# app.py
import asyncio
from functools import lru_cache
from io import BytesIO
from typing import List

from barcode import Code128
from barcode.writer import ImageWriter
from brother_ql.backends.helpers import send
from brother_ql.conversion import convert
from brother_ql.raster import BrotherQLRaster
from fastapi import FastAPI, HTTPException
from PIL import Image, ImageOps
from pydantic import BaseModel, Field
from pylibdmtx.pylibdmtx import encode

if not hasattr(Image, "ANTIALIAS"):
    Image.ANTIALIAS = Image.Resampling.LANCZOS

app = FastAPI(title="QL-1060N Stacked Barcode Printer")


@lru_cache(maxsize=256)
def make_code128(data: str) -> Image.Image:
    # 1) Instantiate the barcode object (checksum auto-added for Code128)
    code = Code128(data, writer=ImageWriter())

    # 2) Render to a PIL.Image, passing any writer options and optional text override
    pil_img = code.render(
        writer_options={
            "module_height": 15.0,  # bar height
            "module_width": 0.5,  # bar thickness
            "quiet_zone": 1.0,  # margin on each side
            "font_size": 10,  # text size
            "text_distance": 1.0,  # gap between bars and text
            # you can also pass 'format': 'PNG' here if needed
        },
        text=data,  # explicitly draw your data string under the bars
    )

    # 3) Convert to 1-bit for your Brother QL workflow
    return pil_img.convert("1")


@lru_cache(maxsize=256)
def make_datamatrix(data: str) -> Image.Image:
    dm = encode(data.encode("utf-8"))
    pil_img = Image.frombytes("RGB", (dm.width, dm.height), dm.pixels)
    return pil_img.convert("1")


class PrintRequest(BaseModel):
    data: str = Field(..., description="String to encode")
    printer_ip: str = Field(
        "192.168.178.49", description="Brother QL-1060N IP on your LAN"
    )
    model: str = Field("QL-1060N", description="Brother model")
    label: str = Field("12", description="12 mm continuous tape")


def compose_label(images: List[Image.Image]) -> Image.Image:
    border, spacing = 10, 20
    framed = [ImageOps.expand(img, border=border, fill="white") for img in images]
    max_h = max(img.height for img in framed)
    total_w = sum(img.width for img in framed) + spacing * (len(framed) - 1)

    canvas = Image.new("1", (total_w, max_h), 1)
    x = 0
    for img in framed:
        y = (max_h - img.height) // 2
        canvas.paste(img, (x, y))
        x += img.width + spacing

    return canvas


def send_to_printer(image: Image.Image, printer_ip: str, model: str, label: str):
    qlr = BrotherQLRaster(model)
    qlr.exception_on_warning = True

    instructions = convert(
        qlr=qlr,
        images=[image],
        label=label,
        rotate="90",  # landscape
        threshold=70.0,
        dither=False,
        compress=True,
        cut=True,
    )

    send(
        instructions=instructions,
        printer_identifier=printer_ip,
        backend_identifier="network",
        blocking=True,
    )


@app.post("/print", summary="Print Code128 + DataMatrix side-by-side")
async def print_stacked(req: PrintRequest):
    try:
        loop = asyncio.get_running_loop()
        code_task = loop.run_in_executor(None, make_code128, req.data)
        dm_task = loop.run_in_executor(None, make_datamatrix, req.data)
        code_img, dm_img = await asyncio.gather(code_task, dm_task)

        label_img = compose_label([code_img, dm_img])
        send_to_printer(label_img, req.printer_ip, req.model, req.label)

    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

    return {
        "status": "printed",
        "model": req.model,
        "label_width_mm": req.label,
        "layout": "code128 + datamatrix side by side",
    }