implement package synchronization and validation; update database schema and add error handling

pkg/main.go

@@ -2,19 +2,27 @@ package pkg
 
 import (
 	"archive/tar"
+	"bytes"
+	"crypto/ed25519"
+	"database/sql"
+	"fmt"
 	"io"
 	"os"
 	"packets/configs"
+	"packets/internal/consts"
+	errors_packets "packets/internal/errors"
 	"packets/internal/utils"
 	utils_lua "packets/internal/utils/lua"
+	"path"
 	"path/filepath"
 	"strings"
 
 	"github.com/klauspost/compress/zstd"
 	lua "github.com/yuin/gopher-lua"
+	_ "modernc.org/sqlite"
 )
 
-// Install exctract and install from a package file ( tar.zst )
+// Install exctract and fully install from a package file ( tar.zst )
 func InstallPackage(file *os.File) error {
 
 	manifest, err := utils.ReadManifest(file)
@@ -107,6 +115,7 @@ func InstallPackage(file *os.File) error {
 	return nil
 }
 
+// ExecuteRemoveScript executes the remove script from the package
 func ExecuteRemoveScript(path string) error {
 
 	L, err := utils_lua.GetSandBox(".")
@@ -124,3 +133,78 @@ func ExecuteRemoveScript(path string) error {
 
 	return nil
 }
+
+// GetPackage retrieves package information from the index database and downloads the package file
+func GetPackage(name string) (utils.Package, error) {
+
+	var this utils.Package
+	db, err := sql.Open("sqlite", consts.IndexDB)
+	if err != nil {
+		return this, err
+	}
+	defer db.Close()
+
+	var packageUrl string
+	err = db.QueryRow("SELECT query_name, version, package_url, image_url, description, author, author_verified, os, arch, signature, public_key, family, serial, size FROM packages WHERE name = ?", name).
+		Scan(
+			&this.QueryName,
+			&this.Version,
+			&packageUrl,
+			&this.ImageUrl,
+			&this.Description,
+			&this.Author,
+			&this.AuthorVerified,
+			&this.OS,
+			&this.Arch,
+			&this.Signature,
+			&this.PublicKey,
+			&this.Family,
+			&this.Serial,
+			&this.Size,
+		)
+	if err != nil {
+		return utils.Package{}, err
+	}
+
+	filename := path.Base(packageUrl)
+	this.Filename = filename
+	peers, err := utils.AskLAN(filename)
+	if err != nil {
+		return utils.Package{}, err
+	}
+
+	if len(peers) > 0 {
+		this.PackageF, err = utils.GetFileHTTP(packageUrl)
+		if err != nil {
+			return utils.Package{}, err
+		}
+	} else {
+		var totalerrors int = 0
+		for _, peer := range peers {
+			this.PackageF, err = utils.GetFileHTTP(fmt.Sprintf("http://%s:%d/%s", peer.IP, peer.Port, filename))
+			if err == nil {
+				break
+			} else {
+				totalerrors++
+			}
+		}
+		if totalerrors == len(peers) {
+			this.PackageF, err = utils.GetFileHTTP(packageUrl)
+			if err != nil {
+				return utils.Package{}, err
+			}
+		}
+	}
+
+	reader := bytes.NewReader(this.PackageF)
+	this.Manifest, err = utils.ReadManifest(reader)
+	if err != nil {
+		return utils.Package{}, err
+	}
+
+	if !ed25519.Verify(this.PublicKey, this.PackageF, this.Signature) {
+		return utils.Package{}, errors_packets.ErrInvalidSignature
+	}
+
+	return this, nil
+}