import os
import sys

from git import Repo, IndexFile, DiffIndex


def filter_assets(path: str):
    lower_case = path.lower()
    return lower_case.startswith("assets")


def path_to_meta_file(path: str):
    return path + ".meta"

def meta_file_exists(meta_file: str):
    return os.path.isfile(meta_file)

def meta_file_in_index(meta_file: str, index: IndexFile):
    return any(x for x in index.entries.keys() if x[0] == meta_file)

def meta_file_in_diff(meta_file: str, diff: DiffIndex):
    return any(x for x in diff if x.a_path == meta_file)


def run():
    files = [path for path in sys.argv[1:] if filter_assets(path)]
    repo = Repo(os.getcwd())
    index = repo.index
    modified = index.diff(None)
    errors = []
    for file in files:
        meta_file = path_to_meta_file(file)
        if not meta_file_exists(meta_file):
            errors.append(f"{file} does not have a matching meta file {meta_file}")
            continue

        if not meta_file_in_index(meta_file, index):
            errors.append(f"{meta_file} is not in the git index")
            continue

        if meta_file_in_diff(meta_file, modified):
            errors.append(f"{meta_file} has been changed but is not staged")

    if len(errors) > 0:
        print("At least one file has an issue with it's meta file:")
        print("  * " + "\n  * ".join(errors))
        sys.exit(1)


if __name__ == "__main__":
    run()