import json
import logging
import socket


class RpcError(ValueError):
    def __init__(self, method, payload, error):
        super(ValueError, self).__init__("RPC call failed: method: {}, payload: {}, error: {}"
                                         .format(method, payload, error))

        self.method = method
        self.payload = payload
        self.error = error


class UnixDomainSocketRpc(object):
    def __init__(self, socket_path, executor=None, logger=logging):
        self.socket_path = socket_path
        self.decoder = json.JSONDecoder()
        self.executor = executor
        self.logger = logger

        # Do we require the compatibility mode?
        self._compat = True

    @staticmethod
    def _writeobj(sock, obj):
        s = json.dumps(obj)
        sock.sendall(bytearray(s, 'UTF-8'))

    def _readobj_compat(self, sock, buff=b''):
        if not self._compat:
            return self._readobj(sock, buff)
        while True:
            try:
                b = sock.recv(max(1024, len(buff)))
                buff += b

                if b'\n\n' in buff:
                    # The next read will use the non-compatible read instead
                    self._compat = False

                if len(b) == 0:
                    return {'error': 'Connection to RPC server lost.'}
                if b' }\n' not in buff:
                    continue
                # Convert late to UTF-8 so glyphs split across recvs do not
                # impact us
                objs, len_used = self.decoder.raw_decode(buff.decode("UTF-8"))
                return objs, buff[len_used:].lstrip()
            except ValueError:
                # Probably didn't read enough
                pass

    def _readobj(self, sock, buff=b''):
        """Read a JSON object, starting with buff; returns object and any buffer left over"""
        while True:
            parts = buff.split(b'\n\n', 1)
            if len(parts) == 1:
                # Didn't read enough.
                b = sock.recv(max(1024, len(buff)))
                buff += b
                if len(b) == 0:
                    return {'error': 'Connection to RPC server lost.'}, buff
            else:
                buff = parts[1]
                obj, _ = self.decoder.raw_decode(parts[0].decode("UTF-8"))
                return obj, buff

    def __getattr__(self, name):
        """Intercept any call that is not explicitly defined and call @call

        We might still want to define the actual methods in the subclasses for
        documentation purposes.
        """
        name = name.replace('_', '-')

        def wrapper(*args, **kwargs):
            if len(args) != 0 and len(kwargs) != 0:
                raise RpcError("Cannot mix positional and non-positional arguments")
            elif len(args) != 0:
                return self.call(name, payload=args)
            else:
                return self.call(name, payload=kwargs)
        return wrapper

    def call(self, method, payload=None):
        self.logger.debug("Calling %s with payload %r", method, payload)

        if payload is None:
            payload = {}
        # Filter out arguments that are None
        if isinstance(payload, dict):
            payload = {k: v for k, v in payload.items() if v is not None}

        # FIXME: we open a new socket for every readobj call...
        sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
        sock.connect(self.socket_path)
        self._writeobj(sock, {
            "method": method,
            "params": payload,
            "id": 0
        })
        resp, _ = self._readobj_compat(sock)
        sock.close()

        self.logger.debug("Received response for %s call: %r", method, resp)
        if "error" in resp:
            raise RpcError(method, payload, resp['error'])
        elif "result" not in resp:
            raise ValueError("Malformed response, \"result\" missing.")
        return resp["result"]


class LightningRpc(UnixDomainSocketRpc):
    """
    RPC client for the `lightningd` daemon.

    This RPC client connects to the `lightningd` daemon through a unix
    domain socket and passes calls through. Since some of the calls
    are blocking, the corresponding python methods include an `async`
    keyword argument. If `async` is set to true then the method
    returns a future immediately, instead of blocking indefinitely.

    This implementation is thread safe in that it locks the socket
    between calls, but it does not (yet) support concurrent calls.
    """

    def getpeer(self, peer_id, level=None):
        """
        Show peer with {peer_id}, if {level} is set, include {log}s
        """
        payload = {
            "id": peer_id,
            "level": level
        }
        res = self.call("listpeers", payload)
        return res.get("peers") and res["peers"][0] or None

    def listnodes(self, node_id=None):
        """
        Show all nodes in our local network view, filter on node {id}
        if provided
        """
        payload = {
            "id": node_id
        }
        return self.call("listnodes", payload)

    def getroute(self, peer_id, msatoshi, riskfactor, cltv=9, fromid=None, fuzzpercent=None, seed=None, exclude=[]):
        """
        Show route to {id} for {msatoshi}, using {riskfactor} and optional
        {cltv} (default 9). If specified search from {fromid} otherwise use
        this node as source. Randomize the route with up to {fuzzpercent}
        (0.0 -> 100.0, default 5.0) using {seed} as an arbitrary-size string
        seed. {exclude} is an optional array of scids[xDirection] to exclude.
        """
        payload = {
            "id": peer_id,
            "msatoshi": msatoshi,
            "riskfactor": riskfactor,
            "cltv": cltv,
            "fromid": fromid,
            "fuzzpercent": fuzzpercent,
            "seed": seed,
            "exclude": exclude
        }
        return self.call("getroute", payload)

    def listchannels(self, short_channel_id=None, source=None):
        """
        Show all known channels, accept optional {short_channel_id} or {source}
        """
        payload = {
            "short_channel_id": short_channel_id,
            "source": source
        }
        return self.call("listchannels", payload)

    def invoice(self, msatoshi, label, description, expiry=None, fallbacks=None, preimage=None, exposeprivatechannels=None):
        """
        Create an invoice for {msatoshi} with {label} and {description} with
        optional {expiry} seconds (default 1 hour)
        """
        payload = {
            "msatoshi": msatoshi,
            "label": label,
            "description": description,
            "expiry": expiry,
            "fallbacks": fallbacks,
            "preimage": preimage,
            "exposeprivatechannels": exposeprivatechannels
        }
        return self.call("invoice", payload)

    def listinvoices(self, label=None):
        """
        Show invoice {label} (or all, if no {label))
        """
        payload = {
            "label": label
        }
        return self.call("listinvoices", payload)

    def delinvoice(self, label, status):
        """
        Delete unpaid invoice {label} with {status}
        """
        payload = {
            "label": label,
            "status": status
        }
        return self.call("delinvoice", payload)

    def waitanyinvoice(self, lastpay_index=None):
        """
        Wait for the next invoice to be paid, after {lastpay_index}
        (if supplied)
        """
        payload = {
            "lastpay_index": lastpay_index
        }
        return self.call("waitanyinvoice", payload)

    def waitinvoice(self, label):
        """
        Wait for an incoming payment matching the invoice with {label}
        """
        payload = {
            "label": label
        }
        return self.call("waitinvoice", payload)

    def decodepay(self, bolt11, description=None):
        """
        Decode {bolt11}, using {description} if necessary
        """
        payload = {
            "bolt11": bolt11,
            "description": description
        }
        return self.call("decodepay", payload)

    def help(self):
        """
        Show available commands
        """
        return self.call("help")

    def stop(self):
        """
        Shut down the lightningd process
        """
        return self.call("stop")

    def getlog(self, level=None):
        """
        Show logs, with optional log {level} (info|unusual|debug|io)
        """
        payload = {
            "level": level
        }
        return self.call("getlog", payload)

    def dev_rhash(self, secret):
        """
        Show SHA256 of {secret}
        """
        payload = {
            "secret": secret
        }
        return self.call("dev-rhash", payload)

    def dev_crash(self):
        """
        Crash lightningd by calling fatal()
        """
        return self.call("dev-crash")

    def dev_query_scids(self, id, scids):
        """
        Ask peer for a particular set of scids
        """
        payload = {
            "id": id,
            "scids": scids
        }
        return self.call("dev-query-scids", payload)

    def getinfo(self):
        """
        Show information about this node
        """
        return self.call("getinfo")

    def sendpay(self, route, payment_hash, description=None, msatoshi=None):
        """
        Send along {route} in return for preimage of {payment_hash}
        """
        payload = {
            "route": route,
            "payment_hash": payment_hash,
            "description": description,
            "msatoshi": msatoshi,
        }
        return self.call("sendpay", payload)

    def waitsendpay(self, payment_hash, timeout=None):
        """
        Wait for payment for preimage of {payment_hash} to complete
        """
        payload = {
            "payment_hash": payment_hash,
            "timeout": timeout
        }
        return self.call("waitsendpay", payload)

    def pay(self, bolt11, msatoshi=None, description=None, riskfactor=None):
        """
        Send payment specified by {bolt11} with {msatoshi}
        (ignored if {bolt11} has an amount),

        {description} (required if {bolt11} uses description hash)
        and {riskfactor} (default 1.0)
        """
        payload = {
            "bolt11": bolt11,
            "msatoshi": msatoshi,
            "description": description,
            "riskfactor": riskfactor
        }
        return self.call("pay", payload)

    def listpayments(self, bolt11=None, payment_hash=None):
        """
        Show outgoing payments, regarding {bolt11} or {payment_hash} if set
        Can only specify one of {bolt11} or {payment_hash}
        """
        assert not (bolt11 and payment_hash)
        payload = {
            "bolt11": bolt11,
            "payment_hash": payment_hash
        }
        return self.call("listpayments", payload)

    def connect(self, peer_id, host=None, port=None):
        """
        Connect to {peer_id} at {host} and {port}
        """
        payload = {
            "id": peer_id,
            "host": host,
            "port": port
        }
        return self.call("connect", payload)

    def listpeers(self, peerid=None, level=None):
        """
        Show current peers, if {level} is set, include {log}s"
        """
        payload = {
            "id": peerid,
            "level": level,
        }
        return self.call("listpeers", payload)

    def fundchannel(self, node_id, satoshi, feerate=None, announce=True):
        """
        Fund channel with {id} using {satoshi} satoshis
        with feerate of {feerate} (uses default feerate if unset).
        If {announce} is False, don't send channel announcements.
        """
        payload = {
            "id": node_id,
            "satoshi": satoshi,
            "feerate": feerate,
            "announce": announce
        }
        return self.call("fundchannel", payload)

    def close(self, peer_id, force=None, timeout=None):
        """
        Close the channel with peer {id}, forcing a unilateral
        close if {force} is True, and timing out with {timeout}
        seconds.
        """
        payload = {
            "id": peer_id,
            "force": force,
            "timeout": timeout
        }
        return self.call("close", payload)

    def dev_sign_last_tx(self, peer_id):
        """
        Sign and show the last commitment transaction with peer {id}
        """
        payload = {
            "id": peer_id
        }
        return self.call("dev-sign-last-tx", payload)

    def dev_fail(self, peer_id):
        """
        Fail with peer {peer_id}
        """
        payload = {
            "id": peer_id
        }
        return self.call("dev-fail", payload)

    def dev_reenable_commit(self, peer_id):
        """
        Re-enable the commit timer on peer {id}
        """
        payload = {
            "id": peer_id
        }
        return self.call("dev-reenable-commit", payload)

    def ping(self, peer_id, length=128, pongbytes=128):
        """
        Send {peer_id} a ping of length {len} asking for {pongbytes}"
        """
        payload = {
            "id": peer_id,
            "len": length,
            "pongbytes": pongbytes
        }
        return self.call("ping", payload)

    def dev_memdump(self):
        """
        Show memory objects currently in use
        """
        return self.call("dev-memdump")

    def dev_memleak(self):
        """
        Show unreferenced memory objects
        """
        return self.call("dev-memleak")

    def withdraw(self, destination, satoshi, feerate=None):
        """
        Send to {destination} address {satoshi} (or "all")
        amount via Bitcoin transaction
        """
        payload = {
            "destination": destination,
            "satoshi": satoshi,
            "feerate": feerate
        }
        return self.call("withdraw", payload)

    def newaddr(self, addresstype=None):
        """Get a new address of type {addresstype} of the internal wallet.
        """
        return self.call("newaddr", {"addresstype": addresstype})

    def listfunds(self):
        """
        Show funds available for opening channels
        """
        return self.call("listfunds")

    def listforwards(self):
        """List all forwarded payments and their information
        """
        return self.call("listforwards")

    def dev_rescan_outputs(self):
        """
        Synchronize the state of our funds with bitcoind
        """
        return self.call("dev-rescan-outputs")

    def dev_forget_channel(self, peerid, force=False):
        """ Forget the channel with id=peerid
        """
        return self.call(
            "dev-forget-channel",
            payload={"id": peerid, "force": force}
        )

    def disconnect(self, peer_id, force=False):
        """
        Disconnect from peer with {peer_id}, optional {force} even if has active channel
        """
        payload = {
            "id": peer_id,
            "force": force,
        }
        return self.call("disconnect", payload)

    def feerates(self, style, urgent=None, normal=None, slow=None):
        """
        Supply feerate estimates manually.
        """
        payload = {
            "style": style,
            "urgent": urgent,
            "normal": normal,
            "slow": slow
        }
        return self.call("feerates", payload)