#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""Rename the main Flask module to a non-common name"""

import os
import re
import sys
import typing as t
from warnings import filterwarnings as filter_warnings

COMMON_MODULES: t.Final[t.Set[str]] = {
    "abc",
    "aifc",
    "argparse",
    "array",
    "ast",
    "asynchat",
    "asyncio",
    "asyncore",
    "base64",
    "bdb",
    "bin",
    "binascii",
    "bisect",
    "builtins",
    "bz2",
    "calendar",
    "cgi",
    "cgitb",
    "chunk",
    "cmath",
    "cmd",
    "code",
    "click",
    "codecs",
    "collections",
    "colorsys",
    "compileall",
    "concurrent",
    "configparser",
    "contextlib",
    "copy",
    "copyreg",
    "crypt",
    "csv",
    "ctypes",
    "curses",
    "dataclasses",
    "datetime",
    "dbm",
    "decimal",
    "difflib",
    "dis",
    "distutils",
    "doctest",
    "email",
    "encodings",
    "enum",
    "errno",
    "faulthandler",
    "fcntl",
    "filecmp",
    "fileinput",
    "fnmatch",
    "formatter",
    "fractions",
    "ftplib",
    "functools",
    "gc",
    "getopt",
    "getpass",
    "gettext",
    "glob",
    "gzip",
    "hashlib",
    "heapq",
    "hmac",
    "html",
    "http",
    "idlelib",
    "imaplib",
    "imghdr",
    "imp",
    "importlib",
    "inspect",
    "io",
    "ipaddress",
    "itertools",
    "json",
    "keyword",
    "lib2to3",
    "linecache",
    "locale",
    "logging",
    "lzma",
    "mailcap",
    "marshal",
    "math",
    "mimetypes",
    "mmap",
    "modulefinder",
    "multiprocessing",
    "netrc",
    "nis",
    "nntplib",
    "numbers",
    "operator",
    "optparse",
    "os",
    "parser",
    "pathlib",
    "pdb",
    "pickle",
    "pickletools",
    "pip",
    "pkgutil",
    "platform",
    "plistlib",
    "poplib",
    "posix",
    "pprint",
    "profile",
    "pstats",
    "pty",
    "pwd",
    "py_compile",
    "pyclbr",
    "pydoc",
    "queue",
    "quopri",
    "random",
    "re",
    "readline",
    "reprlib",
    "resource",
    "rlcompleter",
    "runpy",
    "sched",
    "secrets",
    "select",
    "selectors",
    "shelve",
    "shlex",
    "shutil",
    "signal",
    "site",
    "smtp",
    "socket",
    "socketserver",
    "sqlite3",
    "sre_compile",
    "sre_constants",
    "sre_parse",
    "ssl",
    "stat",
    "statistics",
    "string",
    "stringprep",
    "struct",
    "subprocess",
    "sunau",
    "symtable",
    "sys",
    "sysconfig",
    "tabnanny",
    "tarfile",
    "telnetlib",
    "tempfile",
    "termios",
    "test",
    "textwrap",
    "threading",
    "time",
    "timeit",
    "tkinter",
    "token",
    "tokenize",
    "trace",
    "traceback",
    "tracemalloc",
    "tty",
    "turtle",
    "turtledemo",
    "types",
    "typing",
    "unicodedata",
    "unittest",
    "urllib",
    "uu",
    "uuid",
    "venv",
    "warnings",
    "wave",
    "weakref",
    "webbrowser",
    "winreg",
    "winsound",
    "wsgiref",
    "xdrlib",
    "xml",
    "xmlrpc",
    "zipapp",
    "zipfile",
    "zipimport",
    "zlib",
    "werkzeug",
    "jinja2",
    "sqlalchemy",
    "requests",
    "pytest",
    "celery",
    "gunicorn",
    "alembic",
    "bcrypt",
    "pillow",
    "marshmallow",
    "main",
    "app",
    "init",
    "src",
    "env",
    "dotenv",
    "application",
    "web",
    "www",
    "webapp",
    "cryptography",
    "pycryptodome",
    "hashing",
    "aes",
    "rsa",
    "des",
    "ssh",
    "itsdangerous",
    "werkzeug",
    "portalocker",
    "all",
    "any",
    "max",
    "min",
    "pow",
    "bleach",
}


def sanitize_module_name(name: str) -> str:
    """Sanitize module name to be a valid Python module name token"""

    name = name.strip()
    name = name.lower()
    name = re.sub(r"[^a-z0-9_]", "_", name)
    name = re.sub(r"_+", "_", name)
    name = name.strip("_")

    if re.match(r"^[0-9]", name):
        name = f"_{name}"

    return name


def replace_in_file(filepath: str, old: str, new: str) -> None:
    """Read file, replace all occurrences of old with new, write back"""

    with open(filepath, "r", encoding="utf-8") as fr:
        content: str = fr.read()

    new_content: str = content.replace(old, new)

    if new_content != content:
        with open(filepath, "w", encoding="utf-8") as fw:
            fw.write(new_content)


def main() -> int:
    """entry / main function"""

    if len(sys.argv) < 2:
        print("Rename this template to your preferred name", file=sys.stderr)
        print(f"Usage: {sys.argv[0]} <newname>", file=sys.stderr)
        return 1

    flask_app_dir: str = os.path.join(".", "src", "flask_app")
    if not os.path.isdir(flask_app_dir):
        print("The application has already been renamed", file=sys.stderr)
        return 1

    module: str = sanitize_module_name(sys.argv[1])
    if not module:
        print("The module name must be non-empty", file=sys.stderr)
        return 1

    if module.startswith("flask"):
        print(
            "Module name cannot start with 'flask' to avoid conflicts", file=sys.stderr
        )
        return 1

    if module.startswith("_"):
        print("Module name cannot start with '_' to avoid conflicts", file=sys.stderr)
        return 1

    if module in COMMON_MODULES:
        print(
            f"'{module}' is a reserved module name, please choose another",
            file=sys.stderr,
        )
        return 1

    module_dir: str = os.path.join(".", "src", module)
    module_file: str = os.path.join(".", "src", f"{module}.py")
    if os.path.exists(module_dir) or os.path.exists(module_file):
        print(
            f"Invalid module name {module} (already exists)", file=sys.stderr
        )
        return 1

    yn: str = input(f"Rename application module to {module}? (y/n) ").strip().lower()
    if not yn.startswith("y"):
        print("Not renaming the app", file=sys.stderr)
        return 1

    os.rename(flask_app_dir, module_dir)

    for root, _, files in os.walk(os.path.join(".", "src")):
        for filename in files:
            if filename.endswith(".py"):
                filepath: str = os.path.join(root, filename)
                replace_in_file(filepath, "flask_app", module)

    print(
        f"Main module successfully renamed to {module}! You may now remove {sys.argv[0]}"
    )

    return 0


if __name__ == "__main__":
    assert main.__annotations__.get("return") is int, "main() should return an integer"

    filter_warnings("error", category=Warning)
    raise SystemExit(main())