#!/bin/env python3

import sys
import openai
import pickle
import os
import datetime

from collections import defaultdict
from dataclasses import dataclass
from typing import Tuple, Optional

import subprocess
import tempfile
import os

from .openai_wrappers import (
    create_chat_completion,
    OpenAIChatResponse,
    OpenAIChatResponseStream,
    FinishReason,
    Role,
    ChatMessage
)

from .openai_wrappers import list_models as openai_list_models

from .argvalidation import (
    Arguments,
    DisplayArguments,
    CompletionArguments,
    DebugArguments,
    MessageSource
)

from .version import VERSION
from .color import (
    get_color_codes,
    surround_ansi_escapes
)

from .chat_colorizer import ChatColorizer
from .prompt import Prompter

###########################
####      UTILS        ####
###########################

def resolve_initial_message(src: MessageSource, interactive=False) -> str:
    msg = None

    if src.message:
        msg = src.message
    elif src.prompt_from_fd:
        with os.fdopen(src.prompt_from_fd, "r") as f:
            msg = f.read()
    elif src.prompt_from_file:
        with open(src.prompt_from_file, "r") as f:
            msg = f.read()
    elif not interactive:
        msg = sys.stdin.read()

    return msg

def get_system_message(system_message : Optional[str]):

    if not system_message:

        current_date_time = datetime.datetime.now()

        system_message = f'The current date is {current_date_time}. When emitting code or producing markdown, ensure to label fenced code blocks with the language in use.'

    return ChatMessage(Role.SYSTEM, system_message)

def _resolve_system_editor() -> Optional[str]:
    '''
        Attempt to resolve the system if one is not explicitly specified.
        This is either the editor stored in the EDITOR environmental variable
        or one of editor, vim, emacs, vi, or nano.
    '''

    fallback_editors = [
        "editor", # debian default
        "vim",
        "emacs",
        "vi",
        "nano",
    ]

    editor = os.getenv("EDITOR")

    if editor:
        return editor

    paths = os.getenv("PATH")

    if not paths:
        return None

    for editor in fallback_editors:
        for path in paths.split(os.pathsep):
            if os.path.exists(os.path.join(path, editor)):
                return editor

    return None

def _launch_interactive_editor(editor : Optional[str] = None) -> str:

    with tempfile.NamedTemporaryFile(suffix="gpt.msg") as tmp_file:

        editor = editor or _resolve_system_editor()

        try:
            subprocess.call([editor, tmp_file.name])
        except FileNotFoundError:
            print(f'error: the specified editor \"{editor}\" does not exist')
            sys.exit(1)

        # Read the resulting file into a string
        with open(tmp_file.name, "r") as edited_file:
            edited_content = edited_file.read()

        return edited_content


###########################
####   SAVE / REPLAY   ####
###########################

@dataclass
class CompletionContext:
    message: str
    completion_args: CompletionArguments
    system_message: Optional[str] = None

def create_singleton_chat_completion(ctx : CompletionContext):

    hist = [
        get_system_message(ctx.system_message),
        ChatMessage(Role.USER, ctx.message)
    ]

    completion = create_chat_completion(hist, ctx.completion_args)

    return completion

def save_response_and_arguments(args : Arguments) -> None:

    message = resolve_initial_message(args.initial_message)

    ctx = CompletionContext(
        message=message,
        completion_args=args.completion_args,
        system_message=args.system_message
    )

    completion = create_singleton_chat_completion(
        message,
        args.completion_args,
        args.system_message,
    )

    completion = list(completion)

    filename = args.debug_args.save_response_to_file

    with open(filename, 'wb') as f:
        pickle.dump((ctx, completion,), f)

def load_response_and_arguments(args : Arguments) \
        -> Tuple[CompletionContext, OpenAIChatResponseStream]:

    filename = args.debug_args.load_response_from_file

    with open(filename, 'rb') as f:
        ctx, completion = pickle.load(f)

    return (ctx, completion)

#########################
#### PRETTY PRINTING ####
#########################

@dataclass
class CumulativeResponse:
    delta_content: str = ""
    finish_reason: FinishReason = FinishReason.NONE
    content: str = ""

    def take_delta(self : "CumulativeResponse"):
        chunk = self.delta_content
        self.delta_content = ""
        return chunk

    def add_content(self : "CumulativeResponse", new_chunk : str):
        self.content += new_chunk
        self.delta_content += new_chunk

def print_streamed_response(
        display_args : DisplayArguments,
        completion : OpenAIChatResponseStream,
        n_completions : int,
        return_responses : bool = False
    ) -> None:
    """
    Print the response in real time by printing the deltas as they occur. If multiple responses
    are requested, print the first in real-time, accumulating the others in the background. One the
    first response completes, move on to the second response printing the deltas in real time. Continue
    on until all responses have been printed.
    """

    no_color = not display_args.color

    COLOR_CODE = get_color_codes(no_color = no_color)
    adornments = display_args.adornments

    cumu_responses = defaultdict(CumulativeResponse)
    display_idx = 0
    prompt_printed = False

    chat_colorizer = ChatColorizer(no_color = no_color)

    for update in completion:

        for choice in update.choices:
            delta = choice.delta

            if delta.content:
                cumu_responses[choice.index].add_content(delta.content)

            if choice.finish_reason is not FinishReason.NONE:
                cumu_responses[choice.index].finish_reason = choice.finish_reason

        display_response = cumu_responses[display_idx]

        if not prompt_printed and adornments:
            res_indicator = '' if n_completions == 1 else \
                    f' {display_idx + 1}/{n_completions}'
            PROMPT = f'[{COLOR_CODE.GREEN}{update.model}{COLOR_CODE.RESET}{COLOR_CODE.RED}{res_indicator}{COLOR_CODE.RESET}]'
            prompt_printed = True
            print(PROMPT, end=' ', flush=True)

        content = display_response.take_delta()
        chat_colorizer.add_chunk( content )

        chat_colorizer.print()

        if display_response.finish_reason is not FinishReason.NONE:
            chat_colorizer.finish()
            chat_colorizer.print()
            chat_colorizer = ChatColorizer( no_color=no_color )

            if display_idx < n_completions:
                display_idx += 1
                prompt_printed = False

            if adornments:
                print(end='\n\n', flush=True)
            else:
                print(end='\n', flush=True)

    if return_responses:
        return [ cumu_responses[i].content for i in range(n_completions) ]

#########################
####    COMMANDS     ####
#########################

def version():
    print(f'version {VERSION}')

def list_models():
    for model in openai_list_models():
        print(model)

def interactive(args : Arguments):

    completion_args = args.completion_args
    display_args = args.display_args

    system_message = get_system_message(args.system_message)
    interactive_editor = args.interactive_editor

    hist = [ system_message ]

    no_color = not display_args.color

    prompter = Prompter(no_color = no_color)

    CLEAR = prompter.add_command('clear', 'clears the context (excluding the system message)')
    EDIT = prompter.add_command('edit', 'launches a terminal editor')
    EXIT = prompter.add_command('exit', 'exit the terminal')
    HELP = prompter.add_command('help', 'print all interactive commands')

    print(f'GPT Chat CLI version {VERSION}')
    print(f'Press Control-D to exit')

    initial_message = resolve_initial_message(args.initial_message, interactive=True)

    if initial_message:
        print( PROMPT, initial_message, sep='', flush=True )

    with prompter as prompt:
        while True:
            try:
                if initial_message:
                    cmd, args = None, initial_message
                    initial_message = None
                else:
                    cmd, args = prompt.input()

                if cmd == CLEAR:
                    hist = [ system_message ]
                    continue
                elif cmd == EDIT:
                    message = _launch_interactive_editor(
                        editor=interactive_editor
                    )
                    print( prompt.prompt, end='')
                    print( message, end='' )
                elif cmd == EXIT:
                    return
                elif cmd == HELP:
                    prompt.print_help()
                    continue
                else:
                    message = args

                if message == '':
                    continue

                hist.append( ChatMessage( Role.USER, message ) )

                completion = create_chat_completion(hist, completion_args)

                response = print_streamed_response(
                    display_args, completion, 1, return_responses=True,
                )[0]

                hist.append( ChatMessage(Role.ASSISTANT, response) )
            except KeyboardInterrupt: # Skip to next prompt
                continue
            except EOFError: # Exit on Control-D
                print()
                sys.exit(1)

def singleton(args: Arguments):
    completion_args = args.completion_args

    debug_args : DebugArguments = args.debug_args
    message = args.initial_message

    if debug_args.save_response_to_file:
        save_response_and_arguments(args)
        return
    elif debug_args.load_response_from_file:
        ctx, completion = load_response_and_arguments(args)

        message = ctx.message
        completion_args = ctx.completion_args
    else:
        # message is only None is a TTY is not attached
        message = resolve_initial_message(args.initial_message)

        ctx = CompletionContext(
            message=message,
            completion_args=completion_args,
            system_message=args.system_message
        )

        completion = create_singleton_chat_completion(ctx)

    print_streamed_response(
        args.display_args,
        completion,
        completion_args.n_completions
    )