#!/usr/bin/env python3
from pyln.client import Plugin, Millisatoshi
from packaging import version
from collections import namedtuple
import pyln.client
from math import floor, log10
import requests
import threading
import time

plugin = Plugin(autopatch=True)

have_utf8 = False

# __version__ was introduced in 0.0.7.1, with utf8 passthrough support.
try:
    if version.parse(pyln.client.__version__) >= version.parse("0.0.7.1"):
        have_utf8 = True
except Exception:
    pass

Charset = namedtuple('Charset', ['double_left', 'left', 'bar', 'mid', 'right', 'double_right', 'empty'])
if have_utf8:
    draw = Charset('╟', '├', '─', '┼', '┤', '╢', '║')
else:
    draw = Charset('#', '[', '-', '/', ']', '#', '|')

summary_description = "Gets summary information about this node.\n"\
                      "Pass a list of scids to the {exclude} parameter"\
                      " to exclude some channels from the outputs."

class PriceThread(threading.Thread):
    def __init__(self):
        super().__init__()
        self.daemon = True

    def run(self):
        while True:
            try:
                r = requests.get('https://www.bitstamp.net/api/v2/ticker/BTC{}'.format(plugin.currency))
                plugin.fiat_per_btc = float(r.json()['last'])
            except Exception as ex:
                plugin.log("[PriceThread] " + str(ex), 'error')
            # Six hours is more than often enough for polling
            time.sleep(6*3600)


def to_fiatstr(msat: Millisatoshi):
    return "{}{:.2f}".format(plugin.currency_prefix,
                              int(msat) / 10**11 * plugin.fiat_per_btc)


# This is part of pylightning, but its just merged,
# so old releases wont have it yet.
def msat_to_approx_str(msat, digits: int = 3):
    """Returns the shortmost string using common units representation.

    Rounds to significant `digits`. Default: 3
    """
    round_to_n = lambda x, n: round(x, -int(floor(log10(x))) + (n - 1))
    result = None

    # we try to increase digits to check if we did loose out on precision
    # without gaining a shorter string, since this is a rarely used UI
    # function, performance is not an issue. Adds at least one iteration.
    while True:
        # first round everything down to effective digits
        amount_rounded = round_to_n(msat.millisatoshis, digits)
        # try different units and take shortest resulting normalized string
        amounts_str = [
            "%gbtc" % (amount_rounded / 1000 / 10**8),
            "%gsat" % (amount_rounded / 1000),
            "%gmsat" % (amount_rounded),
        ]
        test_result = min(amounts_str, key=len)

        # check result and do another run if necessary
        if test_result == result:
            return result
        elif not result or len(test_result) <= len(result):
            digits = digits + 1
            result = test_result
        else:
            return result


# appends an output table header that explains fields and capacity
def append_header(table, max_msat):
    short_str = msat_to_approx_str(Millisatoshi(max_msat))
    table.append("%c%-13sOUT/OURS %c IN/THEIRS%12s%c SCID           FLAG ALIAS"
            % (draw.left, short_str, draw.mid, short_str, draw.right))


@plugin.method("summary", long_desc=summary_description)
def summary(plugin, exclude=''):
    """Gets summary information about this node."""

    reply = {}
    info = plugin.rpc.getinfo()
    funds = plugin.rpc.listfunds()
    peers = plugin.rpc.listpeers()

    # Make it stand out if we're not on mainnet.
    if info['network'] != 'bitcoin':
        reply['network'] = info['network'].upper()

    if hasattr(plugin, 'my_address') and plugin.my_address:
        reply['my_address'] = plugin.my_address
    else:
        reply['warning_no_address'] = "NO PUBLIC ADDRESSES"

    utxos = [int(f['amount_msat']) for f in funds['outputs']
             if f['status'] == 'confirmed']
    reply['num_utxos'] = len(utxos)
    utxo_amount = Millisatoshi(sum(utxos))
    reply['utxo_amount'] = utxo_amount.to_btc_str()

    avail_out = Millisatoshi(0)
    avail_in = Millisatoshi(0)
    chans = []
    reply['num_channels'] = 0
    reply['num_connected'] = 0
    reply['num_gossipers'] = 0
    for p in peers['peers']:
        active_channel = False
        for c in p['channels']:
            if c['state'] != 'CHANNELD_NORMAL':
                continue
            active_channel = True
            if c['short_channel_id'] in exclude:
                continue
            if p['connected']:
                reply['num_connected'] += 1
            if c['our_reserve_msat'] < c['to_us_msat']:
                to_us = c['to_us_msat'] - c['our_reserve_msat']
            else:
                to_us = Millisatoshi(0)
            avail_out += to_us

            # We have to derive amount to them
            to_them = c['total_msat'] - c['to_us_msat']
            if c['their_reserve_msat'] < to_them:
                to_them = to_them - c['their_reserve_msat']
            else:
                to_them = Millisatoshi(0)
            avail_in += to_them
            reply['num_channels'] += 1
            chans.append((c['total_msat'], to_us, to_them, p['id'], c['private'], p['connected'], c['short_channel_id']))

        if not active_channel and p['connected']:
            reply['num_gossipers'] += 1

    reply['avail_out'] = avail_out.to_btc_str()
    reply['avail_in'] = avail_in.to_btc_str()

    if plugin.fiat_per_btc > 0:
        reply['utxo_amount'] += ' ({})'.format(to_fiatstr(utxo_amount))
        reply['avail_out'] += ' ({})'.format(to_fiatstr(avail_out))
        reply['avail_in'] += ' ({})'.format(to_fiatstr(avail_in))

    if chans != []:
        reply['channels_flags'] = 'P:private O:offline'
        reply['channels'] = ["\n"]
        biggest = max(max(int(c[1]), int(c[2])) for c in chans)
        append_header(reply['channels'], biggest)
        for c in chans:
            # Create simple line graph, 47 chars wide.
            our_len = int(round(int(c[1]) / biggest * 23))
            their_len = int(round(int(c[2]) / biggest * 23))
            divided = False

            # We put midpoint in the middle.
            mid = draw.mid
            if our_len == 0:
                left = "{:>23}".format('')
                mid = draw.double_left
            else:
                left = "{:>23}".format(draw.left + draw.bar * (our_len - 1))

            if their_len == 0:
                right = "{:23}".format('')
                # Both 0 is a special case.
                if our_len == 0:
                    mid = draw.empty
                else:
                    mid = draw.double_right
            else:
                right = "{:23}".format(draw.bar * (their_len - 1) + draw.right)

            s = left + mid + right

            # output short channel id, so things can be copyNpasted easily
            s += " {:14} ".format(c[6])

            extra = ''
            if c[4]:
                extra += 'P'
            else:
                extra += '_'
            if not c[5]:
                extra += 'O'
            else:
                extra += '_'
            s += '[{}] '.format(extra)

            node = plugin.rpc.listnodes(c[3])['nodes']
            if len(node) != 0 and 'alias' in node[0]:
                s += node[0]['alias']
            else:
                s += c[3][0:32]
            reply['channels'].append(s)

    # Make modern lightning-cli format this human-readble by default!
    reply['format-hint'] = 'simple'
    return reply


@plugin.init()
def init(options, configuration, plugin):
    plugin.currency = options['summary-currency']
    plugin.currency_prefix = options['summary-currency-prefix']
    plugin.fiat_per_btc = 0
    info = plugin.rpc.getinfo()

    # Try to grab conversion price
    PriceThread().start()

    # Prefer IPv4, otherwise take any to give out address.
    best_address = None
    for a in info['address']:
        if best_address is None:
            best_address = a
        elif a['type'] == 'ipv4' and best_address['type'] != 'ipv4':
            best_address = a

    if best_address:
        plugin.my_address = info['id'] + '@' + best_address['address']
        if best_address['port'] != 9735:
            plugin.my_address += ':' + str(best_address['port'])
    else:
        plugin.my_address = None

    plugin.log("Plugin summary.py initialized")


plugin.add_option(
    'summary-currency',
    'USD',
    'What currency should I look up on btcaverage?'
)
plugin.add_option(
    'summary-currency-prefix',
    'USD $',
    'What prefix to use for currency'
)
plugin.run()