refactor: split code into multiple files (#4044)

A followup to #4043 to split code into multiple files to make the
interaction
and reuse more intentional and explicit.

Work towards #2948.

---------

Co-authored-by: Richard Levasseur <richardlev@gmail.com>

Author: aignas

docs/BUILD.bazel

@@ -146,7 +146,9 @@ sphinx_stardocs(
         "//python/private/api:py_common_api",
         "//python/private/pypi:config_settings",
         "//python/private/pypi:env_marker_info",
+        "//python/private/pypi:pip_archive",
         "//python/private/pypi:pkg_aliases",
+        "//python/private/pypi:whl_archive",
         "//python/private/pypi:whl_config_setting",
         "//python/private/pypi:whl_library",
         "//python/private/zipapp:py_zipapp_rule",

python/private/pypi/BUILD.bazel

@@ -473,20 +473,8 @@ bzl_library(
     name = "whl_library",
     srcs = ["whl_library.bzl"],
     deps = [
-        ":attrs",
-        ":deps",
-        ":generate_whl_library_build_bazel",
-        ":patch_whl",
-        ":pep508_requirement",
-        ":pypi_repo_utils",
-        ":urllib",
-        ":whl_extract",
-        ":whl_metadata",
-        "//python/private:auth",
-        "//python/private:envsubst",
-        "//python/private:is_standalone_interpreter",
-        "//python/private:normalize_name",
-        "//python/private:repo_utils",
+        ":pip_archive",
+        ":whl_archive",
     ],
 )
 
@@ -547,6 +535,61 @@ bzl_library(
     deps = [":hash"],
 )
 
+bzl_library(
+    name = "pip_archive",
+    srcs = ["pip_archive.bzl"],
+    deps = [
+        ":attrs",
+        ":deps",
+        ":patch_and_extract_whl",
+        ":pypi_repo_utils",
+        ":urllib",
+        ":whl_archive",
+        "//python/private:auth",
+        "//python/private:envsubst",
+        "//python/private:is_standalone_interpreter",
+        "//python/private:repo_utils",
+    ],
+)
+
+bzl_library(
+    name = "whl_archive",
+    srcs = ["whl_archive.bzl"],
+    deps = [
+        ":attrs",
+        ":patch_and_extract_whl",
+        ":urllib",
+        ":whl_deps_repo",
+        "//python/private:auth",
+        "//python/private:repo_utils",
+    ],
+)
+
+bzl_library(
+    name = "whl_deps_repo",
+    srcs = ["whl_deps_repo.bzl"],
+    deps = [
+        ":generate_whl_library_build_bazel",
+        ":pep508_requirement",
+        "//python/private:repo_utils",
+    ],
+)
+
+bzl_library(
+    name = "patch_and_extract_whl",
+    srcs = ["patch_and_extract_whl.bzl"],
+    deps = [
+        ":generate_whl_library_build_bazel",
+        ":patch_whl",
+        ":pep508_requirement",
+        ":pypi_repo_utils",
+        ":whl_extract",
+        ":whl_metadata",
+        "//python/private:normalize_name",
+        "//python/private:repo_utils",
+    ],
+)
+
 bzl_library(
     name = "argparse",
     srcs = ["argparse.bzl"],

python/private/pypi/patch_and_extract_whl.bzl

@@ -0,0 +1,164 @@
+""
+
+load("//python/private:normalize_name.bzl", "normalize_name")
+load("//python/private:repo_utils.bzl", "repo_utils")
+load(":generate_whl_library_build_bazel.bzl", "generate_whl_library_build_bazel")
+load(":patch_whl.bzl", "patch_whl")
+load(":pep508_requirement.bzl", "requirement")
+load(":pypi_repo_utils.bzl", "pypi_repo_utils")
+load(":whl_extract.bzl", "whl_extract")
+load(":whl_metadata.bzl", "parse_entry_points", "whl_metadata")
+
+def _get_entry_points(rctx, install_dir_path, metadata):
+    dist_info_dir = "{}-{}.dist-info".format(
+        metadata.name.replace("-", "_"),
+        metadata.version.replace("-", "_"),
+    )
+    entry_points_txt = install_dir_path.get_child(dist_info_dir).get_child("entry_points.txt")
+    if entry_points_txt.exists:
+        return parse_entry_points(rctx.read(entry_points_txt))
+    return {}
+
+def _move_scripts_needing_shebang_rewrite(rctx, entry_points):
+    bin_dir = rctx.path("bin")
+    if not bin_dir.exists:
+        return
+
+    ep_names = {name.lower(): True for name in entry_points}
+    for script in bin_dir.readdir():
+        if script.is_dir:
+            continue
+        if script.basename.lower() in ep_names:
+            rctx.delete(script)
+            continue
+        if script.basename.endswith(".exe") or script.basename.endswith(".dll"):
+            continue
+        content = rctx.read(script)
+        if content.startswith("#!python"):
+            rewrite_bin_dir = rctx.path("rewrite-bin")
+            repo_utils.mkdir(rctx, rewrite_bin_dir)
+            repo_utils.rename(rctx, script, rctx.path("rewrite-bin/" + script.basename))
+
+def _to_purl(*, index, metadata, filename):
+    """
+    Produce a PyPI PURL from the metadata.
+
+    https://github.com/package-url/purl-spec/blob/main/types-doc/pypi-definition.md
+    """
+
+    # https://github.com/package-url/purl-spec/blob/main/types-doc/pypi-definition.md#name-definition
+    name = normalize_name(metadata.name).replace("_", "-")
+
+    qualifiers = {}
+    if index:
+        qualifiers["repository_url"] = index
+    if filename:
+        qualifiers["file_name"] = filename
+
+    return "pkg:pypi/{}@{}?{}".format(name, metadata.version, "&".join(["{}={}".format(key, val) for key, val in qualifiers.items()]))
+
+def _remove_files(rctx, *basenames):
+    paths = list(rctx.path(".").readdir())
+    for _ in range(10000000):
+        if not paths:
+            break
+        path = paths.pop()
+
+        if path.basename in basenames:
+            rctx.delete(path)
+        elif path.is_dir:
+            paths.extend(path.readdir())
+
+def patch_and_extract_whl(rctx, *, whl_path, logger, sdist_filename = None):
+    """Extract the wheel, apply patches and generate BUILD.bazel files.
+
+    Reused in pip and http wheel download code.
+
+    Args:
+        rctx: the repository ctx.
+        whl_path: the whl path to extract.
+        logger: The logger to use
+        sdist_filename: The filename to ignore in the BUILD.bazel files as sources.
+
+    Returns:
+        The repository metadata if the extraction is reproducible
+    """
+    if rctx.attr.whl_patches:
+        patches = {}
+        for patch_file, json_args in rctx.attr.whl_patches.items():
+            patch_dst = struct(**json.decode(json_args))
+            if whl_path.basename in patch_dst.whls:
+                patches[patch_file] = patch_dst.patch_strip
+
+        if patches:
+            whl_path = patch_whl(
+                rctx,
+                whl_path = whl_path,
+                patches = patches,
+            )
+
+    whl_extract(rctx, whl_path = whl_path, logger = logger)
+
+    install_dir_path = whl_path.dirname.get_child("site-packages")
+    metadata = whl_metadata(
+        install_dir = install_dir_path,
+        read_fn = rctx.read,
+        logger = logger,
+    )
+    rctx.file("metadata.json", json.encode_indent({
+        "name": metadata.name,
+        "provides_extra": metadata.provides_extra,
+        "requires_dist": metadata.requires_dist,
+        "version": metadata.version,
+    }))
+    namespace_package_files = pypi_repo_utils.find_namespace_package_files(rctx, install_dir_path)
+
+    entry_points = _get_entry_points(rctx, install_dir_path, metadata)
+    _move_scripts_needing_shebang_rewrite(rctx, entry_points)
+
+    build_file_contents = generate_whl_library_build_bazel(
+        name = whl_path.basename,
+        dep_template = rctx.attr.dep_template,
+        sdist_filename = sdist_filename,
+        config_load = rctx.attr.config_load,
+        metadata_name = metadata.name,
+        metadata_version = metadata.version,
+        requires_dist = metadata.requires_dist,
+        # TODO @aignas 2025-05-17: maybe have a build flag for this instead
+        enable_implicit_namespace_pkgs = rctx.attr.enable_implicit_namespace_pkgs,
+        # TODO @aignas 2025-04-14: load through the hub:
+        annotation = None if not rctx.attr.annotation else struct(**json.decode(rctx.read(rctx.attr.annotation))),
+        data_exclude = rctx.attr.pip_data_exclude,
+        group_deps = rctx.attr.group_deps,
+        group_name = rctx.attr.group_name,
+        namespace_package_files = namespace_package_files,
+        extras = requirement(rctx.attr.requirement).extras,
+        entry_points = entry_points,
+        purl = _to_purl(
+            index = rctx.attr.index_url,
+            metadata = metadata,
+            filename = sdist_filename or whl_path.basename,
+        ),
+    )
+
+    # Delete these in case the wheel had them. They generally don't cause
+    # a problem, but let's avoid the chance of that happening.
+    rctx.file("WORKSPACE")
+    rctx.file("WORKSPACE.bazel")
+    rctx.file("MODULE.bazel")
+    rctx.file("REPO.bazel", """\
+repo(
+    default_package_metadata = [
+        "//:package_metadata",
+    ],
+)
+""")
+
+    # BUILD files interfere with globbing and Bazel package boundaries.
+    _remove_files(rctx, "BUILD", "BUILD.bazel")
+    rctx.file("BUILD.bazel", build_file_contents)
+
+    if hasattr(rctx, "repo_metadata"):
+        return rctx.repo_metadata(reproducible = True)
+
+    return None