import discord
import logging
import re
from typing import Tuple, Optional

from pluralkit import db, System, Member
from pluralkit.bot import embeds, utils

logger = logging.getLogger("pluralkit.bot.commands")


def next_arg(arg_string: str) -> Tuple[str, Optional[str]]:
    if arg_string.startswith("\""):
        end_quote = arg_string.find("\"", start=1)
        if end_quote > 0:
            return arg_string[1:end_quote], arg_string[end_quote + 1:].strip()
        else:
            return arg_string[1:], None

    next_space = arg_string.find(" ")
    if next_space >= 0:
        return arg_string[:next_space].strip(), arg_string[next_space:].strip()
    else:
        return arg_string.strip(), None


class CommandResponse:
    def to_embed(self):
        pass


class CommandSuccess(CommandResponse):
    def __init__(self, text):
        self.text = text

    def to_embed(self):
        return embeds.success("\u2705 " + self.text)


class CommandError(Exception, CommandResponse):
    def __init__(self, embed: str, help: Tuple[str, str] = None):
        self.text = embed
        self.help = help

    def to_embed(self):
        return embeds.error("\u274c " + self.text, self.help)


class CommandContext:
    def __init__(self, client: discord.Client, message: discord.Message, conn, args: str):
        self.client = client
        self.message = message
        self.conn = conn
        self.args = args

    async def get_system(self) -> Optional[System]:
        return await db.get_system_by_account(self.conn, self.message.author.id)

    async def ensure_system(self) -> System:
        system = await self.get_system()

        if not system:
            raise CommandError("No system registered to this account. Use `pk;system new` to register one.")

        return system

    def has_next(self) -> bool:
        return bool(self.args)

    def pop_str(self, error: CommandError = None) -> str:
        if not self.args:
            if error:
                raise error
            return None

        popped, self.args = next_arg(self.args)
        return popped

    async def pop_system(self, error: CommandError = None) -> System:
        name = self.pop_str(error)
        system = await utils.get_system_fuzzy(self.conn, self.client, name)

        if not system:
            raise CommandError("Unable to find system '{}'.".format(name))

        return system

    async def pop_member(self, error: CommandError = None, system_only: bool = True) -> Member:
        name = self.pop_str(error)

        if system_only:
            system = await self.ensure_system()
        else:
            system = await self.get_system()

        member = await utils.get_member_fuzzy(self.conn, system.id if system else None, name, system_only)
        if not member:
            raise CommandError("Unable to find member '{}'{}.".format(name, " in your system" if system_only else ""))

        return member

    def remaining(self):
        return self.args

    async def reply(self, content=None, embed=None):
        return await self.client.send_message(self.message.channel, content=content, embed=embed)


import pluralkit.bot.commands.import_commands
import pluralkit.bot.commands.member_commands
import pluralkit.bot.commands.message_commands
import pluralkit.bot.commands.misc_commands
import pluralkit.bot.commands.mod_commands
import pluralkit.bot.commands.switch_commands
import pluralkit.bot.commands.system_commands


async def run_command(ctx: CommandContext, func):
    try:
        result = await func(ctx)
        if isinstance(result, CommandResponse):
            await ctx.reply(embed=result.to_embed())
    except CommandError as e:
        await ctx.reply(embed=e.to_embed())
    except Exception:
        logger.exception("Exception while dispatching command")


async def command_dispatch(client: discord.Client, message: discord.Message, conn) -> bool:
    prefix = "^pk(;|!)"
    commands = [
        (r"system (new|register|create|init)", system_commands.new_system),
        (r"system set", system_commands.system_set),
        (r"system link", system_commands.system_link),
        (r"system unlink", system_commands.system_unlink),
        (r"system fronter", system_commands.system_fronter),
        (r"system fronthistory", system_commands.system_fronthistory),
        (r"system (delete|remove|destroy|erase)", system_commands.system_delete),
        (r"system frontpercent(age)?", system_commands.system_frontpercent),
        (r"system", system_commands.system_info),

        (r"import tupperware", import_commands.import_tupperware),

        (r"member (new|create|add|register)", member_commands.new_member),
        (r"member set", member_commands.member_set),
        (r"member proxy", member_commands.member_proxy),
        (r"member (delete|remove|destroy|erase)", member_commands.member_delete),
        (r"member", member_commands.member_info),

        (r"message", message_commands.message_info),

        (r"mod log", mod_commands.set_log),

        (r"invite", misc_commands.invite_link),
        (r"export", misc_commands.export),

        (r"help", misc_commands.show_help),

        (r"switch move", switch_commands.switch_move),
        (r"switch out", switch_commands.switch_out),
        (r"switch", switch_commands.switch_member)
    ]

    for pattern, func in commands:
        regex = re.compile(prefix + pattern, re.IGNORECASE)

        cmd = message.content
        match = regex.match(cmd)
        if match:
            remaining_string = cmd[match.span()[1]:].strip()

            ctx = CommandContext(
                client=client,
                message=message,
                conn=conn,
                args=remaining_string
            )

            await run_command(ctx, func)
            return True
    return False