# Copyright (c) Sebastian Raschka under Apache License 2.0 (see LICENSE.txt).
# Source for "Build a Large Language Model From Scratch"
#   - https://www.manning.com/books/build-a-large-language-model-from-scratch
# Code: https://github.com/rasbt/LLMs-from-scratch

from importlib.metadata import PackageNotFoundError, import_module
import importlib.metadata
from os.path import dirname, join, realpath
from packaging.version import parse as version_parse
import platform
import sys

if version_parse(platform.python_version()) < version_parse('3.9'):
    print('[FAIL] We recommend Python 3.9 or newer but'
          ' found version %s' % (sys.version))
else:
    print('[OK] Your Python version is %s' % (platform.python_version()))


def get_packages(pkgs):
    versions = []
    for p in pkgs:
        try:
            imported = import_module(p)
            try:
                version = (getattr(imported, '__version__', None) or
                           getattr(imported, 'version', None) or
                           getattr(imported, 'version_info', None))
                if version is None:
                    # If common attributes don't exist, use importlib.metadata
                    version = importlib.metadata.version(p)
                versions.append(version)
            except PackageNotFoundError:
                # Handle case where package is not installed
                versions.append('0.0')
        except ImportError:
            # Fallback if importlib.import_module fails for unexpected reasons
            versions.append('0.0')
    return versions


def get_requirements_dict():
    PROJECT_ROOT = dirname(realpath(__file__))
    PROJECT_ROOT_UP_TWO = dirname(dirname(PROJECT_ROOT))
    REQUIREMENTS_FILE = join(PROJECT_ROOT_UP_TWO, "requirements.txt")
    d = {}
    with open(REQUIREMENTS_FILE) as f:
        for line in f:
            if not line.strip():
                continue
            line = line.split("#")[0].strip()
            line = line.split(" ")
            line = [l.strip() for l in line]
            d[line[0]] = line[-1]
    return d


def check_packages(d):
    versions = get_packages(d.keys())

    for (pkg_name, suggested_ver), actual_ver in zip(d.items(), versions):
        if actual_ver == 'N/A':
            continue
        actual_ver, suggested_ver = version_parse(actual_ver), version_parse(suggested_ver)
        if actual_ver < suggested_ver:
            print(f'[FAIL] {pkg_name} {actual_ver}, please upgrade to >= {suggested_ver}')
        else:
            print(f'[OK] {pkg_name} {actual_ver}')


def main():
    d = get_requirements_dict()
    check_packages(d)


if __name__ == '__main__':
    main()