2 files changed, 119 insertions, 4 deletions

diff --git a/gerbonara/cad/kicad/pcb.py b/gerbonara/cad/kicad/pcb.py
index bb608bb..8a90a7e 100644
--- a/gerbonara/cad/kicad/pcb.py
+++ b/gerbonara/cad/kicad/pcb.py
@@ -33,12 +33,12 @@ class PageSettings:
     page_format: str = 'A4'
     width: float = None
     height: float = None
-    portrait: bool = False
+    portrait: Flag() = False
 
 
 @sexp_type('layers')
 class LayerSettings:
-    index: int = None
+    index: int = 0
     canonical_name: str = None
     layer_type: AtomChoice(Atom.jumper, Atom.mixed, Atom.power, Atom.signal, Atom.user) = Atom.signal
     custom_name: str = None
@@ -206,7 +206,7 @@ class Board:
     generator: Named(Atom) = Atom.gerbonara
     general: GeneralSection = field(default_factory=GeneralSection)
     page: PageSettings = field(default_factory=PageSettings)
-    layers: Named(Array(LayerSettings)) = field(default_factory=list)
+    layers: Named(Array(Untagged(LayerSettings))) = field(default_factory=list)
     setup: BoardSetup = field(default_factory=BoardSetup)
     properties: List(Property) = field(default_factory=list)
     nets: List(Net) = field(default_factory=list)
@@ -245,7 +245,10 @@ class Board:
 
     def write(self, filename=None):
         with open(filename or self.original_filename, 'w') as f:
-            f.write(build_sexp(sexp(self)))
+            f.write(self.serialize())
+
+    def serialize(self):
+        return build_sexp(sexp(type(self), self)[0])
 
     @classmethod
     def open(kls, pcb_file, *args, **kwargs):
diff --git a/gerbonara/cad/kicad/sexp_mapper.py b/gerbonara/cad/kicad/sexp_mapper.py
index fa5f702..0f52340 100644
--- a/gerbonara/cad/kicad/sexp_mapper.py
+++ b/gerbonara/cad/kicad/sexp_mapper.py
@@ -191,6 +191,118 @@ class Array(WrapperType):
             yield from sexp(self.next_type, e)
 
 
+class Untagged(WrapperType):
+    def __map__(self, value, parent=None):
+        value, = value
+        return self.next_type.__map__([self.next_type.name_atom, *value], parent=parent)
+    
+    def __sexp__(self, value):
+        for inner in sexp(self.next_type, value):
+            _tag, *rest = inner
+            yield rest
+
+
+class List(WrapperType):
+    def __bind_field__(self, field):
+        self.attr = field.name
+
+    def __map__(self, value, parent):
+        l = getattr(parent, self.attr, [])
+        mapped = map_sexp(self.next_type, value, parent=parent)
+        l.append(mapped)
+        setattr(parent, self.attr, l)
+
+    def __sexp__(self, value):
+        for elem in value:
+            yield from sexp(self.next_type, elem)
+
+
+class _SexpTemplate:
+    @staticmethod
+    def __atoms__(kls):
+        return [kls.name_atom]
+
+    @staticmethod
+    def __map__(kls, value, *args, parent=None, **kwargs):
+        positional = iter(kls.positional)
+        inst = kls(*args, **kwargs)
+
+        for v in value[1:]: # skip key
+            if isinstance(v, Atom) and v in kls.keys:
+                name, etype = kls.keys[v]
+                mapped = map_sexp(etype, [v], parent=inst)
+                if mapped is not None:
+                    setattr(inst, name, mapped)
+
+            elif isinstance(v, list):
+                name, etype = kls.keys[v[0]]
+                mapped = map_sexp(etype, v, parent=inst)
+                if mapped is not None:
+                    setattr(inst, name, mapped)
+
+            else:
+                try:
+                    pos_key = next(positional)
+                    setattr(inst, pos_key.name, v)
+                except StopIteration:
+                    raise TypeError(f'Unhandled positional argument {v!r} while parsing {kls}')
+
+        getattr(inst, '__after_parse__', lambda x: None)(parent)
+        return inst
+
+    @staticmethod
+    def __sexp__(kls, value):
+        getattr(value, '__before_sexp__', lambda: None)()
+
+        out = [kls.name_atom]
+        for f in fields(kls):
+            if f.type is SEXP_END:
+                break
+            out += sexp(f.type, getattr(value, f.name))
+        yield out
+
+    @staticmethod
+    def parse(kls, data, *args, **kwargs):
+        return kls.__map__(parse_sexp(data), *args, **kwargs)
+
+    @staticmethod
+    def sexp(self):
+        return next(self.__sexp__(self))
+
+
+def sexp_type(name=None):
+    def register(cls):
+        cls = dataclass(cls)
+        cls.name_atom = Atom(name) if name is not None else None
+        for key in '__sexp__', '__map__', '__atoms__', 'parse':
+            if not hasattr(cls, key):
+                setattr(cls, key, classmethod(getattr(_SexpTemplate, key)))
+
+        if not hasattr(cls, 'sexp'):
+            setattr(cls, 'sexp', getattr(_SexpTemplate, 'sexp'))
+        cls.positional = []
+        cls.keys = {}
+        for f in fields(cls):
+            f_type = f.type
+            if f_type is SEXP_END:
+                break
+
+            if hasattr(f_type, '__bind_field__'):
+                f_type.__bind_field__(f)
+
+            atoms = getattr(f_type, '__atoms__', lambda: [])
+            atoms = list(atoms())
+            for atom in atoms:
+                cls.keys[atom] = (f.name, f_type)
+            if not atoms:
+                cls.positional.append(f)
+
+        return cls
+    return register
+
+
+
+
 class List(WrapperType):
     def __bind_field__(self, field):
         self.attr = field.name