PROPOSAL: add preload and library type

.coveragerc

@@ -6,6 +6,8 @@ source =
     tests
 
 omit =
+    */_secp256k1_library_info.py
+    */_version.py
     */_windows_libsecp256k1.py
     */test_bench.py
 

.github/workflows/build.yml

@@ -157,6 +157,45 @@ jobs:
         path: dist/*
         if-no-files-found: error
 
+  windows-wheels-conda-x86_64:
+    name: Build Windows (CONDA) wheels AMD64
+    needs:
+    - test
+    runs-on: windows-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Python ${{ env.PYTHON_VERSION }}
+      uses: actions/setup-python@v5
+      with:
+        python-version: '3.12'
+
+    - name: Install Miniconda
+      uses: conda-incubator/setup-miniconda@v3
+
+    - name: Build wheels
+      uses: pypa/[email protected]
+      env:
+        CIBW_ENVIRONMENT:
+            COINCURVE_IGNORE_SYSTEM_LIB="0"
+            COINCURVE_UPSTREAM_REF="__no_tag__"
+            COINCURVE_SECP256K1_BUILD='SHARED'
+        CIBW_BUILD: "cp312-win_amd64"
+        CIBW_ARCHS_WINDOWS: "AMD64"
+        CIBW_BEFORE_ALL: >
+            conda install -c conda-forge pkg-config libsecp256k1
+        CIBW_BUILD_VERBOSITY: 1
+        # pytest needs to be defined here to find 'coincurve' package?
+        CIBW_TEST_REQUIRES: pytest pytest-benchmark
+        CIBW_TEST_COMMAND: >
+            conda install -c conda-forge libsecp256k1 &&
+            python -c
+            "from coincurve import PrivateKey;
+            a=PrivateKey();
+            b=PrivateKey();
+            assert a.ecdh(b.public_key.format())==b.ecdh(a.public_key.format())
+
   linux-wheels-arm:
     name: Build Linux wheels for ARM
     needs:

coincurve/__init__.py

@@ -1,6 +1,43 @@
-from coincurve.context import GLOBAL_CONTEXT, Context
-from coincurve.keys import PrivateKey, PublicKey, PublicKeyXOnly
-from coincurve.utils import verify_signature
+def load_secp256k1_conda_library():
+    """Load the secp256k1 library from the conda environment."""
+    import warnings
+
+    from coincurve._secp256k1_library_info import SECP256K1_LIBRARY_NAME, SECP256K1_LIBRARY_TYPE
+
+    if SECP256K1_LIBRARY_TYPE != 'EXTERNAL':
+        # coincurve was built with an internal library, either static or shared. It 'knows' where the library is.
+        return
+
+    import os
+    from ctypes import CDLL
+    from ctypes.util import find_library
+
+    try:
+        # Find the library in the typical installation paths
+        if library := find_library(SECP256K1_LIBRARY_NAME):
+            CDLL(library)
+            return
+
+        # Find the library in the conda environment
+        if (conda := os.getenv('CONDA_PREFIX')) is not None:
+            import platform
+
+            if platform.system() == 'Windows':
+                library = os.path.join(conda, 'Library', 'bin', SECP256K1_LIBRARY_NAME)
+            else:
+                library = os.path.join(conda, 'lib', SECP256K1_LIBRARY_NAME)
+
+            CDLL(library)
+            return
+    except Exception as e:
+        warnings.warn(f'The required library {SECP256K1_LIBRARY_NAME}l is not loaded.\n{e}', stacklevel=2)
+
+
+load_secp256k1_conda_library()
+
+from coincurve.context import GLOBAL_CONTEXT, Context  # noqa: E402
+from coincurve.keys import PrivateKey, PublicKey, PublicKeyXOnly  # noqa: E402
+from coincurve.utils import verify_signature  # noqa: E402
 
 __all__ = [
     'GLOBAL_CONTEXT',

coincurve/_secp256k1_library_info.py

@@ -0,0 +1,2 @@
+SECP256K1_LIBRARY_TYPE = 'INTERNAL'
+SECP256K1_LIBRARY_NAME = 'libsecp256k1-2.dll'

coincurve/_version.py

@@ -0,0 +1,11 @@
+# This file is imported from __init__.py and exec'd from setup.py
+
+MAJOR = 19
+MINOR = 0
+MICRO = 1
+RELEASE = True
+
+__version__ = '%d.%d.%d' % (MAJOR, MINOR, MICRO)
+
+if not RELEASE:
+    __version__ += '.dev0'

setup.py

@@ -7,6 +7,9 @@
 import tarfile
 from io import BytesIO
 import sys
+from os.path import dirname, abspath, join
+from sys import path as PATH
+
 
 from setuptools import Distribution as _Distribution, setup, find_packages, __version__ as setuptools_version
 from setuptools._distutils import log
@@ -24,8 +27,10 @@
 except ImportError:
     _bdist_wheel = None
 
-sys.path.append(os.path.abspath(os.path.dirname(__file__)))
-from setup_support import absolute, build_flags, detect_dll, has_system_lib
+COINCURVE_SRC_DIR = dirname(abspath(__file__))
+PATH.append(COINCURVE_SRC_DIR)
+
+from setup_support import absolute, build_flags, detect_dll, has_system_lib  # noqa: E402
 
 BUILDING_FOR_WINDOWS = detect_dll()
 
@@ -38,6 +43,15 @@
 
 LIB_TARBALL_URL = f'https://github.com/bitcoin-core/secp256k1/archive/{UPSTREAM_REF}.tar.gz'
 
+globals_ = {}
+with open(join(COINCURVE_SRC_DIR, 'coincurve', '_version.py')) as fp:
+    exec(fp.read(), globals_)  # noqa S102
+    __version__ = globals_['__version__']
+
+with open(join(COINCURVE_SRC_DIR, 'coincurve', '_secp256k1_library_info.py'), 'w') as fp:
+    fp.write("SECP256K1_LIBRARY_TYPE = 'INTERNAL'\n")
+    fp.write("SECP256K1_LIBRARY_NAME = '_TBD_'\n")
+
 # We require setuptools >= 3.3
 if [int(i) for i in setuptools_version.split('.', 2)[:2]] < [3, 3]:
     raise SystemExit(
@@ -331,7 +345,7 @@ def has_c_libraries(self):
 
 setup(
     name='coincurve',
-    version='19.0.1',
+    version=__version__,
 
     description='Cross-platform Python CFFI bindings for libsecp256k1',
     long_description=open('README.md', 'r').read(),

tests/conftest.py

@@ -73,3 +73,10 @@ def samples():
         'X_ONLY_PUBKEY': X_ONLY_PUBKEY,
         'X_ONLY_PUBKEY_INVALID': X_ONLY_PUBKEY_INVALID,
     }
+
+
+@pytest.fixture(autouse=True)
+def load_secp256k1_library():
+    from coincurve import load_secp256k1_conda_library
+
+    load_secp256k1_conda_library()