#!/usr/bin/env python

import asyncio
import logging
import signal
import time
import sqlite3
import pickle
from os import path
from pprint import pprint
from aioupnp import upnp, fault as upnpfault
from aiohttp import web
import json


from lbry.dht import node, peer

log = logging.getLogger("lbry")
log.addHandler(logging.StreamHandler())
log.setLevel(logging.INFO)


async def main():
    data_dir = "/home/grin/code/lbry/sdk"
    state_dir = data_dir + '/nodestate/'
    loop = asyncio.get_event_loop()

    try:
        loop.add_signal_handler(signal.SIGINT, shutdown)
        loop.add_signal_handler(signal.SIGTERM, shutdown)
    except NotImplementedError:
        pass  # Not implemented on Windows

    db = sqlite3.connect(data_dir + "/tracker.sqlite3")
    db.execute('CREATE TABLE IF NOT EXISTS announce (local_id TEXT, hash TEXT, node_id TEXT, ip TEXT, port INT, timestamp INT)')
    db.execute('CREATE UNIQUE INDEX IF NOT EXISTS node_id_hash_idx ON announce (node_id, hash)')

    asyncio.create_task(run_web_api(loop, db))

    num_nodes = 128
    u = await upnp.UPnP.discover()
    external_ip = await u.get_external_ip()

    try:
        nodes = await start_nodes(loop, num_nodes, external_ip, state_dir)

        await asyncio.gather(*map(lambda n: n.started_listening.wait(), nodes), loop=loop)
        print("joined")

        queue = asyncio.Queue(maxsize=100*num_nodes)
        for n in nodes:
            asyncio.create_task(drain_events(n, queue))

        while True:
            (n, node_id, ip, method, args) = await queue.get()
            local_node_id = bytes.hex(n.protocol.node_id)
            if method != b'store':
                # print(f"{local_node_id[:8]}: {method} from {bytes.hex(node_id)} ({ip})")
                continue

            blob_hash, token, port, original_publisher_id, age = args[:5]
            print(f"STORE to {local_node_id[:8]} from {bytes.hex(node_id)[:8]} ({ip}) for blob {bytes.hex(blob_hash)[:8]}")

            try:
                cur = db.cursor()
                cur.execute(
                    '''
                    INSERT INTO announce (local_id, hash, node_id, ip, port, timestamp) VALUES (?,?,?,?,?,?)
                    ON CONFLICT (node_id, hash) DO UPDATE SET 
                    local_id=excluded.local_id, ip=excluded.ip, port=excluded.port, timestamp=excluded.timestamp
                    ''',
                    (local_node_id, bytes.hex(blob_hash), bytes.hex(node_id), ip, port, int(time.time()))
                )
                db.commit()
                cur.close()
            except sqlite3.Error as err:
                print("failed insert", err)
    finally:
        print("shutting down")
        for n in nodes:
            node_id = bytes.hex(n.protocol.node_id)
            n.stop()
            # print(f'deleting upnp port mapping {n.protocol.udp_port}')
            try:
                await u.delete_port_mapping(n.protocol.udp_port, "UDP")
            except upnpfault.UPnPError:
                pass

            state = n.get_state()
            # keep existing rt if there is one
            if len(state.routing_table_peers) == 0 and path.exists(state_dir + node_id):
                with open(state_dir + node_id, 'rb') as f:
                    existing_state = pickle.load(f)
                    if len(existing_state.routing_table_peers) > 0:
                        state.routing_table_peers = existing_state.routing_table_peers
                        print(f'rt empty on save, but old rt was recovered ({len(state.routing_table_peers)} peers)')
            with open(state_dir + node_id, 'wb') as f:
                # pprint(state.routing_table_peers)
                # pprint(state.datastore)
                print(f'{node_id[:8]}: saved {len(state.routing_table_peers)} rt peers, {len(state.datastore)} in store')
                pickle.dump(state, f)
        db.close()


class ShutdownErr(BaseException):
    pass


def shutdown():
    print("got interrupt signal...")
    raise ShutdownErr()


def make_node_id(i: int, n: int) -> str:
    """
    split dht address space into N chunks and return the first id of the i'th chunk
    make_node_id(0,n) returns 000...000 for any n
    """
    if not 0 <= i < n:
        raise ValueError("i must be between 0 (inclusive) and n (exclusive)")
    bytes_in_id = 48
    return "{0:0{1}x}".format(i * ((2**8)**bytes_in_id // n), bytes_in_id*2)


async def start_nodes(loop, num_nodes, external_ip, state_dir):
    start_port = 4445
    known_node_urls = [("lbrynet1.lbry.com", 4444), ("lbrynet2.lbry.com", 4444), ("lbrynet3.lbry.com", 4444)]
    peer_manager = peer.PeerManager(loop)

    nodes = []
    for i in range(num_nodes):
        node_id = make_node_id(i, num_nodes)
        # pprint(node_id)

        port = start_port + i
        # await u.get_next_mapping(port, "UDP", "lbry dht tracker") # not necessary, i just opened ports in router

        n = node.Node(loop, peer_manager, node_id=bytes.fromhex(node_id), external_ip=external_ip,
                      udp_port=port, internal_udp_port=port, peer_port=3333)

        persisted_peers = []
        if path.exists(state_dir + node_id):
            with open(state_dir + node_id, 'rb') as f:
                state = pickle.load(f)
                # pprint(state.routing_table_peers)
                # pprint(state.datastore)
                print(f'{node_id[:8]}: loaded {len(state.routing_table_peers)} rt peers, {len(state.datastore)} in store')
                n.load_state(state)
                persisted_peers = state.routing_table_peers
                # if len(persisted_peers) == 0 and len(state.datastore) > 0:
                #     peers_to_import = map(lambda p: (p[0], p[1], p[2], p[3]), n.get_state().datastore)
                #     persisted_peers.extend(peers_to_import)
                #     print(f'{node_id[:8]}: rt is empty but we recovered {len(state.datastore)} '
                #           f'peers from the datastore. {len(peers_to_import)} of those were recent enough to import')

        n.start("0.0.0.0", known_node_urls, persisted_peers)
        nodes.append(n)
    return nodes


async def drain_events(n, q):
    print(f'drain started on {bytes.hex(n.protocol.node_id)[:8]}')
    while True:
        (node_id, ip, method, args) = await n.protocol.event_queue.get()
        try:
            q.put_nowait((n, node_id, ip, method, args))
        except asyncio.QueueFull:
            pass


async def run_web_api(loop, db):
    app = web.Application(loop=loop)
    app['db'] = db
    app.add_routes([
        web.get('/', api_handler),
        web.get('/seeds/{hash}', seeds_handler),
    ])
    # server = web.Server(api_handler, loop=loop)
    # runner = web.ServerRunner(server)
    runner = web.AppRunner(app)
    await runner.setup()
    site = web.TCPSite(runner, 'localhost', 8080)
    await site.start()
    # web.run_app(app)


async def seeds_handler(request):
    blobhash = request.match_info['hash']
    db = request.app['db']
    try:
        cur = db.cursor()
        c = cur.execute("""
            select count(distinct(node_id)) from announce where hash = ? and timestamp > strftime('%s','now','-1 day')
        """, (blobhash,)).fetchone()[0]
        cur.close()
        return web.Response(text=json.dumps({'seeds': c})+"\n")
    except Exception as err:
        return web.Response(text=json.dumps({'error': err})+"\n")


async def api_handler(request):
    return web.Response(text="tracker OK")

if __name__ == "__main__":
    try:
        asyncio.run(main())
    except ShutdownErr:
        pass