#!/usr/bin/env python3
"""Minimal path-style S3 HEAD-only stub server, used only by test_publish.sh
to test publish.sh's credential check and APK-existence check entirely
offline -- no real bucket, no real credentials, nothing beyond loopback.

Only implements what those two checks actually call:

    HEAD /<bucket>            -- head-bucket, used to verify credentials
    HEAD /<bucket>/<key...>   -- head-object, used to check for an existing APK

`aws`'s S3 client only uses path-style addressing (rather than
`<bucket>.<host>` virtual-hosted style) when the endpoint host is a literal
IP address, which `--endpoint-url http://127.0.0.1:<port>` is -- so no
`--endpoint-url` or config trickery is needed to get requests shaped this
way.

Existing objects are given on the command line; every other key 404s, as
does any bucket name other than the one given -- so a test that passes the
wrong bucket name notices, rather than getting a silent "yes" back.

Deliberately never handles PUT/GET/LIST: publish.sh must never reach the
`aws s3 sync` calls in a test that uses this stub, since both a rejected
credential and an existing APK are supposed to abort before any upload is
attempted. If a future test needs sync to succeed against this stub, that is
new scope for this file, not an oversight here.

    test_s3_stub.py <bucket> [<existing-key> ...]

Prints the bound port as the one line on stdout, then serves until killed.
"""
import http.server
import socketserver
import sys


def main():
    bucket = sys.argv[1]
    existing = set(sys.argv[2:])

    class Handler(http.server.BaseHTTPRequestHandler):
        def do_HEAD(self):
            path = self.path.lstrip("/")
            parts = path.split("/", 1)
            if not parts or parts[0] != bucket:
                self.send_response(404)
                self.end_headers()
                return
            if len(parts) == 1 or parts[1] == "":
                # head-bucket: the one bucket named on the command line
                # always "exists" and is reachable with these "credentials".
                self.send_response(200)
                self.end_headers()
                return
            key = parts[1]
            self.send_response(200 if key in existing else 404)
            self.end_headers()

        def log_message(self, fmt, *args):
            pass  # keep test output quiet; nothing here is diagnostic

    class Server(socketserver.TCPServer):
        allow_reuse_address = True

    with Server(("127.0.0.1", 0), Handler) as httpd:
        print(httpd.server_address[1], flush=True)
        httpd.serve_forever()


if __name__ == "__main__":
    main()