"""
curl phus.lu/fileserver.py | env PORT=8001 python
"""

import os
import re
import sys
import time
try:
    from http.server import SimpleHTTPRequestHandler, HTTPServer
    from socketserver import ThreadingMixIn
except ImportError:
    from BaseHTTPServer import SimpleHTTPRequestHandler, HTTPServer
    from SocketServer import ThreadingMixIn

class Handler(SimpleHTTPRequestHandler):
    def do_GET(self):
        m = re.search(r'bytes=(\d*)-(\d*)', self.headers.get('Range', ''))
        if m is None:
            SimpleHTTPRequestHandler.do_GET(self)
            return
        filename = os.path.join(os.getcwd(), self.path[1:].split('?')[0])
        begin = int(m.group(1)) if m.group(1) else 0
        end = int(m.group(2)) if m.group(2) else 0
        end = end if end else os.path.getsize(filename) - 1
        length = end - begin + 1
        self.send_response(206, 'Partial Content')
        self.send_header('Accept-Ranges', 'bytes')
        self.send_header('Content-Length', str(length))
        self.send_header('Content-Type', 'application/octet-stream')
        self.send_header('Last-Modified', time.strftime('%a, %d %b %Y %H:%M:%S GMT', time.gmtime(os.path.getmtime(filename))))
        self.end_headers()
        fd = 0
        try:
            fd = os.open(filename, os.O_RDONLY, 0o666)
            sendfile = getattr(os, 'sendfile')
            if sendfile:
                sendfile(self.wfile.fileno(), fd, begin, length)
            else:
                os.lseek(fd, begin, 0)
                while length:
                    size = length if length < 256*1024 else 256*1024
                    data = os.read(fd, size)
                    if not data:
                        break
                    self.wfile.write(data)
                    length -= size
        finally:
            if fd:
                os.close(fd)

class Server(ThreadingMixIn, HTTPServer):
    pass

if __name__ == '__main__':
    port = int(sys.argv[1] if len(sys.argv) > 1 else os.environ.get('PORT', '8000'))
    print('Serving HTTP on 0.0.0.0 port %d ...' % port)
    Server(('0.0.0.0', port), Handler).serve_forever()