fix: shared renamed to pkg, formatting changes

pkg/plugin/manager.go

@@ -0,0 +1,129 @@
+package plugin
+
+import (
+	"context"
+	"fmt"
+	"path/filepath"
+	"plugin"
+	"strings"
+
+	"github.com/beckn/beckn-onix/pkg/plugin/definition"
+)
+
+// Config represents the plugin manager configuration.
+type Config struct {
+	Root     string       `yaml:"root"`
+	Signer   PluginConfig `yaml:"signer"`
+	Verifier PluginConfig `yaml:"verifier"`
+	Publisher PluginConfig `yaml:"publisher"`
+}
+
+// PluginConfig represents configuration details for a plugin.
+type PluginConfig struct {
+	ID     string            `yaml:"id"`
+	Config map[string]string `yaml:"config"`
+}
+
+// Manager handles dynamic plugin loading and management.
+type Manager struct {
+	sp  definition.SignerProvider
+	vp  definition.VerifierProvider
+	pb  definition.PublisherProvider
+	cfg *Config
+}
+
+// NewManager initializes a new Manager with the given configuration file.
+func NewManager(ctx context.Context, cfg *Config) (*Manager, error) {
+	if cfg == nil {
+		return nil, fmt.Errorf("configuration cannot be nil")
+	}
+
+	// Load signer plugin
+	sp, err := provider[definition.SignerProvider](cfg.Root, cfg.Signer.ID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load signer plugin: %w", err)
+	}
+
+	// Load publisher plugin
+	pb, err := provider[definition.PublisherProvider](cfg.Root, cfg.Publisher.ID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load publisher plugin: %w", err)
+	}
+
+	// Load verifier plugin
+	vp, err := provider[definition.VerifierProvider](cfg.Root, cfg.Verifier.ID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load Verifier plugin: %w", err)
+	}
+
+	return &Manager{sp: sp, vp: vp, pb: pb, cfg: cfg}, nil
+}
+
+// provider loads a plugin dynamically and retrieves its provider instance.
+func provider[T any](root, id string) (T, error) {
+	var zero T
+	if len(strings.TrimSpace(id)) == 0 {
+		return zero, nil
+	}
+
+	p, err := plugin.Open(pluginPath(root, id))
+	if err != nil {
+		return zero, fmt.Errorf("failed to open plugin %s: %w", id, err)
+	}
+
+	symbol, err := p.Lookup("Provider")
+	if err != nil {
+		return zero, fmt.Errorf("failed to find Provider symbol in plugin %s: %w", id, err)
+	}
+
+	prov, ok := symbol.(*T)
+	if !ok {
+		return zero, fmt.Errorf("failed to cast Provider for %s", id)
+	}
+
+	return *prov, nil
+}
+
+// pluginPath constructs the path to the plugin shared object file.
+func pluginPath(root, id string) string {
+	return filepath.Join(root, id+".so")
+}
+
+// Signer retrieves the signing plugin instance.
+func (m *Manager) Signer(ctx context.Context) (definition.Signer, func() error, error) {
+	if m.sp == nil {
+		return nil, nil, fmt.Errorf("signing plugin provider not loaded")
+	}
+
+	signer, close, err := m.sp.New(ctx, m.cfg.Signer.Config)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to initialize signer: %w", err)
+	}
+	return signer, close, nil
+}
+
+// Verifier retrieves the verification plugin instance.
+func (m *Manager) Verifier(ctx context.Context) (definition.Verifier, func() error, error) {
+	if m.vp == nil {
+		return nil, nil, fmt.Errorf("Verifier plugin provider not loaded")
+	}
+
+	Verifier, close, err := m.vp.New(ctx, m.cfg.Verifier.Config)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to initialize Verifier: %w", err)
+	}
+	return Verifier, close, nil
+}
+
+// Publisher retrieves the publisher plugin instance.
+func (m *Manager) Publisher(ctx context.Context) (definition.Publisher, error) {
+	if m.pb == nil {
+		return nil, fmt.Errorf("publisher plugin provider not loaded")
+	}
+
+	publisher,  err := m.pb.New(ctx, m.cfg.Publisher.Config)
+	if err != nil {
+		return nil,  fmt.Errorf("failed to initialize publisher: %w", err)
+	}
+	return publisher,  nil
+}