#!/usr/bin/env python
from __future__ import print_function
import os
import sys
from collections import namedtuple
CacheFile = namedtuple('CacheFile', ['path', 'key'])
def read_cache_file(path):
    with open(path, 'r') as f:
        f.seek(0x28)    # skip header
        key_magic = f.read(6)
        if key_magic != '\nKEY: ':
            raise ValueError('Not a cache file: ' + str(path))
        key = f.readline()[:-1]
        return CacheFile(path, key)
 
def read_cache_dirs(dirs):
    cacheFiles = []
    for cachedir in dirs:
        for root, dirs, files in os.walk(cachedir):
            for f in files:
                try:
                    cacheFiles.append(read_cache_file(os.path.join(root, f)))
                except ValueError as e:
                    print('Problem:', str(e), file=sys.stderr)
    return cacheFiles
 
if __name__ == '__main__':
    command = None
    if len(sys.argv) >= 3:
        command = sys.argv[1]
    if command == 'list':
        cacheFiles = read_cache_dirs(sys.argv[2:])
        for cf in cacheFiles:
            print(cf.path, cf.key)
    elif command == 'purge':
        cacheFiles = read_cache_dirs(sys.argv[2:])
        for f in cacheFiles:
            os.remove(f.path)
        print('Purged', len(cacheFiles), "files")
    else:
        print(sys.argv[0], "<list|purge>", "<cache_dir>", "[cache_dir...]")