4 files changed, 114 insertions, 4 deletions
diff --git a/src/ee/part/__init__.py b/src/ee/part/__init__.py
index ff6c7f1..a2face8 100644
--- a/src/ee/part/__init__.py
+++ b/src/ee/part/__init__.py
@@ -1,11 +1,13 @@
 from pathlib import Path
 from typing import List, Optional, Iterator, Union
 
-from ee import EeException
+from ee import EeException, EeValType
 from ee.money import Money
 from ee.xml import types
 
 __all__ = [
+    "FactType",
+    "EeValueFactType",
     "Part",
     "PartDb",
     "load_db",
@@ -13,6 +15,18 @@ __all__ = [
 ]
 
 
+class FactType(object):
+    def __init__(self, uri: str, label: str):
+        self.uri = uri
+        self.label = label
+
+
+class EeValueFactType(FactType):
+    def __init__(self, uri: str, label, ee_type: EeValType):
+        super().__init__(uri, label)
+        self.ee_type = ee_type
+
+
 class Reference(object):
     pass
 
@@ -324,12 +338,42 @@ class Part(object):
         self.xml.factsProp.fact = [f for f in self.xml.factsProp.fact if f.keyProp != key]
 
 
+class Fact(object):
+    def __init__(self, xml: types.Fact):
+        self.xml = xml
+
+    @property
+    def key(self) -> str:
+        return self.xml.keyProp
+
+    @property
+    def value(self) -> str:
+        return self.xml.valueProp
+
+
 class Facts(object):
-    def __init__(self, part):
+    def __init__(self, part: Part):
         self.part = part
 
-    def add(self, key: str, value: str, label=None):
-        self.part.get_facts().append(types.Fact(key=key, label=label, value=value))
+    @staticmethod
+    def _get_key(key: Union[str, FactType]):
+        return key if isinstance(key, str) else key.uri
+
+    def add(self, key: Union[str, FactType], value: str, label=None):
+        k = self._get_key(key)
+        self.part.get_facts().append(types.Fact(key=k, label=label, value=value))
+
+    def get(self, key: Union[str, FactType]) -> Fact:
+        k = self._get_key(key)
+        return next((Fact(f) for f in self.part.get_facts() if f.keyProp == k), None)
+
+    def all(self, key: Union[str, FactType]) -> List[Fact]:
+        k = self._get_key(key)
+        return [Fact(f) for f in self.part.get_facts() if f.keyProp == k]
+
+    def get_value(self, key: Union[str, FactType]) -> Optional[str]:
+        k = self._get_key(key)
+        return next((f.valueProp for f in self.part.get_facts() if f.keyProp == k), None)
 
 
 class Entry(object):
diff --git a/src/ee/part/common_fact_types.py b/src/ee/part/common_fact_types.py
new file mode 100644
index 0000000..12c099e
--- /dev/null
+++ b/src/ee/part/common_fact_types.py
@@ -0,0 +1,7 @@
+import ee
+from ee.part import EeValueFactType, fact_keys
+
+resistance = EeValueFactType(fact_keys.resistance, "Resistance", ee.resistance_type)
+capacitance = EeValueFactType(fact_keys.capacitance, "Capacitance", ee.capacitance_type)
+
+ee_component_type = EeValueFactType(fact_keys.ee_component_type, "EE component type", ee.capacitance_type)
diff --git a/src/ee/part/fact_keys.py b/src/ee/part/fact_keys.py
index f1f02c5..65dc699 100644
--- a/src/ee/part/fact_keys.py
+++ b/src/ee/part/fact_keys.py
@@ -1,3 +1,4 @@
+ee_component_type = "http://purl.org/ee/fact-type/ee-component-type"
 capacitance = "http://purl.org/ee/fact-type/capacitance"
 max_voltage = "http://purl.org/ee/fact-type/voltage"
 # https://en.wikipedia.org/wiki/Ceramic_capacitor#Class_2_ceramic_capacitors
diff --git a/src/ee/part/requirement.py b/src/ee/part/requirement.py
new file mode 100644
index 0000000..a9381df
--- /dev/null
+++ b/src/ee/part/requirement.py
@@ -0,0 +1,58 @@
+from typing import List
+
+from ee.part import Part, fact_keys, FactType, common_fact_types
+
+
+class Requirement(object):
+    def __init__(self, part: Part):
+        self.part = part
+
+
+class EqualRequirement(Requirement):
+    def __init__(self, part: Part, fact_type: FactType, value: str):
+        super().__init__(part)
+        self.fact_type = fact_type
+        self.value = value
+
+    def __str__(self):
+        return "{}.{} == {}".format(self.part.printable_reference, self.fact_type, self.value)
+
+
+class MinRequirement(Requirement):
+    def __init__(self, part: Part, fact_type: FactType, value: str):
+        super().__init__(part)
+        self.fact_type = fact_type
+        self.value = value
+
+    def __str__(self):
+        return "{}.{} == {}".format(self.part.printable_reference, self.fact_type, self.value)
+
+
+class MaxRequirement(Requirement):
+    def __init__(self, part: Part, fact_type: FactType, value: str):
+        super().__init__(part)
+        self.fact_type = fact_type
+        self.value = value
+
+    def __str__(self):
+        return "{}.{} == {}".format(self.part.printable_reference, self.fact_type, self.value)
+
+
+class PartAnalysis(object):
+    def __init__(self, part: Part, requirements: List[Requirement]):
+        self.part = part
+        self.requirements = requirements
+
+
+def analyze_requirements(part: Part) -> PartAnalysis:
+    rs = []
+
+    resistance = part.find_fact(common_fact_types.resistance.uri)
+    if resistance:
+        rs.append(EqualRequirement(part, common_fact_types.resistance, resistance.valueProp))
+
+    capacitance = part.find_fact(common_fact_types.capacitance.uri)
+    if capacitance:
+        rs.append(EqualRequirement(part, common_fact_types.capacitance, capacitance.valueProp))
+
+    return PartAnalysis(part, rs)