# gui.py — Tk-App mit Interface-Dropdown, Link Up/Down, Settings-View/Save + CAN-Trace
from __future__ import annotations
import json
import threading
import time
import tkinter as tk
from tkinter import ttk, messagebox
from collections import deque, defaultdict

import can  # nur für Trace-Reader

from .config import load_settings, setup_logging, SETTINGS_PATH, APP_ROOT
from .simulator import EcuState, DrivelineModel
from .can import (
    ObdResponder, make_speed_response, make_rpm_response,
    list_can_ifaces, link_up, link_down,
    have_cap_netadmin, link_state, link_kind
)


# ---------- kleine Trace-Helfer ----------
class TraceCollector:
    """
    Liest mit eigenem BufferedReader vom SocketCAN und sammelt Frames.
    - stream_buffer: deque mit (ts, id, dlc, data_bytes)
    - aggregate: dict[(id, dir)] -> {count, last_ts, last_data}
    """
    def __init__(self, channel: str):
        self.channel = channel
        self.bus = None
        self._run = threading.Event(); self._run.set()
        self._thread = threading.Thread(target=self._rx_loop, name="CAN-TRACE", daemon=True)
        self.stream_buffer = deque(maxlen=2000)
        self.lock = threading.Lock()

    def _open(self):
        self._close()
        self.bus = can.interface.Bus(channel=self.channel, interface="socketcan")

    def _close(self):
        try:
            if self.bus: self.bus.shutdown()
        except Exception: pass
        self.bus = None

    def start(self):
        self._thread.start()

    def stop(self):
        self._run.clear()
        try: self._thread.join(timeout=1.0)
        except RuntimeError: pass
        self._close()

    def _rx_loop(self):
        backoff = 0.5
        while self._run.is_set():
            if self.bus is None:
                if link_state(self.channel) == "UP":
                    try:
                        self._open()
                        backoff = 0.5
                    except Exception:
                        time.sleep(backoff); backoff = min(5.0, backoff*1.7)
                        continue
                else:
                    time.sleep(0.5); continue
            try:
                msg = self.bus.recv(0.05)
                if msg and not msg.is_error_frame and not msg.is_remote_frame:
                    ts = time.time()
                    with self.lock:
                        self.stream_buffer.append((ts, msg.arbitration_id, msg.dlc, bytes(msg.data)))
            except (can.CanOperationError, OSError):
                # IF down → ruhig schließen, kein Traceback
                self._close()
                time.sleep(0.5)
            except Exception:
                time.sleep(0.05)

    def snapshot_stream(self):
        with self.lock:
            return list(self.stream_buffer)


def launch_gui():
    cfg = load_settings()
    logger = setup_logging(cfg)

    # read config values
    can_iface = (cfg.get("can", {}).get("interface")) or "can0"
    resp_id_raw = (cfg.get("can", {}).get("resp_id")) or "0x7E8"
    try:
        resp_id = int(resp_id_raw, 16) if isinstance(resp_id_raw, str) else int(resp_id_raw)
    except Exception:
        resp_id = 0x7E8
    timeout_ms = cfg.get("can", {}).get("timeout_ms", 200)
    bitrate = cfg.get("can", {}).get("baudrate", 500000)

    ecu = EcuState(DrivelineModel())
    responder = ObdResponder(interface=can_iface, resp_id=resp_id, timeout_ms=timeout_ms, logger=logger)

    # register providers
    responder.register_pid(0x0D, lambda: make_speed_response(int(round(ecu.snapshot()[3]))))
    responder.register_pid(0x0C, lambda: make_rpm_response(int(ecu.snapshot()[2])))

    # physics thread
    running = True
    def physics_loop():
        while running:
            ecu.update()
            time.sleep(0.02)
    t = threading.Thread(target=physics_loop, daemon=True)
    t.start()

    # Trace-Collector (eigener Bus, hört alles auf can_iface)
    tracer = TraceCollector(can_iface)
    tracer.start()

    # --- Tk UI ---
    root = tk.Tk()
    root.title("OBD-II ECU Simulator – SocketCAN")

    # window size from cfg
    try:
        w = int(cfg["ui"]["window"]["width"]); h = int(cfg["ui"]["window"]["height"])
        root.geometry(f"{w}x{h}")
    except Exception:
        pass

    # fonts/styles
    family = cfg.get("ui", {}).get("font_family", "TkDefaultFont")
    size = int(cfg.get("ui", {}).get("font_size", 10))
    style = ttk.Style()
    style.configure("TLabel", font=(family, size))
    style.configure("Header.TLabel", font=(family, size+2, "bold"))
    style.configure("TButton", font=(family, size))

    # layout
    root.columnconfigure(0, weight=1); root.rowconfigure(0, weight=1)
    main = ttk.Frame(root, padding=10); main.grid(row=0, column=0, sticky="nsew")
    main.columnconfigure(1, weight=1)

    # === Controls: Gear + Throttle ===
    ttk.Label(main, text="Gang").grid(row=0, column=0, sticky="w")
    gear_var = tk.IntVar(value=0)
    gear_box = ttk.Combobox(main, textvariable=gear_var, state="readonly", values=[0,1,2,3,4,5,6], width=5)
    gear_box.grid(row=0, column=1, sticky="w", padx=(6,12))
    gear_box.bind("<<ComboboxSelected>>", lambda _e: ecu.set_gear(gear_var.get()))

    ttk.Label(main, text="Gas (%)").grid(row=1, column=0, sticky="w")
    thr = ttk.Scale(main, from_=0, to=100, orient="horizontal",
                    command=lambda v: ecu.set_throttle(int(float(v))))
    thr.set(0)
    thr.grid(row=1, column=1, sticky="ew", padx=(6,12))

    lbl_speed = ttk.Label(main, text="Speed: 0 km/h", style="Header.TLabel")
    lbl_rpm = ttk.Label(main, text="RPM: 0")
    lbl_speed.grid(row=2, column=0, columnspan=2, sticky="w", pady=(10,0))
    lbl_rpm.grid(row=3, column=0, columnspan=2, sticky="w")

    # === CAN Panel ===
    sep = ttk.Separator(main); sep.grid(row=4, column=0, columnspan=2, sticky="ew", pady=(10,10))

    can_frame = ttk.LabelFrame(main, text="CAN & Settings", padding=10)
    can_frame.grid(row=5, column=0, columnspan=2, sticky="nsew")
    can_frame.columnconfigure(1, weight=1)

    ttk.Label(can_frame, text="Interface").grid(row=0, column=0, sticky="w")
    iface_var = tk.StringVar(value=can_iface)
    iface_list = list_can_ifaces() or [can_iface]
    iface_dd = ttk.Combobox(can_frame, textvariable=iface_var, values=iface_list, state="readonly", width=12)
    iface_dd.grid(row=0, column=1, sticky="w", padx=(6,12))

    def refresh_ifaces():
        lst = list_can_ifaces()
        if not lst:
            messagebox.showwarning("Interfaces", "Keine can*/vcan* Interfaces gefunden.")
            return
        iface_dd.config(values=lst)
    ttk.Button(can_frame, text="Refresh", command=refresh_ifaces).grid(row=0, column=2, padx=4)

    ttk.Label(can_frame, text="RESP-ID (hex)").grid(row=1, column=0, sticky="w")
    resp_var = tk.StringVar(value=f"0x{resp_id:03X}")
    resp_entry = ttk.Entry(can_frame, textvariable=resp_var, width=10)
    resp_entry.grid(row=1, column=1, sticky="w", padx=(6,12))

    ttk.Label(can_frame, text="Timeout (ms)").grid(row=2, column=0, sticky="w")
    to_var = tk.IntVar(value=int(timeout_ms))
    to_spin = ttk.Spinbox(can_frame, from_=10, to=5000, increment=10, textvariable=to_var, width=8)
    to_spin.grid(row=2, column=1, sticky="w", padx=(6,12))

    ttk.Label(can_frame, text="Bitrate").grid(row=3, column=0, sticky="w")
    br_var = tk.IntVar(value=int(bitrate))
    br_spin = ttk.Spinbox(can_frame, from_=20000, to=1000000, increment=10000, textvariable=br_var, width=10)
    br_spin.grid(row=3, column=1, sticky="w", padx=(6,12))

    # unter Bitrate-Spinbox
    set_params = tk.BooleanVar(value=True)
    ttk.Checkbutton(can_frame, text="Bitrate beim UP setzen", variable=set_params).grid(row=3, column=2, sticky="w")

    # add Kind-Anzeige
    kind_label = ttk.Label(can_frame, text=f"Kind: {link_kind(can_iface)}")
    kind_label.grid(row=0, column=3, sticky="w", padx=(12,0))

    # Link control
    def do_link_up():
        try:
            # Kind-Anzeige aktualisieren (falls Interface gewechselt)
            kind_label.config(text=f"Kind: {link_kind(iface_var.get())}")

            if link_state(iface_var.get()) == "UP":
                messagebox.showinfo("CAN", f"{iface_var.get()} ist bereits UP")
                return
            # NEU: set_params aus Checkbox
            link_up(iface_var.get(), bitrate=br_var.get(), fd=False, set_params=set_params.get())
            msg = f"{iface_var.get()} ist UP"
            if set_params.get():
                msg += f" @ {br_var.get()} bit/s (falls vom Treiber unterstützt)"
            else:
                msg += " (Bitrate unverändert)"
            messagebox.showinfo("CAN", msg)
        except PermissionError as e:
            messagebox.showerror("Berechtigung", str(e))
        except Exception as e:
            messagebox.showerror("CAN", f"Link UP fehlgeschlagen:\n{e}")

    def do_link_down():
        try:
            if link_state(iface_var.get()) == "DOWN":
                messagebox.showinfo("CAN", f"{iface_var.get()} ist bereits DOWN")
                return
            link_down(iface_var.get())
            messagebox.showinfo("CAN", f"{iface_var.get()} ist DOWN")
        except PermissionError as e:
            messagebox.showerror("Berechtigung", str(e))
        except Exception as e:
            messagebox.showerror("CAN", f"Link DOWN fehlgeschlagen:\n{e}")

    btn_up   = ttk.Button(can_frame, text="Link UP", command=do_link_up)
    btn_down = ttk.Button(can_frame, text="Link DOWN", command=do_link_down)
    btn_up.grid(row=4, column=0, pady=(8,0), sticky="w")
    btn_down.grid(row=4, column=1, pady=(8,0), sticky="w")

    # Rebind responder
    def do_rebind():
        nonlocal can_iface, resp_id, timeout_ms, bitrate, tracer
        can_iface = iface_var.get()
        try:
            new_resp = int(resp_var.get(), 16)
        except Exception:
            messagebox.showerror("RESP-ID", "Bitte gültige Hex-Zahl, z.B. 0x7E8")
            return
        resp_id = new_resp
        timeout_ms = to_var.get()
        bitrate = br_var.get()
        try:
            responder.rebind(interface=can_iface, resp_id=resp_id)
            # Trace-Collector auf neues IF neu binden
            try:
                tracer.stop()
            except Exception:
                pass
            tracer = TraceCollector(can_iface)
            tracer.start()
            messagebox.showinfo("CAN", f"Responder neu gebunden: {can_iface}, RESP 0x{resp_id:03X}")
        except Exception as e:
            messagebox.showerror("CAN", f"Rebind fehlgeschlagen:\n{e}")

    ttk.Button(can_frame, text="Responder Rebind", command=do_rebind).grid(row=4, column=2, pady=(8,0), sticky="w")

    # CAP-Status
    caps_ok = have_cap_netadmin()
    cap_label = ttk.Label(can_frame, text=f"CAP_NET_ADMIN: {'yes' if caps_ok else 'no'}")
    cap_label.grid(row=6, column=0, columnspan=2, sticky="w", pady=(6,0))
    if not caps_ok:
        btn_up.state(["disabled"]); btn_down.state(["disabled"])

    # Statusbar
    status = ttk.Label(main, text=f"CAN: {can_iface} | RESP-ID: 0x{resp_id:03X}", relief="sunken", anchor="w")
    status.grid(row=6, column=0, columnspan=2, sticky="ew", pady=(10,0))

    # === TRACE-FENSTER (unten) ===
    trace_frame = ttk.LabelFrame(root, text="CAN Trace", padding=6)
    trace_frame.grid(row=1, column=0, sticky="nsew")
    root.rowconfigure(1, weight=1)
    trace_frame.columnconfigure(0, weight=1)
    trace_frame.rowconfigure(1, weight=1)

    # Controls: Mode, Pause, Clear, Autoscroll
    ctrl = ttk.Frame(trace_frame)
    ctrl.grid(row=0, column=0, sticky="ew", pady=(0,4))
    ctrl.columnconfigure(5, weight=1)

    mode_var = tk.StringVar(value="stream")  # "stream" | "aggregate"
    ttk.Label(ctrl, text="Modus:").grid(row=0, column=0, sticky="w")
    mode_dd = ttk.Combobox(ctrl, textvariable=mode_var, state="readonly", width=10,
                           values=["stream", "aggregate"])
    mode_dd.grid(row=0, column=1, sticky="w", padx=(4,12))

    paused = tk.BooleanVar(value=False)
    ttk.Checkbutton(ctrl, text="Pause", variable=paused).grid(row=0, column=2, sticky="w")

    autoscroll = tk.BooleanVar(value=True)
    ttk.Checkbutton(ctrl, text="Auto-Scroll", variable=autoscroll).grid(row=0, column=3, sticky="w")

    def do_clear():
        nonlocal aggregate_cache
        tree.delete(*tree.get_children())
        aggregate_cache.clear()
    ttk.Button(ctrl, text="Clear", command=do_clear).grid(row=0, column=4, padx=(8,0), sticky="w")

    # Treeview
    cols_stream = ("time", "dir", "id", "dlc", "data")
    cols_agg    = ("id", "dir", "count", "last_time", "last_dlc", "last_data")

    tree = ttk.Treeview(trace_frame, columns=cols_stream, show="headings", height=10)
    tree.grid(row=1, column=0, sticky="nsew")
    sb_y = ttk.Scrollbar(trace_frame, orient="vertical", command=tree.yview)
    tree.configure(yscrollcommand=sb_y.set)
    sb_y.grid(row=1, column=1, sticky="ns")

    def setup_columns(mode: str):
        tree.delete(*tree.get_children())
        if mode == "stream":
            tree.config(columns=cols_stream)
            headings = [("time","Time"),("dir","Dir"),("id","ID"),("dlc","DLC"),("data","Data")]
            widths   = [140, 60, 90, 60, 520]
        else:
            tree.config(columns=cols_agg)
            headings = [("id","ID"),("dir","Dir"),("count","Count"),("last_time","Last Time"),("last_dlc","DLC"),("last_data","Last Data")]
            widths   = [90, 60, 80, 140, 60, 520]
        for (col, text), w in zip(headings, widths):
            tree.heading(col, text=text)
            tree.column(col, width=w, anchor="w")
    setup_columns("stream")

    aggregate_cache: dict[tuple[int,str], dict] = {}

    def fmt_time(ts: float) -> str:
        # hh:mm:ss.mmm
        lt = time.localtime(ts)
        return time.strftime("%H:%M:%S", lt) + f".{int((ts%1)*1000):03d}"

    def fmt_id(i: int) -> str:
        return f"0x{i:03X}"

    def fmt_data(b: bytes) -> str:
        return " ".join(f"{x:02X}" for x in b)

    # periodic UI update
    last_index = 0
    def tick():
        nonlocal can_iface, resp_id, last_index
        # Top-Status
        g, tval, rpm, spd = ecu.snapshot()
        caps = "CAP:yes" if have_cap_netadmin() else "CAP:no"
        st = link_state(can_iface)
        lbl_speed.config(text=f"Speed: {int(round(spd))} km/h")
        lbl_rpm.config(text=f"RPM: {rpm}")
        st = link_state(can_iface)
        kd = link_kind(can_iface)
        status.config(text=f"CAN: {can_iface}({st},{kd}) | RESP-ID: 0x{resp_id:03X} | Gear {g} | Throttle {tval}% | {caps}")


        # Trace
        if not paused.get():
            mode = mode_var.get()
            if mode == "stream":
                setup_columns("stream") if tree["columns"] != cols_stream else None
                # append new items
                buf = tracer.snapshot_stream()
                # nur neue ab letztem Index
                for ts, cid, dlc, data in buf[last_index:]:
                    # Richtung heuristisch
                    if cid == 0x7DF:
                        d = "RX"
                    elif cid == resp_id:
                        d = "TX"
                    else:
                        d = "?"
                    tree.insert("", "end",
                                values=(fmt_time(ts), d, fmt_id(cid), dlc, fmt_data(data)))
                # autoscroll
                if autoscroll.get() and buf[last_index:]:
                    tree.see(tree.get_children()[-1])
                last_index = len(buf)
            else:
                setup_columns("aggregate") if tree["columns"] != cols_agg else None
                # baue Aggregat neu (leicht, schnell)
                buf = tracer.snapshot_stream()
                agg: dict[tuple[int,str], dict] = {}
                for ts, cid, dlc, data in buf:
                    if cid == 0x7DF:
                        d = "RX"
                    elif cid == resp_id:
                        d = "TX"
                    else:
                        d = "?"
                    key = (cid, d)
                    entry = agg.get(key)
                    if entry is None:
                        agg[key] = {"count":1, "last_ts":ts, "last_dlc":dlc, "last_data":data}
                    else:
                        entry["count"] += 1
                        if ts >= entry["last_ts"]:
                            entry["last_ts"] = ts
                            entry["last_dlc"] = dlc
                            entry["last_data"] = data
                # nur neu zeichnen, wenn sich was ändert
                if agg != aggregate_cache:
                    tree.delete(*tree.get_children())
                    # sortiert nach ID, RX vor TX
                    for (cid, d) in sorted(agg.keys(), key=lambda k:(k[0], 0 if k[1]=="RX" else 1)):
                        e = agg[(cid,d)]
                        tree.insert("", "end",
                                    values=(fmt_id(cid), d, e["count"],
                                            fmt_time(e["last_ts"]),
                                            e["last_dlc"], fmt_data(e["last_data"])))
                    aggregate_cache.clear()
                    aggregate_cache.update(agg)

        root.after(50, tick)

    tick()

    def on_close():
        nonlocal running
        running = False
        try:
            tracer.stop()
        except Exception:
            pass
        try:
            responder.stop()
        finally:
            root.destroy()

    root.protocol("WM_DELETE_WINDOW", on_close)
    root.mainloop()