import re
import random
from datetime import datetime, timedelta
from inspect import Parameter
from collections import OrderedDict
from typing import Iterable, List, Mapping, Tuple, Dict, Set
from urllib.parse import quote_plus

import discord
from fuzzywuzzy import process

from redbot.core import Config, checks, commands
from redbot.core.i18n import Translator, cog_i18n
from redbot.core.utils import menus
from redbot.core.utils.chat_formatting import box, pagify, escape, humanize_list
from redbot.core.utils.predicates import MessagePredicate

_ = Translator("CustomCommands", __file__)


class CCError(Exception):
    pass


class AlreadyExists(CCError):
    pass


class ArgParseError(CCError):
    pass


class NotFound(CCError):
    pass


class OnCooldown(CCError):
    pass


class CommandObj:
    def __init__(self, **kwargs):
        config = kwargs.get("config")
        self.bot = kwargs.get("bot")
        self.db = config.guild

    @staticmethod
    async def get_commands(config) -> dict:
        _commands = await config.commands()
        return {k: v for k, v in _commands.items() if _commands[k]}

    async def get_responses(self, ctx):
        intro = _(
            "Welcome to the interactive random {cc} maker!\n"
            "Every message you send will be added as one of the random "
            "responses to choose from once this {cc} is "
            "triggered. To exit this interactive menu, type `{quit}`"
        ).format(cc="customcommand", quit="exit()")
        await ctx.send(intro)

        responses = []
        args = None
        while True:
            await ctx.send(_("Add a random response:"))
            msg = await self.bot.wait_for("message", check=MessagePredicate.same_context(ctx))

            if msg.content.lower() == "exit()":
                break
            else:
                try:
                    this_args = ctx.cog.prepare_args(msg.content)
                except ArgParseError as e:
                    await ctx.send(e.args[0])
                    continue
                if args and args != this_args:
                    await ctx.send(_("Random responses must take the same arguments!"))
                    continue
                args = args or this_args
                responses.append(msg.content)
        return responses

    @staticmethod
    def get_now() -> str:
        # Get current time as a string, for 'created_at' and 'edited_at' fields
        # in the ccinfo dict
        return "{:%d/%m/%Y %H:%M:%S}".format(datetime.utcnow())

    async def get(self, message: discord.Message, command: str) -> Tuple[str, Dict]:
        if not command:
            raise NotFound()
        ccinfo = await self.db(message.guild).commands.get_raw(command, default=None)
        if not ccinfo:
            raise NotFound()
        else:
            return ccinfo["response"], ccinfo.get("cooldowns", {})

    async def get_full(self, message: discord.Message, command: str) -> Dict:
        ccinfo = await self.db(message.guild).commands.get_raw(command, default=None)
        if ccinfo:
            return ccinfo
        else:
            raise NotFound()

    async def create(self, ctx: commands.Context, command: str, *, response):
        """Create a custom command"""
        # Check if this command is already registered as a customcommand
        if await self.db(ctx.guild).commands.get_raw(command, default=None):
            raise AlreadyExists()
        # test to raise
        ctx.cog.prepare_args(response if isinstance(response, str) else response[0])
        author = ctx.message.author
        ccinfo = {
            "author": {"id": author.id, "name": str(author)},
            "command": command,
            "cooldowns": {},
            "created_at": self.get_now(),
            "editors": [],
            "response": response,
        }
        await self.db(ctx.guild).commands.set_raw(command, value=ccinfo)

    async def edit(
        self,
        ctx: commands.Context,
        command: str,
        *,
        response=None,
        cooldowns: Mapping[str, int] = None,
        ask_for: bool = True,
    ):
        """Edit an already existing custom command"""
        ccinfo = await self.db(ctx.guild).commands.get_raw(command, default=None)

        # Check if this command is registered
        if not ccinfo:
            raise NotFound()

        author = ctx.message.author

        if ask_for and not response:
            await ctx.send(_("Do you want to create a 'randomized' custom command? (y/n)"))

            pred = MessagePredicate.yes_or_no(ctx)
            try:
                await self.bot.wait_for("message", check=pred, timeout=30)
            except TimeoutError:
                await ctx.send(_("Response timed out, please try again later."))
                return
            if pred.result is True:
                response = await self.get_responses(ctx=ctx)
            else:
                await ctx.send(_("What response do you want?"))
                try:
                    resp = await self.bot.wait_for(
                        "message", check=MessagePredicate.same_context(ctx), timeout=180
                    )
                except TimeoutError:
                    await ctx.send(_("Response timed out, please try again later."))
                    return
                response = resp.content

        if response:
            # test to raise
            ctx.cog.prepare_args(response if isinstance(response, str) else response[0])
            ccinfo["response"] = response

        if cooldowns:
            ccinfo.setdefault("cooldowns", {}).update(cooldowns)
            for key, value in ccinfo["cooldowns"].copy().items():
                if value <= 0:
                    del ccinfo["cooldowns"][key]

        if author.id not in ccinfo["editors"]:
            # Add the person who invoked the `edit` coroutine to the list of
            # editors, if the person is not yet in there
            ccinfo["editors"].append(author.id)

        ccinfo["edited_at"] = self.get_now()

        await self.db(ctx.guild).commands.set_raw(command, value=ccinfo)

    async def delete(self, ctx: commands.Context, command: str):
        """Delete an already exisiting custom command"""
        # Check if this command is registered
        if not await self.db(ctx.guild).commands.get_raw(command, default=None):
            raise NotFound()
        await self.db(ctx.guild).commands.set_raw(command, value=None)


@cog_i18n(_)
class CustomCommands(commands.Cog):
    """Creates commands used to display text."""

    def __init__(self, bot):
        super().__init__()
        self.bot = bot
        self.key = 414589031223512
        self.config = Config.get_conf(self, self.key)
        self.config.register_guild(commands={})
        self.commandobj = CommandObj(config=self.config, bot=self.bot)
        self.cooldowns = {}

    @commands.group(aliases=["cc"])
    @commands.guild_only()
    async def customcom(self, ctx: commands.Context):
        """Custom commands management."""
        pass

    @customcom.command(name="raw")
    async def cc_raw(self, ctx: commands.Context, command: str.lower):
        """Get the raw response of a custom command, to get the proper markdown.
        
        This is helpful for copy and pasting."""
        commands = await self.config.guild(ctx.guild).commands()
        if command not in commands:
            return await ctx.send("That command doesn't exist.")
        command = commands[command]
        if isinstance(command["response"], str):
            raw = discord.utils.escape_markdown(command["response"])
            if len(raw) > 2000:
                raw = f"{raw[:1997]}..."
            await ctx.send(raw)
        else:
            msglist = []
            if await ctx.embed_requested():
                colour = await ctx.embed_colour()
                for number, response in enumerate(command["response"], start=1):
                    raw = discord.utils.escape_markdown(response)
                    if len(raw) > 2048:
                        raw = f"{raw[:2045]}..."
                    embed = discord.Embed(
                        title=_("Response #{num}/{total}").format(
                            num=number, total=len(command["response"])
                        ),
                        description=raw,
                        colour=colour,
                    )
                    msglist.append(embed)
            else:
                for number, response in enumerate(command["response"], start=1):
                    raw = discord.utils.escape_markdown(response)
                    msg = _("Response #{num}/{total}:\n{raw}").format(
                        num=number, total=len(command["response"]), raw=raw
                    )
                    if len(msg) > 2000:
                        msg = f"{msg[:1997]}..."
                    msglist.append(msg)
            await menus.menu(ctx, msglist, menus.DEFAULT_CONTROLS)

    @customcom.command(name="search")
    @commands.guild_only()
    async def cc_search(self, ctx: commands.Context, *, query):
        """Searches through custom commands, according to the query."""
        cc_commands = await CommandObj.get_commands(self.config.guild(ctx.guild))
        extracted = process.extract(query, list(cc_commands.keys()))
        accepted = []
        for entry in extracted:
            if entry[1] > 60:
                # Match was decently strong
                accepted.append((entry[0], cc_commands[entry[0]]))
            else:
                # Match wasn't strong enough
                pass
        if len(accepted) == 0:
            return await ctx.send(_("No close matches were found."))
        results = self.prepare_command_list(ctx, accepted)
        if await ctx.embed_requested():
            content = " \n".join(map("**{0[0]}** {0[1]}".format, results))
            embed = discord.Embed(
                title=_("Search results"), description=content, colour=await ctx.embed_colour()
            )
            await ctx.send(embed=embed)
        else:
            content = "\n".join(map("{0[0]:<12} : {0[1]}".format, results))
            await ctx.send(_("The following matches have been found:") + box(content))

    @customcom.group(name="create", aliases=["add"], invoke_without_command=True)
    @checks.mod_or_permissions(administrator=True)
    async def cc_create(self, ctx: commands.Context, command: str.lower, *, text: str):
        """Create custom commands.

        If a type is not specified, a simple CC will be created.
        CCs can be enhanced with arguments, see the guide
        [here](https://docs.discord.red/en/stable/cog_customcom.html).
        """
        await ctx.invoke(self.cc_create_simple, command=command, text=text)

    @cc_create.command(name="random")
    @checks.mod_or_permissions(administrator=True)
    async def cc_create_random(self, ctx: commands.Context, command: str.lower):
        """Create a CC where it will randomly choose a response!

        Note: This command is interactive.
        """
        if any(char.isspace() for char in command):
            # Haha, nice try
            await ctx.send(_("Custom command names cannot have spaces in them."))
            return
        if command in (*self.bot.all_commands, *commands.RESERVED_COMMAND_NAMES):
            await ctx.send(_("There already exists a bot command with the same name."))
            return
        responses = await self.commandobj.get_responses(ctx=ctx)
        if not responses:
            await ctx.send(_("Custom command process cancelled."))
            return
        try:
            await self.commandobj.create(ctx=ctx, command=command, response=responses)
            await ctx.send(_("Custom command successfully added."))
        except AlreadyExists:
            await ctx.send(
                _("This command already exists. Use `{command}` to edit it.").format(
                    command=f"{ctx.clean_prefix}customcom edit"
                )
            )

    @cc_create.command(name="simple")
    @checks.mod_or_permissions(administrator=True)
    async def cc_create_simple(self, ctx, command: str.lower, *, text: str):
        """Add a simple custom command.

        Example:
        - `[p]customcom create simple yourcommand Text you want`
        """
        if any(char.isspace() for char in command):
            # Haha, nice try
            await ctx.send(_("Custom command names cannot have spaces in them."))
            return
        if command in (*self.bot.all_commands, *commands.RESERVED_COMMAND_NAMES):
            await ctx.send(_("There already exists a bot command with the same name."))
            return
        try:
            await self.commandobj.create(ctx=ctx, command=command, response=text)
            await ctx.send(_("Custom command successfully added."))
        except AlreadyExists:
            await ctx.send(
                _("This command already exists. Use `{command}` to edit it.").format(
                    command=f"{ctx.clean_prefix}customcom edit"
                )
            )
        except ArgParseError as e:
            await ctx.send(e.args[0])

    @customcom.command(name="cooldown")
    @checks.mod_or_permissions(administrator=True)
    async def cc_cooldown(
        self, ctx, command: str.lower, cooldown: int = None, *, per: str.lower = "member"
    ):
        """Set, edit, or view the cooldown for a custom command.

        You may set cooldowns per member, channel, or guild. Multiple
        cooldowns may be set. All cooldowns must be cooled to call the
        custom command.

        Example:
        - `[p]customcom cooldown yourcommand 30`
        """
        if cooldown is None:
            try:
                cooldowns = (await self.commandobj.get(ctx.message, command))[1]
            except NotFound:
                return await ctx.send(_("That command doesn't exist."))
            if cooldowns:
                cooldown = []
                for per, rate in cooldowns.items():
                    cooldown.append(
                        _("A {} may call this command every {} seconds").format(per, rate)
                    )
                return await ctx.send("\n".join(cooldown))
            else:
                return await ctx.send(_("This command has no cooldown."))
        per = {"server": "guild", "user": "member"}.get(per, per)
        allowed = ("guild", "member", "channel")
        if per not in allowed:
            return await ctx.send(_("{} must be one of {}").format("per", ", ".join(allowed)))
        cooldown = {per: cooldown}
        try:
            await self.commandobj.edit(ctx=ctx, command=command, cooldowns=cooldown, ask_for=False)
            await ctx.send(_("Custom command cooldown successfully edited."))
        except NotFound:
            await ctx.send(
                _("That command doesn't exist. Use `{command}` to add it.").format(
                    command=f"{ctx.clean_prefix}customcom create"
                )
            )

    @customcom.command(name="delete", aliases=["del", "remove"])
    @checks.mod_or_permissions(administrator=True)
    async def cc_delete(self, ctx, command: str.lower):
        """Delete a custom command.

        Example:
        - `[p]customcom delete yourcommand`
        """
        try:
            await self.commandobj.delete(ctx=ctx, command=command)
            await ctx.send(_("Custom command successfully deleted."))
        except NotFound:
            await ctx.send(_("That command doesn't exist."))

    @customcom.command(name="edit")
    @checks.mod_or_permissions(administrator=True)
    async def cc_edit(self, ctx, command: str.lower, *, text: str = None):
        """Edit a custom command.

        Example:
        - `[p]customcom edit yourcommand Text you want`
        """
        try:
            await self.commandobj.edit(ctx=ctx, command=command, response=text)
            await ctx.send(_("Custom command successfully edited."))
        except NotFound:
            await ctx.send(
                _("That command doesn't exist. Use `{command}` to add it.").format(
                    command=f"{ctx.clean_prefix}customcom create"
                )
            )
        except ArgParseError as e:
            await ctx.send(e.args[0])

    @customcom.command(name="list")
    @checks.bot_has_permissions(add_reactions=True)
    async def cc_list(self, ctx: commands.Context):
        """List all available custom commands.

        The list displays a preview of each command's response, with
        markdown escaped and newlines replaced with spaces.
        """
        cc_dict = await CommandObj.get_commands(self.config.guild(ctx.guild))

        if not cc_dict:
            await ctx.send(
                _(
                    "There are no custom commands in this server."
                    " Use `{command}` to start adding some."
                ).format(command=f"{ctx.clean_prefix}customcom create")
            )
            return

        results = self.prepare_command_list(ctx, sorted(cc_dict.items(), key=lambda t: t[0]))

        if await ctx.embed_requested():
            # We need a space before the newline incase the CC preview ends in link (GH-2295)
            content = " \n".join(map("**{0[0]}** {0[1]}".format, results))
            pages = list(pagify(content, page_length=1024))
            embed_pages = []
            for idx, page in enumerate(pages, start=1):
                embed = discord.Embed(
                    title=_("Custom Command List"),
                    description=page,
                    colour=await ctx.embed_colour(),
                )
                embed.set_footer(text=_("Page {num}/{total}").format(num=idx, total=len(pages)))
                embed_pages.append(embed)
            await menus.menu(ctx, embed_pages, menus.DEFAULT_CONTROLS)
        else:
            content = "\n".join(map("{0[0]:<12} : {0[1]}".format, results))
            pages = list(map(box, pagify(content, page_length=2000, shorten_by=10)))
            await menus.menu(ctx, pages, menus.DEFAULT_CONTROLS)

    @customcom.command(name="show")
    async def cc_show(self, ctx, command_name: str):
        """Shows a custom command's responses and its settings."""

        try:
            cmd = await self.commandobj.get_full(ctx.message, command_name)
        except NotFound:
            await ctx.send(_("I could not not find that custom command."))
            return

        responses = cmd["response"]

        if isinstance(responses, str):
            responses = [responses]

        author = ctx.guild.get_member(cmd["author"]["id"])
        # If the author is still in the server, show their current name
        if author:
            author = "{} ({})".format(author, cmd["author"]["id"])
        else:
            author = "{} ({})".format(cmd["author"]["name"], cmd["author"]["id"])

        _type = _("Random") if len(responses) > 1 else _("Normal")

        text = _(
            "Command: {command_name}\n"
            "Author: {author}\n"
            "Created: {created_at}\n"
            "Type: {type}\n"
        ).format(
            command_name=command_name, author=author, created_at=cmd["created_at"], type=_type
        )

        cooldowns = cmd["cooldowns"]

        if cooldowns:
            cooldown_text = _("Cooldowns:\n")
            for rate, per in cooldowns.items():
                cooldown_text += _("{num} seconds per {period}\n").format(num=per, period=rate)
            text += cooldown_text

        text += _("Responses:\n")
        responses = ["- " + r for r in responses]
        text += "\n".join(responses)

        for p in pagify(text):
            await ctx.send(box(p, lang="yaml"))

    @commands.Cog.listener()
    async def on_message_without_command(self, message):
        is_private = isinstance(message.channel, discord.abc.PrivateChannel)

        # user_allowed check, will be replaced with self.bot.user_allowed or
        # something similar once it's added
        user_allowed = True

        if len(message.content) < 2 or is_private or not user_allowed or message.author.bot:
            return

        if await self.bot.cog_disabled_in_guild(self, message.guild):
            return

        ctx = await self.bot.get_context(message)

        if ctx.prefix is None:
            return

        try:
            raw_response, cooldowns = await self.commandobj.get(
                message=message, command=ctx.invoked_with
            )
            if isinstance(raw_response, list):
                raw_response = random.choice(raw_response)
            elif isinstance(raw_response, str):
                pass
            else:
                raise NotFound()
            if cooldowns:
                self.test_cooldowns(ctx, ctx.invoked_with, cooldowns)
        except CCError:
            return

        # wrap the command here so it won't register with the bot
        fake_cc = commands.command(name=ctx.invoked_with)(self.cc_callback)
        fake_cc.params = self.prepare_args(raw_response)
        fake_cc.requires.ready_event.set()
        ctx.command = fake_cc

        await self.bot.invoke(ctx)
        if not ctx.command_failed:
            await self.cc_command(*ctx.args, **ctx.kwargs, raw_response=raw_response)

    async def cc_callback(self, *args, **kwargs) -> None:
        """
        Custom command.

        Created via the CustomCom cog. See `[p]customcom` for more details.
        """
        # fake command to take advantage of discord.py's parsing and events
        pass

    async def cc_command(self, ctx, *cc_args, raw_response, **cc_kwargs) -> None:
        cc_args = (*cc_args, *cc_kwargs.values())
        results = re.findall(r"{([^}]+)\}", raw_response)
        for result in results:
            param = self.transform_parameter(result, ctx.message)
            raw_response = raw_response.replace("{" + result + "}", param)
        results = re.findall(r"{((\d+)[^.}]*(\.[^:}]+)?[^}]*)\}", raw_response)
        if results:
            low = min(int(result[1]) for result in results)
            for result in results:
                index = int(result[1]) - low
                arg = self.transform_arg(result[0], result[2], cc_args[index])
                raw_response = raw_response.replace("{" + result[0] + "}", arg)
        await ctx.send(raw_response)

    @staticmethod
    def prepare_args(raw_response) -> Mapping[str, Parameter]:
        args = re.findall(r"{(\d+)[^:}]*(:[^.}]*)?[^}]*\}", raw_response)
        default = [("ctx", Parameter("ctx", Parameter.POSITIONAL_OR_KEYWORD))]
        if not args:
            return OrderedDict(default)
        allowed_builtins = {
            "bool": bool,
            "complex": complex,
            "float": float,
            "frozenset": frozenset,
            "int": int,
            "list": list,
            "set": set,
            "str": str,
            "tuple": tuple,
            "query": quote_plus,
        }
        indices = [int(a[0]) for a in args]
        low = min(indices)
        indices = [a - low for a in indices]
        high = max(indices)
        if high > 9:
            raise ArgParseError(_("Too many arguments!"))
        gaps = set(indices).symmetric_difference(range(high + 1))
        if gaps:
            raise ArgParseError(
                _("Arguments must be sequential. Missing arguments: ")
                + ", ".join(str(i + low) for i in gaps)
            )
        fin = [Parameter("_" + str(i), Parameter.POSITIONAL_OR_KEYWORD) for i in range(high + 1)]
        for arg in args:
            index = int(arg[0]) - low
            anno = arg[1][1:]  # strip initial colon
            if anno.lower().endswith("converter"):
                anno = anno[:-9]
            if not anno or anno.startswith("_"):  # public types only
                name = "{}_{}".format("text", index if index < high else "final")
                fin[index] = fin[index].replace(name=name)
                continue
            # allow type hinting only for discord.py and builtin types
            try:
                anno = getattr(discord, anno)
                # force an AttributeError if there's no discord.py converter
                getattr(commands, anno.__name__ + "Converter")
            except AttributeError:
                anno = allowed_builtins.get(anno.lower(), Parameter.empty)
            if (
                anno is not Parameter.empty
                and fin[index].annotation is not Parameter.empty
                and anno != fin[index].annotation
            ):
                raise ArgParseError(
                    _(
                        'Conflicting colon notation for argument {index}: "{name1}" and "{name2}".'
                    ).format(
                        index=index + low,
                        name1=fin[index].annotation.__name__,
                        name2=anno.__name__,
                    )
                )
            if anno is not Parameter.empty:
                fin[index] = fin[index].replace(annotation=anno)
        # consume rest
        fin[-1] = fin[-1].replace(kind=Parameter.KEYWORD_ONLY)
        # name the parameters for the help text
        for i, param in enumerate(fin):
            anno = param.annotation
            name = "{}_{}".format(
                "text" if anno is Parameter.empty else anno.__name__.lower(),
                i if i < high else "final",
            )
            fin[i] = fin[i].replace(name=name)
        # insert ctx parameter for discord.py parsing
        fin = default + [(p.name, p) for p in fin]
        return OrderedDict(fin)

    def test_cooldowns(self, ctx, command, cooldowns):
        now = datetime.utcnow()
        new_cooldowns = {}
        for per, rate in cooldowns.items():
            if per == "guild":
                key = (command, ctx.guild)
            elif per == "channel":
                key = (command, ctx.guild, ctx.channel)
            elif per == "member":
                key = (command, ctx.guild, ctx.author)
            else:
                raise ValueError(per)
            cooldown = self.cooldowns.get(key)
            if cooldown:
                cooldown += timedelta(seconds=rate)
                if cooldown > now:
                    raise OnCooldown()
            new_cooldowns[key] = now
        # only update cooldowns if the command isn't on cooldown
        self.cooldowns.update(new_cooldowns)

    @classmethod
    def transform_arg(cls, result, attr, obj) -> str:
        attr = attr[1:]  # strip initial dot
        if not attr:
            return cls.maybe_humanize_list(obj)
        raw_result = "{" + result + "}"
        # forbid private members and nested attr lookups
        if attr.startswith("_") or "." in attr:
            return raw_result
        return cls.maybe_humanize_list(getattr(obj, attr, raw_result))

    @staticmethod
    def maybe_humanize_list(thing) -> str:
        if isinstance(thing, str):
            return thing
        try:
            return humanize_list(list(map(str, thing)))
        except TypeError:
            return str(thing)

    @staticmethod
    def transform_parameter(result, message) -> str:
        """
        For security reasons only specific objects are allowed
        Internals are ignored
        """
        raw_result = "{" + result + "}"
        objects = {
            "message": message,
            "author": message.author,
            "channel": message.channel,
            "guild": message.guild,
            "server": message.guild,
        }
        if result in objects:
            return str(objects[result])
        try:
            first, second = result.split(".")
        except ValueError:
            return raw_result
        if first in objects and not second.startswith("_"):
            first = objects[first]
        else:
            return raw_result
        return str(getattr(first, second, raw_result))

    async def get_command_names(self, guild: discord.Guild) -> Set[str]:
        """Get all custom command names in a guild.

        Returns
        --------
        Set[str]
            A set of all custom command names.

        """
        return set(await CommandObj.get_commands(self.config.guild(guild)))

    @staticmethod
    def prepare_command_list(
        ctx: commands.Context, command_list: Iterable[Tuple[str, dict]]
    ) -> List[Tuple[str, str]]:
        results = []
        for command, body in command_list:
            responses = body["response"]
            if isinstance(responses, list):
                result = ", ".join(responses)
            elif isinstance(responses, str):
                result = responses
            else:
                continue
            # Cut preview to 52 characters max
            if len(result) > 52:
                result = result[:49] + "..."
            # Replace newlines with spaces
            result = result.replace("\n", " ")
            # Escape markdown and mass mentions
            result = escape(result, formatting=True, mass_mentions=True)
            results.append((f"{ctx.clean_prefix}{command}", result))
        return results