Refactor fetch and pacman packages into subpackages

Split fetch into alpm and aur subpackages for better organization.
Rename state to log. Split pacman into read and sync subpackages.
Remove validation in favor of read.DBFreshness.

pkg/fetch/alpm/alpm.go

@@ -0,0 +1,137 @@
+package alpm
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/Jguer/dyalpm"
+)
+
+var (
+	Root        = "/"
+	PacmanState = "/var/lib/pacman"
+)
+
+type Handle struct {
+	handle  dyalpm.Handle
+	localDB dyalpm.Database
+	syncDBs []dyalpm.Database
+}
+
+func New() (*Handle, error) {
+	start := time.Now()
+	fmt.Fprintf(os.Stderr, "[debug] alpm.New: starting...\n")
+
+	handle, err := dyalpm.Initialize(Root, PacmanState)
+	if err != nil {
+		return nil, fmt.Errorf("failed to initialize alpm: %w", err)
+	}
+
+	localDB, err := handle.LocalDB()
+	if err != nil {
+		handle.Release()
+		return nil, fmt.Errorf("failed to get local database: %w", err)
+	}
+
+	syncDBs, err := handle.SyncDBs()
+	if err != nil {
+		handle.Release()
+		return nil, fmt.Errorf("failed to get sync databases: %w", err)
+	}
+
+	if len(syncDBs) == 0 {
+		syncDBs, err = registerSyncDBs(handle)
+		if err != nil {
+			handle.Release()
+			return nil, fmt.Errorf("failed to register sync databases: %w", err)
+		}
+	}
+
+	fmt.Fprintf(os.Stderr, "[debug] alpm.New: done (%.2fs)\n", time.Since(start).Seconds())
+	return &Handle{
+		handle:  handle,
+		localDB: localDB,
+		syncDBs: syncDBs,
+	}, nil
+}
+
+func (h *Handle) Release() error {
+	if h.handle != nil {
+		h.handle.Release()
+	}
+	return nil
+}
+
+func registerSyncDBs(handle dyalpm.Handle) ([]dyalpm.Database, error) {
+	fmt.Fprintf(os.Stderr, "[debug] registerSyncDBs: starting...\n")
+
+	repos := []string{"core", "extra", "multilib"}
+	var dbs []dyalpm.Database
+
+	for _, repo := range repos {
+		db, err := handle.RegisterSyncDB(repo, 0)
+		if err != nil {
+			continue
+		}
+
+		count := 0
+		db.PkgCache().ForEach(func(pkg dyalpm.Package) error {
+			count++
+			return nil
+		})
+
+		if count > 0 {
+			dbs = append(dbs, db)
+		}
+	}
+
+	fmt.Fprintf(os.Stderr, "[debug] registerSyncDBs: done (%d dbs)\n", len(dbs))
+	return dbs, nil
+}
+
+func (h *Handle) LocalPackages() (map[string]dyalpm.Package, error) {
+	start := time.Now()
+	fmt.Fprintf(os.Stderr, "[debug] LocalPackages: starting...\n")
+
+	localPkgs := make(map[string]dyalpm.Package)
+
+	err := h.localDB.PkgCache().ForEach(func(pkg dyalpm.Package) error {
+		localPkgs[pkg.Name()] = pkg
+		return nil
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed to iterate local package cache: %w", err)
+	}
+
+	fmt.Fprintf(os.Stderr, "[debug] LocalPackages: done (%.2fs)\n", time.Since(start).Seconds())
+	return localPkgs, nil
+}
+
+func (h *Handle) SyncPackages(pkgNames []string) (map[string]dyalpm.Package, error) {
+	start := time.Now()
+	fmt.Fprintf(os.Stderr, "[debug] SyncPackages: starting...\n")
+
+	syncPkgs := make(map[string]dyalpm.Package)
+	pkgSet := make(map[string]bool)
+	for _, name := range pkgNames {
+		pkgSet[name] = true
+	}
+
+	for _, db := range h.syncDBs {
+		err := db.PkgCache().ForEach(func(pkg dyalpm.Package) error {
+			if pkgSet[pkg.Name()] {
+				if _, exists := syncPkgs[pkg.Name()]; !exists {
+					syncPkgs[pkg.Name()] = pkg
+				}
+			}
+			return nil
+		})
+		if err != nil {
+			return nil, fmt.Errorf("failed to iterate sync database %s: %w", db.Name(), err)
+		}
+	}
+
+	fmt.Fprintf(os.Stderr, "[debug] SyncPackages: done (%.2fs)\n", time.Since(start).Seconds())
+	return syncPkgs, nil
+}