add support for connecting to postgres database

internal/module/db-postgres.go

@@ -0,0 +1,103 @@
+package module
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"log/slog"
+	"sync"
+
+	"github.com/google/jsonschema-go/jsonschema"
+	"github.com/jwetzell/showbridge-go/internal/common"
+	"github.com/jwetzell/showbridge-go/internal/config"
+
+	_ "github.com/jackc/pgx/v5/stdlib"
+)
+
+func init() {
+	RegisterModule(ModuleRegistration{
+		Type:  "db.postgres",
+		Title: "PostgreSQL Database",
+		ParamsSchema: &jsonschema.Schema{
+			Type: "object",
+			Properties: map[string]*jsonschema.Schema{
+				"url": {
+					Title:       "Database URL",
+					Description: "the connection URL for the PostgreSQL database",
+					Type:        "string",
+					MinLength:   new(1),
+				},
+			},
+			Required:             []string{"url"},
+			AdditionalProperties: &jsonschema.Schema{Not: &jsonschema.Schema{}},
+		},
+		New: func(config config.ModuleConfig) (common.Module, error) {
+			params := config.Params
+
+			urlString, err := params.GetString("url")
+			if err != nil {
+				return nil, fmt.Errorf("db.postgres url error: %w", err)
+			}
+
+			return &DbPostgres{Url: urlString, config: config, logger: CreateLogger(config)}, nil
+		},
+	})
+}
+
+type DbPostgres struct {
+	config       config.ModuleConfig
+	Url          string
+	ctx          context.Context
+	inputHandler common.InputHandler
+	db           *sql.DB
+	logger       *slog.Logger
+	dbMu         sync.Mutex
+	cancel       context.CancelFunc
+}
+
+func (dbs *DbPostgres) Id() string {
+	return dbs.config.Id
+}
+
+func (dbs *DbPostgres) Type() string {
+	return dbs.config.Type
+}
+
+func (dbs *DbPostgres) Start(ctx context.Context, inputHandler common.InputHandler) error {
+	dbs.logger.Debug("running")
+	dbs.inputHandler = inputHandler
+	moduleContext, cancel := context.WithCancel(ctx)
+	dbs.ctx = moduleContext
+	dbs.cancel = cancel
+
+	db, err := sql.Open("pgx", dbs.Url)
+	if err != nil {
+		return fmt.Errorf("db.postgres error connecting to database: %w", err)
+	}
+	dbs.dbMu.Lock()
+	dbs.db = db
+	dbs.dbMu.Unlock()
+	<-dbs.ctx.Done()
+	dbs.logger.Debug("done")
+	return nil
+}
+
+func (dbs *DbPostgres) Stop() {
+	if dbs.cancel != nil {
+		defer dbs.cancel()
+	}
+	dbs.dbMu.Lock()
+	defer dbs.dbMu.Unlock()
+	if dbs.db != nil {
+		dbs.db.Close()
+	}
+}
+
+func (dbs *DbPostgres) QueryContext(ctx context.Context, query string, args ...any) (*sql.Rows, error) {
+	dbs.dbMu.Lock()
+	defer dbs.dbMu.Unlock()
+	if dbs.db == nil {
+		return nil, fmt.Errorf("database not initialized")
+	}
+	return dbs.db.QueryContext(ctx, query, args...)
+}