from __future__ import annotations

import json
import pprint
import re
from dataclasses import dataclass
from functools import wraps
from typing import Callable, Dict, List, Optional, Tuple

import weechat

from slack.error import SlackRtmError, UncaughtError
from slack.log import print_error
from slack.python_compatibility import format_exception, removeprefix, removesuffix
from slack.shared import shared
from slack.slack_conversation import (
    SlackConversation,
    get_conversation_from_buffer_pointer,
)
from slack.slack_user import name_from_user_info_without_spaces
from slack.slack_workspace import SlackWorkspace
from slack.task import run_async
from slack.util import get_callback_name, with_color
from slack.weechat_config import WeeChatOption, WeeChatOptionTypes

commands: Dict[str, Command] = {}


# def parse_help_docstring(cmd):
#     doc = textwrap.dedent(cmd.__doc__).strip().split("\n", 1)
#     cmd_line = doc[0].split(None, 1)
#     args = "".join(cmd_line[1:])
#     return cmd_line[0], args, doc[1].strip()


def parse_options(args: str):
    regex = re.compile("(?:^| )+-([^ =]+)(?:=([^ ]+))?")
    pos_args = regex.sub("", args)
    options: Dict[str, Optional[str]] = {
        match.group(1): match.group(2) for match in regex.finditer(args)
    }
    return pos_args, options


@dataclass
class Command:
    cmd: str
    top_level: bool
    description: str
    args: str
    args_description: str
    completion: str
    cb: Callable[[str, str], None]


def weechat_command(
    completion: str = "",
    min_args: int = 0,
    split_all_args: bool = False,
    slack_buffer_required: bool = False,
) -> Callable[
    [Callable[[str, List[str], Dict[str, Optional[str]]], None]],
    Callable[[str, str], None],
]:
    def decorator(
        f: Callable[[str, List[str], Dict[str, Optional[str]]], None]
    ) -> Callable[[str, str], None]:
        cmd = removeprefix(f.__name__, "command_").replace("_", " ")
        top_level = " " not in cmd

        @wraps(f)
        def wrapper(buffer: str, args: str):
            pos_args, options = parse_options(args)
            maxsplit = -1 if split_all_args else 0 if min_args == 0 else min_args - 1
            split_args = pos_args.split(" ", maxsplit)
            if min_args and not pos_args or len(split_args) < min_args:
                print_error(
                    f'Too few arguments for command "/{cmd}" (help on command: /help {cmd})'
                )
                return
            return f(buffer, split_args, options)

        commands[cmd] = Command(cmd, top_level, "", "", "", completion, wrapper)

        return wrapper

    return decorator


def list_workspaces(workspace_name: Optional[str] = None, detailed_list: bool = False):
    weechat.prnt("", "")
    weechat.prnt("", "All workspaces:")
    for workspace in shared.workspaces.values():
        display_workspace(workspace, detailed_list)


def display_workspace(workspace: SlackWorkspace, detailed_list: bool):
    if workspace.is_connected:
        weechat.prnt(
            "",
            f" * "
            f"{with_color('chat_server', workspace.name)} "
            f"{with_color('chat_delimiters', '[')}"
            f"connected"
            f"{with_color('chat_delimiters', ']')}"
            f", nick: {workspace.my_user.nick()}"
            f", 0 channel(s), 0 pv",
        )
    else:
        weechat.prnt("", f"   {with_color('chat_server', workspace.name)}")


@weechat_command()
def command_slack(buffer: str, args: List[str], options: Dict[str, Optional[str]]):
    """
    slack command
    """
    print("ran slack")


def workspace_connect(workspace: SlackWorkspace):
    if workspace.is_connected:
        print_error(f'already connected to workspace "{workspace.name}"!')
        return
    elif workspace.is_connecting:
        print_error(f'already connecting to workspace "{workspace.name}"!')
        return
    run_async(workspace.connect())


@weechat_command("%(slack_workspaces)|-all", split_all_args=True)
def command_slack_connect(
    buffer: str, args: List[str], options: Dict[str, Optional[str]]
):
    if options.get("all", False) is None:
        for workspace in shared.workspaces.values():
            run_async(workspace.connect())
    elif args[0]:
        for arg in args:
            workspace = shared.workspaces.get(arg)
            if workspace is None:
                print_error(f'workspace "{arg}" not found')
            else:
                workspace_connect(workspace)
    else:
        conversation = get_conversation_from_buffer_pointer(buffer)
        if conversation:
            workspace_connect(conversation.workspace)


def workspace_disconnect(workspace: SlackWorkspace):
    if not workspace.is_connected and not workspace.is_connecting:
        print_error(f'not connected to workspace "{workspace.name}"!')
        return
    workspace.disconnect()


@weechat_command("%(slack_workspaces)|-all", split_all_args=True)
def command_slack_disconnect(
    buffer: str, args: List[str], options: Dict[str, Optional[str]]
):
    if options.get("all", False) is None:
        for workspace in shared.workspaces.values():
            workspace.disconnect()
    elif args[0]:
        for arg in args:
            workspace = shared.workspaces.get(arg)
            if workspace is None:
                print_error(f'workspace "{arg}" not found')
            else:
                workspace_disconnect(workspace)
    else:
        conversation = get_conversation_from_buffer_pointer(buffer)
        if conversation:
            workspace_disconnect(conversation.workspace)


@weechat_command()
def command_slack_workspace(
    buffer: str, args: List[str], options: Dict[str, Optional[str]]
):
    list_workspaces()


@weechat_command("%(slack_workspaces)")
def command_slack_workspace_list(
    buffer: str, args: List[str], options: Dict[str, Optional[str]]
):
    list_workspaces()


@weechat_command("%(slack_workspaces)")
def command_slack_workspace_listfull(
    buffer: str, args: List[str], options: Dict[str, Optional[str]]
):
    list_workspaces(detailed_list=True)


@weechat_command(min_args=1)
def command_slack_workspace_add(
    buffer: str, args: List[str], options: Dict[str, Optional[str]]
):
    name = args[0]
    if name in shared.workspaces:
        print_error(f'workspace "{name}" already exists, can\'t add it!')
        return

    shared.workspaces[name] = SlackWorkspace(name)

    for option_name, option_value in options.items():
        if hasattr(shared.workspaces[name].config, option_name):
            config_option: WeeChatOption[WeeChatOptionTypes] = getattr(
                shared.workspaces[name].config, option_name
            )
            value = "on" if option_value is None else option_value
            config_option.value_set_as_str(value)

    weechat.prnt(
        "",
        f"{shared.SCRIPT_NAME}: workspace added: {weechat.color('chat_server')}{name}{weechat.color('reset')}",
    )


@weechat_command("%(slack_workspaces)", min_args=2)
def command_slack_workspace_rename(
    buffer: str, args: List[str], options: Dict[str, Optional[str]]
):
    old_name = args[0]
    new_name = args[1]
    workspace = shared.workspaces.get(old_name)
    if not workspace:
        print_error(f'workspace "{old_name}" not found for "workspace rename" command')
        return
    workspace.name = new_name
    shared.workspaces[new_name] = workspace
    del shared.workspaces[old_name]
    weechat.prnt(
        "",
        f"server {with_color('chat_server', old_name)} has been renamed to {with_color('chat_server', new_name)}",
    )
    # TODO: Rename buffers and config


@weechat_command("%(slack_workspaces)", min_args=1)
def command_slack_workspace_del(
    buffer: str, args: List[str], options: Dict[str, Optional[str]]
):
    name = args[0]
    workspace = shared.workspaces.get(name)
    if not workspace:
        print_error(f'workspace "{name}" not found for "workspace del" command')
        return
    if workspace.is_connected:
        print_error(
            f'you can not delete server "{name}" because you are connected to it. Try "/slack disconnect {name}" first.'
        )
        return
    # TODO: Delete config
    del shared.workspaces[name]
    weechat.prnt(
        "",
        f"server {with_color('chat_server', name)} has been deleted",
    )


def print_uncaught_error(
    error: UncaughtError, detailed: bool, options: Dict[str, Optional[str]]
):
    weechat.prnt("", f"  {error.id} ({error.time}): {error.exception}")
    if detailed:
        for line in format_exception(error.exception):
            weechat.prnt("", f"  {line}")
    data = options.get("data", False) is None
    if data:
        if isinstance(error.exception, SlackRtmError):
            weechat.prnt("", f"  data: {json.dumps(error.exception.message_json)}")
        else:
            print_error("This error does not have any data")


@weechat_command("tasks|buffer|errors|error", split_all_args=True)
def command_slack_debug(
    buffer: str, args: List[str], options: Dict[str, Optional[str]]
):
    if args[0] == "tasks":
        weechat.prnt("", "Active tasks:")
        weechat.prnt("", pprint.pformat(shared.active_tasks))
        weechat.prnt("", "Active futures:")
        weechat.prnt("", pprint.pformat(shared.active_futures))
    elif args[0] == "buffer":
        conversation = get_conversation_from_buffer_pointer(buffer)
        if conversation:
            weechat.prnt("", f"Conversation id: {conversation.id}")
    elif args[0] == "errors":
        num_arg = int(args[1]) if len(args) > 1 and args[1].isdecimal() else 5
        num = min(num_arg, len(shared.uncaught_errors))
        weechat.prnt("", f"Last {num} errors:")
        for error in shared.uncaught_errors[-num:]:
            print_uncaught_error(error, False, options)
    elif args[0] == "error":
        if len(args) > 1:
            if args[1].isdecimal() and args[1] != "0":
                num = int(args[1])
                if num > len(shared.uncaught_errors):
                    print_error(
                        f"Only {len(shared.uncaught_errors)} error(s) have occurred"
                    )
                    return
                error = shared.uncaught_errors[-num]
            else:
                errors = [e for e in shared.uncaught_errors if e.id == args[1]]
                if not errors:
                    print_error(f"Error {args[1]} not found")
                    return
                error = errors[0]
            weechat.prnt("", f"Error {error.id}:")
        elif not shared.uncaught_errors:
            weechat.prnt("", "No errors have occurred")
            return
        else:
            error = shared.uncaught_errors[-1]
            weechat.prnt("", "Last error:")
        print_uncaught_error(error, True, options)


def completion_slack_workspaces_cb(
    data: str, completion_item: str, buffer: str, completion: str
) -> int:
    for workspace_name in shared.workspaces:
        weechat.completion_list_add(
            completion, workspace_name, 0, weechat.WEECHAT_LIST_POS_SORT
        )
    return weechat.WEECHAT_RC_OK


def find_command(start_cmd: str, args: str) -> Optional[Tuple[Command, str]]:
    args_parts = re.finditer("[^ ]+", args)
    cmd = start_cmd
    cmd_args_startpos = 0

    for part in args_parts:
        next_cmd = f"{cmd} {part.group(0)}"
        if next_cmd not in commands:
            cmd_args_startpos = part.start(0)
            break
        cmd = next_cmd
    else:
        cmd_args_startpos = len(args)

    cmd_args = args[cmd_args_startpos:]
    if cmd in commands:
        return commands[cmd], cmd_args
    return None


def command_cb(data: str, buffer: str, args: str) -> int:
    found_cmd_with_args = find_command(data, args)
    if found_cmd_with_args:
        command = found_cmd_with_args[0]
        cmd_args = found_cmd_with_args[1]
        command.cb(buffer, cmd_args)
    else:
        print_error(
            f'Error with command "/{data} {args}" (help on command: /help {data})'
        )

    return weechat.WEECHAT_RC_OK


def completion_list_add(completion: str, word: str, nick_completion: int, where: str):
    if word == "%(slack_workspaces)":
        completion_slack_workspaces_cb("", "slack_workspaces", "", completion)
    else:
        # TODO: Consider WeeChat verison support, in < 2.9 one must use hook_completion_list_add
        weechat.completion_list_add(completion, word, nick_completion, where)


def completion_slack_workspace_commands_cb(
    data: str, completion_item: str, buffer: str, completion: str
) -> int:
    # TODO: Consider WeeChat verison support, in < 2.9 one must use hook_completion_get_string
    base_command = weechat.completion_get_string(completion, "base_command")
    base_word = weechat.completion_get_string(completion, "base_word")
    args = weechat.completion_get_string(completion, "args")
    args_without_base_word = removesuffix(args, base_word)

    found_cmd_with_args = find_command(base_command, args_without_base_word)
    if found_cmd_with_args:
        command = found_cmd_with_args[0]
        matching_cmds = [
            removeprefix(cmd, command.cmd).lstrip()
            for cmd in commands
            if cmd.startswith(command.cmd) and cmd != command.cmd
        ]
        if len(matching_cmds) > 1:
            for match in matching_cmds:
                cmd_arg = match.split(" ")
                completion_list_add(
                    completion, cmd_arg[0], 0, weechat.WEECHAT_LIST_POS_SORT
                )
        else:
            for arg in command.completion.split("|"):
                completion_list_add(completion, arg, 0, weechat.WEECHAT_LIST_POS_SORT)

    return weechat.WEECHAT_RC_OK


def completion_irc_channels_cb(
    data: str, completion_item: str, buffer: str, completion: str
) -> int:
    if weechat.buffer_get_string(buffer, "full_name").startswith("core."):
        weechat.completion_list_add(
            completion, "#asd", 0, weechat.WEECHAT_LIST_POS_SORT
        )
    return weechat.WEECHAT_RC_OK


def complete_input(conversation: SlackConversation, query: str):
    if (
        conversation.completion_context == "ACTIVE_COMPLETION"
        and conversation.completion_values
    ):
        input_value = weechat.buffer_get_string(conversation.buffer_pointer, "input")
        input_pos = weechat.buffer_get_integer(conversation.buffer_pointer, "input_pos")
        result = conversation.completion_values[conversation.completion_index]
        input_before = removesuffix(input_value[:input_pos], query)
        input_after = input_value[input_pos:]
        new_input = input_before + result + input_after
        new_pos = input_pos - len(query) + len(result)

        with conversation.completing():
            weechat.buffer_set(conversation.buffer_pointer, "input", new_input)
            weechat.buffer_set(conversation.buffer_pointer, "input_pos", str(new_pos))


def nick_suffix():
    return weechat.config_string(
        weechat.config_get("weechat.completion.nick_completer")
    )


async def complete_user_next(
    conversation: SlackConversation, query: str, is_first_word: bool
):
    if conversation.completion_context == "NO_COMPLETION":
        conversation.completion_context = "PENDING_COMPLETION"
        search = await conversation.workspace.api.fetch_users_search(query)
        if conversation.completion_context != "PENDING_COMPLETION":
            return
        conversation.completion_context = "ACTIVE_COMPLETION"
        suffix = nick_suffix() if is_first_word else " "
        conversation.completion_values = [
            name_from_user_info_without_spaces(conversation.workspace, user) + suffix
            for user in search["results"]
        ]
        conversation.completion_index = 0
    elif conversation.completion_context == "ACTIVE_COMPLETION":
        conversation.completion_index += 1
        if conversation.completion_index >= len(conversation.completion_values):
            conversation.completion_index = 0

    complete_input(conversation, query)


def complete_previous(conversation: SlackConversation, query: str) -> int:
    if conversation.completion_context == "ACTIVE_COMPLETION":
        conversation.completion_index -= 1
        if conversation.completion_index < 0:
            conversation.completion_index = len(conversation.completion_values) - 1
        complete_input(conversation, query)
        return weechat.WEECHAT_RC_OK_EAT
    return weechat.WEECHAT_RC_OK


def input_complete_cb(data: str, buffer: str, command: str) -> int:
    conversation = get_conversation_from_buffer_pointer(buffer)
    if conversation:
        input_value = weechat.buffer_get_string(buffer, "input")
        input_pos = weechat.buffer_get_integer(buffer, "input_pos")
        input_before_cursor = input_value[:input_pos]

        word_index = (
            -2 if conversation.completion_context == "ACTIVE_COMPLETION" else -1
        )
        word_until_cursor = " ".join(input_before_cursor.split(" ")[word_index:])

        if word_until_cursor.startswith("@"):
            query = word_until_cursor[1:]
            is_first_word = word_until_cursor == input_before_cursor

            if command == "/input complete_next":
                run_async(complete_user_next(conversation, query, is_first_word))
                return weechat.WEECHAT_RC_OK_EAT
            else:
                return complete_previous(conversation, query)
    return weechat.WEECHAT_RC_OK


def register_commands():
    weechat.hook_command_run(
        "/input complete_*", get_callback_name(input_complete_cb), ""
    )
    weechat.hook_completion(
        "slack_workspaces",
        "Slack workspaces (internal names)",
        get_callback_name(completion_slack_workspaces_cb),
        "",
    )
    weechat.hook_completion(
        "slack_commands",
        "completions for Slack commands",
        get_callback_name(completion_slack_workspace_commands_cb),
        "",
    )
    weechat.hook_completion(
        "irc_channels",
        "channels on all Slack workspaces",
        get_callback_name(completion_irc_channels_cb),
        "",
    )

    for cmd, command in commands.items():
        if command.top_level:
            weechat.hook_command(
                command.cmd,
                command.description,
                command.args,
                command.args_description,
                "%(slack_commands)|%*",
                get_callback_name(command_cb),
                cmd,
            )