import configparser
import json
import os
import pathlib
import re
import socket
import subprocess as sp
import sys
from glob import glob
from tempfile import TemporaryDirectory
from typing import Tuple

import pytest

REPO_PATHS = [
    "./test/data/testrepos/baseos/",
    "./test/data/testrepos/custom/",
]

RELEASEVER = "9"
ARCH = "x86_64"
CUSTOMVAR = "test"

# osbuild-depsolve-dnf uses the GPG header to detect if keys are defined in-line or as file paths/URLs
TEST_KEY = "-----BEGIN PGP PUBLIC KEY BLOCK-----\nTEST KEY\n"


def assert_dnf5():
    if sp.run(["/usr/bin/python3", "-c", "import libdnf5"], check=False).returncode != 0:
        raise RuntimeError("Cannot import libdnf5")


def assert_dnf():
    if sp.run(["/usr/bin/python3", "-c", "import libdnf"], check=False).returncode != 0:
        raise RuntimeError("Cannot import libdnf")


def depsolve(transactions, repos, root_dir, cache_dir, dnf_config, opt_metadata) -> Tuple[dict, int]:
    req = {
        "command": "depsolve",
        "arch": ARCH,
        "module_platform_id": f"platform:el{RELEASEVER}",
        "releasever": RELEASEVER,
        "cachedir": cache_dir,
        "arguments": {
            "root_dir": root_dir,
            "repos": repos,
            "optional-metadata": opt_metadata,
            "transactions": transactions,
        }
    }

    # If there is a config file, write it to a temporary file and pass it to the depsolver
    with TemporaryDirectory() as cfg_dir:
        env = None
        if dnf_config:
            cfg_file = pathlib.Path(cfg_dir) / "solver.json"
            cfg_file.write_text(dnf_config)
            env = {"OSBUILD_SOLVER_CONFIG": os.fspath(cfg_file)}

        p = sp.run(["./tools/osbuild-depsolve-dnf"], input=json.dumps(req), env=env,
                   check=False, stdout=sp.PIPE, stderr=sys.stderr, universal_newlines=True)

        return json.loads(p.stdout), p.returncode


def get_rand_port():
    s = socket.socket()
    s.bind(("", 0))
    return s.getsockname()[1]


@pytest.fixture(name="repo_servers", scope="module")
def repo_servers_fixture():
    procs = []
    addresses = []
    for path in REPO_PATHS:
        port = get_rand_port()  # this is racy, but should be okay
        p = sp.Popen(["python3", "-m", "http.server", str(port)], cwd=path, stdout=sp.PIPE, stderr=sp.DEVNULL)
        procs.append(p)
        # use last path component as name
        name = os.path.basename(path.rstrip("/"))
        addresses.append({"name": name, "address": f"http://localhost:{port}"})
    yield addresses
    for p in procs:
        p.kill()


def tcase_idfn(param):
    return param['id']


test_cases = [
    {
        "id": "basic_1pkg_1repo",
        "transactions": [
            {
                "package-specs": [
                    "filesystem",
                ],
            },
        ],
        "results": {
            "packages": {
                "basesystem",
                "bash",
                "centos-gpg-keys",
                "centos-stream-release",
                "centos-stream-repos",
                "filesystem",
                "glibc",
                "glibc-common",
                "glibc-minimal-langpack",
                "libgcc",
                "ncurses-base",
                "ncurses-libs",
                "setup",
                "tzdata",
            },
            "reponames": {
                "baseos",
            },
        }
    },
    # "pkg-with-no-deps" is the only package in the custom repo and has no dependencies
    {
        "id": "basic_1pkg_1repo_no_deps",
        "transactions": [
            {
                "package-specs": [
                    "pkg-with-no-deps",
                ],
            },
        ],
        "results": {
            "packages": {"pkg-with-no-deps"},
            "reponames": {"custom"},
        },
    },
    {
        "id": "basic_2pkgs_2repos",
        "transactions": [
            {
                "package-specs": [
                    "filesystem",
                    "pkg-with-no-deps"
                ],
            },
        ],
        "results": {
            "packages": {
                "basesystem",
                "bash",
                "centos-gpg-keys",
                "centos-stream-release",
                "centos-stream-repos",
                "filesystem",
                "glibc",
                "glibc-common",
                "glibc-minimal-langpack",
                "libgcc",
                "ncurses-base",
                "ncurses-libs",
                "setup",
                "tzdata",
                "pkg-with-no-deps",
            },
            "reponames": {
                "baseos",
                "custom",
            },
        },
    },
    # Test depsolving error due to non-existing package
    {
        "id": "error_non_existing_pkg",
        "transactions": [
            {
                "package-specs": [
                    "non-existing-package",
                ],
            },
        ],
        "error": True,
        "error_kind": "MarkingErrors",
        "error_reason_re": r".*non-existing-package.*",
    },
]


def make_dnf_scafolding(base_dir):
    root_dir = pathlib.Path(TemporaryDirectory(dir=base_dir).name)

    repos_dir = root_dir / "etc/yum.repos.d"
    repos_dir.mkdir(parents=True)
    keys_dir = root_dir / "etc/pki/rpm-gpg"
    keys_dir.mkdir(parents=True)
    vars_dir = root_dir / "etc/dnf/vars"
    vars_dir.mkdir(parents=True)

    vars_path = vars_dir / "customvar"
    vars_path.write_text(CUSTOMVAR, encoding="utf8")

    return root_dir, repos_dir, keys_dir


def config_combos(tmp_path, servers):
    """
    Return all configurations for the provided repositories, either as config files in a directory or as repository
    configs in the depsolve request, or a combination of both.
    """
    # we only have two servers, so let's just enumerate all the combinations
    combo_idxs = [
        ((0, 1), ()),  # all in req
        ((0,), (1,)),    # one in req and one in dir
        ((1,), (0,)),    # same but flipped
        ((), (0, 1)),  # all in dir
    ]
    for combo in combo_idxs:
        repo_configs = []
        for idx in combo[0]:  # servers to be configured through request
            server = servers[idx]
            repo_configs.append({
                "id": server["name"],
                "name": server["name"],
                "baseurl": server["address"],
                "check_gpg": False,
                "sslverify": False,
                "rhsm": False,
                "gpgkeys": [TEST_KEY + server["name"]],
            })
        root_dir, repos_dir, keys_dir = make_dnf_scafolding(tmp_path)
        for idx in combo[1]:  # servers to be configured through root_dir
            server = servers[idx]
            name = server["name"]
            # Use the gpgkey to test both the key reading and the variable substitution.
            # For this test, it doesn't need to be a real key.
            key_url = f"file:///etc/pki/rpm-gpg/RPM-GPG-KEY-$releasever-$basearch-$customvar-{name}"

            key_path = keys_dir / f"RPM-GPG-KEY-{RELEASEVER}-{ARCH}-{CUSTOMVAR}-{name}"
            key_path.write_text(TEST_KEY + name, encoding="utf8")
            parser = configparser.ConfigParser()
            parser.add_section(name)
            # Set some options in a specific order in which they tend to be
            # written in repo files.
            parser.set(name, "name", name)
            parser.set(name, "baseurl", server["address"])
            parser.set(name, "enabled", "1")
            parser.set(name, "gpgcheck", "1")
            parser.set(name, "sslverify", "0")
            parser.set(name, "gpgkey", key_url)

            with (repos_dir / f"{name}.repo").open("w", encoding="utf-8") as fp:
                parser.write(fp, space_around_delimiters=False)

        # for each combo, let's also enable or disable filelists (optional-metadata)
        for opt_metadata in ([], ["filelists"]):
            yield repo_configs, os.fspath(root_dir), opt_metadata


@pytest.mark.parametrize("test_case", test_cases, ids=tcase_idfn)
@pytest.mark.parametrize("dnf_config, detect_fn", [
    (None, assert_dnf),
    ('{"use_dnf5": false}', assert_dnf),
    ('{"use_dnf5": true}', assert_dnf5),
], ids=["no-config", "dnf4", "dnf5"])
def test_depsolve(tmp_path, repo_servers, dnf_config, detect_fn, test_case):
    try:
        detect_fn()
    except RuntimeError as e:
        pytest.skip(e)

    transactions = test_case["transactions"]

    for repo_configs, root_dir, opt_metadata in config_combos(tmp_path, repo_servers):
        with TemporaryDirectory() as cache_dir:
            res, exit_code = depsolve(transactions, repo_configs, root_dir, cache_dir, dnf_config, opt_metadata)

            if test_case.get("error", False):
                assert exit_code != 0
                assert res["kind"] == test_case["error_kind"]
                assert re.match(test_case["error_reason_re"], res["reason"], re.DOTALL)
                continue

            assert exit_code == 0
            assert {pkg["name"] for pkg in res["packages"]} == test_case["results"]["packages"]
            assert res["repos"].keys() == test_case["results"]["reponames"]
            for repo in res["repos"].values():
                assert repo["gpgkeys"] == [TEST_KEY + repo["id"]]
                assert repo["sslverify"] is False

            # if opt_metadata includes 'filelists', then each repository 'repodata' must include a file that matches
            # *filelists*
            n_filelist_files = len(glob(f"{cache_dir}/*/repodata/*filelists*"))
            if "filelists" in opt_metadata:
                assert n_filelist_files == len(REPO_PATHS)
            else:
                assert n_filelist_files == 0

            if dnf_config:
                use_dnf5 = json.loads(dnf_config)["use_dnf5"]
            else:
                use_dnf5 = False
            if use_dnf5:
                assert res["solver"] == "dnf5"
            else:
                assert res["solver"] == "dnf"