#!/home/noise/.local/share/uv/tools/powermon/bin/python
"""eg4-snapshot — single-shot register dump for correlation against the
EG4 BMS Tool UI. Prints a 47-row table with:

    reg | raw u16 | hex | our decode                   | BMS Tool UI field
    ----+---------+-----+------------------------------+-------------------

Run while the BMS Tool is open on the same pack; fill in the BMS Tool
column by reading the matching values off the UI. Send the result back
and we refine `decode_eg4_modbus_regs` in `bin/eg4-battery`.

Usage:
    eg4-snapshot                      # auto-detect FTDI, query 0x40
    eg4-snapshot <port> [addr]        # explicit port / address
"""
import glob, sys, time, serial

PORT = sys.argv[1] if len(sys.argv) > 1 else None
ADDR = int(sys.argv[2], 0) if len(sys.argv) > 2 else 0x40

if PORT is None:
    hits = sorted(glob.glob("/dev/serial/by-id/usb-FTDI_*"))
    if not hits:
        sys.exit("no FTDI adapter visible")
    PORT = hits[0]


def crc16(data):
    c = 0xFFFF
    for b in data:
        c ^= b
        for _ in range(8):
            c = (c >> 1) ^ 0xA001 if c & 1 else c >> 1
    return c


def modbus_read_47(addr):
    body = bytes([addr, 0x03, 0, 0, 0, 47])
    cr = crc16(body)
    return body + bytes([cr & 0xFF, cr >> 8])


def _s16(v):
    return v - 0x10000 if v & 0x8000 else v


# What we THINK each register means right now. Keep in sync with
# bin/eg4-battery::decode_eg4_modbus_regs.
MAP = [
    # (name,                    decode fn)
    ("Total_Voltage",           lambda v, regs: f"{v/100:.2f} V"),
    ("Current_I (signed)",      lambda v, regs: f"{_s16(v)/100:+.2f} A"),
    ("Vol_Cell01 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell02 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell03 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell04 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell05 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell06 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell07 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell08 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell09 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell10 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell11 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell12 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell13 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell14 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell15 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Vol_Cell16 (mV)",         lambda v, regs: f"{v/1000:.3f} V"),
    ("Temp_01",                 lambda v, regs: f"{v} °C"),
    ("Temp_02",                 lambda v, regs: f"{v} °C"),
    ("Temp_03",                 lambda v, regs: f"{v} °C"),
    ("Temp_04 (MOS?)",          lambda v, regs: f"{v} °C"),
    ("SOC",                     lambda v, regs: f"{v} %"),
    ("SOH",                     lambda v, regs: f"{v} %"),
    ("Temp_PCB",                lambda v, regs: f"{v} °C"),
    ("?  reserved-25",          lambda v, regs: f"{v}"),
    ("?  reserved-26",          lambda v, regs: f"{v}"),
    ("?  reserved-27",          lambda v, regs: f"{v}"),
    ("?  reserved-28",          lambda v, regs: f"{v}"),
    ("?  reserved-29",          lambda v, regs: f"{v}"),
    ("Heater/Status",           lambda v, regs: f"{v}"),
    ("MAX_Curren",              lambda v, regs: f"{v/100:.2f} A"),
    ("?  reg-32",               lambda v, regs: f"{v}  (0x{v:04x})"),
    ("Warning bits",            lambda v, regs: f"0x{v:04x}  ({bin(v)[2:].zfill(16)})"),
    ("Protection bits",         lambda v, regs: f"0x{v:04x}  ({bin(v)[2:].zfill(16)})"),
    ("Error_Code",              lambda v, regs: f"{v}"),
    ("Cell_Num",                lambda v, regs: f"{v}"),
    ("Capacity",                lambda v, regs: f"{v/10:.1f} Ah"),
    ("Remaining",               lambda v, regs: f"{v/100:.2f} Ah"),
    ("CycleNum",                lambda v, regs: f"{v}"),
    ("Battery_Mode",            lambda v, regs: f"{v}"),
    ("BMS_Version (hi)",        lambda v, regs: f"0x{v:04x}"),
    ("BMS_Version (lo)",        lambda v, regs: f"0x{v:04x}"),
    ("?  reg-43",               lambda v, regs: f"{v}"),
    ("?  reg-44",               lambda v, regs: f"{v}"),
    ("?  reg-45",               lambda v, regs: f"{v}"),
    ("uptime counter",          lambda v, regs: f"{v}"),
]

assert len(MAP) == 47, f"MAP has {len(MAP)} entries, expected 47"


with serial.Serial(PORT, 9600, bytesize=8, parity="N", stopbits=1, timeout=0.3) as p:
    p.reset_input_buffer()
    p.write(modbus_read_47(ADDR))
    time.sleep(0.5)
    buf = p.read(512)

if len(buf) < 5 + 94 or buf[0] != ADDR or buf[1] != 0x03:
    sys.exit(f"bad response ({len(buf)} B): {buf.hex(' ')[:80]}")

bc = buf[2]
data = buf[3:3 + bc]
regs = [(data[i] << 8) | data[i + 1] for i in range(0, bc, 2)]

print(f"# eg4-snapshot  port={PORT}  addr=0x{ADDR:02x}  time={time.strftime('%Y-%m-%d %H:%M:%S')}")
print()
print(f"{'reg':>4}  {'raw':>6}  {'hex':>7}  {'our decode':<34}  BMS Tool UI value (fill me in)")
print(f"{'---':>4}  {'-----':>6}  {'-----':>7}  {'-'*34}  {'-'*40}")
for i, (label, fn) in enumerate(MAP):
    raw = regs[i]
    try:
        dec = fn(raw, regs)
    except Exception as e:
        dec = f"(decode error: {e})"
    print(f"{i:>4}  {raw:>6}  0x{raw:04x}   {label:<34}  {dec}")