# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

import os
import shutil
import subprocess
from pathlib import Path
from typing import List

import pytest

# Execute the first element in each list of steps within a `repo` directory,
# then copy the whole directory to a `remoterepo`, and finally execute the
# second element on just `repo`.
SETUP = {
    "hg": [
        """
        echo "foo" > foo
        echo "bar" > bar
        hg init
        hg add *
        hg commit -m "Initial commit"
        hg phase --public .
        """,
        """
        echo [paths] > .hg/hgrc
        echo "default = ../remoterepo" >> .hg/hgrc
        """,
    ],
    "git": [
        """
        echo "foo" > foo
        echo "bar" > bar
        git init
        git config user.name "Testing McTesterson"
        git config user.email "<test@example.org>"
        git add *
        git commit -am "Initial commit"
        """,
        """
        git remote add upstream ../remoterepo
        git fetch upstream
        git branch -u upstream/master
        """,
    ],
    "jj": [
        """
        echo "foo" > foo
        echo "bar" > bar
        git init
        git config user.name "Testing McTesterson"
        git config user.email "<test@example.org>"
        git add *
        git commit -am "Initial commit"
        """,
        """
        # Pass in user name/email via env vars because the initial commit
        # will use them before we have a chance to configure them.
        JJ_USER="Testing McTesterson" JJ_EMAIL="test@example.org" jj git init --colocate
        jj config set --repo user.name "Testing McTesterson"
        jj config set --repo user.email "test@example.org"
        jj git remote add upstream ../remoterepo
        jj git fetch --remote upstream
        jj bookmark track master@upstream
        """,
    ],
    "src": [
        """
        echo "foo" > foo
        echo "bar" > bar
        mkdir config
        echo 1.0 > config/milestone.txt
        """,
        "",
    ],
}


class RepoTestFixture:
    def __init__(self, repo_dir: Path, vcs: str, steps: List[str]):
        self.dir = repo_dir
        self.vcs = vcs

        # This creates a step iterator. Each time execute_next_step()
        # is called the next set of instructions will be executed.
        self.steps = (shell(cmd, self.dir) for cmd in steps)

    def execute_next_step(self):
        next(self.steps)


def shell(cmd, working_dir):
    for step in cmd.split(os.linesep):
        subprocess.check_call(step, shell=True, cwd=working_dir)


@pytest.fixture(params=["git", "hg", "jj", "src"])
def repo(tmpdir, request):
    if request.param == "jj":
        if os.getenv("MOZ_AVOID_JJ_VCS") not in (None, "0", ""):
            pytest.skip("jj support disabled")
        try:
            subprocess.call(["jj", "--version"], stdout=subprocess.DEVNULL)
        except OSError:
            pytest.skip("jj unavailable")

    tmpdir = Path(tmpdir)
    vcs = request.param
    steps = SETUP[vcs]

    if hasattr(request.module, "STEPS"):
        if vcs == "src" and vcs not in request.module.STEPS:
            # Special-case SourceRepository: most tests do not handle this case,
            # so allow it to be skipped if STEPS is defined but not for src.
            # (Tests without STEPS will need to skip manually.)
            pytest.skip("not applicable for src repo")
        steps.extend(request.module.STEPS[vcs])

    repo_dir = (tmpdir / "repo").resolve()
    (tmpdir / "repo").mkdir()

    repo_test_fixture = RepoTestFixture(repo_dir, vcs, steps)

    repo_test_fixture.execute_next_step()

    shutil.copytree(str(repo_dir), str(tmpdir / "remoterepo"))

    repo_test_fixture.execute_next_step()

    yield repo_test_fixture