From 429cbdb7a12263250d985790872dfec6aa595549 Mon Sep 17 00:00:00 2001
From: Remco de Boer <29308176+redeboer@users.noreply.github.com>
Date: Mon, 4 Dec 2023 16:29:28 +0100
Subject: [PATCH] FEAT: add `helpers` module (#6)

---
 .cspell.json                     |   1 +
 pyproject.toml                   |   1 +
 src/sphinx_api_relink/helpers.py | 119 +++++++++++++++++++++++++++++++
 3 files changed, 121 insertions(+)
 create mode 100644 src/sphinx_api_relink/helpers.py

diff --git a/.cspell.json b/.cspell.json
index 1143633..90dfc07 100644
--- a/.cspell.json
+++ b/.cspell.json
@@ -31,6 +31,7 @@
     "autodoc",
     "ComPWA",
     "conda",
+    "intersphinx",
     "mypy",
     "PYTHONHASHSEED",
     "SymPy"
diff --git a/pyproject.toml b/pyproject.toml
index d9b430e..0f280ea 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -197,6 +197,7 @@ ignore = [
     "D407",
     "D416",
     "E501",
+    "PLW2901",
     "SIM108",
     "UP036",
 ]
diff --git a/src/sphinx_api_relink/helpers.py b/src/sphinx_api_relink/helpers.py
new file mode 100644
index 0000000..da7a728
--- /dev/null
+++ b/src/sphinx_api_relink/helpers.py
@@ -0,0 +1,119 @@
+"""Helper functions for your :file:`conf.py` Sphinx configuration file."""
+
+# pyright: reportUnnecessaryIsInstance=false
+from __future__ import annotations
+
+import os
+import re
+import sys
+
+__VERSION_REMAPPING: dict[str, dict[str, str]] = {}
+
+
+def get_branch_name() -> str:
+    """Get the branch name from the environment for Read the Docs.
+
+    See https://docs.readthedocs.io/en/stable/builds.html.
+    """
+    branch_name = os.environ.get("READTHEDOCS_VERSION", "stable")
+    if branch_name == "latest":
+        return "main"
+    if re.match(r"^\d+$", branch_name):  # PR preview
+        return "stable"
+    return branch_name
+
+
+def get_execution_mode() -> str:
+    if "FORCE_EXECUTE_NB" in os.environ:
+        print("\033[93;1mWill run ALL Jupyter notebooks!\033[0m")  # noqa: T201
+        return "force"
+    if "EXECUTE_NB" in os.environ:
+        return "cache"
+    return "off"
+
+
+def pin(
+    package_name: str, version_remapping: dict[str, dict[str, str]] | None = None
+) -> str:
+    if version_remapping is None:
+        version_remapping = __VERSION_REMAPPING
+    python_version = f"{sys.version_info.major}.{sys.version_info.minor}"
+    constraints_path = f"../.constraints/py{python_version}.txt"
+    if not os.path.exists(constraints_path):
+        msg = (
+            f"Could not find {constraints_path}. Did you pin your constraints with"
+            " https://github.com/ComPWA/update-pip-constraints?"
+        )
+        raise FileNotFoundError(msg)
+    with open(constraints_path) as stream:
+        constraints = stream.read()
+    package_name = package_name.lower()
+    for line in constraints.split("\n"):
+        line = line.split("#")[0]  # remove comments
+        line = line.strip()
+        line = line.lower()
+        if not line.startswith(package_name):
+            continue
+        if not line:
+            continue
+        line_segments = tuple(line.split("=="))
+        if len(line_segments) != 2:  # noqa: PLR2004
+            continue
+        _, installed_version, *_ = line_segments
+        installed_version = installed_version.strip()
+        remapped_versions = version_remapping.get(package_name)
+        if remapped_versions is not None:
+            existing_version = remapped_versions.get(installed_version)
+            if existing_version is not None:
+                return existing_version
+        return installed_version
+    return "stable"
+
+
+def pin_minor(package_name: str) -> str:
+    installed_version = pin(package_name)
+    if installed_version == "stable":
+        return installed_version
+    matches = re.match(r"^([0-9]+\.[0-9]+).*$", installed_version)
+    if matches is None:
+        msg = f"Could not find documentation for {package_name} v{installed_version}"
+        raise ValueError(msg)
+    return matches[1]
+
+
+def set_intersphinx_version_remapping(
+    version_remapping: dict[str, dict[str, str]]
+) -> None:
+    if not isinstance(version_remapping, dict):
+        msg = (
+            "intersphinx_relink_versions must be a dict, got a"
+            f" {type(version_remapping).__name__}"
+        )
+        raise TypeError(msg)
+    for k, v in version_remapping.items():
+        if not isinstance(k, str):
+            msg = (
+                "intersphinx_relink_versions keys must be str,"
+                f" got a {type(k).__name__}"
+            )
+            raise TypeError(msg)
+        if not isinstance(v, dict):
+            msg = (
+                "intersphinx_relink_versions values must be dict,"
+                f" got a {type(v).__name__}"
+            )
+            raise TypeError(msg)
+        for k2, v2 in v.items():
+            if not isinstance(k2, str):
+                msg = (
+                    "intersphinx_relink_versions values must be dict[str, str],"
+                    f" got a {type(k2).__name__}"
+                )
+                raise TypeError(msg)
+            if not isinstance(v2, str):
+                msg = (
+                    "intersphinx_relink_versions values must be dict[str, str],"
+                    f" got a {type(v2).__name__}"
+                )
+                raise TypeError(msg)
+    __VERSION_REMAPPING.update(version_remapping)