import FreeCAD, Draft, json, ifcopenshell, math

def getObjectsOfIfcType(objects, ifcType):
    results = []
    for object in objects:
        if hasattr(object,"IfcType"):
            if object.IfcType == ifcType:
                results.append(object)
    return results

class SIUnitCreator:
    def __init__(self, file, text, type):
        self.prefixes = ["EXA", "PETA", "TERA", "GIGA", "MEGA", "KILO", "HECTO",
            "DECA", "DECI", "CENTI", "MILLI", "MICRO", "NANO", "PICO", "FEMTO",
            "ATTO"]
        self.unitNames = ["AMPERE", "BECQUEREL", "CANDELA", "COULOMB",
            "CUBIC_METRE", "DEGREE CELSIUS", "FARAD", "GRAM", "GRAY", "HENRY",
            "HERTZ", "JOULE", "KELVIN", "LUMEN", "LUX", "MOLE", "NEWTON", "OHM",
            "PASCAL", "RADIAN", "SECOND", "SIEMENS", "SIEVERT", "SQUARE METRE",
            "METRE", "STERADIAN", "TESLA", "VOLT", "WATT", "WEBER"]
        self.text = text
        self.SIUnit = file.createIfcSIUnit(None, type, self.getSIPrefix(), self.getSIUnitName())

    def getSIPrefix(self):
        for prefix in self.prefixes:
            if prefix in self.text.upper():
                return prefix
        return None

    def getSIUnitName(self):
        for unitName in self.unitNames:
            if unitName in self.text.upper():
                return unitName
        return None

class ContextCreator:
    def __init__(self, file, objects):
        self.file = file
        self.objects = objects
        self.project_object = self.getProjectObject()
        self.project_data = self.getProjectObjectData()
        self.model_context = self.createGeometricRepresentationContext()
        self.model_view_subcontext = self.createGeometricRepresentationSubContext()
        self.target_crs = self.createTargetCRS()
        self.map_conversion = self.createMapConversion()
        self.project = self.createProject()

    def createGeometricRepresentationContext(self):
        return self.file.createIfcGeometricRepresentationContext(
            None, "Model",
            3, 1.0E-05,
            self.file.by_type("IfcAxis2Placement3D")[0],
            self.createTrueNorth())

    def createGeometricRepresentationSubContext(self):
        return self.file.createIfcGeometricRepresentationSubContext(
            "Body", "Model",
            None, None, None, None,
            self.model_context, None, "MODEL_VIEW", None)

    def createTargetCRS(self):
        try:
            SIUnit = SIUnitCreator(self.file, self.project_data["map_unit"], "LENGTHUNIT")
            return self.file.createIfcProjectedCRS(
                self.project_data["name"],
                self.project_data["description"],
                self.project_data["geodetic_datum"],
                self.project_data["vertical_datum"],
                self.project_data["map_projection"],
                self.project_data["map_zone"],
                SIUnit.SIUnit
                )
        except:
            return None

    def createMapConversion(self):
        try:
            return self.file.createIfcMapConversion(
                self.model_context, self.target_crs,
                float(self.project_data["eastings"]),
                float(self.project_data["northings"]),
                float(self.project_data["orthogonal_height"]),
                self.calculateXAxisAbscissa(),
                self.calculateXAxisOrdinate(),
                float(self.project_data["scale"])
                )
        except:
            return None

    def createTrueNorth(self):
        return self.file.createIfcDirection(
            (self.calculateXAxisAbscissa(), self.calculateXAxisOrdinate(), 0.))

    def calculateXAxisAbscissa(self):
        if "true_north" in self.project_data:
            return math.cos(math.radians(float(self.project_data["true_north"]) + 90))
        return 0.

    def calculateXAxisOrdinate(self):
        if "true_north" in self.project_data:
            return math.sin(math.radians(float(self.project_data["true_north"]) + 90))
        return 1.

    def createProject(self):
        if not self.project_object:
            return self.createAutomaticProject()
        return self.createCustomProject()

    def createAutomaticProject(self):
        return self.file.createIfcProject(
            self.getProjectGUID(),
            self.file.by_type("IfcOwnerHistory")[0],
            FreeCAD.ActiveDocument.Name, None,
            None, None, None, [self.model_context],
            self.file.by_type("IfcUnitAssignment")[0])

    def createCustomProject(self):
        return self.file.createIfcProject(
            self.getProjectGUID(),
            self.file.by_type("IfcOwnerHistory")[0],
            self.project_object.Label, self.project_object.Description,
            self.project_object.ObjectType, self.project_object.LongName,
            self.project_object.Phase,
            [self.model_context],
            self.file.by_type("IfcUnitAssignment")[0])

    def getProjectGUID(self):
        # TODO: Do not generate a new one each time, but at least this one
        # conforms to the community consensus on how a GUID is generated.
        return ifcopenshell.guid.new()

    def getProjectObject(self):
        try:
            return getObjectsOfIfcType(self.objects, "Project")[0]
        except:
            return None

    def getProjectObjectData(self):
        if not self.project_object:
            return {}
        return json.loads(self.project_object.IfcData['complex_attributes'])["RepresentationContexts"]