from collections import namedtuple
from datetime import datetime
import logging
from typing import List
import time

import asyncpg
import asyncpg.exceptions
from discord.utils import snowflake_time

from pluralkit import System, Member, stats

logger = logging.getLogger("pluralkit.db")
async def connect(username, password, database, host, port):
    while True:
        try:
            return await asyncpg.create_pool(user=username, password=password, database=database, host=host, port=port)
        except (ConnectionError, asyncpg.exceptions.CannotConnectNowError):
            pass

def db_wrap(func):
    async def inner(*args, **kwargs):
        before = time.perf_counter()
        try:
            res = await func(*args, **kwargs)
            after = time.perf_counter()

            logger.debug(" - DB call {} took {:.2f} ms".format(func.__name__, (after - before) * 1000))
            # TODO: find some way to give this func access to the bot's stats object
            #await stats.report_db_query(func.__name__, after - before, True)

            return res
        except asyncpg.exceptions.PostgresError:
            #await stats.report_db_query(func.__name__, time.perf_counter() - before, False)
            logger.exception("Error from database query {}".format(func.__name__))
    return inner

@db_wrap
async def create_system(conn, system_name: str, system_hid: str) -> System:
    logger.debug("Creating system (name={}, hid={})".format(
        system_name, system_hid))
    row = await conn.fetchrow("insert into systems (name, hid) values ($1, $2) returning *", system_name, system_hid)
    return System(**row) if row else None


@db_wrap
async def remove_system(conn, system_id: int):
    logger.debug("Deleting system (id={})".format(system_id))
    await conn.execute("delete from systems where id = $1", system_id)


@db_wrap
async def create_member(conn, system_id: int, member_name: str, member_hid: str) -> Member:
    logger.debug("Creating member (system={}, name={}, hid={})".format(
        system_id, member_name, member_hid))
    row = await conn.fetchrow("insert into members (name, system, hid) values ($1, $2, $3) returning *", member_name, system_id, member_hid)
    return Member(**row) if row else None


@db_wrap
async def delete_member(conn, member_id: int):
    logger.debug("Deleting member (id={})".format(member_id))
    await conn.execute("delete from members where id = $1", member_id)


@db_wrap
async def link_account(conn, system_id: int, account_id: str):
    logger.debug("Linking account (account_id={}, system_id={})".format(
        account_id, system_id))
    await conn.execute("insert into accounts (uid, system) values ($1, $2)", int(account_id), system_id)


@db_wrap
async def unlink_account(conn, system_id: int, account_id: str):
    logger.debug("Unlinking account (account_id={}, system_id={})".format(
        account_id, system_id))
    await conn.execute("delete from accounts where uid = $1 and system = $2", int(account_id), system_id)


@db_wrap
async def get_linked_accounts(conn, system_id: int) -> List[int]:
    return [row["uid"] for row in await conn.fetch("select uid from accounts where system = $1", system_id)]


@db_wrap
async def get_system_by_account(conn, account_id: str) -> System:
    row = await conn.fetchrow("select systems.* from systems, accounts where accounts.uid = $1 and accounts.system = systems.id", int(account_id))
    return System(**row) if row else None

@db_wrap
async def get_system_by_hid(conn, system_hid: str) -> System:
    row = await conn.fetchrow("select * from systems where hid = $1", system_hid)
    return System(**row) if row else None


@db_wrap
async def get_system(conn, system_id: int) -> System:
    row = await conn.fetchrow("select * from systems where id = $1", system_id)
    return System(**row) if row else None


@db_wrap
async def get_member_by_name(conn, system_id: int, member_name: str) -> Member:
    row = await conn.fetchrow("select * from members where system = $1 and lower(name) = lower($2)", system_id, member_name)
    return Member(**row) if row else None


@db_wrap
async def get_member_by_hid_in_system(conn, system_id: int, member_hid: str) -> Member:
    row = await conn.fetchrow("select * from members where system = $1 and hid = $2", system_id, member_hid)
    return Member(**row) if row else None


@db_wrap
async def get_member_by_hid(conn, member_hid: str) -> Member:
    row = await conn.fetchrow("select * from members where hid = $1", member_hid)
    return Member(**row) if row else None


@db_wrap
async def get_member(conn, member_id: int) -> Member:
    row = await conn.fetchrow("select * from members where id = $1", member_id)
    return Member(**row) if row else None

@db_wrap
async def get_members(conn, members: list) -> List[Member]:
    rows = await conn.fetch("select * from members where id = any($1)", members)
    return [Member(**row) for row in rows]

@db_wrap
async def update_system_field(conn, system_id: int, field: str, value):
    logger.debug("Updating system field (id={}, {}={})".format(
        system_id, field, value))
    await conn.execute("update systems set {} = $1 where id = $2".format(field), value, system_id)


@db_wrap
async def update_member_field(conn, member_id: int, field: str, value):
    logger.debug("Updating member field (id={}, {}={})".format(
        member_id, field, value))
    await conn.execute("update members set {} = $1 where id = $2".format(field), value, member_id)


@db_wrap
async def get_all_members(conn, system_id: int) -> List[Member]:
    rows = await conn.fetch("select * from members where system = $1", system_id)
    return [Member(**row) for row in rows]

@db_wrap
async def get_members_exceeding(conn, system_id: int, length: int) -> List[Member]:
    rows = await conn.fetch("select * from members where system = $1 and length(name) > $2", system_id, length)
    return [Member(**row) for row in rows]


@db_wrap
async def get_webhook(conn, channel_id: str) -> (str, str):
    row = await conn.fetchrow("select webhook, token from webhooks where channel = $1", int(channel_id))
    return (str(row["webhook"]), row["token"]) if row else None


@db_wrap
async def add_webhook(conn, channel_id: str, webhook_id: str, webhook_token: str):
    logger.debug("Adding new webhook (channel={}, webhook={}, token={})".format(
        channel_id, webhook_id, webhook_token))
    await conn.execute("insert into webhooks (channel, webhook, token) values ($1, $2, $3)", int(channel_id), int(webhook_id), webhook_token)

@db_wrap
async def delete_webhook(conn, channel_id: str):
    await conn.execute("delete from webhooks where channel = $1", int(channel_id))

@db_wrap
async def add_message(conn, message_id: str, channel_id: str, member_id: int, sender_id: str, content: str):
    logger.debug("Adding new message (id={}, channel={}, member={}, sender={})".format(
        message_id, channel_id, member_id, sender_id))
    await conn.execute("insert into messages (mid, channel, member, sender, content) values ($1, $2, $3, $4, $5)", int(message_id), int(channel_id), member_id, int(sender_id), content)

class ProxyMember(namedtuple("ProxyMember", ["id", "hid", "prefix", "suffix", "color", "name", "avatar_url", "tag", "system_name", "system_hid"])):
    id: int
    hid: str
    prefix: str
    suffix: str
    color: str
    name: str
    avatar_url: str
    tag: str
    system_name: str
    system_hid: str

@db_wrap
async def get_members_by_account(conn, account_id: str) -> List[ProxyMember]:
    # Returns a "chimera" object
    rows = await conn.fetch("""select
            members.id, members.hid, members.prefix, members.suffix, members.color, members.name, members.avatar_url,
            systems.tag, systems.name as system_name, systems.hid as system_hid
        from
            systems, members, accounts
        where
            accounts.uid = $1
            and systems.id = accounts.system
            and members.system = systems.id""", int(account_id))
    return [ProxyMember(**row) for row in rows]

class MessageInfo(namedtuple("MemberInfo", ["mid", "channel", "member", "content", "sender", "name", "hid", "avatar_url", "system_name", "system_hid"])):
    mid: int
    channel: int
    member: int
    content: str
    sender: int
    name: str
    hid: str
    avatar_url: str
    system_name: str
    system_hid: str

    def to_json(self):
        return {
            "id": str(self.mid),
            "channel": str(self.channel),
            "member": self.hid,
            "system": self.system_hid,
            "message_sender": str(self.sender),
            "content": self.content,
            "timestamp": snowflake_time(self.mid).isoformat()
        }

@db_wrap
async def get_message_by_sender_and_id(conn, message_id: str, sender_id: str) -> MessageInfo:
    row = await conn.fetchrow("""select
        messages.*,
        members.name, members.hid, members.avatar_url,
        systems.name as system_name, systems.hid as system_hid
    from
        messages, members, systems
    where
        messages.member = members.id
        and members.system = systems.id
        and mid = $1
        and sender = $2""", int(message_id), int(sender_id))
    return MessageInfo(**row) if row else None


@db_wrap
async def get_message(conn, message_id: str) -> MessageInfo:
    row = await conn.fetchrow("""select
        messages.*,
        members.name, members.hid, members.avatar_url,
        systems.name as system_name, systems.hid as system_hid
    from
        messages, members, systems
    where
        messages.member = members.id
        and members.system = systems.id
        and mid = $1""", int(message_id))
    return MessageInfo(**row) if row else None


@db_wrap
async def delete_message(conn, message_id: str):
    logger.debug("Deleting message (id={})".format(message_id))
    await conn.execute("delete from messages where mid = $1", int(message_id))

@db_wrap
async def front_history(conn, system_id: int, count: int):
    return await conn.fetch("""select
        switches.*,
        array(
            select member from switch_members
            where switch_members.switch = switches.id
            order by switch_members.id asc
        ) as members
    from switches
    where switches.system = $1
    order by switches.timestamp desc
    limit $2""", system_id, count)

@db_wrap
async def add_switch(conn, system_id: int):
    logger.debug("Adding switch (system={})".format(system_id))
    res = await conn.fetchrow("insert into switches (system) values ($1) returning *", system_id)
    return res["id"]

@db_wrap
async def move_last_switch(conn, system_id: int, switch_id: int, new_time: datetime):
    logger.debug("Moving latest switch (system={}, id={}, new_time={})".format(system_id, switch_id, new_time))
    await conn.execute("update switches set timestamp = $1 where system = $2 and id = $3", new_time, system_id, switch_id)

@db_wrap
async def add_switch_member(conn, switch_id: int, member_id: int):
    logger.debug("Adding switch member (switch={}, member={})".format(switch_id, member_id))
    await conn.execute("insert into switch_members (switch, member) values ($1, $2)", switch_id, member_id)

@db_wrap
async def get_server_info(conn, server_id: str):
    return await conn.fetchrow("select * from servers where id = $1", int(server_id))

@db_wrap
async def update_server(conn, server_id: str, logging_channel_id: str):
    logging_channel_id = int(logging_channel_id) if logging_channel_id else None
    logger.debug("Updating server settings (id={}, log_channel={})".format(server_id, logging_channel_id))
    await conn.execute("insert into servers (id, log_channel) values ($1, $2) on conflict (id) do update set log_channel = $2", int(server_id), logging_channel_id)

@db_wrap
async def member_count(conn) -> int:
    return await conn.fetchval("select count(*) from members")

@db_wrap
async def system_count(conn) -> int:
    return await conn.fetchval("select count(*) from systems")

@db_wrap
async def message_count(conn) -> int:
    return await conn.fetchval("select count(*) from messages")

@db_wrap
async def account_count(conn) -> int:
    return await conn.fetchval("select count(*) from accounts")

async def create_tables(conn):
    await conn.execute("""create table if not exists systems (
        id          serial primary key,
        hid         char(5) unique not null,
        name        text,
        description text,
        tag         text,
        avatar_url  text,
        created     timestamp not null default (current_timestamp at time zone 'utc')
    )""")
    await conn.execute("""create table if not exists members (
        id          serial primary key,
        hid         char(5) unique not null,
        system      serial not null references systems(id) on delete cascade,
        color       char(6),
        avatar_url  text,
        name        text not null,
        birthday    date,
        pronouns    text,
        description text,
        prefix      text,
        suffix      text,
        created     timestamp not null default (current_timestamp at time zone 'utc')
    )""")
    await conn.execute("""create table if not exists accounts (
        uid         bigint primary key,
        system      serial not null references systems(id) on delete cascade
    )""")
    await conn.execute("""create table if not exists messages (
        mid         bigint primary key,
        channel     bigint not null,
        member      serial not null references members(id) on delete cascade,
        content     text not null,
        sender      bigint not null
    )""")
    await conn.execute("""create table if not exists switches (
        id          serial primary key,
        system      serial not null references systems(id) on delete cascade,
        timestamp   timestamp not null default (current_timestamp at time zone 'utc')
    )""")
    await conn.execute("""create table if not exists switch_members (
        id          serial primary key,
        switch      serial not null references switches(id) on delete cascade,
        member      serial not null references members(id) on delete cascade
    )""")
    await conn.execute("""create table if not exists webhooks (
        channel     bigint primary key,
        webhook     bigint not null,
        token       text not null
    )""")
    await conn.execute("""create table if not exists servers (
        id          bigint primary key,
        log_channel bigint
    )""")