#!/usr/bin/env python3

import os
import shutil
import sys

def parse_line(line):
    line = line.strip()
    if not line or line.startswith("#"):
        return None

    for sep in ["→", "->"]:
        if sep in line:
            src, dst = map(str.strip, line.split(sep, 1))
            return src, dst

    return None


def move_with_overwrite(src, dst):
    if not os.path.exists(src) and not os.path.islink(src):
        print(f"[SKIP missing source] {src}")
        return

    # If destination exists, remove it (overwrite behavior)
    if os.path.lexists(dst):
        try:
            if os.path.isdir(dst) and not os.path.islink(dst):
                shutil.rmtree(dst)
            else:
                os.remove(dst)
        except Exception as e:
            print(f"[FAIL delete dst] {dst}: {e}")
            return

    # Ensure parent directory exists
    os.makedirs(os.path.dirname(dst), exist_ok=True)

    try:
        shutil.move(src, dst)
        print(f"[OK] {src} -> {dst}")
    except Exception as e:
        print(f"[FAIL move] {src} -> {dst}: {e}")


def process(file_path):
    with open(file_path, "r") as f:
        for line in f:
            parsed = parse_line(line)
            if not parsed:
                continue

            dst, src  = parsed
            move_with_overwrite(src, dst)


if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage: python rename_apply.py <file>")
        sys.exit(1)

    process(sys.argv[1])