From 25253cf11962d5e29bbfa843c56e77017e768052 Mon Sep 17 00:00:00 2001
From: Romain Dorgueil <romain@dorgueil.net>
Date: Mon, 1 May 2017 15:26:57 +0200
Subject: [PATCH] Positional options (WIP).

---
 Projectfile                    |  2 +-
 bonobo/config/configurables.py | 36 +++++++++++++++++++++++++++++++---
 bonobo/io/csv.py               |  2 +-
 bonobo/io/json.py              |  2 +-
 tests/test_config.py           | 10 ++++++++++
 5 files changed, 46 insertions(+), 6 deletions(-)

diff --git a/Projectfile b/Projectfile
index 73a534c..47844ee 100644
--- a/Projectfile
+++ b/Projectfile
@@ -1,7 +1,7 @@
 # bonobo (see github.com/python-edgy/project)
 
 name = 'bonobo'
-description = 'Bonobo'
+description = 'Bonobo, a simple, modern and atomic extract-transform-load toolkit for python 3.5+.'
 license = 'Apache License, Version 2.0'
 
 url = 'https://www.bonobo-project.org/'
diff --git a/bonobo/config/configurables.py b/bonobo/config/configurables.py
index d5bdeb3..18b5a8c 100644
--- a/bonobo/config/configurables.py
+++ b/bonobo/config/configurables.py
@@ -1,5 +1,32 @@
 from bonobo.config.options import Option
 
+__all__ = [
+    'Configurable',
+    'Option',
+]
+
+_options_insert_order = 0
+
+class Option:
+    def __init__(self, type=None, *, required=False, positional=False, default=None):
+        self.name = None
+        self.type = type
+        self.required = required
+        self.positional = positional
+        self.default = default
+
+        global _options_insert_order
+        self.order = _options_insert_order
+        _options_insert_order += 1
+
+    def __get__(self, inst, typ):
+        if not self.name in inst.__options_values__:
+            inst.__options_values__[self.name] = self.default() if callable(self.default) else self.default
+        return inst.__options_values__[self.name]
+
+    def __set__(self, inst, value):
+        inst.__options_values__[self.name] = self.type(value) if self.type else value
+
 
 class ConfigurableMeta(type):
     """
@@ -25,15 +52,18 @@ class Configurable(metaclass=ConfigurableMeta):
 
     """
 
-    def __init__(self, **kwargs):
+    def __init__(self, *args, **kwargs):
         super().__init__()
 
         self.__options_values__ = {}
 
-        missing = set()
+        missing = list()
         for name, option in type(self).__options__.items():
             if option.required and not option.name in kwargs:
-                missing.add(name)
+                missing.append(name)
+
+        for i in range(min(len(args), len(missing))):
+            kwargs
 
         if len(missing):
             raise TypeError(
diff --git a/bonobo/io/csv.py b/bonobo/io/csv.py
index 9192fc3..df84557 100644
--- a/bonobo/io/csv.py
+++ b/bonobo/io/csv.py
@@ -55,7 +55,7 @@ class CsvReader(CsvHandler, FileReader):
 
         for row in reader:
             if len(row) != field_count:
-                raise ValueError('Got a line with %d fields, expecting %d.' % (len(row), field_count, ))
+                raise ValueError('Got a line with %d fields, expecting %d.' % (len(row), field_count,))
 
             yield dict(zip(headers.value, row))
 
diff --git a/bonobo/io/json.py b/bonobo/io/json.py
index 34f4f0f..f5bc8b1 100644
--- a/bonobo/io/json.py
+++ b/bonobo/io/json.py
@@ -8,7 +8,7 @@ __all__ = [
 ]
 
 
-class JsonHandler:
+class JsonHandler():
     eol = ',\n'
     prefix, suffix = '[', ']'
 
diff --git a/tests/test_config.py b/tests/test_config.py
index 3c46fbc..e6d3916 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -18,6 +18,11 @@ class MyHarderConfigurable(MyConfigurable):
 class MyBetterConfigurable(MyConfigurable):
     required_str = Option(str, required=False, default='kaboom')
 
+class MyConfigurableUsingPositionalOptions(MyConfigurable):
+    first = Option(str, required=True, positional=True)
+    second = Option(str, required=True, positional=True)
+    third = Option(str, required=False, positional=True)
+
 
 class PrinterInterface():
     def print(self, *args):
@@ -133,3 +138,8 @@ def test_service_dependency_unavailable():
     o = MyServiceDependantConfigurable(printer='printer2')
     with pytest.raises(KeyError):
         SERVICES.args_for(o)
+
+
+def test_option_positional():
+    o = MyConfigurableUsingPositionalOptions('1', '2', '3', required_str='hello')
+