feat(newproject): add archduino new project scaffolder

internal/subcommands/newproject/newproject.go

@@ -0,0 +1,75 @@
+// Package newproject scaffolds a new Arduino sketch directory.
+package newproject
+
+import (
+	"embed"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/MDietermann/ArduinoArchSetup/internal/config"
+	"github.com/MDietermann/ArduinoArchSetup/internal/platform"
+)
+
+//go:embed assets
+var assetsFS embed.FS
+
+const clangdContent = `CompileFlags:
+  Add:
+    - -xc++
+    - -std=c++17
+`
+
+// Run creates a new Arduino project directory. It errors if the project
+// directory already exists, if the board is unknown, or if the project name
+// contains a path separator.
+func Run(cfg config.Config, project, board string) error {
+	if project == "" {
+		return fmt.Errorf("project name required")
+	}
+	if strings.ContainsAny(project, "/\\") || strings.HasPrefix(project, ".") {
+		return fmt.Errorf("invalid project name %q", project)
+	}
+
+	var b *config.Board
+	var valid []string
+	for i := range cfg.Scaffolding.Boards {
+		bp := &cfg.Scaffolding.Boards[i]
+		valid = append(valid, bp.Name)
+		if bp.Name == board {
+			b = bp
+		}
+	}
+	if b == nil {
+		return fmt.Errorf("unknown board %q; valid: %s", board, strings.Join(valid, ", "))
+	}
+
+	if _, err := os.Stat(project); err == nil {
+		return fmt.Errorf("project directory %q already exists", project)
+	}
+	if err := os.MkdirAll(project, 0o755); err != nil {
+		return err
+	}
+
+	// Pick .ino template: try <template>.ino, else default.ino.
+	inoData, err := assetsFS.ReadFile(filepath.Join("assets", b.Template+".ino"))
+	if err != nil {
+		inoData, err = assetsFS.ReadFile("assets/default.ino")
+		if err != nil {
+			return err
+		}
+	}
+	if err := platform.WriteUserFile(filepath.Join(project, project+".ino"), inoData, 0o644); err != nil {
+		return err
+	}
+
+	sketch := fmt.Sprintf("default_fqbn: %s\ndefault_port: auto\n", b.FQBN)
+	if err := platform.WriteUserFile(filepath.Join(project, "sketch.yaml"), []byte(sketch), 0o644); err != nil {
+		return err
+	}
+	if err := platform.WriteUserFile(filepath.Join(project, ".clangd"), []byte(clangdContent), 0o644); err != nil {
+		return err
+	}
+	return nil
+}