Extend bild to nix targets properly

Also had to capitalize some stuff, and move some nix files around and rename
the metadata directive from 'exe' to 'out' because that just makes more sense,
and fix some compiler errors. But now bild treats both nix and hs files as
buildable things. So that's cool.

One interesting example is Biz/Pie.{nix,hs} - I can either create a dev build of
the hs file with ghc, or I can create a fully-encapsulated nix build. Its nice
to have both options because a dev build with ghc takes half the amount of time,
and I can rely on my locally cached hi and ho files. I think this shows the
power of bild, but also can be a somewhat subtle thing.

The issue really is with the separate command calls in nix builds vs dev builds.
I figure there are a few ways to fix this:

1. Try to use bild inside the nix rules. That could be interesting, but could
also lead to some weird behavior or worm holes forming.
2. Extract the command line invocation into a separate file, some kind of
really simple template that gets pulled into both programs.

It is important to consider that in the future I might want to have bild do a
module-by-module nix build of programs, but I'm not sure how that would effect
my choice here.

1 files changed, 186 insertions, 0 deletions

diff --git a/Que/Client.py b/Que/Client.py
new file mode 100755
index 0000000..1063eb8
--- /dev/null
+++ b/Que/Client.py
@@ -0,0 +1,186 @@
+#!/usr/bin/env python3
+"""
+simple client for que.run
+"""
+
+import argparse
+import configparser
+import functools
+import http.client
+import logging
+import os
+import subprocess
+import sys
+import time
+import urllib.parse
+import urllib.request as request
+
+MAX_TIMEOUT = 99999999  # basically never timeout
+
+
+def auth(args):
+    "Returns the auth key for the given ns from ~/.config/que.conf"
+    logging.debug("auth")
+    namespace = args.target.split("/")[0]
+    if namespace == "pub":
+        return None
+    conf_file = os.path.expanduser("~/.config/que.conf")
+    if not os.path.exists(conf_file):
+        sys.exit("you need a ~/.config/que.conf")
+    cfg = configparser.ConfigParser()
+    cfg.read(conf_file)
+    return cfg[namespace]["key"]
+
+
+def autodecode(bytestring):
+    """Attempt to decode bytes `bs` into common codecs, preferably utf-8. If
+    no decoding is available, just return the raw bytes.
+
+    For all available codecs, see:
+    <https://docs.python.org/3/library/codecs.html#standard-encodings>
+
+    """
+    logging.debug("autodecode")
+    codecs = ["utf-8", "ascii"]
+    for codec in codecs:
+        try:
+            return bytestring.decode(codec)
+        except UnicodeDecodeError:
+            pass
+    return bytestring
+
+
+def retry(exception, tries=4, delay=3, backoff=2):
+    "Decorator for retrying an action."
+
+    def decorator(func):
+        @functools.wraps(func)
+        def func_retry(*args, **kwargs):
+            mtries, mdelay = tries, delay
+            while mtries > 1:
+                try:
+                    return func(*args, **kwargs)
+                except exception as ex:
+                    logging.debug(ex)
+                    logging.debug("retrying...")
+                    time.sleep(mdelay)
+                    mtries -= 1
+                    mdelay *= backoff
+            return func(*args, **kwargs)
+
+        return func_retry
+
+    return decorator
+
+
+def send(args):
+    "Send a message to the que."
+    logging.debug("send")
+    key = auth(args)
+    data = args.infile
+    req = request.Request(f"{args.host}/{args.target}")
+    req.add_header("User-AgenT", "Que/Client")
+    if key:
+        req.add_header("Authorization", key)
+    if args.serve:
+        logging.debug("serve")
+        while not time.sleep(1):
+            request.urlopen(req, data=data, timeout=MAX_TIMEOUT)
+
+    else:
+        request.urlopen(req, data=data, timeout=MAX_TIMEOUT)
+
+
+def then(args, msg):
+    "Perform an action when passed `--then`."
+    if args.then:
+        logging.debug("then")
+        subprocess.run(
+            args.then.format(msg=msg, que=args.target), check=False, shell=True,
+        )
+
+
+@retry(http.client.IncompleteRead, tries=10, delay=5, backoff=1)
+@retry(http.client.RemoteDisconnected, tries=10, delay=2, backoff=2)
+def recv(args):
+    "Receive a message from the que."
+    logging.debug("recv on: %s", args.target)
+    params = urllib.parse.urlencode({"poll": args.poll})
+    req = request.Request(f"{args.host}/{args.target}?{params}")
+    req.add_header("User-Agent", "Que/Client")
+    key = auth(args)
+    if key:
+        req.add_header("Authorization", key)
+    with request.urlopen(req) as _req:
+        if args.poll:
+            logging.debug("poll")
+            while not time.sleep(1):
+                logging.debug("reading")
+                msg = autodecode(_req.readline())
+                logging.debug("read")
+                print(msg, end="")
+                then(args, msg)
+        else:
+            msg = autodecode(_req.read())
+            print(msg)
+            then(args, msg)
+
+
+def get_args():
+    "Command line parser"
+    cli = argparse.ArgumentParser(description=__doc__)
+    cli.add_argument("--debug", action="store_true", help="log to stderr")
+    cli.add_argument(
+        "--host", default="http://que.run", help="where que-server is running"
+    )
+    cli.add_argument(
+        "--poll", default=False, action="store_true", help="stream data from the que"
+    )
+    cli.add_argument(
+        "--then",
+        help=" ".join(
+            [
+                "when polling, run this shell command after each response,",
+                "presumably for side effects,"
+                r"replacing '{que}' with the target and '{msg}' with the body of the response",
+            ]
+        ),
+    )
+    cli.add_argument(
+        "--serve",
+        default=False,
+        action="store_true",
+        help=" ".join(
+            [
+                "when posting to the que, do so continuously in a loop.",
+                "this can be used for serving a webpage or other file continuously",
+            ]
+        ),
+    )
+    cli.add_argument(
+        "target", help="namespace and path of the que, like 'ns/path/subpath'"
+    )
+    cli.add_argument(
+        "infile",
+        nargs="?",
+        type=argparse.FileType("rb"),
+        help="data to put on the que. Use '-' for stdin, otherwise should be a readable file",
+    )
+    return cli.parse_args()
+
+
+if __name__ == "__main__":
+    ARGV = get_args()
+    if ARGV.debug:
+        logging.basicConfig(
+            format="%(asctime)s %(message)s",
+            level=logging.DEBUG,
+            datefmt="%Y.%m.%d..%H.%M.%S",
+        )
+    try:
+        if ARGV.infile:
+            send(ARGV)
+        else:
+            recv(ARGV)
+    except KeyboardInterrupt:
+        sys.exit(0)