import logging
import traceback
from functools import partial

import gradio as gr

import extensions
import modules.shared as shared

state = {}
available_extensions = []
setup_called = set()


def apply_settings(extension, name):
    if not hasattr(extension, 'params'):
        return

    for param in extension.params:
        _id = f"{name}-{param}"
        if _id not in shared.settings:
            continue

        extension.params[param] = shared.settings[_id]


def load_extensions():
    global state, setup_called
    for i, name in enumerate(shared.args.extensions):
        if name in available_extensions:
            if name != 'api':
                logging.info(f'Loading the extension "{name}"...')
            try:
                exec(f"import extensions.{name}.script")
                extension = getattr(extensions, name).script
                apply_settings(extension, name)
                if extension not in setup_called and hasattr(extension, "setup"):
                    setup_called.add(extension)
                    extension.setup()

                state[name] = [True, i]
            except:
                logging.error(f'Failed to load the extension "{name}".')
                traceback.print_exc()


# This iterator returns the extensions in the order specified in the command-line
def iterator():
    for name in sorted(state, key=lambda x: state[x][1]):
        if state[name][0]:
            yield getattr(extensions, name).script, name


# Extension functions that map string -> string
def _apply_string_extensions(function_name, text):
    for extension, _ in iterator():
        if hasattr(extension, function_name):
            text = getattr(extension, function_name)(text)

    return text


# Input hijack of extensions
def _apply_input_hijack(text, visible_text):
    for extension, _ in iterator():
        if hasattr(extension, 'input_hijack') and extension.input_hijack['state']:
            extension.input_hijack['state'] = False
            if callable(extension.input_hijack['value']):
                text, visible_text = extension.input_hijack['value'](text, visible_text)
            else:
                text, visible_text = extension.input_hijack['value']

    return text, visible_text


# custom_generate_chat_prompt handling
def _apply_custom_generate_chat_prompt(text, state, **kwargs):
    custom_generate_chat_prompt = None
    for extension, _ in iterator():
        if custom_generate_chat_prompt is None and hasattr(extension, 'custom_generate_chat_prompt'):
            custom_generate_chat_prompt = extension.custom_generate_chat_prompt

    if custom_generate_chat_prompt is not None:
        return custom_generate_chat_prompt(text, state, **kwargs)

    return None


# Extension that modifies the input parameters before they are used
def _apply_state_modifier_extensions(state):
    for extension, _ in iterator():
        if hasattr(extension, "state_modifier"):
            state = getattr(extension, "state_modifier")(state)

    return state
 

# Extension functions that override the default tokenizer output
def _apply_tokenizer_extensions(function_name, state, prompt, input_ids, input_embeds):
    for extension, _ in iterator():
        if hasattr(extension, function_name):
            prompt, input_ids, input_embeds = getattr(extension, function_name)(state, prompt, input_ids, input_embeds)

    return prompt, input_ids, input_embeds


# Custom generate reply handling
def _apply_custom_generate_reply():
    for extension, _ in iterator():
        if hasattr(extension, 'custom_generate_reply'):
            return getattr(extension, 'custom_generate_reply')

    return None


EXTENSION_MAP = {
    "input": partial(_apply_string_extensions, "input_modifier"),
    "output": partial(_apply_string_extensions, "output_modifier"),
    "state": _apply_state_modifier_extensions,
    "bot_prefix": partial(_apply_string_extensions, "bot_prefix_modifier"),
    "tokenizer": partial(_apply_tokenizer_extensions, "tokenizer_modifier"),
    "input_hijack": _apply_input_hijack,
    "custom_generate_chat_prompt": _apply_custom_generate_chat_prompt,
    "custom_generate_reply": _apply_custom_generate_reply
}


def apply_extensions(typ, *args, **kwargs):
    if typ not in EXTENSION_MAP:
        raise ValueError(f"Invalid extension type {typ}")

    return EXTENSION_MAP[typ](*args, **kwargs)


def create_extensions_block():
    global setup_called

    should_display_ui = False
    for extension, name in iterator():
        if hasattr(extension, "ui"):
            should_display_ui = True
            break

    # Creating the extension ui elements
    if should_display_ui:
        with gr.Column(elem_id="extensions"):
            for extension, name in iterator():
                if hasattr(extension, "ui"):
                    gr.Markdown(f"\n### {name}")
                    extension.ui()