# A minimal client for Mercurial's command server

from __future__ import absolute_import, print_function

import io

import os

import re

import signal

import socket

import struct

import subprocess

import sys

import time

if sys.version_info[0] >= 3:

    stdout = sys.stdout.buffer

    stderr = sys.stderr.buffer

    stringio = io.BytesIO

    def bprint(*args):

        # remove b'' as well for ease of test migration

        pargs = [re.sub(br'''\bb(['"])''', br'\1', b'%s' % a) for a in args]

        stdout.write(b' '.join(pargs) + b'\n')

else:

    import cStringIO

    stdout = sys.stdout

    stderr = sys.stderr

    stringio = cStringIO.StringIO

    bprint = print

    cmdline = [b'hg', b'serve', b'--cmdserver', b'pipe']

    if path:

        cmdline += [b'-R', path]

    server = subprocess.Popen(cmdline, stdin=subprocess.PIPE,

                              stdout=subprocess.PIPE)

    return server

class unixconnection(object):

    def __init__(self, sockpath):

        self.sock = sock = socket.socket(socket.AF_UNIX)

        sock.connect(sockpath)

        self.stdin = sock.makefile('wb')

        self.stdout = sock.makefile('rb')

    def wait(self):

        self.stdin.close()

        self.stdout.close()

        self.sock.close()

class unixserver(object):

    def __init__(self, sockpath, logpath=None, repopath=None):

        self.sockpath = sockpath

        cmdline = [b'hg', b'serve', b'--cmdserver', b'unix', b'-a', sockpath]

        if repopath:

            cmdline += [b'-R', repopath]

        if logpath:

            stdout = open(logpath, 'a')

            stderr = subprocess.STDOUT

        else:

            stdout = stderr = None

        self.server = subprocess.Popen(cmdline, stdout=stdout, stderr=stderr)

        # wait for listen()

        while self.server.poll() is None:

            if os.path.exists(sockpath):

                break

            time.sleep(0.1)

    def connect(self):

        return unixconnection(self.sockpath)

    def shutdown(self):

        os.kill(self.server.pid, signal.SIGTERM)

        self.server.wait()

def writeblock(server, data):

    server.stdin.write(struct.pack(b'>I', len(data)))

    server.stdin.write(data)

    server.stdin.flush()

def readchannel(server):

    data = server.stdout.read(5)

    if not data:

        raise EOFError

    channel, length = struct.unpack('>cI', data)

    if channel in b'IL':

        return channel, length

    else:

        return channel, server.stdout.read(length)

def sep(text):

    return text.replace(b'\\', b'/')

def runcommand(server, args, output=stdout, error=stderr, input=None,

               outfilter=lambda x: x):

    bprint(b'*** runcommand', b' '.join(args))

    stdout.flush()

    server.stdin.write(b'runcommand\n')

    writeblock(server, b'\0'.join(args))

    if not input:

        input = stringio()

    while True:

        ch, data = readchannel(server)

        if ch == b'o':

            output.write(outfilter(data))

            output.flush()

        elif ch == b'e':

            error.write(data)

            error.flush()

        elif ch == b'I':

            writeblock(server, input.read(data))

        elif ch == b'L':

            writeblock(server, input.readline(data))

        elif ch == b'r':

            ret, = struct.unpack('>i', data)

            if ret != 0:

                bprint(b' [%d]' % ret)

            return ret

        else:

            bprint(b"unexpected channel %c: %r" % (ch, data))

            if ch.isupper():

                return

def check(func, connect=connectpipe):

    stdout.flush()

    server = connect()

    try:

        return func(server)

    finally:

        server.stdin.close()

        server.wait()