@mytec: 1.4iter ready for testing

backend/app/services/materials_service.py

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+import math
+from enum import Enum
+from typing import Optional
+
+
+class BuildingMaterial(Enum):
+    """Building materials with RF properties"""
+    CONCRETE = "concrete"
+    BRICK = "brick"
+    GLASS = "glass"
+    WOOD = "wood"
+    METAL = "metal"
+    STONE = "stone"
+    PLASTER = "plaster"
+    UNKNOWN = "unknown"
+
+
+# ITU-R P.2040 based attenuation (dB per wall at 1-3 GHz)
+MATERIAL_LOSS = {
+    BuildingMaterial.CONCRETE: 15.0,
+    BuildingMaterial.BRICK: 10.0,
+    BuildingMaterial.GLASS: 3.0,
+    BuildingMaterial.WOOD: 5.0,
+    BuildingMaterial.METAL: 25.0,  # Or full reflection
+    BuildingMaterial.STONE: 12.0,
+    BuildingMaterial.PLASTER: 4.0,
+    BuildingMaterial.UNKNOWN: 10.0,  # Default assumption
+}
+
+# Reflection coefficient (0-1, portion of signal reflected)
+MATERIAL_REFLECTION = {
+    BuildingMaterial.CONCRETE: 0.6,
+    BuildingMaterial.BRICK: 0.5,
+    BuildingMaterial.GLASS: 0.3,
+    BuildingMaterial.WOOD: 0.2,
+    BuildingMaterial.METAL: 0.9,
+    BuildingMaterial.STONE: 0.55,
+    BuildingMaterial.PLASTER: 0.3,
+    BuildingMaterial.UNKNOWN: 0.4,
+}
+
+
+class MaterialsService:
+    """Building material detection and RF properties"""
+
+    # OSM building:material tag mapping
+    OSM_MATERIAL_MAP = {
+        "concrete": BuildingMaterial.CONCRETE,
+        "brick": BuildingMaterial.BRICK,
+        "glass": BuildingMaterial.GLASS,
+        "wood": BuildingMaterial.WOOD,
+        "metal": BuildingMaterial.METAL,
+        "steel": BuildingMaterial.METAL,
+        "stone": BuildingMaterial.STONE,
+        "plaster": BuildingMaterial.PLASTER,
+        "cement_block": BuildingMaterial.CONCRETE,
+        "timber": BuildingMaterial.WOOD,
+    }
+
+    # Fallback by building type
+    BUILDING_TYPE_MATERIAL = {
+        "industrial": BuildingMaterial.METAL,
+        "warehouse": BuildingMaterial.METAL,
+        "garage": BuildingMaterial.METAL,
+        "shed": BuildingMaterial.WOOD,
+        "house": BuildingMaterial.BRICK,
+        "residential": BuildingMaterial.CONCRETE,
+        "apartments": BuildingMaterial.CONCRETE,
+        "commercial": BuildingMaterial.GLASS,  # Often glass facades
+        "office": BuildingMaterial.GLASS,
+        "retail": BuildingMaterial.GLASS,
+        "church": BuildingMaterial.STONE,
+        "cathedral": BuildingMaterial.STONE,
+        "school": BuildingMaterial.BRICK,
+        "hospital": BuildingMaterial.CONCRETE,
+        "university": BuildingMaterial.CONCRETE,
+    }
+
+    def detect_material(self, building_tags: dict) -> BuildingMaterial:
+        """Detect building material from OSM tags"""
+
+        # Direct material tag
+        if "building:material" in building_tags:
+            material_str = building_tags["building:material"].lower()
+            if material_str in self.OSM_MATERIAL_MAP:
+                return self.OSM_MATERIAL_MAP[material_str]
+
+        # Facade material (often more relevant for RF)
+        if "building:facade:material" in building_tags:
+            material_str = building_tags["building:facade:material"].lower()
+            if material_str in self.OSM_MATERIAL_MAP:
+                return self.OSM_MATERIAL_MAP[material_str]
+
+        # Fallback by building type
+        building_type = building_tags.get("building", "yes").lower()
+        if building_type in self.BUILDING_TYPE_MATERIAL:
+            return self.BUILDING_TYPE_MATERIAL[building_type]
+
+        return BuildingMaterial.UNKNOWN
+
+    def get_penetration_loss(self, material: BuildingMaterial, frequency_mhz: float = 1800) -> float:
+        """
+        Get RF penetration loss through wall
+
+        Frequency correction: +2dB per octave above 1GHz
+        """
+        base_loss = MATERIAL_LOSS[material]
+
+        # Frequency correction (simplified)
+        freq_factor = max(0, (frequency_mhz - 1000) / 1000) * 2
+
+        return base_loss + freq_factor
+
+    def get_reflection_coefficient(self, material: BuildingMaterial) -> float:
+        """Get reflection coefficient (0-1)"""
+        return MATERIAL_REFLECTION[material]
+
+    def get_reflection_loss(self, material: BuildingMaterial) -> float:
+        """Get loss due to reflection (dB)"""
+        coeff = MATERIAL_REFLECTION[material]
+        if coeff <= 0:
+            return 30.0  # Effectively no reflection
+
+        # Reflection loss in dB = -10 * log10(coefficient)
+        return -10 * math.log10(coeff)
+
+
+materials_service = MaterialsService()