#!/usr/bin/env python3
"""Curses TUI for the filament dryer Arduino."""

from __future__ import annotations

import curses
import re
import sys
import threading
from collections import deque
from dataclasses import dataclass, field
from datetime import datetime
from pathlib import Path

from capture_csv import (
    decode_line,
    write_csv_row,
)

PRESETS: list[tuple[str, float]] = [
    ("PLA", 55),
    ("PETG", 65),
    ("ABS", 65),
    ("ASA", 65),
    ("HIPS", 65),
    ("Nylon", 75),
    ("PC", 75),
    ("PVA", 45),
    ("TPU/TPE", 55),
    ("PP", 55),
    ("Idle", 0),
]

STATUS_RE = re.compile(
    r"target=(?P<target>\S+)\s+"
    r"cutoff=(?P<cutoff_temp>\S+)\s+"
    r"avg=(?P<avg>[\d.]+)C\s+"
    r"min=(?P<min>[\d.]+)C\s+"
    r"max=(?P<max>[\d.]+)C\s+"
    r"spread=(?P<spread>[\d.]+)C\s+"
    r"heatlim=(?P<heatlim>\d+)%\s+"
    r"heater=(?P<heater>[\d.]+)%\s+"
    r"fan=(?P<fan>\d+)(?P<fan_note>\([^)]*\))?\s+"
    r"cutoff=(?P<cutoff_active>\S+)\s+"
    r"failsafe=(?P<failsafe>\S+)\s+"
    r"mode=(?P<mode>\S+)\s+"
    r"sensors=\[(?P<sensors>.*)\]"
)

SENSOR_RE = re.compile(r"ch(\d+):([\d.]+)C/(\d+)%|ch(\d+):ERR")


@dataclass
class DryerState:
    target: str = "—"
    cutoff: str = "—"
    avg: str = "—"
    min_temp: str = "—"
    max_temp: str = "—"
    spread: str = "—"
    heatlim: str = "—"
    heater: str = "—"
    fan: str = "—"
    fan_note: str = ""
    cutoff_active: str = "no"
    failsafe: str = "no"
    mode: str = "—"
    sensors: list[tuple[str, str, str]] = field(default_factory=list)
    messages: deque[str] = field(default_factory=lambda: deque(maxlen=12))
    csv_logging: bool = False
    csv_path: Path | None = None
    port: str = ""
    connected: bool = False


def parse_status(line: str) -> dict | None:
    match = STATUS_RE.search(line)
    if not match:
        return None
    data = match.groupdict()
    sensors: list[tuple[str, str, str]] = []
    for part in data["sensors"].split(", "):
        part = part.strip()
        if not part:
            continue
        m = SENSOR_RE.match(part)
        if not m:
            continue
        if m.group(4):
            sensors.append((m.group(4), "ERR", ""))
        else:
            sensors.append((m.group(1), m.group(2), m.group(3)))
    data["sensor_list"] = sensors
    data["fan_note"] = data.get("fan_note") or ""
    return data


def apply_status(state: DryerState, data: dict) -> None:
    target = data["target"]
    if target.startswith("idle"):
        state.target = "idle"
    elif target.endswith("C"):
        state.target = target[:-1]
    else:
        state.target = target
    cutoff = data["cutoff_temp"]
    if cutoff in ("n/aC", "n/a"):
        state.cutoff = "n/a"
    elif cutoff.endswith("C"):
        state.cutoff = cutoff[:-1]
    else:
        state.cutoff = cutoff
    state.avg = data["avg"]
    state.min_temp = data["min"]
    state.max_temp = data["max"]
    state.spread = data["spread"]
    state.heatlim = data["heatlim"]
    state.heater = data["heater"]
    state.fan = data["fan"]
    state.fan_note = data["fan_note"]
    state.cutoff_active = data["cutoff_active"]
    state.failsafe = data["failsafe"]
    state.mode = data["mode"]
    state.sensors = data["sensor_list"]


class SerialWorker:
    def __init__(self, ser, state: DryerState, lock: threading.Lock):
        self.ser = ser
        self.state = state
        self.lock = lock
        self.stop = threading.Event()
        self._log_fh = None
        self._header_written = [False]
        self._thread: threading.Thread | None = None

    def start(self) -> None:
        self._thread = threading.Thread(target=self._run, daemon=True)
        self._thread.start()
        with self.lock:
            self.state.connected = True
            self.state.port = getattr(self.ser, "port", "") or getattr(self.ser, "name", "")
            self.state.messages.append("Connected")

    def close(self) -> None:
        self.stop.set()
        if self._thread is not None:
            self._thread.join(timeout=1.5)
        if self._log_fh is not None:
            self._log_fh.close()
            self._log_fh = None

    def send(self, command: str) -> None:
        if self.ser is None:
            return
        self.ser.write((command.strip() + "\n").encode("utf-8"))
        self.ser.flush()

    def set_csv_logging(self, enabled: bool, log_dir: Path) -> None:
        with self.lock:
            if enabled and not self.state.csv_logging:
                log_dir.mkdir(parents=True, exist_ok=True)
                path = log_dir / f"dryer_{datetime.now():%Y%m%d_%H%M%S}.csv"
                self._log_fh = path.open("w", encoding="utf-8")
                self._header_written = [False]
                self.state.csv_path = path
                self.state.csv_logging = True
                self.state.messages.append(f"CSV -> {path.name}")
                self.send("log on")
            elif not enabled and self.state.csv_logging:
                self.send("log off")
                self.state.csv_logging = False
                self.state.csv_path = None
                if self._log_fh is not None:
                    self._log_fh.close()
                    self._log_fh = None
                self.state.messages.append("CSV logging off")

    def _note(self, line: str) -> None:
        with self.lock:
            self.state.messages.append(line)

    def _run(self) -> None:
        assert self.ser is not None
        while not self.stop.is_set():
            try:
                raw = self.ser.readline()
            except Exception as exc:
                with self.lock:
                    self.state.messages.append(f"Serial error: {exc}")
                break
            if not raw:
                continue
            line = decode_line(raw)
            if not line:
                continue

            if line.startswith("csv,") or line.startswith("csv_hdr,"):
                if self._log_fh is not None:
                    write_csv_row(self._log_fh, line, self._header_written)
                continue

            parsed = parse_status(line)
            if parsed:
                with self.lock:
                    apply_status(self.state, parsed)
                continue

            if line.startswith("OK") or line.startswith("ERR") or line.startswith("WARN"):
                self._note(line)


def _draw_box(win, y: int, x: int, h: int, w: int, title: str) -> None:
    if h < 2 or w < 4:
        return
    try:
        win.addstr(y, x, "+" + "-" * (w - 2) + "+")
        win.addstr(y, x + 2, f" {title} "[: max(0, w - 4)])
        for row in range(1, h - 1):
            win.addstr(y + row, x, "|" + " " * (w - 2) + "|")
        win.addstr(y + h - 1, x, "+" + "-" * (w - 2) + "+")
    except curses.error:
        pass


def _safe_addstr(win, y: int, x: int, text: str, attr: int = 0) -> None:
    height, width = win.getmaxyx()
    if y < 0 or y >= height or x >= width:
        return
    win.addnstr(y, x, text, max(0, width - x - 1), attr)


def _prompt(stdscr, label: str) -> str | None:
    stdscr.nodelay(False)
    stdscr.timeout(-1)
    curses.curs_set(1)
    height, width = stdscr.getmaxyx()
    prompt = f" {label}: "
    row = height - 1
    col = len(prompt)
    buf: list[str] = []

    _safe_addstr(stdscr, row, 0, " " * max(0, width - 1))
    _safe_addstr(stdscr, row, 0, prompt)
    stdscr.move(row, col)
    stdscr.refresh()

    try:
        while True:
            ch = stdscr.getch()
            if ch in (10, 13, curses.KEY_ENTER):
                break
            if ch in (27,):  # Esc
                return None
            if ch in (curses.KEY_BACKSPACE, 127, 8):
                if buf:
                    buf.pop()
            elif ch == curses.KEY_DC:  # Delete — ignore
                pass
            elif 32 <= ch <= 126 and len(buf) < 24:
                buf.append(chr(ch))
            _safe_addstr(stdscr, row, col, (" " * 24))
            _safe_addstr(stdscr, row, col, "".join(buf))
            stdscr.move(row, col + len(buf))
            stdscr.refresh()
    finally:
        curses.curs_set(0)
        stdscr.nodelay(True)
        stdscr.timeout(200)

    text = "".join(buf).strip()
    return text


def _preset_menu(stdscr, worker: SerialWorker) -> None:
    height, width = stdscr.getmaxyx()
    menu_h = min(len(PRESETS) + 2, height - 4)
    menu_w = 28
    y0 = (height - menu_h) // 2
    x0 = (width - menu_w) // 2
    selected = 0

    while True:
        stdscr.erase()
        _draw_box(stdscr, y0, x0, menu_h, menu_w, "Presets")
        for i, (name, temp) in enumerate(PRESETS):
            label = f" {name:<10} {temp:>5.0f} °C"
            attr = curses.A_REVERSE if i == selected else 0
            _safe_addstr(stdscr, y0 + 1 + i, x0 + 1, label.ljust(menu_w - 2), attr)
        _safe_addstr(stdscr, y0 + menu_h - 1, x0 + 2, "Enter select  Esc cancel")
        stdscr.refresh()
        key = stdscr.getch()
        if key in (27, ord("q")):
            return
        if key in (curses.KEY_UP, ord("k")):
            selected = (selected - 1) % len(PRESETS)
        elif key in (curses.KEY_DOWN, ord("j")):
            selected = (selected + 1) % len(PRESETS)
        elif key in (10, 13, curses.KEY_ENTER):
            name, temp = PRESETS[selected]
            worker.send(f"target {temp:g}")
            worker._note(f"Preset {name} -> {temp:g} °C")
            return


def _draw_dashboard(stdscr, state: DryerState) -> None:
    stdscr.erase()
    height, width = stdscr.getmaxyx()
    if height < 18 or width < 60:
        _safe_addstr(stdscr, 0, 0, "Terminal too small (need 60x18).")
        stdscr.refresh()
        return

    title = f" Filament Dryer — {state.port} "
    _safe_addstr(stdscr, 0, 1, title, curses.A_BOLD)

    row = 2
    _safe_addstr(stdscr, row, 2, f"Target:   {state.target:>8} °C", curses.A_BOLD)
    _safe_addstr(stdscr, row, 28, f"Mode: {state.mode}")
    cutoff_attr = curses.A_BOLD | curses.color_pair(1) if state.cutoff_active == "YES" else 0
    _safe_addstr(stdscr, row, 48, f"Cutoff: {state.cutoff_active}", cutoff_attr)

    row += 1
    _safe_addstr(stdscr, row, 2, f"Avg: {state.avg} °C   Min: {state.min_temp} °C   Max: {state.max_temp} °C   Spread: {state.spread} °C")

    row += 1
    fan_text = f"{state.fan} %{state.fan_note}"
    _safe_addstr(stdscr, row, 2, f"Heater: {state.heater} %   Fan: {fan_text}   Limit: {state.heatlim} %")

    row += 2
    _draw_box(stdscr, row, 1, 5, width - 2, "Sensors")
    sensor_row = row + 1
    col = 3
    if state.sensors:
        for ch, temp, hum in state.sensors:
            if temp == "ERR":
                text = f"ch{ch}: ERR"
            else:
                text = f"ch{ch}: {temp} °C  {hum} %"
            _safe_addstr(stdscr, sensor_row, col, text.ljust(22))
            col += 24
            if col + 22 >= width - 2:
                sensor_row += 1
                col = 3
    else:
        _safe_addstr(stdscr, sensor_row, 3, "Waiting for readings…")

    row += 5
    help_y = height - 2
    log_h = help_y - row - 1
    if log_h < 4:
        _safe_addstr(stdscr, row, 2, "Terminal too small for message panel.")
        stdscr.refresh()
        return

    _draw_box(stdscr, row, 1, log_h, width - 2, "Messages")
    csv_line = "on" if state.csv_logging else "off"
    if state.csv_path:
        csv_line += f" ({state.csv_path.name})"
    _safe_addstr(stdscr, row + 1, 3, f"CSV: {csv_line}")
    msg_row = row + 2
    for msg in list(state.messages)[-(log_h - 3) :]:
        _safe_addstr(stdscr, msg_row, 3, msg[: width - 6])
        msg_row += 1

    help_y = height - 2
    _safe_addstr(
        stdscr,
        help_y,
        1,
        "0 idle | t target | p presets | f fan | l log | a autotune | : cmd | q quit",
        curses.A_DIM,
    )
    stdscr.refresh()


def _curses_main(stdscr, ser, log_dir: Path, auto_log_on: bool) -> int:
    curses.curs_set(0)
    curses.start_color()
    curses.use_default_colors()
    curses.init_pair(1, curses.COLOR_RED, -1)
    stdscr.nodelay(True)
    stdscr.timeout(200)
    stdscr.clear()

    state = DryerState()
    lock = threading.Lock()
    worker = SerialWorker(ser, state, lock)
    worker.start()
    worker.send("status")
    if auto_log_on:
        worker.set_csv_logging(True, log_dir)

    try:
        while True:
            with lock:
                snapshot = DryerState(
                    target=state.target,
                    cutoff=state.cutoff,
                    avg=state.avg,
                    min_temp=state.min_temp,
                    max_temp=state.max_temp,
                    spread=state.spread,
                    heatlim=state.heatlim,
                    heater=state.heater,
                    fan=state.fan,
                    fan_note=state.fan_note,
                    cutoff_active=state.cutoff_active,
                    failsafe=state.failsafe,
                    mode=state.mode,
                    sensors=list(state.sensors),
                    messages=deque(state.messages, maxlen=12),
                    csv_logging=state.csv_logging,
                    csv_path=state.csv_path,
                    port=state.port,
                    connected=state.connected,
                )
            _draw_dashboard(stdscr, snapshot)

            key = stdscr.getch()
            if key == -1:
                continue
            if key in (ord("q"), ord("Q"), 27):
                break
            if key == ord("0"):
                worker.send("target 0")
            elif key == ord("t"):
                value = _prompt(stdscr, "Target °C (0 = idle)")
                if value is not None and value != "":
                    worker.send(f"target {value}")
            elif key == ord("p"):
                stdscr.nodelay(False)
                stdscr.timeout(-1)
                _preset_menu(stdscr, worker)
                stdscr.nodelay(True)
                stdscr.timeout(200)
            elif key == ord("f"):
                worker.send("fan on")
            elif key == ord("F"):
                worker.send("fan off")
            elif key == ord("l"):
                with lock:
                    enable = not state.csv_logging
                worker.set_csv_logging(enable, log_dir)
            elif key == ord("a"):
                value = _prompt(stdscr, "Autotune °C (Enter = 40)")
                if value is not None:
                    cmd = "autotune" if value == "" else f"autotune {value}"
                    worker.send(cmd)
            elif key == ord(":"):
                value = _prompt(stdscr, "Command")
                if value is not None and value != "":
                    worker.send(value)
            elif key == ord("s"):
                worker.send("status")
    finally:
        worker.close()

    return 0


def run_tui(port: str | None, baud: int, log_dir: Path, auto_log_on: bool = True) -> int:
    if not sys.stdin.isatty() or not sys.stdout.isatty():
        print("TUI requires an interactive terminal.", file=sys.stderr)
        print("Use: ssh -t user@host 'python3 scripts/capture_csv.py tui'", file=sys.stderr)
        print("Headless logging: python3 scripts/capture_csv.py log", file=sys.stderr)
        return 1

    from capture_csv import import_serial, open_serial, resolve_port

    resolved = resolve_port(port)
    import_serial()
    try:
        ser = open_serial(resolved, baud)
    except Exception as exc:
        print(f"Cannot open serial port {resolved}: {exc}", file=sys.stderr)
        return 1

    try:
        return curses.wrapper(
            lambda stdscr: _curses_main(stdscr, ser, log_dir, auto_log_on)
        )
    except curses.error as exc:
        print(f"TUI failed: {exc}", file=sys.stderr)
        return 1
    except Exception as exc:
        print(f"Error: {exc}", file=sys.stderr)
        return 1
    finally:
        if ser.is_open:
            ser.close()


if __name__ == "__main__":
    raise SystemExit(run_tui(None, 115200, Path("logs"), True))