feat(PROJ-9): implement labels backend - DB schema, labelstore, API handlers, Xapian integration

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-03-18 08:32:30 +01:00
parent bd09992441
commit 5a6289c83d
8 changed files with 995 additions and 2 deletions
@@ -0,0 +1,329 @@
+// Package labelstore manages labels, email-label assignments, and auto-label
+// rules in PostgreSQL. Part of PROJ-9: Ordner- & Label-Verwaltung.
+package labelstore
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// Label represents a user-defined or global (admin) label.
+type Label struct {
+	ID        int64     `json:"id"`
+	Name      string    `json:"name"`
+	Color     string    `json:"color"`
+	OwnerID   *int64    `json:"owner_id,omitempty"`
+	TenantID  int64     `json:"tenant_id"`
+	CreatedAt time.Time `json:"created_at"`
+	IsGlobal  bool      `json:"is_global"`
+}
+
+// LabelRule describes an automatic label assignment rule (admin-only).
+type LabelRule struct {
+	ID             int64  `json:"id"`
+	ConditionField string `json:"condition_field"`
+	ConditionValue string `json:"condition_value"`
+	LabelID        int64  `json:"label_id"`
+	TenantID       int64  `json:"tenant_id"`
+}
+
+// Store is a PostgreSQL-backed label store.
+type Store struct {
+	db *pgxpool.Pool
+}
+
+const schemaSQL = `
+CREATE TABLE IF NOT EXISTS labels (
+    id         BIGSERIAL PRIMARY KEY,
+    name       VARCHAR(100) NOT NULL,
+    color      VARCHAR(7) NOT NULL DEFAULT '#6366f1',
+    owner_id   BIGINT REFERENCES users(id) ON DELETE CASCADE,
+    tenant_id  BIGINT REFERENCES tenants(id) ON DELETE CASCADE,
+    created_at TIMESTAMPTZ DEFAULT NOW(),
+    UNIQUE(name, owner_id, tenant_id)
+);
+
+CREATE TABLE IF NOT EXISTS email_labels (
+    email_id    VARCHAR(64) NOT NULL,
+    label_id    BIGINT NOT NULL REFERENCES labels(id) ON DELETE CASCADE,
+    assigned_at TIMESTAMPTZ DEFAULT NOW(),
+    assigned_by VARCHAR(20) NOT NULL DEFAULT 'user',
+    PRIMARY KEY (email_id, label_id)
+);
+
+CREATE TABLE IF NOT EXISTS label_rules (
+    id               BIGSERIAL PRIMARY KEY,
+    condition_field  VARCHAR(30) NOT NULL,
+    condition_value  VARCHAR(255) NOT NULL,
+    label_id         BIGINT NOT NULL REFERENCES labels(id) ON DELETE CASCADE,
+    tenant_id        BIGINT REFERENCES tenants(id) ON DELETE CASCADE,
+    created_at       TIMESTAMPTZ DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_email_labels_label_id ON email_labels(label_id);
+CREATE INDEX IF NOT EXISTS idx_email_labels_email_id ON email_labels(email_id);
+CREATE INDEX IF NOT EXISTS idx_label_rules_tenant_id ON label_rules(tenant_id);
+CREATE INDEX IF NOT EXISTS idx_labels_tenant_id ON labels(tenant_id);
+CREATE INDEX IF NOT EXISTS idx_labels_owner_id ON labels(owner_id);
+`
+
+// New connects to PostgreSQL and initialises the labels schema.
+func New(dsn string) (*Store, error) {
+	ctx := context.Background()
+	pool, err := pgxpool.New(ctx, dsn)
+	if err != nil {
+		return nil, fmt.Errorf("labelstore: connect: %w", err)
+	}
+
+	s := &Store{db: pool}
+	if err := s.initSchema(ctx); err != nil {
+		pool.Close()
+		return nil, fmt.Errorf("labelstore: init schema: %w", err)
+	}
+
+	return s, nil
+}
+
+func (s *Store) initSchema(ctx context.Context) error {
+	_, err := s.db.Exec(ctx, schemaSQL)
+	return err
+}
+
+// Close closes the underlying connection pool.
+func (s *Store) Close() error {
+	s.db.Close()
+	return nil
+}
+
+// ── Label CRUD ────────────────────────────────────────────────────────────
+
+// GetLabelsForUser returns the user's own labels plus global labels (owner_id IS NULL)
+// for the given tenant.
+func (s *Store) GetLabelsForUser(ctx context.Context, userID int64, tenantID int64) ([]Label, error) {
+	rows, err := s.db.Query(ctx, `
+		SELECT id, name, color, owner_id, tenant_id, created_at
+		FROM labels
+		WHERE tenant_id = $1 AND (owner_id = $2 OR owner_id IS NULL)
+		ORDER BY name
+	`, tenantID, userID)
+	if err != nil {
+		return nil, fmt.Errorf("labelstore: get labels: %w", err)
+	}
+	defer rows.Close()
+
+	var labels []Label
+	for rows.Next() {
+		var l Label
+		if err := rows.Scan(&l.ID, &l.Name, &l.Color, &l.OwnerID, &l.TenantID, &l.CreatedAt); err != nil {
+			return nil, fmt.Errorf("labelstore: scan label: %w", err)
+		}
+		l.IsGlobal = l.OwnerID == nil
+		labels = append(labels, l)
+	}
+	return labels, rows.Err()
+}
+
+// CreateLabel creates a user-owned label.
+func (s *Store) CreateLabel(ctx context.Context, name, color string, ownerID *int64, tenantID int64) (Label, error) {
+	var l Label
+	err := s.db.QueryRow(ctx, `
+		INSERT INTO labels (name, color, owner_id, tenant_id)
+		VALUES ($1, $2, $3, $4)
+		RETURNING id, name, color, owner_id, tenant_id, created_at
+	`, name, color, ownerID, tenantID).Scan(&l.ID, &l.Name, &l.Color, &l.OwnerID, &l.TenantID, &l.CreatedAt)
+	if err != nil {
+		return Label{}, fmt.Errorf("labelstore: create label: %w", err)
+	}
+	l.IsGlobal = l.OwnerID == nil
+	return l, nil
+}
+
+// UpdateLabel updates name and color of a label owned by the given user.
+func (s *Store) UpdateLabel(ctx context.Context, labelID int64, name, color string, userID int64) error {
+	tag, err := s.db.Exec(ctx, `
+		UPDATE labels SET name = $1, color = $2
+		WHERE id = $3 AND owner_id = $4
+	`, name, color, labelID, userID)
+	if err != nil {
+		return fmt.Errorf("labelstore: update label: %w", err)
+	}
+	if tag.RowsAffected() == 0 {
+		return fmt.Errorf("labelstore: label not found or not owned by user")
+	}
+	return nil
+}
+
+// DeleteLabel deletes a label owned by the given user.
+func (s *Store) DeleteLabel(ctx context.Context, labelID int64, userID int64) error {
+	tag, err := s.db.Exec(ctx, `
+		DELETE FROM labels WHERE id = $1 AND owner_id = $2
+	`, labelID, userID)
+	if err != nil {
+		return fmt.Errorf("labelstore: delete label: %w", err)
+	}
+	if tag.RowsAffected() == 0 {
+		return fmt.Errorf("labelstore: label not found or not owned by user")
+	}
+	return nil
+}
+
+// ── Email-Label Assignment ────────────────────────────────────────────────
+
+// AssignLabel assigns a label to an email. Duplicate assignments are silently ignored.
+func (s *Store) AssignLabel(ctx context.Context, emailID string, labelID int64, assignedBy string) error {
+	_, err := s.db.Exec(ctx, `
+		INSERT INTO email_labels (email_id, label_id, assigned_by)
+		VALUES ($1, $2, $3)
+		ON CONFLICT (email_id, label_id) DO NOTHING
+	`, emailID, labelID, assignedBy)
+	if err != nil {
+		return fmt.Errorf("labelstore: assign label: %w", err)
+	}
+	return nil
+}
+
+// RemoveLabel removes a label assignment from an email.
+func (s *Store) RemoveLabel(ctx context.Context, emailID string, labelID int64) error {
+	_, err := s.db.Exec(ctx, `
+		DELETE FROM email_labels WHERE email_id = $1 AND label_id = $2
+	`, emailID, labelID)
+	if err != nil {
+		return fmt.Errorf("labelstore: remove label: %w", err)
+	}
+	return nil
+}
+
+// GetLabelIDsForEmail returns all label IDs assigned to a given email.
+func (s *Store) GetLabelIDsForEmail(ctx context.Context, emailID string) ([]int64, error) {
+	rows, err := s.db.Query(ctx, `
+		SELECT label_id FROM email_labels WHERE email_id = $1
+	`, emailID)
+	if err != nil {
+		return nil, fmt.Errorf("labelstore: get label ids: %w", err)
+	}
+	defer rows.Close()
+
+	var ids []int64
+	for rows.Next() {
+		var id int64
+		if err := rows.Scan(&id); err != nil {
+			return nil, fmt.Errorf("labelstore: scan label id: %w", err)
+		}
+		ids = append(ids, id)
+	}
+	return ids, rows.Err()
+}
+
+// GetEmailIDsByLabel returns all email IDs that have a specific label assigned.
+func (s *Store) GetEmailIDsByLabel(ctx context.Context, labelID int64) ([]string, error) {
+	rows, err := s.db.Query(ctx, `
+		SELECT email_id FROM email_labels WHERE label_id = $1
+	`, labelID)
+	if err != nil {
+		return nil, fmt.Errorf("labelstore: get email ids by label: %w", err)
+	}
+	defer rows.Close()
+
+	var ids []string
+	for rows.Next() {
+		var id string
+		if err := rows.Scan(&id); err != nil {
+			return nil, fmt.Errorf("labelstore: scan email id: %w", err)
+		}
+		ids = append(ids, id)
+	}
+	return ids, rows.Err()
+}
+
+// ── Admin Labels (Global) ─────────────────────────────────────────────────
+
+// CreateAdminLabel creates a global label (owner_id = NULL) for a tenant.
+func (s *Store) CreateAdminLabel(ctx context.Context, name, color string, tenantID int64) (Label, error) {
+	return s.CreateLabel(ctx, name, color, nil, tenantID)
+}
+
+// ── Label Rules ───────────────────────────────────────────────────────────
+
+// GetLabelRules returns all auto-label rules for a tenant.
+func (s *Store) GetLabelRules(ctx context.Context, tenantID int64) ([]LabelRule, error) {
+	rows, err := s.db.Query(ctx, `
+		SELECT id, condition_field, condition_value, label_id, tenant_id
+		FROM label_rules
+		WHERE tenant_id = $1
+		ORDER BY id
+	`, tenantID)
+	if err != nil {
+		return nil, fmt.Errorf("labelstore: get rules: %w", err)
+	}
+	defer rows.Close()
+
+	var rules []LabelRule
+	for rows.Next() {
+		var r LabelRule
+		if err := rows.Scan(&r.ID, &r.ConditionField, &r.ConditionValue, &r.LabelID, &r.TenantID); err != nil {
+			return nil, fmt.Errorf("labelstore: scan rule: %w", err)
+		}
+		rules = append(rules, r)
+	}
+	return rules, rows.Err()
+}
+
+// CreateLabelRule creates an auto-label rule for a tenant.
+func (s *Store) CreateLabelRule(ctx context.Context, field, value string, labelID int64, tenantID int64) (LabelRule, error) {
+	var r LabelRule
+	err := s.db.QueryRow(ctx, `
+		INSERT INTO label_rules (condition_field, condition_value, label_id, tenant_id)
+		VALUES ($1, $2, $3, $4)
+		RETURNING id, condition_field, condition_value, label_id, tenant_id
+	`, field, value, labelID, tenantID).Scan(&r.ID, &r.ConditionField, &r.ConditionValue, &r.LabelID, &r.TenantID)
+	if err != nil {
+		return LabelRule{}, fmt.Errorf("labelstore: create rule: %w", err)
+	}
+	return r, nil
+}
+
+// DeleteLabelRule deletes an auto-label rule within a tenant.
+func (s *Store) DeleteLabelRule(ctx context.Context, ruleID int64, tenantID int64) error {
+	tag, err := s.db.Exec(ctx, `
+		DELETE FROM label_rules WHERE id = $1 AND tenant_id = $2
+	`, ruleID, tenantID)
+	if err != nil {
+		return fmt.Errorf("labelstore: delete rule: %w", err)
+	}
+	if tag.RowsAffected() == 0 {
+		return fmt.Errorf("labelstore: rule not found")
+	}
+	return nil
+}
+
+// ── Batch Helpers ─────────────────────────────────────────────────────────
+
+// GetLabelsForEmails returns a map of email_id -> []int64 (label IDs) for a
+// batch of email IDs. Useful for enriching search results.
+func (s *Store) GetLabelsForEmails(ctx context.Context, emailIDs []string) (map[string][]int64, error) {
+	if len(emailIDs) == 0 {
+		return nil, nil
+	}
+	rows, err := s.db.Query(ctx, `
+		SELECT email_id, label_id FROM email_labels WHERE email_id = ANY($1)
+	`, emailIDs)
+	if err != nil {
+		return nil, fmt.Errorf("labelstore: get labels for emails: %w", err)
+	}
+	defer rows.Close()
+
+	result := make(map[string][]int64)
+	for rows.Next() {
+		var emailID string
+		var labelID int64
+		if err := rows.Scan(&emailID, &labelID); err != nil {
+			return nil, fmt.Errorf("labelstore: scan: %w", err)
+		}
+		result[emailID] = append(result[emailID], labelID)
+	}
+	return result, rows.Err()
+}