from multiprocessing import set_start_method
from multiprocessing import get_context
from itertools import product
import os
import sys
import time
from datetime import datetime
import requests
import json
import psycopg2
import ray
import pdb

ray.init(num_cpus = 25) # Specify this system CPUs.

def get_totals():

    conn = None

    try:

        conn = psycopg2.connect(database = cleanserver_db, user = cleanserver_db_user, password = "", host = "/var/run/postgresql", port = "5432")

        cur = conn.cursor()

        cur.execute('select count(*) from peers')

        row = cur.fetchone()

        total_peers = row[0] if row != None else 0

        cur.execute('select count(*) from peers where not alive')
        
        row = cur.fetchone()

        not_alive_peers = row[0] if row != None else 0

        cur.execute('select count(*) from peers where alive')
        
        row = cur.fetchone()

        alive_peers = row[0] if row != None else 0

        cur.close()

    except (Exception, psycopg2.DatabaseError) as error:

        print(error)

    finally:

        if conn is not None:

            conn.close()

    return (alive_peers, not_alive_peers, total_peers)

def dead():

    dead_lst = []

    conn = None

    try:

        conn = psycopg2.connect(database = cleanserver_db, user = cleanserver_db_user, password = "", host = "/var/run/postgresql", port = "5432")

        cur = conn.cursor()

        cur.execute("select server from peers where downs >=(%s)", (purge_days,))

        rows = cur.fetchall()

        for row in rows:

            dead_lst.append(row)

        cur.close()

    except (Exception, psycopg2.DatabaseError) as error:

        print(error)

    finally:

        if conn is not None:

            conn.close()

    return dead_lst

def delete_deads():

    conn = None

    try:

        conn = psycopg2.connect(database = cleanserver_db, user = cleanserver_db_user, password = "", host = "/var/run/postgresql", port = "5432")

        cur = conn.cursor()

        cur.execute("delete from peers where downs >=(%s)", (purge_days,))

        conn.commit()

        cur.close()

    except (Exception, psycopg2.DatabaseError) as error:

        print(error)

    finally:

        if conn is not None:

            conn.close()

def write_server(server, alive, checked):

    cleanserver_db, cleanserver_db_user = dbconfig()
    
    updated_at = datetime.now() 

    saved_at = datetime.now()

    select_sql = 'SELECT downs from peers where server=(%s)'

    if alive:

        insert_sql = "INSERT INTO peers(server, updated_at, saved_at, alive, checked, downs) VALUES(%s,%s,%s,%s,%s,%s) ON CONFLICT (server) DO UPDATE SET (server, updated_at, saved_at, alive, checked, downs) = (EXCLUDED.server, EXCLUDED.updated_at, EXCLUDED.saved_at, EXCLUDED.alive, EXCLUDED.checked, EXCLUDED.downs)"

    else:

        insert_sql = "INSERT INTO peers(server, updated_at, alive, checked, downs) VALUES(%s,%s,%s,%s,%s) ON CONFLICT (server) DO UPDATE SET (server, updated_at, alive, checked, downs) = (EXCLUDED.server, EXCLUDED.updated_at, EXCLUDED.alive, EXCLUDED.checked, EXCLUDED.downs)"
    
    conn = None

    try:

        conn = psycopg2.connect(database = cleanserver_db, user = cleanserver_db_user, password = "", host = "/var/run/postgresql", port = "5432")

        cur = conn.cursor()

        cur.execute(select_sql, (server,))

        row = cur.fetchone()

        downs_before = row[0] if row != None else 0

        downs_now = downs_before + 1 if not alive else 0

        if alive:

            cur.execute(insert_sql, (server, updated_at, saved_at, alive, checked, downs_now))

        else:

            cur.execute(insert_sql, (server, updated_at, alive, checked, downs_now))

        conn.commit()

        cur.close()

    except (Exception, psycopg2.DatabaseError) as error:

        print(error)

    finally:

        if conn is not None:

            conn.close()

def write_totals(alive, not_alive, total):

    now = datetime.now()

    insert_sql = "INSERT INTO totals(datetime, alive, dead, total) VALUES(%s,%s,%s,%s) ON CONFLICT DO NOTHING"

    conn = None

    try:

        conn = psycopg2.connect(database = cleanserver_db, user = cleanserver_db_user, password = "", host = "/var/run/postgresql", port = "5432")

        cur = conn.cursor()

        cur.execute(insert_sql, (now, alive, not_alive, total))

        conn.commit()

        cur.close()

    except (Exception, psycopg2.DatabaseError) as error:

        print(error)

    finally:

        if conn is not None:

            conn.close()

@ray.remote
def check_peers(peer):

    cleanserver_db, cleanserver_db_user = dbconfig()
    
    user_agent = {'User-agent': 'Mozilla/5.0'}

    try:

        response = requests.get(f'https://{peer}', headers = user_agent, timeout=3)

        if response.status_code == 200:

            print(f'Server: {peer} is alive')

            alive = True

            checked = True

            write_server(peer, alive, checked)

    except requests.exceptions.ChunkedEncodingError as chunk_err:

        print(f'Server: {peer} is dead')

        alive = False

        checked = True

        write_server(peer, alive, checked)

    except requests.exceptions.InvalidSchema as invalid_err:

        print(f'Server: {peer} is dead')

        alive = False

        checked = True

        write_server(peer, alive, checked)

    except requests.exceptions.ConnectTimeout as err_ct:

        print(f'Server: {peer} is dead')

        alive = False

        checked = True

        write_server(peer, alive, checked)

    except requests.exceptions.ConnectionError as err_ce:

        print(f'Server: {peer} is dead')

        alive = False

        checked = True

        write_server(peer, alive, checked)

    except requests.exceptions.ReadTimeout as err_rt:

        print(f'Server: {peer} is dead')

        alive = False

        checked = True

        write_server(peer, alive, checked)

    except requests.exceptions.TooManyRedirects as err_mr:

        print(f'Server: {peer} is dead')

        alive = False

        checked = True

        write_server(peer, alive, checked)

def purge(server):

    print(f'Purging server {server}')
    os.system(f'RAILS_ENV=production {rvm_ruby} {mastodon_full_path}/bin/tootctl domains purge {server}')

def dbconfig():

    # Load database config from db_config file
    db_config_filepath = "config/db_config.txt"
    cleanserver_db = get_parameter("cleanserver_db", db_config_filepath)
    cleanserver_db_user = get_parameter("cleanserver_db_user", db_config_filepath)

    return (cleanserver_db, cleanserver_db_user)

def get_parameter( parameter, file_path ):

    # Check if secrets file exists
    if not os.path.isfile(file_path):
        print("File %s not found, exiting."%file_path)
        sys.exit(0)

    # Find parameter in file
    with open( file_path ) as f:
        for line in f:
            if line.startswith( parameter ):
                return line.replace(parameter + ":", "").strip()

    # Cannot find parameter, exit
    print(file_path + "  Missing parameter %s "%parameter)
    sys.exit(0)

###############################################################################
# main

if __name__ == '__main__':

    rvm_ruby = os.environ['HOME'] + "/.rbenv/shims/ruby"
    
    start_time = time.time()

    updated_at = datetime.now()

    peers_api = '/api/v1/instance/peers?'

    # Load configuration from config file
    config_filepath = "config/config.txt"
    mastodon_hostname = get_parameter("mastodon_hostname", config_filepath)
    mastodon_full_path = get_parameter("mastodon_full_path", config_filepath)
    purge_days = get_parameter("purge_days", config_filepath)

    cleanserver_db, cleanserver_db_user = dbconfig()

    ##########################################
    # purge dead servers 

    dead_lst = dead()

    if len(dead_lst) > 0:

        servers_count = 1

        for server in dead_lst:

            print(f'Purging server {servers_count} of {len(dead_lst)}...')
            
            purge(server[0])

            servers_count+=1

    ##########################################
    # delete dead servers old than purge_days

    delete_deads()

    ##########################################
    # get current hostname peers

    user_agent = {'User-agent': 'Mozilla/5.0'}

    res = requests.get('https://' + mastodon_hostname + peers_api, headers = user_agent, timeout=3)

    hostname_peers = res.json()

    ray.get([check_peers.remote(peer) for peer in hostname_peers])

    alive_peers, not_alive_peers, total_peers = get_totals()
    
    print(f"\nTotal {mastodon_hostname}'s federated servers: {total_peers}")
    print(f'Alive servers: {alive_peers}')
    print(f'Not Alive servers: {not_alive_peers}')

    write_totals(alive_peers, not_alive_peers, total_peers)

    exec_time = str(round((time.time() - start_time), 2))
    print(f'Execution time: {exec_time} seconds')