#!/usr/bin/env python
"""
all your lint are belong to us
"""
import os
import subprocess
import sys


def run(cmd, file):
    "Exec a linter for a file."
    global ERRORS  # pylint: disable=global-statement
    args = {
        "ormolu": ["--mode", "check"],
        "hlint": [],
        "black": ["--quiet", "--check"],
        "pylint": [],
    }
    # pylint: disable=subprocess-run-check
    ret = subprocess.run([cmd, *args[cmd], file], stdout=subprocess.PIPE)
    if ret.returncode != 0:
        ERRORS += 1  # pylint: disable=undefined-variable
        msg = ret.stdout.decode("utf-8").strip()
        print(f"lint error: {cmd} on {file}")
        if msg:
            print(msg)


def changed_files():
    "Return a list of changed files according to git."
    return (
        subprocess.check_output(["git", "diff", "--cached", "--name-only"])
        .decode("utf-8")
        .strip()
    )


def group_files(files, extensions):
    """Given a list of files and list of extensions, return a dict of:
       {ext: [files]}

    """
    root = os.getenv("BIZ_ROOT")
    ret = {k: [] for k in extensions}
    for ext in extensions:
        for file in files:
            if file.endswith(ext):
                ret[ext].append(os.path.join(root, file))
    return ret


if __name__ == "__main__":
    ERRORS = 0
    if "-h" in sys.argv:
        print(f"usage: {os.path.basename(__file__)} <files...>")
        print("if no files given, lint files staged in git")
        sys.exit(0)
    elif len(sys.argv) == 1:
        FILES = group_files(changed_files(), [".hs", ".py"])
    else:
        FILES = group_files(sys.argv[1:], [".hs", ".py"])
    for hs in FILES[".hs"]:
        print(f"lint: {hs}")
        run("ormolu", hs)
        run("hlint", hs)
    for py in FILES[".py"]:
        print(f"lint: {py}")
        run("black", py)
        run("pylint", py)
    run("black", __file__)
    run("pylint", __file__)
    sys.exit(ERRORS)