"""
An ECG monitor sweep, drawing left to right
===============================================

The same six-second rhythm strip as :doc:`plot_06_ecg_rhythm_strip`, drawn
the way a bedside monitor actually renders it: a trace sweeping left to
right across a fixed window, each beat appearing only once the sweep
reaches it. A monitor does not show the whole strip instantly and it does
not scroll -- it draws, the same progressive reveal used for a live control
chart (:doc:`../manufacturing/plot_06_control_chart_live`) and a live
training run (:doc:`../computing/plot_06_training_curve_live`), just at ECG
speed instead of theirs.

The premature beat is the reason this view matters clinically, not only
visually. On a finished static strip it is one odd complex among many,
already contextualized by everything before and after it. Watching the
sweep reach it -- no P wave, a QRS shaped wrong, arriving early -- is closer
to how it is actually caught at the bedside: a single beat that looks wrong
the instant it is drawn, followed by the pause while the rhythm resets,
rather than a pattern spotted by scanning a completed printout.
"""
import os
import tempfile

import numpy as np
import plotpress

rng = np.random.default_rng(60)

FS = 250.0                                          # samples per second
DURATION = 6.0
t = np.arange(0.0, DURATION, 1.0 / FS)


def gaussian(t, centre, amp, width):
    return amp * np.exp(-((t - centre) ** 2) / (2.0 * width ** 2))


def normal_beat(t, onset):
    return (gaussian(t, onset + 0.00, 0.13, 0.022)
            + gaussian(t, onset + 0.16, -0.10, 0.008)
            + gaussian(t, onset + 0.19, 1.15, 0.009)
            + gaussian(t, onset + 0.22, -0.22, 0.010)
            + gaussian(t, onset + 0.42, 0.28, 0.038))


def ectopic_beat(t, onset):
    return (gaussian(t, onset + 0.18, -0.75, 0.030)
            + gaussian(t, onset + 0.26, 0.35, 0.045)
            + gaussian(t, onset + 0.46, 0.30, 0.070))


onsets, kinds, clock = [], [], 0.35
while clock < DURATION - 0.6:
    onsets.append(clock)
    kinds.append("N")
    clock += 0.833 + 0.035 * np.sin(2 * np.pi * clock / 4.0)
onsets[3], kinds[3] = onsets[3] - 0.24, "V"
for i in range(4, len(onsets)):
    onsets[i] += 0.20

ecg = np.zeros_like(t)
for onset, kind in zip(onsets, kinds):
    ecg += (ectopic_beat if kind == "V" else normal_beat)(t, onset)
ecg += 0.06 * np.sin(2 * np.pi * 0.28 * t)
ecg += 0.008 * np.sin(2 * np.pi * 50.0 * t)
ecg += rng.normal(0.0, 0.011, t.size)

n = t.size
N_FRAMES = 60
checkpoints = np.linspace(0, n - 1, N_FRAMES).astype(int)
revealed = np.full((N_FRAMES, n), np.nan)
for f, stop in enumerate(checkpoints):
    revealed[f, :stop + 1] = ecg[:stop + 1]

fig, ax = plotpress.subplots(figsize=(11.0, 3.4))
ax.plot_frames(t, revealed, slider_values=t[checkpoints], slider_label="t (s)",
              color="#111111", label="lead II")
ax.set_aspect(0.4)                                  # ECG paper convention: 25 mm/s, 10 mm/mV
ax.set_xlim(0.0, DURATION)
ax.set_ylim(-0.72, 1.50)
ax.set_xlabel("time (s)")
ax.set_ylabel("lead II (mV)")
ax.set_title("Monitor sweep: the PVC looks wrong the instant it is drawn")
ax.legend(loc="upper right")
fig.tight_layout()

gif_path = os.path.join(tempfile.gettempdir(), "plotpress_ecg_monitor_sweep.gif")
fig.save(gif_path, fps=15)