From 00ede99bca46949f7aea1e9b30c8ca8a8a290f9e Mon Sep 17 00:00:00 2001
From: Kenneth Reitz <me@kennethreitz.org>
Date: Thu, 6 Sep 2018 04:53:34 -0400
Subject: [PATCH] fingerings are working

---
 pytheory/bootstrap.py |  4 ++--
 pytheory/chords.py    | 10 ++++++++--
 pytheory/systems.py   | 19 ++++++++++---------
 pytheory/tones.py     | 35 +++++++++++++++++++++++++----------
 4 files changed, 45 insertions(+), 23 deletions(-)

diff --git a/pytheory/bootstrap.py b/pytheory/bootstrap.py
index 33a4470..8812cff 100644
--- a/pytheory/bootstrap.py
+++ b/pytheory/bootstrap.py
@@ -1,7 +1,7 @@
-
+from .tones import Tone
 # SYSTEMS = {"western": System(tones=TONES["western"], degrees=DEGREES["western"])}
 
-def SYSTEMS(SYSTEMS, DEGREES, TONES, Tone, System):
+def SYSTEMS(SYSTEMS, DEGREES, TONES, System):
     western_tones = [Tone.from_string(t) for t in TONES["western"]]
     SYSTEMS = {"western": System(tones=western_tones, degrees=DEGREES["western"])}
     return SYSTEMS
diff --git a/pytheory/chords.py b/pytheory/chords.py
index 8b345b0..c2b5257 100644
--- a/pytheory/chords.py
+++ b/pytheory/chords.py
@@ -2,6 +2,10 @@ class Chord:
     def __init__(self, *, tones):
         self.tones = tones
 
+    def __repr__(self):
+        l = tuple([tone.full_name for tone in self.tones])
+        return f"<Chord tones={l!r}>"
+
     # @property
     # def harmony(self):
     #     pass
@@ -23,6 +27,8 @@ class Fretboard:
         if not len(positions) == len(self.tones):
             raise ValueError("The number of positions must match the number of tones (strings).")
 
-        results = []
+        tones = []
         for (i, tone) in enumerate(self.tones):
-            pass
+            tones.append(tone.add(positions[i]))
+
+        return Chord(tones=tones)
diff --git a/pytheory/systems.py b/pytheory/systems.py
index 818c0e9..59bf466 100644
--- a/pytheory/systems.py
+++ b/pytheory/systems.py
@@ -1,15 +1,10 @@
 from ._statics import TEMPERAMENTS, TONES, DEGREES, SCALES, SYSTEMS
-from .tones import Tone
 from . import bootstrap
 
 
 class System:
-    def __init__(self, *, tones, degrees, scales=None):
-        self.tones = tones
-
-        # Add current system to tones (a bit of a hack).
-        for tone in self.tones:
-            tone.system = self
+    def __init__(self, *, tone_names, degrees, scales=None):
+        self.tone_names = tone_names
 
         self.degrees = degrees
         self._scales = scales
@@ -19,7 +14,13 @@ class System:
 
     @property
     def semitones(self):
-        return len(self.tones)
+        return len(self.tone_names)
+
+    @property
+    def tones(self):
+        from . import Tone
+        return tuple([Tone.from_string(tone) for tone in self.tone_names])
+
 
     @property
     def scales(self):
@@ -119,4 +120,4 @@ class System:
     def __repr__(self):
         return f"<System semitones={self.semitones!r}>"
 
-SYSTEMS = bootstrap.SYSTEMS(SYSTEMS=SYSTEMS, DEGREES=DEGREES, TONES=TONES, Tone=Tone, System=System)
+SYSTEMS = {"western": System(tone_names=TONES["western"], degrees=DEGREES["western"])}
diff --git a/pytheory/tones.py b/pytheory/tones.py
index d48055a..169f98b 100644
--- a/pytheory/tones.py
+++ b/pytheory/tones.py
@@ -3,18 +3,30 @@ from ._statics import REFERENCE_A, TEMPERAMENTS
 class Tone:
     # __slots__ = ("name", "octave", "system")
 
-    def __init__(self, *, name, octave=None, system=None):
+    def __init__(self, *, name, octave=None, system='western'):
         self.name = name
         self.octave = octave
-        self.system = system
 
-        if self.system:
-            try:
-                assert self.name in self.system.tones
-            except AssertionError:
-                raise ValueError(
-                    f"Tone {self.name!r} was not found in system: {self.system.tones!r}"
-                )
+        if isinstance(system, str):
+            self.system_name = system
+            self._system = None
+        else:
+            self.system_name = None
+            self._system = system
+
+    @property
+    def exists(self):
+        return self.name in self.system.tones
+
+    @property
+    def system(self):
+        from .systems import SYSTEMS
+
+        if self._system:
+            return self._system
+
+        if self.system_name:
+            return SYSTEMS[self.system_name]
 
     @property
     def full_name(self):
@@ -47,7 +59,10 @@ class Tone:
         except ValueError:
             octave = None
 
-        return klass(name=tone, octave=octave, system=system)
+        if system:
+            return klass(name=tone, octave=octave, system=system)
+        else:
+            return klass(name=tone, octave=octave)
 
     @classmethod
     def from_index(klass, i, *, octave, system):