# Copyright Spack Project Developers. See COPYRIGHT file for details.
#
# SPDX-License-Identifier: (Apache-2.0 OR MIT)

import argparse
import collections
import io
import os
import re
import sys

import spack.extensions

try:
    import pytest
except ImportError:
    pytest = None  # type: ignore

import spack.llnl.util.filesystem
import spack.llnl.util.tty as tty
import spack.llnl.util.tty.color as color
import spack.paths
from spack.llnl.util.tty.colify import colify

description = "run spack's unit tests (wrapper around pytest)"
section = "developer"
level = "long"


def setup_parser(subparser: argparse.ArgumentParser) -> None:
    subparser.add_argument(
        "-H",
        "--pytest-help",
        action="store_true",
        default=False,
        help="show full pytest help, with advanced options",
    )
    subparser.add_argument(
        "-n",
        "--numprocesses",
        type=int,
        default=1,
        help="run tests in parallel up to this wide, default 1 for sequential",
    )

    # extra spack arguments to list tests
    list_group = subparser.add_argument_group("listing tests")
    list_mutex = list_group.add_mutually_exclusive_group()
    list_mutex.add_argument(
        "-l",
        "--list",
        action="store_const",
        default=None,
        dest="list",
        const="list",
        help="list test filenames",
    )
    list_mutex.add_argument(
        "-L",
        "--list-long",
        action="store_const",
        default=None,
        dest="list",
        const="long",
        help="list all test functions",
    )
    list_mutex.add_argument(
        "-N",
        "--list-names",
        action="store_const",
        default=None,
        dest="list",
        const="names",
        help="list full names of all tests",
    )

    # use tests for extension
    subparser.add_argument(
        "--extension", default=None, help="run test for a given spack extension"
    )

    # spell out some common pytest arguments, so they'll show up in help
    pytest_group = subparser.add_argument_group(
        "common pytest arguments (spack unit-test --pytest-help for more)"
    )
    pytest_group.add_argument(
        "-s",
        action="append_const",
        dest="parsed_args",
        const="-s",
        help="print output while tests run (disable capture)",
    )
    pytest_group.add_argument(
        "-k",
        action="store",
        metavar="EXPRESSION",
        dest="expression",
        help="filter tests by keyword (can also use w/list options)",
    )
    pytest_group.add_argument(
        "--showlocals",
        action="append_const",
        dest="parsed_args",
        const="--showlocals",
        help="show local variable values in tracebacks",
    )

    # remainder is just passed to pytest
    subparser.add_argument("pytest_args", nargs=argparse.REMAINDER, help="arguments for pytest")


def do_list(args, extra_args):
    """Print a lists of tests than what pytest offers."""

    def colorize(c, prefix):
        if isinstance(prefix, tuple):
            return "::".join(color.colorize("@%s{%s}" % (c, p)) for p in prefix if p != "()")
        return color.colorize("@%s{%s}" % (c, prefix))

    # To list the files we just need to inspect the filesystem,
    # which doesn't need to wait for pytest collection and doesn't
    # require parsing pytest output
    files = spack.llnl.util.filesystem.find(
        root=spack.paths.test_path, files="*.py", recursive=True
    )
    files = [
        os.path.relpath(f, start=spack.paths.spack_root)
        for f in files
        if not f.endswith(("conftest.py", "__init__.py"))
    ]

    old_output = sys.stdout
    try:
        sys.stdout = output = io.StringIO()
        pytest.main(["--collect-only"] + extra_args)
    finally:
        sys.stdout = old_output

    lines = output.getvalue().split("\n")
    tests = collections.defaultdict(set)

    # collect tests into sections
    node_regexp = re.compile(r"(\s*)<([^ ]*) ['\"]?([^']*)['\"]?>")
    key_parts, name_parts = [], []
    for line in lines:
        match = node_regexp.match(line)
        if not match:
            continue
        indent, nodetype, name = match.groups()

        # strip parametrized tests
        if "[" in name:
            name = name[: name.index("[")]

        len_indent = len(indent)
        if os.path.isabs(name):
            name = os.path.relpath(name, start=spack.paths.spack_root)

        item = (len_indent, name, nodetype)

        # Reduce the parts to the scopes that are of interest
        name_parts = [x for x in name_parts if x[0] < len_indent]
        key_parts = [x for x in key_parts if x[0] < len_indent]

        # From version 3.X to version 6.X the output format
        # changed a lot in pytest, and probably will change
        # in the future - so this manipulation might be fragile
        if nodetype.lower() == "function":
            name_parts.append(item)
            key_end = os.path.join(*key_parts[-1][1].split("/"))
            key = next(f for f in files if f.endswith(key_end))
            tests[key].add(tuple(x[1] for x in name_parts))
        elif nodetype.lower() == "class":
            name_parts.append(item)
        elif nodetype.lower() in ("package", "module"):
            key_parts.append(item)

    if args.list == "list":
        files = set(tests.keys())
        color_files = [colorize("B", file) for file in sorted(files)]
        colify(color_files)

    elif args.list == "long":
        for prefix, functions in sorted(tests.items()):
            path = colorize("*B", prefix) + "::"
            functions = [colorize("c", f) for f in sorted(functions)]
            color.cprint(path)
            colify(functions, indent=4)
            print()

    else:  # args.list == "names"
        all_functions = [
            colorize("*B", prefix) + "::" + colorize("c", f)
            for prefix, functions in sorted(tests.items())
            for f in sorted(functions)
        ]
        colify(all_functions)


def add_back_pytest_args(args, unknown_args):
    """Add parsed pytest args, unknown args, and remainder together.

    We add some basic pytest arguments to the Spack parser to ensure that
    they show up in the short help, so we have to reassemble things here.
    """
    result = args.parsed_args or []
    result += unknown_args or []
    result += args.pytest_args or []
    if args.expression:
        result += ["-k", args.expression]
    return result


def unit_test(parser, args, unknown_args):
    global pytest
    import spack.bootstrap

    # Ensure clingo is available before switching to the
    # mock configuration used by unit tests
    with spack.bootstrap.ensure_bootstrap_configuration():
        spack.bootstrap.ensure_clingo_importable_or_raise()
        if pytest is None:
            spack.bootstrap.ensure_environment_dependencies()
            import pytest

    if args.pytest_help:
        # make the pytest.main help output more accurate
        sys.argv[0] = "spack unit-test"
        return pytest.main(["-h"])

    # add back any parsed pytest args we need to pass to pytest
    pytest_args = add_back_pytest_args(args, unknown_args)

    # The default is to test the core of Spack. If the option `--extension`
    # has been used, then test that extension.
    pytest_root = spack.paths.spack_root
    if args.extension:
        pytest_root = spack.extensions.load_extension(args.extension)

    if args.numprocesses is not None and args.numprocesses > 1:
        try:
            import xdist  # noqa: F401
        except ImportError:
            tty.error("parallel unit-test requires pytest-xdist module")
            return 1

        pytest_args.extend(
            [
                "--dist",
                "loadfile",
                "--tx",
                f"{args.numprocesses}*popen//python=spack-tmpconfig spack python",
            ]
        )

    # pytest.ini lives in the root of the spack repository.
    with spack.llnl.util.filesystem.working_dir(pytest_root):
        if args.list:
            do_list(args, pytest_args)
            return

        return pytest.main(pytest_args)
