from __future__ import annotations

from functools import partial

import gradio as gr

from config import APP_NAME, APP_SUBTITLE, get_openai_api_key, get_openai_model
from openai_service import format_openai_error, stream_tutor_response
from prompts import ABOUT_PAK_ANGELS, MODULES, build_system_instructions


BUILD_ID = "pak-angels-zerogpu-2026-07-11-v2"


try:
    import spaces
except ImportError:
    class _SpacesFallback:
        @staticmethod
        def GPU(*args, **kwargs):
            if args and callable(args[0]) and len(args) == 1 and not kwargs:
                return args[0]

            def decorator(function):
                return function

            return decorator

    spaces = _SpacesFallback()


print(f"Starting {APP_NAME} build {BUILD_ID}")


PRIVACY_NOTICE = (
    "Privacy notice: Do not enter confidential, proprietary, financial, medical, "
    "personal, or otherwise sensitive information into the AI Tutor."
)


CSS = """
:root {
    --pak-blue: #0b5cab;
    --pak-blue-dark: #073f78;
    --pak-blue-soft: #eaf4ff;
    --pak-line: #d8e5f2;
    --pak-text: #14213d;
}
body,
.gradio-container {
    background: #f7fbff !important;
    color: var(--pak-text);
}
.main-shell {
    max-width: 1180px;
    margin: 0 auto;
}
.hero {
    background: linear-gradient(135deg, #ffffff 0%, #eaf4ff 62%, #d6ebff 100%);
    border: 1px solid var(--pak-line);
    border-radius: 8px;
    padding: 24px;
    margin-bottom: 14px;
}
.hero h1 {
    color: var(--pak-blue-dark);
    font-size: 38px;
    line-height: 1.1;
    margin: 0 0 8px 0;
}
.hero p {
    margin: 5px 0;
    font-size: 16px;
}
.mode-label {
    border-left: 5px solid var(--pak-blue);
    background: #ffffff;
    border-radius: 8px;
    padding: 14px 16px;
    box-shadow: 0 1px 4px rgba(11, 92, 171, 0.08);
}
.privacy {
    background: #fff8e8;
    border: 1px solid #f1d28c;
    border-radius: 8px;
    padding: 12px 14px;
    font-size: 14px;
}
.side-panel {
    background: #ffffff;
    border: 1px solid var(--pak-line);
    border-radius: 8px;
    padding: 14px;
}
.suggestion-button {
    min-height: 46px;
}
button.primary {
    background: var(--pak-blue) !important;
    border-color: var(--pak-blue) !important;
}
"""


def hero_html() -> str:
    return f"""
    <div class="hero">
        <h1>{APP_NAME}</h1>
        <p><strong>{APP_SUBTITLE}</strong></p>
        <p>Pak Angels AI Tutor helps students, faculty, professionals,
        entrepreneurs, and startup founders learn Artificial Intelligence,
        build practical applications, design intelligent workflows, automate
        business processes, and develop AI-powered startups.</p>
    </div>
    """


def module_summary_html(module_name: str) -> str:
    module = MODULES[module_name]
    about = ""
    if module_name == "About Pak Angels":
        about = f"<p>{ABOUT_PAK_ANGELS}</p>"
    return f"""
    <div class="mode-label">
        <strong>Selected learning mode:</strong> {module_name}<br>
        <span>{module["summary"]}</span>
        {about}
    </div>
    """


def topics_markdown(module_name: str) -> str:
    topics = "\n".join(f"- {topic}" for topic in MODULES[module_name]["topics"])
    return f"### Topics in this mode\n{topics}"


def get_suggestion(module_name: str, index: int) -> str:
    suggestions = MODULES[module_name]["suggestions"]
    return suggestions[index] if index < len(suggestions) else ""


def update_module(module_name: str):
    suggestions = MODULES[module_name]["suggestions"]
    button_updates = [
        gr.update(value=suggestion, visible=True) for suggestion in suggestions[:5]
    ]
    while len(button_updates) < 5:
        button_updates.append(gr.update(value="", visible=False))

    return (
        module_summary_html(module_name),
        topics_markdown(module_name),
        *button_updates,
    )


def add_user_message(message: str, history: list[dict[str, str]] | None):
    history = list(history or [])
    message = (message or "").strip()
    if not message:
        return "", history
    history.append({"role": "user", "content": message})
    return "", history


def generate_response(history: list[dict[str, str]] | None, module_name: str):
    history = list(history or [])
    if not history or history[-1]["role"] != "user":
        yield history
        return

    api_key = get_openai_api_key()
    if not api_key:
        message = (
            "OPENAI_API_KEY is not configured. In Hugging Face Spaces, add it under "
            "Settings -> Variables and secrets -> New secret, then restart the Space."
        )
        history.append({"role": "assistant", "content": message})
        yield history
        return

    history.append({"role": "assistant", "content": ""})
    try:
        for delta in stream_tutor_response(
            api_key=api_key,
            model=get_openai_model(),
            system_instructions=build_system_instructions(module_name),
            messages=history[:-1],
        ):
            history[-1]["content"] += delta
            yield history
    except Exception as error:
        history[-1]["content"] = format_openai_error(error)
        yield history


@spaces.GPU(duration=120)
def submit_message(message: str, history: list[dict[str, str]] | None, module_name: str):
    textbox, updated_history = add_user_message(message, history)
    yield textbox, updated_history
    for streamed_history in generate_response(updated_history, module_name):
        yield textbox, streamed_history


def submit_suggestion(
    suggestion_index: int,
    history: list[dict[str, str]] | None,
    module_name: str,
):
    question = get_suggestion(module_name, suggestion_index)
    yield from submit_message(question, history, module_name)


def clear_conversation():
    return []


def build_app() -> gr.Blocks:
    with gr.Blocks(
        title=APP_NAME,
        css=CSS,
        theme=gr.themes.Soft(primary_hue="blue", neutral_hue="slate"),
    ) as demo:
        with gr.Column(elem_classes=["main-shell"]):
            gr.HTML(hero_html())

            with gr.Row(equal_height=False):
                with gr.Column(scale=1, min_width=260, elem_classes=["side-panel"]):
                    module_selector = gr.Radio(
                        choices=list(MODULES.keys()),
                        value="Home",
                        label="Learning mode",
                    )
                    gr.Textbox(
                        value=get_openai_model(),
                        label="OpenAI model",
                        interactive=False,
                    )
                    new_button = gr.Button("New Conversation")
                    clear_button = gr.Button("Clear Chat")
                    with gr.Accordion("About Pak Angels", open=False):
                        gr.Markdown(ABOUT_PAK_ANGELS)

                with gr.Column(scale=3, min_width=420):
                    module_summary = gr.HTML(module_summary_html("Home"))
                    gr.HTML(f'<div class="privacy">{PRIVACY_NOTICE}</div>')
                    topics = gr.Markdown(topics_markdown("Home"))

                    gr.Markdown("### Suggested questions")
                    suggestion_buttons = []
                    with gr.Row():
                        suggestion_buttons.append(
                            gr.Button(get_suggestion("Home", 0), elem_classes=["suggestion-button"])
                        )
                        suggestion_buttons.append(
                            gr.Button(get_suggestion("Home", 1), elem_classes=["suggestion-button"])
                        )
                    with gr.Row():
                        suggestion_buttons.append(
                            gr.Button(get_suggestion("Home", 2), elem_classes=["suggestion-button"])
                        )
                        suggestion_buttons.append(
                            gr.Button(get_suggestion("Home", 3), elem_classes=["suggestion-button"])
                        )
                    suggestion_buttons.append(
                        gr.Button(get_suggestion("Home", 4), elem_classes=["suggestion-button"])
                    )

                    chatbot = gr.Chatbot(
                        label="Pak Angels AI Tutor",
                        type="messages",
                        height=520,
                        show_copy_button=True,
                        allow_tags=False,
                    )
                    message_box = gr.Textbox(
                        label="Ask Pak Angels AI Tutor",
                        placeholder="Ask a question or choose a suggested question above.",
                        lines=3,
                    )
                    send_button = gr.Button("Send", variant="primary")

            module_selector.change(
                update_module,
                inputs=[module_selector],
                outputs=[module_summary, topics, *suggestion_buttons],
            )

            send_button.click(
                submit_message,
                inputs=[message_box, chatbot, module_selector],
                outputs=[message_box, chatbot],
            )
            message_box.submit(
                submit_message,
                inputs=[message_box, chatbot, module_selector],
                outputs=[message_box, chatbot],
            )

            for index, button in enumerate(suggestion_buttons):
                button.click(
                    partial(submit_suggestion, index),
                    inputs=[chatbot, module_selector],
                    outputs=[message_box, chatbot],
                )

            new_button.click(clear_conversation, outputs=[chatbot])
            clear_button.click(clear_conversation, outputs=[chatbot])

        return demo


demo = build_app()


if __name__ == "__main__":
    demo.queue().launch(server_name="0.0.0.0", server_port=7860, ssr_mode=False)