# ===--- SchemeMock.py ----------------------------------------------------===#
#
#  This source file is part of the Swift.org open source project
#
#  Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
#  Licensed under Apache License v2.0 with Runtime Library Exception
#
#  See https:#swift.org/LICENSE.txt for license information
#  See https:#swift.org/CONTRIBUTORS.txt for the list of Swift project authors
#
# ===----------------------------------------------------------------------===#
"""This file defines objects for mocking an update-checkout scheme. It creates
a json .config file and a series of .git repos with "fake commits".
"""

import json
import os
import subprocess
import unittest

# For now we only use a config with a single scheme. We should add support for
# handling multiple schemes.
MOCK_REMOTE = {
    "repo1": [
        # This is a series of changes to repo1. (File, NewContents)
        ("A.txt", "A"),
        ("B.txt", "B"),
        ("A.txt", "a"),
    ],
    "repo2": [
        # This is a series of changes to repo2. (File, NewContents)
        ("X.txt", "X"),
        ("Y.txt", "Y"),
        ("X.txt", "z"),
    ],
}

MOCK_CONFIG = {
    # This is here just b/c we expect it. We should consider consolidating
    # clone-patterns into a dictionary where we map protocols (i.e. ['ssh,
    # 'https'] to patterns). Then we can define this issue.
    "ssh-clone-pattern": "DO_NOT_USE",
    # We reset this value with our remote path when we process
    "https-clone-pattern": "",
    "repos": {
        "repo1": {
            "remote": {"id": "repo1"},
        },
        "repo2": {
            "remote": {"id": "repo2"},
        },
    },
    "default-branch-scheme": "main",
    "branch-schemes": {
        "main": {
            "aliases": ["main"],
            "repos": {
                "repo1": "main",
                "repo2": "main",
            },
        }
    },
}

MOCK_ADDITIONAL_SCHEME = {
    "branch-schemes": {
        "extra": {
            "aliases": ["extra"],
            "repos": {
                # Spell this differently just to make it distinguishable in
                # test output, even though we only have one branch.
                # TODO: Support multiple test branches in the repo instead.
                "repo1": "refs/heads/main",
                "repo2": "refs/heads/main",
            },
        }
    }
}


class CallQuietlyException(Exception):
    def __init__(self, command, returncode, output):
        self.command = command
        self.returncode = returncode
        self.output = output

    def __str__(self):
        return (
            f"Command returned a non-zero exit status {self.returncode}:\n"
            f"Command: {' '.join(self.command)}\n"
            f"Output: {self.output.decode('utf-8')}"
        )


def call_quietly(*args, **kwargs):
    kwargs["stderr"] = subprocess.STDOUT
    kwargs["encoding"] = "utf-8"
    try:
        return subprocess.check_output(*args, **kwargs)
    except subprocess.CalledProcessError as e:
        raise CallQuietlyException(
            command=e.cmd, returncode=e.returncode, output=e.stdout
        ) from e


def create_dir(d):
    if not os.path.isdir(d):
        os.makedirs(d)


def teardown_mock_remote(base_dir):
    call_quietly(["rm", "-rf", base_dir])


def get_config_path(base_dir):
    return os.path.join(base_dir, "test-config.json")


def get_additional_config_path(base_dir):
    return os.path.join(base_dir, "test-additional-config.json")


def setup_mock_remote(base_dir, base_config):
    create_dir(base_dir)

    # We use local as a workspace for creating commits.
    LOCAL_PATH = os.path.join(base_dir, "local")
    # We use remote as a directory that simulates our remote unchecked out
    # repo.
    REMOTE_PATH = os.path.join(base_dir, "remote")

    create_dir(REMOTE_PATH)
    create_dir(LOCAL_PATH)

    for k, v in MOCK_REMOTE.items():
        local_repo_path = os.path.join(LOCAL_PATH, k)
        remote_repo_path = os.path.join(REMOTE_PATH, k)
        create_dir(remote_repo_path)
        create_dir(local_repo_path)
        call_quietly(["git", "init", "--bare", remote_repo_path])
        call_quietly(
            ["git", "symbolic-ref", "HEAD", "refs/heads/main"], cwd=remote_repo_path
        )
        call_quietly(["git", "clone", "-l", remote_repo_path, local_repo_path])
        call_quietly(
            ["git", "config", "--local", "user.name", "swift_test"], cwd=local_repo_path
        )
        call_quietly(
            ["git", "config", "--local", "user.email", "no-reply@swift.org"],
            cwd=local_repo_path,
        )
        call_quietly(
            ["git", "config", "--local", "commit.gpgsign", "false"], cwd=local_repo_path
        )
        call_quietly(
            ["git", "symbolic-ref", "HEAD", "refs/heads/main"], cwd=local_repo_path
        )
        for i, (filename, contents) in enumerate(v):
            filename_path = os.path.join(local_repo_path, filename)
            with open(filename_path, "w") as f:
                f.write(contents)
            call_quietly(["git", "add", filename], cwd=local_repo_path)
            call_quietly(["git", "commit", "-m", "Commit %d" % i], cwd=local_repo_path)
            call_quietly(["git", "push", "origin", "main"], cwd=local_repo_path)

    https_clone_pattern = os.path.join("file://%s" % REMOTE_PATH, "%s")
    base_config["https-clone-pattern"] = https_clone_pattern

    with open(get_config_path(base_dir), "w") as f:
        json.dump(base_config, f)

    with open(get_additional_config_path(base_dir), "w") as f:
        json.dump(MOCK_ADDITIONAL_SCHEME, f)

    return (LOCAL_PATH, REMOTE_PATH)


BASEDIR_ENV_VAR = "UPDATECHECKOUT_TEST_WORKSPACE_DIR"
CURRENT_FILE_DIR = os.path.dirname(os.path.abspath(__file__))
UPDATE_CHECKOUT_EXECUTABLE = (
    "update-checkout.cmd" if os.name == "nt" else "update-checkout"
)
UPDATE_CHECKOUT_PATH = os.path.abspath(
    os.path.join(
        CURRENT_FILE_DIR, os.path.pardir, os.path.pardir, UPDATE_CHECKOUT_EXECUTABLE
    )
)


class SchemeMockTestCase(unittest.TestCase):

    def __init__(self, *args, **kwargs):
        super(SchemeMockTestCase, self).__init__(*args, **kwargs)

        self.config = MOCK_CONFIG.copy()
        self.workspace = os.getenv(BASEDIR_ENV_VAR)
        if self.workspace is None:
            raise RuntimeError(
                "Misconfigured test suite! Environment "
                "variable %s must be set!" % BASEDIR_ENV_VAR
            )
        self.config_path = get_config_path(self.workspace)
        self.additional_config_path = get_additional_config_path(self.workspace)
        self.update_checkout_path = UPDATE_CHECKOUT_PATH
        if not os.access(self.update_checkout_path, os.X_OK):
            raise RuntimeError(
                "Error! Could not find executable "
                "update-checkout at path: %s" % self.update_checkout_path
            )
        self.source_root = os.path.join(self.workspace, "source_root")

    def setUp(self):
        create_dir(self.source_root)
        (self.local_path, self.remote_path) = setup_mock_remote(
            self.workspace, self.config
        )

    def tearDown(self):
        teardown_mock_remote(self.workspace)

    def call(self, *args, **kwargs):
        kwargs["cwd"] = self.source_root
        return call_quietly(*args, **kwargs)

    def get_all_repos(self):
        return list(self.config["repos"].keys())

    def add_branch_scheme(self, name, scheme):
        self.config["branch-schemes"][name] = scheme