"""
Museum AI Studio - Unified Interactive Experience
Backend: FastAPI + WebSocket + ONNX Style Transfer
Frontend: MediaPipe + Canvas (see index.html)

Modes:
1. Anime Studio - Real-time style transfer (Hayao, Shinkai, Disney, Cyberpunk)
2. Pose Challenge - Strike poses, get scored
3. Face Filters - AR masks (glasses, cat, crown, mustache, anime eyes)
4. Hand Painter - Gesture-controlled drawing
5. Rock-Paper-Scissors - Play against AI
"""
import os
import io
import base64
import json
import asyncio
from typing import Optional, Dict
from contextlib import asynccontextmanager

import cv2
import numpy as np
import onnxruntime as ort
from fastapi import FastAPI, WebSocket, WebSocketDisconnect
from fastapi.staticfiles import StaticFiles
from fastapi.responses import HTMLResponse
from huggingface_hub import hf_hub_download

# ─── Configuration ─────────────────────────────────────────────
MODELS = {
    "hayao": {
        "repo": "vumichien/AnimeGANv2_Hayao",
        "file": "AnimeGANv2_Hayao.onnx",
        "name": "Hayao / Ghibli",
    },
    "shinkai": {
        "repo": "vumichien/AnimeGANv2_Shinkai",
        "file": "AnimeGANv2_Shinkai.onnx",
        "name": "Shinkai / Your Name",
    },
}

MODELS_DIR = os.environ.get("MODELS_DIR", "./models")
os.makedirs(MODELS_DIR, exist_ok=True)

STYLE_TRANSFER_SIZE = int(os.environ.get("STYLE_SIZE", "512"))
JPEG_QUALITY = int(os.environ.get("JPEG_QUALITY", "75"))

# ─── Model Manager ─────────────────────────────────────────────
class ONNXStyleTransfer:
    def __init__(self):
        self.sessions: Dict[str, ort.InferenceSession] = {}
        self.input_names: Dict[str, str] = {}
        self.input_shapes: Dict[str, tuple] = {}

    def _load(self, key: str):
        if key in self.sessions:
            return
        cfg = MODELS[key]
        local_path = os.path.join(MODELS_DIR, cfg["file"])
        # Download if missing
        if not os.path.exists(local_path):
            print(f"[Model] Downloading {cfg['name']}...")
            hf_hub_download(
                repo_id=cfg["repo"],
                filename=cfg["file"],
                local_dir=MODELS_DIR,
                local_dir_use_symlinks=False,
            )
        print(f"[Model] Loading {cfg['name']} ONNX...")
        sess = ort.InferenceSession(
            local_path,
            providers=["CPUExecutionProvider"],
        )
        inp = sess.get_inputs()[0]
        self.sessions[key] = sess
        self.input_names[key] = inp.name
        # Store expected shape (usually NCHW, sometimes NHWC)
        self.input_shapes[key] = tuple(inp.shape)  # e.g. (1,3,512,512) or (1,512,512,3)
        print(f"[Model] {cfg['name']} ready. Input shape: {inp.shape}")

    def stylize(self, frame_bgr: np.ndarray, key: str) -> np.ndarray:
        self._load(key)
        sess = self.sessions[key]
        inp_name = self.input_names[key]

        # AnimeGANv2 expects NHWC [1, H, W, 3] at 512x512
        target_h = 512
        target_w = 512

        img = cv2.cvtColor(frame_bgr, cv2.COLOR_BGR2RGB)
        img = cv2.resize(img, (target_w, target_h))
        img = img.astype(np.float32)

        # AnimeGANv2 normalization: [-1, 1]
        img = img / 127.5 - 1.0
        # NHWC: add batch dimension as the first axis
        img = img[np.newaxis, ...]

        outputs = sess.run(None, {inp_name: img})
        out = outputs[0]
        # Output is NHWC [1, H, W, 3]
        out = out[0]

        out = (out + 1.0) * 127.5
        out = np.clip(out, 0, 255).astype(np.uint8)
        # Resize back to original
        h, w = frame_bgr.shape[:2]
        out = cv2.resize(out, (w, h))
        return cv2.cvtColor(out, cv2.COLOR_RGB2BGR)


# ─── Global State ──────────────────────────────────────────────
style_engine = ONNXStyleTransfer()


# ─── Utility: Frame ↔ Base64 ─────────────────────────────────
def frame_to_base64(frame: np.ndarray) -> str:
    _, buf = cv2.imencode(".jpg", frame, [int(cv2.IMWRITE_JPEG_QUALITY), JPEG_QUALITY])
    return base64.b64encode(buf).decode("utf-8")


def base64_to_frame(data: str) -> np.ndarray:
    buf = base64.b64decode(data)
    arr = np.frombuffer(buf, dtype=np.uint8)
    return cv2.imdecode(arr, cv2.IMREAD_COLOR)


# ─── WebSocket Connection Manager ────────────────────────────
class ConnectionManager:
    def __init__(self):
        self.active: Dict[str, WebSocket] = {}

    async def connect(self, ws: WebSocket, client_id: str):
        await ws.accept()
        self.active[client_id] = ws
        print(f"[WS] Client {client_id} connected ({len(self.active)} active)")

    def disconnect(self, client_id: str):
        self.active.pop(client_id, None)
        print(f"[WS] Client {client_id} disconnected ({len(self.active)} active)")

    async def send_json(self, client_id: str, data: dict):
        ws = self.active.get(client_id)
        if ws:
            await ws.send_json(data)

    async def broadcast_json(self, data: dict):
        for ws in list(self.active.values()):
            try:
                await ws.send_json(data)
            except Exception:
                pass


manager = ConnectionManager()


# ─── FastAPI Lifecycle ───────────────────────────────────────
@asynccontextmanager
async def lifespan(app: FastAPI):
    print("[Startup] Museum AI Studio backend starting...")
    # Pre-download models
    for key in MODELS:
        try:
            style_engine._load(key)
        except Exception as e:
            print(f"[Startup] Warning: could not preload {key}: {e}")
    print("[Startup] Ready.")
    yield
    print("[Shutdown] Cleaning up...")


app = FastAPI(title="Museum AI Studio", lifespan=lifespan)

# Serve static frontend
app.mount("/static", StaticFiles(directory="static", html=True), name="static")


@app.get("/", response_class=HTMLResponse)
async def root():
    with open("static/index.html", "r", encoding="utf-8") as f:
        return f.read()


@app.get("/health")
async def health():
    loaded = list(style_engine.sessions.keys())
    return {"status": "ok", "loaded_models": loaded, "available_models": list(MODELS.keys())}


# ─── WebSocket: Main Data Channel ─────────────────────────────
@app.websocket("/ws/{client_id}")
async def websocket_endpoint(ws: WebSocket, client_id: str):
    await manager.connect(ws, client_id)
    current_mode = "studio"
    current_style = "hayao"
    paint_history = []  # For hand painter (server-side backup)

    try:
        while True:
            msg = await ws.receive_json()
            action = msg.get("action", "frame")

            # ── 1. Mode Switching ──────────────────────────────
            if action == "set_mode":
                current_mode = msg.get("mode", "studio")
                await manager.send_json(client_id, {"type": "mode_set", "mode": current_mode})
                continue

            # ── 2. Style Switching ───────────────────────────
            if action == "set_style":
                new_style = msg.get("style", "hayao")
                if new_style in MODELS:
                    current_style = new_style
                    await manager.send_json(client_id, {"type": "style_set", "style": new_style, "name": MODELS[new_style]["name"]})
                else:
                    await manager.send_json(client_id, {"type": "error", "message": f"Unknown style: {new_style}"})
                continue

            # ── 3. Receive raw frame from browser ──────────────
            if action == "frame":
                frame_b64 = msg.get("frame", "")
                if not frame_b64:
                    continue
                frame = base64_to_frame(frame_b64)
                if frame is None:
                    continue

                h, w = frame.shape[:2]
                result = None

                # ── Anime Studio: Style Transfer ───────────────
                if current_mode == "studio":
                    result = style_engine.stylize(frame, current_style)

                # ── Pose Challenge: Mirror + Scoring ───────────
                elif current_mode == "pose":
                    # Just mirror flip + minimal overlay text
                    # Full pose detection is client-side via MediaPipe
                    result = cv2.flip(frame, 1)
                    cv2.putText(result, "Pose Challenge Mode", (10, 30),
                               cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 255, 255), 2)
                    cv2.putText(result, "Strike a pose!", (10, 60),
                               cv2.FONT_HERSHEY_SIMPLEX, 0.6, (0, 255, 0), 1)

                # ── Face Filters: Just pass-through ────────────
                elif current_mode == "face":
                    result = cv2.flip(frame, 1)
                    cv2.putText(result, "AR Face Filters Mode", (10, 30),
                               cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 255, 255), 2)
                    cv2.putText(result, "Select filter in UI", (10, 60),
                               cv2.FONT_HERSHEY_SIMPLEX, 0.6, (0, 255, 0), 1)

                # ── Hand Painter: Pass-through ─────────────────
                elif current_mode == "painter":
                    result = cv2.flip(frame, 1)
                    cv2.putText(result, "Hand Painter Mode", (10, 30),
                               cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 255, 255), 2)
                    cv2.putText(result, "Draw with your hand!", (10, 60),
                               cv2.FONT_HERSHEY_SIMPLEX, 0.6, (0, 255, 0), 1)

                # ── Rock-Paper-Scissors: Pass-through ──────────
                elif current_mode == "rps":
                    result = cv2.flip(frame, 1)
                    cv2.putText(result, "Rock-Paper-Scissors", (10, 30),
                               cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0, 255, 255), 2)

                else:
                    result = frame

                # Send back stylized/processed frame
                out_b64 = frame_to_base64(result)
                await manager.send_json(client_id, {
                    "type": "frame",
                    "mode": current_mode,
                    "style": current_style if current_mode == "studio" else None,
                    "frame": out_b64,
                })

            # ── 4. RPS Game Logic (server-side) ───────────────
            elif action == "rps_play":
                player_move = msg.get("move")
                import random
                ai_move = random.choice(["Rock", "Paper", "Scissors"])
                beats = {"Rock": "Scissors", "Paper": "Rock", "Scissors": "Paper"}
                if player_move == ai_move:
                    result_text = "Draw!"
                elif beats.get(player_move) == ai_move:
                    result_text = "You Win!"
                else:
                    result_text = "AI Wins!"
                await manager.send_json(client_id, {
                    "type": "rps_result",
                    "player": player_move,
                    "ai": ai_move,
                    "result": result_text,
                })

    except WebSocketDisconnect:
        manager.disconnect(client_id)
    except Exception as e:
        print(f"[WS] Error for {client_id}: {e}")
        manager.disconnect(client_id)


if __name__ == "__main__":
    import uvicorn
    port = int(os.environ.get("PORT", 7860))
    uvicorn.run("app:app", host="0.0.0.0", port=port, reload=False)