feat: adding embedded db-studio

Signed-off-by: allanice001 <allanice001@gmail.com>

internal/web/pgweb_embed.go

@@ -0,0 +1,85 @@
+package web
+
+import (
+	"crypto/sha256"
+	"embed"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"runtime"
+)
+
+//go:embed pgwebbin/*
+var pgwebFS embed.FS
+
+type pgwebAsset struct {
+	Path   string
+	SHA256 string
+}
+
+var pgwebIndex = map[string]pgwebAsset{
+	"linux/amd64":  {Path: "pgwebbin/pgweb-linux-amd64", SHA256: ""},
+	"linux/arm64":  {Path: "pgwebbin/pgweb-linux-arm64", SHA256: ""},
+	"darwin/amd64": {Path: "pgwebbin/pgweb-darwin-amd64", SHA256: ""},
+	"darwin/arm64": {Path: "pgwebbin/pgweb-darwin-arm64", SHA256: ""},
+}
+
+func ExtractPgweb() (string, error) {
+	key := runtime.GOOS + "/" + runtime.GOARCH
+	as, ok := pgwebIndex[key]
+	if !ok {
+		return "", fmt.Errorf("pgweb not embedded for %s", key)
+	}
+	f, err := pgwebFS.Open(as.Path)
+	if err != nil {
+		return "", fmt.Errorf("embedded pgweb missing: %w", err)
+	}
+	defer f.Close()
+
+	tmpDir, err := os.MkdirTemp("", "pgweb-*")
+	if err != nil {
+		return "", err
+	}
+
+	filename := "pgweb"
+	if runtime.GOOS == "windows" {
+		filename += ".exe"
+	}
+	outPath := filepath.Join(tmpDir, filename)
+
+	out, err := os.OpenFile(outPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0o700)
+	if err != nil {
+		return "", err
+	}
+	defer out.Close()
+
+	h := sha256.New()
+	if _, err = io.Copy(io.MultiWriter(out, h), f); err != nil {
+		return "", err
+	}
+
+	if as.SHA256 != "" {
+		got := hex.EncodeToString(h.Sum(nil))
+		if got != as.SHA256 {
+			return "", fmt.Errorf("pgweb checksum mismatch: got=%s want=%s", got, as.SHA256)
+		}
+	}
+
+	// Make sure it’s executable on Unix; Windows ignores this.
+	_ = os.Chmod(outPath, 0o700)
+	return outPath, nil
+}
+
+func CleanupPgweb(pgwebPath string) error {
+	if pgwebPath == "" {
+		return nil
+	}
+	dir := filepath.Dir(pgwebPath)
+	if dir == "" || dir == "/" || dir == "." {
+		return errors.New("refusing to remove suspicious directory")
+	}
+	return os.RemoveAll(dir)
+}