[ENH] Fix color generator initialization and improve basement color handling (#1038)

# Description
This PR refactors the `ColorsGenerator` class to use `__post_init__` instead of `__init__` and improves the basement color generation in `StructuralFrame`. The changes include:

- Refactored `ColorsGenerator` to use `__post_init__` for proper dataclass initialization
- Added `color_generator` as a proper field with default factory in `StructuralFrame`
- Improved basement color generation logic to ensure uniqueness
- Fixed a tensor detachment issue in nugget optimization by converting to numpy
- Removed unused imports in serialization and test modules
- Updated test validation settings

Relates to #optimization-and-refactoring

# Checklist
- [x] My code uses type hinting for function and method arguments and return values.
- [x] I have created tests which cover my code.
- [x] The test code either 1. demonstrates at least one valuable use case (e.g. integration tests) or 2. verifies that outputs are as expected for given inputs (e.g. unit tests).
- [x] New tests pass locally with my changes.

Author: Leguark

gempy/core/color_generator.py

@@ -35,7 +35,7 @@ class ColorsGenerator:
     )
     _index: int = 0
 
-    def __init__(self):
+    def __post_init__(self):
         self.regenerate_color_palette()
 
     @staticmethod

gempy/core/data/structural_frame.py

@@ -3,7 +3,7 @@
 import numpy as np
 import warnings
 from dataclasses import dataclass
-from pydantic import model_validator, computed_field, ValidationError
+from pydantic import model_validator, computed_field, ValidationError, Field
 from pydantic.functional_validators import ModelWrapValidatorHandler
 from typing import Generator, Union
 
@@ -32,14 +32,19 @@ class StructuralFrame:
     """
 
     structural_groups: list[StructuralGroup]
+    color_generator: ColorsGenerator =  Field(default_factory=ColorsGenerator)
+    basement_color: str = None
     # ? Should I create some sort of structural options class? For example, the masking descriptor and faults relations pointer
     is_dirty: bool = True
 
     # region Constructor
-
+    # 
     def __init__(self, structural_groups: list[StructuralGroup], color_gen: ColorsGenerator):
         self.structural_groups = structural_groups  # ? This maybe could be optional
         self.color_generator = color_gen
+        
+    def __post_init__(self):
+        pass
 
     @classmethod
     def from_data_tables(cls, surface_points: SurfacePointsTable, orientations: OrientationsTable):
@@ -202,22 +207,28 @@ def n_elements(self) -> int:
         """Returns the total number of elements in the structural frame."""
         return len(self.structural_elements)
 
-    basement_color: str = None
 
     @property
     def _basement_element(self) -> StructuralElement:
-        # Check if the basement color is already defined
+        """Returns the basement structural element with a unique color."""
+
+        def _get_unique_basement_color(color_generator: ColorsGenerator, used_colors: list[str]) -> str:
+            color = next(color_generator)
+            if color in used_colors:
+                return _get_unique_basement_color(color_generator, used_colors)
+            return color
+
         elements = []
         for group in self.structural_groups:
             elements.extend(group.elements)
-        basement_color_in_elements = self.basement_color in [element.color for element in elements]
 
-        if self.basement_color is None or basement_color_in_elements:
-            self.basement_color = self.color_generator.up_next()
+        used_colors = [element.color for element in elements]
 
-        if basement_color_in_elements:
-            warnings.warn(f"The basement color was already used in the structural elements."
-                          f"Changing the basement color to {self.basement_color}.")
+        if self.basement_color is None or self.basement_color in used_colors:
+            self.basement_color = _get_unique_basement_color(
+                color_generator=self.color_generator, 
+                used_colors=used_colors
+            )
 
         basement = StructuralElement(
             name="basement",

gempy/modules/optimize_nuggets/_ops.py

@@ -43,7 +43,9 @@ def run_optimization(lr, max_epochs, min_impr, model, nugget, patience, target_c
         if _has_converged(cur_cond, prev_cond, target_cond_num, epoch, min_impr, patience):
             break
         prev_cond = cur_cond
-        
+
+    # Condition number to numpy
+    model.interpolation_options.kernel_options.condition_number = model.interpolation_options.kernel_options.condition_number.detach().numpy()
     return nugget
 
 

gempy/modules/serialization/save_load.py

@@ -169,7 +169,6 @@ def make_info(name):
     return buf.getvalue()
 
 def _load_model_from_bytes(data: bytes) -> GeoModel:
-    import json, zlib
     from ...core.data.encoders.converters import loading_model_from_binary
 
     buf = io.BytesIO(data)

test/test_modules/_geophysics_TO_UPDATE/test_gravity.test_gravity.verify/2-layers.approved.txt

@@ -53,8 +53,11 @@
                 "solution": null
             }
         ],
-        "is_dirty": true,
+        "color_generator": {
+            "_index": 3
+        },
         "basement_color": "#ffbe00",
+        "is_dirty": true,
         "binary_meta_data": {
             "sp_binary_length": 144,
             "ori_binary_length": 60

test/test_modules/test_faults/test_finite_faults.test_finite_fault_scalar_field_on_fault.verify/fault.approved.txt

@@ -127,8 +127,11 @@
                 "solution": null
             }
         ],
-        "is_dirty": true,
+        "color_generator": {
+            "_index": 4
+        },
         "basement_color": "#728f02",
+        "is_dirty": true,
         "binary_meta_data": {
             "sp_binary_length": 792,
             "ori_binary_length": 300

test/test_modules/test_grids/test_custom_grid.test_custom_grid.verify/fold.approved.txt

@@ -59,8 +59,11 @@
                 "solution": null
             }
         ],
-        "is_dirty": true,
+        "color_generator": {
+            "_index": 3
+        },
         "basement_color": "#ffbe00",
+        "is_dirty": true,
         "binary_meta_data": {
             "sp_binary_length": 1296,
             "ori_binary_length": 120

test/test_modules/test_grids/test_grids_sections.test_section_grids.verify/fold.approved.txt

@@ -59,8 +59,11 @@
                 "solution": null
             }
         ],
-        "is_dirty": true,
+        "color_generator": {
+            "_index": 3
+        },
         "basement_color": "#ffbe00",
+        "is_dirty": true,
         "binary_meta_data": {
             "sp_binary_length": 1296,
             "ori_binary_length": 120

test/test_modules/test_grids/test_grids_sections.test_topography_II.verify/Model1.approved.txt

@@ -13,7 +13,7 @@
                     {
                         "name": "fault1",
                         "is_active": true,
-                        "_color": "#728f02",
+                        "_color": "#443988",
                         "surface_points": {
                             "name_id_map": {
                                 "fault1": 26244822
@@ -56,7 +56,7 @@
                     {
                         "name": "surface2",
                         "is_active": true,
-                        "_color": "#9f0052",
+                        "_color": "#ffbe00",
                         "surface_points": {
                             "name_id_map": {
                                 "surface2": 21816406
@@ -73,7 +73,7 @@
                     {
                         "name": "surface3",
                         "is_active": true,
-                        "_color": "#ffbe00",
+                        "_color": "#728f02",
                         "surface_points": {
                             "name_id_map": {
                                 "surface3": 98435767
@@ -94,8 +94,11 @@
                 "solution": null
             }
         ],
+        "color_generator": {
+            "_index": 5
+        },
+        "basement_color": "#9f0052",
         "is_dirty": true,
-        "basement_color": "#443988",
         "binary_meta_data": {
             "sp_binary_length": 360,
             "ori_binary_length": 120

test/test_modules/test_serialize_model.test_generate_horizontal_stratigraphic_model.verify/Horizontal Stratigraphic Model serialization.approved.txt

@@ -59,8 +59,11 @@
                 "solution": null
             }
         ],
-        "is_dirty": true,
+        "color_generator": {
+            "_index": 3
+        },
         "basement_color": "#ffbe00",
+        "is_dirty": true,
         "binary_meta_data": {
             "sp_binary_length": 432,
             "ori_binary_length": 120