#!/usr/bin/env bash
# Mic-path host-side diagnostic for the DS5Dongle (OLED Edition).
#
# Subcommands:
#   status   — one-shot snapshot of dongle USB / ALSA / capture stream state.
#              Prints whether the dongle enumerated, what ALSA card # it
#              took, the capture stream's current alt setting + sync mode,
#              and whether a paired DualSense is reachable.
#   capture  — runs a 3-second arecord on the mic IN endpoint, reports
#              ALSA result code, captured byte count, and a non-silence
#              indicator (peak abs sample value via Python's wave module).
#              Tells us in one shot whether the firmware is producing
#              actual isoc-IN data and whether anything audio-like is
#              showing up.
#   watch    — loops `status` every 2 seconds, prints only on changes —
#              useful for catching the moment pairing completes or the
#              arecord stream opens/closes.
#
# Why a script: lets the assistant query mic-path state directly from
# the host rather than waiting for the user to relay OLED counters
# through chat, which dominated the early Phase-3 debugging time.
#
# Requirements (all already installed on the user's machine):
#   - arecord (alsa-utils)
#   - lsusb (usbutils)
#   - python3 (for wave-file stats)

set -u

VID=054c
PID=0ce6
DEV_NAME_RE='DualSense Wireless Controller'

find_card() {
    arecord -l 2>/dev/null | awk -v re="$DEV_NAME_RE" '
        $0 ~ re {
            for (i = 1; i <= NF; i++) {
                if ($i == "card") { gsub(":", "", $(i+1)); print $(i+1); exit }
            }
        }'
}

show_status() {
    local card
    card="$(find_card)"

    # USB layer — is the device visible?
    if lsusb -d "${VID}:${PID}" >/dev/null 2>&1; then
        printf 'usb: present (%s:%s)\n' "$VID" "$PID"
    else
        printf 'usb: NOT FOUND — is the dongle plugged in?\n'
        return 1
    fi

    if [[ -z "$card" ]]; then
        printf 'alsa: dongle is on USB but not exposed as an audio card\n'
        return 1
    fi
    printf 'alsa: card %s\n' "$card"

    # Capture stream details (interface 2 alt 1 mic-IN endpoint)
    if [[ -r "/proc/asound/card${card}/stream0" ]]; then
        # Grep just the Capture block so we see status + altset + endpoint
        awk '/^Capture:/,0' "/proc/asound/card${card}/stream0" | head -10 | sed 's/^/  /'
    else
        printf '  (no /proc/asound/card%s/stream0 — older kernel?)\n' "$card"
    fi
}

run_capture() {
    local card secs="${1:-3}"
    card="$(find_card)"
    if [[ -z "$card" ]]; then
        printf 'no dongle capture device found\n'
        return 1
    fi

    local tmp
    tmp="$(mktemp -t mic_diag.XXXXXX.wav)"
    printf 'capturing %ss from card %s into %s ...\n' "$secs" "$card" "$tmp"

    local err
    err="$(arecord -q -D "plughw:${card},0" -f S16_LE -c 2 -r 48000 -d "$secs" "$tmp" 2>&1)"
    local rc=$?
    if (( rc != 0 )); then
        printf 'arecord exit=%d: %s\n' "$rc" "$err"
        rm -f "$tmp"
        return "$rc"
    fi

    # Stats via Python — peak abs sample is enough to distinguish "stream
    # produced silence" from "stream produced actual audio".
    python3 - "$tmp" <<'PY'
import sys, wave, struct
path = sys.argv[1]
with wave.open(path, 'rb') as w:
    nframes = w.getnframes()
    sw = w.getsampwidth()
    ch = w.getnchannels()
    fr = w.getframerate()
    raw = w.readframes(nframes)
nsamples = nframes * ch
fmt = '<' + ('h' * nsamples)
data = struct.unpack(fmt, raw)
peak = max(abs(s) for s in data) if data else 0
nonzero = sum(1 for s in data if s != 0)
rms = (sum(s*s for s in data) / max(len(data), 1)) ** 0.5
print(f'wav: {nframes} frames, {ch} ch, {sw*8}-bit, {fr} Hz')
print(f'samples: nonzero={nonzero}/{nsamples}  peak={peak}  rms={rms:.1f}')
if peak == 0:
    print('verdict: STREAM IS SILENT — firmware not producing isoc-IN data')
elif peak < 100:
    print('verdict: extremely quiet — possibly DC offset only')
else:
    print('verdict: AUDIO PRESENT')
PY
    rm -f "$tmp"
}

watch_status() {
    local prev=""
    while :; do
        local now
        now="$(show_status 2>&1)"
        if [[ "$now" != "$prev" ]]; then
            printf '\n=== %s ===\n%s\n' "$(date '+%H:%M:%S')" "$now"
            prev="$now"
        fi
        sleep 2
    done
}

bt_trace() {
    # Query the firmware's 0xFD vendor feature report via /dev/hidraw —
    # exposes BT-side packet counts, last seen non-0x31 report ID, byte
    # prefixes. Lets us find where the mic stream actually lives without
    # an OLED-relay flash cycle per change.
    python3 - <<'PY'
import fcntl, glob, struct, sys, time

VID, PID = 0x054c, 0x0ce6

def find_dongle():
    for path in sorted(glob.glob('/dev/hidraw*')):
        try:
            f = open(path, 'rb+')
            info = bytearray(8)
            HIDIOCGRAWINFO = 0x80084803
            try:
                fcntl.ioctl(f, HIDIOCGRAWINFO, info)
            except OSError:
                pass
            # Try feature 0xFD; if it returns 64 bytes we know it's our dongle
            buf = bytearray(32); buf[0] = 0xFD
            ioctl_num = (3 << 30) | (32 << 16) | (ord('H') << 8) | 0x07
            try:
                fcntl.ioctl(f, ioctl_num, buf)
                return f
            except OSError:
                f.close()
        except (OSError, PermissionError):
            pass
    return None

f = find_dongle()
if f is None:
    print('no dongle found (or no /dev/hidraw permission)')
    sys.exit(1)

ioctl_num = (3 << 30) | (64 << 16) | (ord('H') << 8) | 0x07

def query():
    buf = bytearray(32); buf[0] = 0xFD
    ioctl_num_32 = (3 << 30) | (32 << 16) | (ord('H') << 8) | 0x07
    fcntl.ioctl(f, ioctl_num_32, buf)
    # Kernel prepends the report ID at byte 0; firmware payload starts at byte 1.
    return bytes(buf[1:])

def decode(b):
    bt31    = struct.unpack('<I', b[0:4])[0]
    btoth   = struct.unpack('<I', b[4:8])[0]
    other_id = b[8]
    other_or = b[9]
    b2_or   = b[10]
    b2_last = b[11]
    lmin    = struct.unpack('<H', b[12:14])[0]
    lmax    = struct.unpack('<H', b[14:16])[0]
    othpfx  = b[16:24].hex()
    anypfx  = b[24:32].hex()
    return (bt31, btoth, other_id, other_or, b2_or, b2_last,
            lmin, lmax, othpfx, anypfx)

s1 = query(); time.sleep(1.0); s2 = query()
d1 = decode(s1); d2 = decode(s2)
bt31_rate = d2[0] - d1[0]
btoth_rate = d2[1] - d1[1]
print(f'rates: 0x31={bt31_rate}/s, non-0x31={btoth_rate}/s')
print(f'len range: {d2[6]}-{d2[7]} bytes')
print(f'byte[2] OR mask across 0x31 frames: 0x{d2[4]:02X}  last=0x{d2[5]:02X}')
print(f'non-0x31 report IDs: OR mask=0x{d2[3]:02X}  most recent=0x{d2[2]:02X}')
print(f'last non-0x31 prefix (data[0..7]): {d2[8]}')
print(f'last ANY frame (data[0..7]):       {d2[9]}')
PY
}

case "${1:-status}" in
    status)   show_status ;;
    capture)  shift; run_capture "${1:-3}" ;;
    watch)    watch_status ;;
    bt-trace) bt_trace ;;
    *)
        printf 'usage: %s {status|capture [secs]|watch|bt-trace}\n' "$0" >&2
        exit 2
        ;;
esac