feat(lidarrconfig): typed singleton config wrapper

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

internal/lidarrconfig/service.go

@@ -0,0 +1,88 @@
+// Package lidarrconfig is a thin wrapper over the singleton lidarr_config
+// row. Get returns a typed Config; Save updates it. Callers branch on
+// Config.Enabled — never on raw NULL fields.
+package lidarrconfig
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+
+	"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
+)
+
+// Config is the typed projection of lidarr_config (no NULL fields exposed
+// to callers — empty strings / zero ints carry the "unset" meaning).
+type Config struct {
+	Enabled                 bool
+	BaseURL                 string
+	APIKey                  string
+	DefaultQualityProfileID int
+	DefaultRootFolderPath   string
+}
+
+// Service reads and writes the singleton.
+type Service struct {
+	pool *pgxpool.Pool
+}
+
+func New(pool *pgxpool.Pool) *Service { return &Service{pool: pool} }
+
+func (s *Service) Get(ctx context.Context) (Config, error) {
+	row, err := dbq.New(s.pool).GetLidarrConfig(ctx)
+	if err != nil {
+		return Config{}, fmt.Errorf("lidarrconfig: %w", err)
+	}
+	cfg := Config{Enabled: row.Enabled}
+	if row.BaseUrl != nil {
+		cfg.BaseURL = *row.BaseUrl
+	}
+	if row.ApiKey != nil {
+		cfg.APIKey = *row.ApiKey
+	}
+	if row.DefaultQualityProfileID != nil {
+		cfg.DefaultQualityProfileID = int(*row.DefaultQualityProfileID)
+	}
+	if row.DefaultRootFolderPath != nil {
+		cfg.DefaultRootFolderPath = *row.DefaultRootFolderPath
+	}
+	return cfg, nil
+}
+
+// Save writes the entire row. Callers pass the full Config they want
+// stored — this is not a partial update.
+func (s *Service) Save(ctx context.Context, cfg Config) error {
+	var (
+		baseURL  = strPtr(cfg.BaseURL)
+		apiKey   = strPtr(cfg.APIKey)
+		qpID     = int32Ptr(cfg.DefaultQualityProfileID)
+		rootPath = strPtr(cfg.DefaultRootFolderPath)
+	)
+	_, err := dbq.New(s.pool).UpdateLidarrConfig(ctx, dbq.UpdateLidarrConfigParams{
+		Enabled:                 cfg.Enabled,
+		BaseUrl:                 baseURL,
+		ApiKey:                  apiKey,
+		DefaultQualityProfileID: qpID,
+		DefaultRootFolderPath:   rootPath,
+	})
+	if err != nil {
+		return fmt.Errorf("lidarrconfig: %w", err)
+	}
+	return nil
+}
+
+func strPtr(s string) *string {
+	if s == "" {
+		return nil
+	}
+	return &s
+}
+
+func int32Ptr(i int) *int32 {
+	if i == 0 {
+		return nil
+	}
+	v := int32(i)
+	return &v
+}