1 files changed, 98 insertions, 0 deletions
diff --git a/src/installer/__main__.py b/src/installer/__main__.py
new file mode 100644
index 0000000..51014b9
--- /dev/null
+++ b/src/installer/__main__.py
@@ -0,0 +1,98 @@
+"""Installer CLI."""
+
+import argparse
+import os.path
+import sys
+import sysconfig
+from typing import Dict, Optional, Sequence
+
+import installer
+from installer.destinations import SchemeDictionaryDestination
+from installer.sources import WheelFile
+from installer.utils import get_launcher_kind
+
+
+def _get_main_parser() -> argparse.ArgumentParser:
+    """Construct the main parser."""
+    parser = argparse.ArgumentParser()
+    parser.add_argument("wheel", type=str, help="wheel file to install")
+    parser.add_argument(
+        "--destdir",
+        "-d",
+        metavar="path",
+        type=str,
+        help="destination directory (prefix to prepend to each file)",
+    )
+    parser.add_argument(
+        "--prefix",
+        "-p",
+        metavar="path",
+        type=str,
+        help="override prefix to install packages to",
+    )
+    parser.add_argument(
+        "--compile-bytecode",
+        action="append",
+        metavar="level",
+        type=int,
+        choices=[0, 1, 2],
+        help="generate bytecode for the specified optimization level(s) (default=0, 1)",
+    )
+    parser.add_argument(
+        "--no-compile-bytecode",
+        action="store_true",
+        help="don't generate bytecode for installed modules",
+    )
+    return parser
+
+
+def _get_scheme_dict(
+    distribution_name: str, prefix: Optional[str] = None
+) -> Dict[str, str]:
+    """Calculate the scheme dictionary for the current Python environment."""
+    vars = {}
+    if prefix is None:
+        installed_base = sysconfig.get_config_var("base")
+        assert installed_base
+    else:
+        vars["base"] = vars["platbase"] = installed_base = prefix
+
+    scheme_dict = sysconfig.get_paths(vars=vars)
+
+    # calculate 'headers' path, not currently in sysconfig - see
+    # https://bugs.python.org/issue44445. This is based on what distutils does.
+    # TODO: figure out original vs normalised distribution names
+    scheme_dict["headers"] = os.path.join(
+        sysconfig.get_path("include", vars={"installed_base": installed_base}),
+        distribution_name,
+    )
+
+    return scheme_dict
+
+
+def _main(cli_args: Sequence[str], program: Optional[str] = None) -> None:
+    """Process arguments and perform the install."""
+    parser = _get_main_parser()
+    if program:
+        parser.prog = program
+    args = parser.parse_args(cli_args)
+
+    bytecode_levels = args.compile_bytecode
+    if args.no_compile_bytecode:
+        bytecode_levels = []
+    elif not bytecode_levels:
+        bytecode_levels = [0, 1]
+
+    with WheelFile.open(args.wheel) as source:
+        destination = SchemeDictionaryDestination(
+            scheme_dict=_get_scheme_dict(source.distribution, prefix=args.prefix),
+            interpreter=sys.executable,
+            script_kind=get_launcher_kind(),
+            bytecode_optimization_levels=bytecode_levels,
+            destdir=args.destdir,
+        )
+        installer.install(source, destination, {})
+
+
+if __name__ == "__main__":  # pragma: no cover
+    _main(sys.argv[1:], "python -m installer")