import urllib.request
import os

files = {
    "blacklist": "https://raw.githubusercontent.com/Cleanuparr/Cleanuparr/main/blacklist",
    "blacklist_permissive": "https://raw.githubusercontent.com/Cleanuparr/Cleanuparr/main/blacklist_permissive",
    "whitelist": "https://raw.githubusercontent.com/Cleanuparr/Cleanuparr/main/whitelist",
    "whitelist_with_subtitles": "https://raw.githubusercontent.com/Cleanuparr/Cleanuparr/main/whitelist_with_subtitles",
}

def merge_blocklist(filename, url):
    prev_file = f"{filename}.prev"

    # Fetch new upstream
    with urllib.request.urlopen(url) as r:
        upstream_new = set(line.strip() for line in r.read().decode().splitlines() if line.strip())

    # Read previous upstream (empty set if first run)
    try:
        with open(prev_file) as f:
            upstream_prev = set(line.strip() for line in f if line.strip())
    except FileNotFoundError:
        upstream_prev = upstream_new.copy()

    # Read current local file
    try:
        with open(filename) as f:
            local = set(line.strip() for line in f if line.strip())
    except FileNotFoundError:
        local = set()

    # Three-way merge
    custom = local - upstream_prev
    result = upstream_new | custom

    print(f"[{filename}] Custom preserved: {sorted(custom)}")
    print(f"[{filename}] Upstream added: {sorted(upstream_new - upstream_prev)}")
    print(f"[{filename}] Upstream removed: {sorted(upstream_prev - upstream_new)}")

    # Write merged result sorted
    with open(filename, "w") as f:
        f.write("\n".join(sorted(result)) + "\n")

    # Store new upstream as prev for next run
    with open(prev_file, "w") as f:
        f.write("\n".join(sorted(upstream_new)) + "\n")

for filename, url in files.items():
    merge_blocklist(filename, url)