import os
import shutil
from pathlib import Path
from uuid import uuid4

import gradio as gr

from agent_core.config import ARTIFACT_ROOT
from agent_core.service import run_chat_turn


def new_session_state() -> dict:
    return {
        "session_id": uuid4().hex[:12],
        "agent_messages": [],
        "chat_messages": [],
        "latest_tool_payload": None,
    }


def copy_uploaded_image(image_path: str | None, session_id: str) -> str | None:
    if not image_path:
        return None

    source = Path(image_path)
    suffix = source.suffix or ".png"
    upload_dir = ARTIFACT_ROOT / "uploads" / session_id
    upload_dir.mkdir(parents=True, exist_ok=True)
    target = upload_dir / f"{uuid4().hex[:8]}{suffix}"
    shutil.copy2(source, target)
    return str(target)


def parse_user_message(message) -> tuple[str, str | None]:
    if message is None:
        return "", None
    if isinstance(message, str):
        return message.strip(), None

    text = (message.get("text") or "").strip()
    files = message.get("files") or []
    image_path = files[0] if files else None
    return text, image_path


def format_status(result: dict) -> str:
    payload = result.get("tool_payload") or {}
    if not payload:
        return "No model generated yet."

    if payload.get("ok"):
        return "\n".join([
            f"Run: `{payload.get('run_id')}`",
            f"Output: `{payload.get('output_path')}`",
            f"Preview: `{payload.get('preview_path') or payload.get('output_path')}`",
            f"Manifest: `{payload.get('manifest_path')}`",
        ])

    return "\n".join([
        "Generation failed.",
        f"Stage: `{payload.get('stage')}`",
        f"Error: `{payload.get('error')}`",
        f"Manifest: `{payload.get('manifest_path')}`" if payload.get("manifest_path") else "",
    ]).strip()


def submit_message(message, state):
    state = state or new_session_state()
    text, image_path = parse_user_message(message)
    uploaded_image = copy_uploaded_image(image_path, state["session_id"])

    if not text and not uploaded_image:
        return state["chat_messages"], state, None, None, "Enter a message or upload an image.", {"text": "", "files": []}

    display_text = text or "Generate a 3D model from the uploaded image."
    if uploaded_image:
        display_text = f"{display_text}\n\n[uploaded image]"
    state["chat_messages"].append({"role": "user", "content": display_text})

    try:
        result = run_chat_turn(
            messages=state["agent_messages"],
            user_text=text or "Generate a 3D model from the uploaded image.",
            image_path=uploaded_image,
        )
        state["agent_messages"] = result["messages"]
        assistant_text = result["assistant_text"] or "Done."
        if result.get("error") and not assistant_text:
            assistant_text = result["error"]
        state["chat_messages"].append({"role": "assistant", "content": assistant_text})
        state["latest_tool_payload"] = result.get("tool_payload")
        status = format_status(result)
        return (
            state["chat_messages"],
            state,
            result.get("preview_path"),
            result.get("download_path"),
            status,
            {"text": "", "files": []},
        )
    except Exception as exc:
        state["chat_messages"].append({"role": "assistant", "content": f"Failed: {exc}"})
        return state["chat_messages"], state, None, None, f"Failed: `{exc}`", {"text": "", "files": []}


def reset_session():
    state = new_session_state()
    return [], state, None, None, "New session started.", {"text": "", "files": []}


with gr.Blocks(title="ForgeCAD", fill_height=True) as demo:
    gr.Markdown("# AI CAD Agent")

    state = gr.State(new_session_state())

    with gr.Row():
        with gr.Column(scale=5):
            chatbot = gr.Chatbot(height=560, label="Conversation")
            composer = gr.MultimodalTextbox(
                sources=["upload"],
                file_types=["image"],
                file_count="single",
                lines=2,
                max_lines=6,
                label="Message",
                placeholder="Describe a CAD model, ask for an edit, or upload an image as reference.",
                submit_btn="Send",
            )
            with gr.Row():
                clear = gr.Button("New Session")

        with gr.Column(scale=4):
            preview = gr.Model3D(label="Model Preview", height=560)
            download = gr.File(label="Download Latest Model")
            status = gr.Markdown("No model generated yet.")

    composer.submit(
        submit_message,
        inputs=[composer, state],
        outputs=[
            chatbot,
            state,
            preview,
            download,
            status,
            composer,
        ],
    )
    clear.click(
        reset_session,
        outputs=[
            chatbot,
            state,
            preview,
            download,
            status,
            composer,
        ],
    )


if __name__ == "__main__":
    server_name = os.getenv("GRADIO_SERVER_NAME", "127.0.0.1")
    server_port = int(os.getenv("GRADIO_SERVER_PORT", "7860"))
    demo.queue(default_concurrency_limit=1).launch(
        server_name=server_name,
        server_port=server_port,
        allowed_paths=[str(ARTIFACT_ROOT)],
    )