Project skeleton

custom_components/pv_microinverter/units.py

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+from typing import Self
+
+# SI prefix multipliers
+SI_PREFIXES = {
+    "Y": 1e24,
+    "Z": 1e21,
+    "E": 1e18,
+    "P": 1e15,
+    "T": 1e12,
+    "G": 1e9,
+    "M": 1e6,
+    "k": 1e3,
+    "h": 1e2,
+    "da": 1e1,
+    "d": 1e-1,
+    "c": 1e-2,
+    "m": 1e-3,
+    "µ": 1e-6,
+    "u": 1e-6,
+    "n": 1e-9,
+    "p": 1e-12,
+    "f": 1e-15,
+    "a": 1e-18,
+    "z": 1e-21,
+    "y": 1e-24,
+}
+
+
+def _get_unit_symbol(unit_val: str) -> str:
+    """Extract the unit symbol from a unit value string."""
+    # Assuming the unit value is in the format "value unit"
+    return unit_val.strip().split(" ")[-1]
+
+
+class SIUnit:
+    """SI Units with automatic unit conversion."""
+
+    def __init__(self, name: str, quantity: str, symbol: str, factor: float):
+        self.name = name
+        self.quantity = quantity
+        self.symbol = symbol
+        self.factor = factor
+
+    def __str__(self):
+        return f"{self.name} ({self.symbol})"
+
+    def __repr__(self):
+        return f"SIUnit(name={self.name}, symbol={self.symbol}, factor={self.factor})"
+
+    @classmethod
+    def parse(cls, unit_str: str) -> Self:
+        """
+        Return an SIUnit by parsing the given unit string, supporting SI prefixes.
+        """
+        # If the unit is registered directly, return it.
+        if unit_str in BASE_UNITS:
+            return BASE_UNITS[unit_str]
+        # Otherwise, check for a valid prefix.
+        for prefix in sorted(SI_PREFIXES, key=len, reverse=True):
+            if unit_str.startswith(prefix):
+                base_symbol = unit_str[len(prefix) :]
+                if base_symbol in BASE_UNITS:
+                    base_unit = BASE_UNITS[base_symbol]
+                    multiplier = SI_PREFIXES[prefix]
+                    return SIUnit(
+                        f"{prefix}{base_unit.name}",
+                        base_unit.quantity,
+                        f"{prefix}{base_unit.symbol}",
+                        base_unit.factor * multiplier,
+                    )
+        raise ValueError(f"Unknown unit: {unit_str}")
+
+
+class Dimension:
+    """Class to represent a dimension with a unit."""
+
+    def __init__(self, value: float, unit: SIUnit):
+        self.value = value
+        self.unit = unit
+
+    def __str__(self):
+        return f"{self.value} {self.unit.symbol}"
+
+    def to_base_unit(self) -> float:
+        """Convert the dimension value to its base unit."""
+        return float(self.value) * self.unit.factor
+
+    def __repr__(self):
+        return f"Dimension(value={self.value}, unit={self.unit})"
+
+    @classmethod
+    def parse(cls, unit_val: str) -> Self:
+        """
+        Parse a unit value string into a Dimension object, supporting SI unit prefixes.
+        Expects the format "value unit", e.g. "3.5 kW" or "10 Wh".
+        """
+        parts = unit_val.strip().split()
+        if len(parts) != 2:
+            raise ValueError(f"Invalid unit value format: {unit_val}")
+        value, unit_str = parts
+        unit = SIUnit.parse(unit_str)
+        return cls(float(value), unit)
+
+
+# Define SI units
+WATT = SIUnit("Watt", "Power", "W", 1)
+WATT_HOUR = SIUnit("Watt-hour", "Energy", "Wh", 1)
+
+
+# Mapping of base unit symbols to registered SIUnit objects
+BASE_UNITS = {
+    "W": WATT,
+    "Wh": WATT_HOUR,
+}