,
		GameID:         row.GameID,
		GameName:       row.GameName,
		Kind:           row.Kind,
		SenderKind:     row.SenderKind,
		SenderIP:       row.SenderIP,
		Subject:        row.Subject,
		Body:           row.Body,
		BodyLang:       row.BodyLang,
		BroadcastScope: row.BroadcastScope,
		CreatedAt:      row.CreatedAt,
	}
	if row.SenderUserID != nil {
		id := *row.SenderUserID
		out.SenderUserID = &id
	}
	if row.SenderUsername != nil {
		name := *row.SenderUsername
		out.SenderUsername = &name
	}
	if row.SenderRaceName != nil {
		name := *row.SenderRaceName
		out.SenderRaceName = &name
	}
	return out
}

// recipientFromModel converts a jet-generated row to the domain type.
func recipientFromModel(row model.DiplomailRecipients) Recipient {
	out := Recipient{
		RecipientID:                row.RecipientID,
		MessageID:                  row.MessageID,
		GameID:                     row.GameID,
		UserID:                     row.UserID,
		RecipientUserName:          row.RecipientUserName,
		RecipientPreferredLanguage: row.RecipientPreferredLanguage,
		AvailableAt:                row.AvailableAt,
		TranslationAttempts:        row.TranslationAttempts,
		NextTranslationAttemptAt:   row.NextTranslationAttemptAt,
		DeliveredAt:                row.DeliveredAt,
		ReadAt:                     row.ReadAt,
		DeletedAt:                  row.DeletedAt,
		NotifiedAt:                 row.NotifiedAt,
	}
	if row.RecipientRaceName != nil {
		name := *row.RecipientRaceName
		out.RecipientRaceName = &name
	}
	return out
}

// recipientsFromModel converts a slice in place. Used by
// InsertMessageWithRecipients.
func recipientsFromModel(rows []model.DiplomailRecipients) []Recipient {
	out := make([]Recipient, 0, len(rows))
	for _, row := range rows {
		out = append(out, recipientFromModel(row))
	}
	return out
}

// uuidPtrArg returns the jet argument expression for a nullable UUID.
// Pre-NULL handling here avoids a custom NULL literal at every call
// site.
func uuidPtrArg(v *uuid.UUID) postgres.Expression {
	if v == nil {
		return postgres.NULL
	}
	return postgres.UUID(*v)
}

// stringPtrArg returns the jet argument expression for a nullable
// text column.
func stringPtrArg(v *string) postgres.Expression {
	if v == nil {
		return postgres.NULL
	}
	return postgres.String(*v)
}

// timePtrArg returns the jet argument expression for a nullable
// timestamptz column.
func timePtrArg(v *time.Time) postgres.Expression {
	if v == nil {
		return postgres.NULL
	}
	return postgres.TimestampzT(v.UTC())
}