import io
import os
import uuid
import logging
from typing import Optional

from fastapi import FastAPI, UploadFile, File, HTTPException, Depends, Header
from fastapi.responses import FileResponse, JSONResponse
from pydantic import BaseModel
import torch

import numpy as np
from PIL import Image

from infer_full import StableHair


LOGGER = logging.getLogger("hair_server")
logging.basicConfig(level=logging.INFO, format="%(asctime)s - %(levelname)s - %(name)s - %(message)s")

EXPECTED_BEARER = "logicgo@123"


def verify_bearer(authorization: Optional[str] = Header(None)):
    if not authorization:
        raise HTTPException(status_code=401, detail="Missing Authorization header")
    try:
        scheme, token = authorization.split(" ", 1)
    except ValueError:
        raise HTTPException(status_code=401, detail="Invalid Authorization header format")
    if scheme.lower() != "bearer":
        raise HTTPException(status_code=401, detail="Invalid auth scheme")
    if token != EXPECTED_BEARER:
        raise HTTPException(status_code=401, detail="Invalid token")
    return True


app = FastAPI(title="Hair Swap API", version="1.0.0")


@app.get("/health")
def health():
    return {"status": "healthy"}


class HairSwapRequest(BaseModel):
    source_id: str
    reference_id: str
    converter_scale: float = 1.0
    scale: float = 1.0
    guidance_scale: float = 1.5
    controlnet_conditioning_scale: float = 1.0


# Initialize model lazily on first request
_model: Optional[StableHair] = None


def get_model() -> StableHair:
    global _model
    if _model is None:
        LOGGER.info("Loading StableHair model ...")
        device = "cuda" if torch.cuda.is_available() else "cpu"
        dtype = torch.float16 if device == "cuda" else torch.float32
        _model = StableHair(config="./configs/hair_transfer.yaml", device=device, weight_dtype=dtype)
        LOGGER.info("Model loaded")
    return _model


UPLOAD_DIR = os.path.join(os.getcwd(), "uploads")
RESULTS_DIR = os.path.join(os.getcwd(), "results")
LOGS_DIR = os.path.join(os.getcwd(), "logs")
os.makedirs(UPLOAD_DIR, exist_ok=True)
os.makedirs(RESULTS_DIR, exist_ok=True)
os.makedirs(LOGS_DIR, exist_ok=True)


@app.post("/upload")
async def upload_image(image: UploadFile = File(...), _=Depends(verify_bearer)):
    if not image.filename:
        raise HTTPException(status_code=400, detail="No file name provided")
    contents = await image.read()
    try:
        Image.open(io.BytesIO(contents)).convert("RGB")
    except Exception:
        raise HTTPException(status_code=400, detail="Invalid image file")

    image_id = str(uuid.uuid4())
    ext = os.path.splitext(image.filename)[1] or ".png"
    path = os.path.join(UPLOAD_DIR, image_id + ext)
    with open(path, "wb") as f:
        f.write(contents)
    return {"id": image_id, "filename": os.path.basename(path)}


@app.post("/get-hairswap")
def get_hairswap(req: HairSwapRequest, _=Depends(verify_bearer)):
    # Resolve file paths
    def find_file(image_id: str) -> str:
        for name in os.listdir(UPLOAD_DIR):
            if name.startswith(image_id):
                return os.path.join(UPLOAD_DIR, name)
        raise HTTPException(status_code=404, detail=f"Image id not found: {image_id}")

    source_path = find_file(req.source_id)
    reference_path = find_file(req.reference_id)

    model = get_model()
    # Prepare kwargs similar to infer_full
    id_np, out_np, bald_np, ref_np = model.Hair_Transfer(
        source_image=source_path,
        reference_image=reference_path,
        random_seed=-1,
        step=30,
        guidance_scale=req.guidance_scale,
        scale=req.scale,
        controlnet_conditioning_scale=req.controlnet_conditioning_scale,
        size=512,
    )

    # Save result
    result_id = str(uuid.uuid4())
    out_img = Image.fromarray((out_np * 255.).astype(np.uint8))
    filename = f"{result_id}.png"
    out_path = os.path.join(RESULTS_DIR, filename)
    out_img.save(out_path)

    return {"result": filename}


@app.get("/download/{filename}")
def download(filename: str, _=Depends(verify_bearer)):
    path = os.path.join(RESULTS_DIR, filename)
    if not os.path.exists(path):
        raise HTTPException(status_code=404, detail="File not found")
    return FileResponse(path, media_type="image/png", filename=filename)


@app.get("/logs")
def logs(_=Depends(verify_bearer)):
    # Simple in-memory/log-file placeholder
    return JSONResponse({"logs": ["service running"]})