"""Monitor de port serial: identifica formatul unui cantar necunoscut."""
from __future__ import annotations

import math

from flask import Blueprint, current_app, flash, redirect, render_template, request, url_for

from ..probe import BAUD_RATES, FRAMINGS, ProbeError, list_ports, save_capture, sweep
from ..scale import get_scale

bp = Blueprint("monitor", __name__, url_prefix="/monitor")


def _form_values() -> dict:
    def number(name: str, default: float) -> float:
        raw = (request.form.get(name) or "").strip().replace(",", ".")
        try:
            value = float(raw)
        except ValueError:
            return default
        return value if math.isfinite(value) else default

    return {
        "port": (request.form.get("port") or "").strip(),
        "baud": int(number("baud", 9600)),
        "framing": (request.form.get("framing") or "8N1").strip().upper(),
        "seconds": min(max(number("seconds", 5), 0.5), 30),
        "save": bool(request.form.get("save")),
        "name": (request.form.get("name") or "capture").strip()[:60],
        "scan": bool(request.form.get("scan")),
    }


@bp.route("", methods=["GET", "POST"])
def index():
    scale = get_scale(current_app)
    values = _form_values() if request.method == "POST" else {
        "port": "", "baud": 9600, "framing": "8N1", "seconds": 5.0,
        "save": False, "name": "capture", "scan": False,
    }

    result = None
    scan_hits = None
    saved_path = None
    error = None

    if request.method == "POST":
        if not values["port"]:
            error = "Alege portul serial."
        elif values["scan"]:
            try:
                rows = sweep(values["port"], seconds=min(values["seconds"], 2.0),
                             framings=(values["framing"],), bauds=BAUD_RATES)
                scan_hits = [r for r in rows if r.get("bytes")]
                if not scan_hits:
                    error = "Niciun byte primit la vitezele incercate. Verifica cablul si setarile cantarului."
            except ProbeError as exc:
                error = str(exc)
        else:
            result = scale.probe(values["port"], values["baud"], values["framing"], values["seconds"])
            if not result.get("ok"):
                error = result.get("error") or "Portul nu a putut fi deschis."
            elif values["save"] and result.get("frames"):
                try:
                    saved_path = save_capture(
                        current_app.config["INSTANCE_DIR"] / "captures",
                        values["name"],
                        result["frames"],
                    )
                    flash(f"Captura a fost salvata in {saved_path}.", "success")
                except OSError as exc:
                    error = f"Captura nu a putut fi scrisa: {exc}"

    return render_template(
        "monitor.html",
        values=values,
        ports=list_ports(),
        profiles=scale.profiles(),
        result=result,
        scan_hits=scan_hits,
        saved_path=saved_path,
        error=error,
        baud_rates=BAUD_RATES,
        framings=FRAMINGS,
    )