#!/usr/bin/env python3
import time,socket,subprocess,configparser,signal,re,errno,threading,argparse,json,os,platform
from pathlib import Path
APP_VERSION="3.7.0"
from smbus2 import SMBus
from PIL import Image
from shutil import disk_usage

OLED=0x3C; MCU=0x0D; W,H=128,32
CFG="/etc/pigway-pi-control.conf"
STATUS_PATH="/run/pigway-pi-control/status.json"
running=True

def stop(*_):
    global running; running=False
signal.signal(signal.SIGTERM,stop); signal.signal(signal.SIGINT,stop)

def log(level,event,**fields):
    parts=[f"level={level}",f"event={event}"]
    for k,v in fields.items(): parts.append(f"{k}={str(v).replace(chr(32),'_')}")
    print(" ".join(parts),flush=True)

def uptime_seconds():
    try:return int(float(Path("/proc/uptime").read_text().split()[0]))
    except Exception:return 0

def load_average():
    try:
        x=Path("/proc/loadavg").read_text().split();return (float(x[0]),float(x[1]),float(x[2]))
    except Exception:return (0.0,0.0,0.0)

def memory_usage():
    try:
        values={}
        for line in Path("/proc/meminfo").read_text().splitlines():
            key,value=line.split(":",1); values[key]=int(value.split()[0])*1024
        total=values["MemTotal"]; available=values.get("MemAvailable",values.get("MemFree",0))
        used=max(0,total-available)
        return total,used,available,(used*100.0/total if total else 0.0)
    except Exception:return 0,0,0,0.0

def wifi_percent(metric):
    try:return max(0,min(100,round((float(metric)+100.0)*2.0)))
    except Exception:return None

def device_details():
    info={}
    try:
        for line in Path("/proc/cpuinfo").read_text().splitlines():
            if ":" in line:
                key,value=(x.strip() for x in line.split(":",1))
                if key in ("Serial","Revision","Hardware","Model"): info[key.lower()]=value
    except Exception: pass
    try: info["model"]=Path("/proc/device-tree/model").read_bytes().rstrip(b"\0").decode()
    except Exception: pass
    try:
        os_release={}
        for line in Path("/etc/os-release").read_text().splitlines():
            if "=" in line:
                key,value=line.split("=",1); os_release[key]=value.strip().strip('"')
        info["os"]=os_release.get("PRETTY_NAME",platform.platform())
    except Exception: info["os"]=platform.platform()
    info.update({"hostname":socket.gethostname(),"kernel":platform.release(),
                 "architecture":platform.machine(),"cpu_count":os.cpu_count() or 0})
    return info

def cpu_freq_mhz():
    for q in ("/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq","/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq"):
        try:return int(Path(q).read_text().strip())/1000.0
        except Exception:pass
    return 0.0

def root_readonly():
    try:
        for line in Path("/proc/mounts").read_text().splitlines():
            a=line.split()
            if len(a)>=4 and a[1]=="/":return "ro" in a[3].split(",")
    except Exception:pass
    return False

def throttled_state():
    raw=_run(["vcgencmd","get_throttled"])
    m=re.search(r"0x([0-9a-fA-F]+)",raw);v=int(m.group(1),16) if m else 0
    if not m: return {"raw":"UNKNOWN","error":"vcgencmd get_throttled unavailable or invalid"}
    return {"raw":f"0x{v:x}","under_voltage_now":bool(v&1),"freq_capped_now":bool(v&2),"throttled_now":bool(v&4),"soft_temp_limit_now":bool(v&8),"under_voltage_occurred":bool(v&(1<<16)),"freq_capped_occurred":bool(v&(1<<17)),"throttled_occurred":bool(v&(1<<18)),"soft_temp_limit_occurred":bool(v&(1<<19))}

bus=None
bus_lock=threading.RLock()
FONT_PATH="/usr/local/share/pigway-pi-control/oled_font_5x7.bin"
FONT5=b""
agent={"loop_errors":0,"i2c_errors":0}

def bus_write(method,*args):
    with bus_lock:
        try: return getattr(bus,method)(*args)
        except OSError:
            agent["i2c_errors"]+=1
            raise

fan_level=0
prev_cpu=None
page=0; page_since=time.monotonic()
cpu_hi=mem_hi=0
net_ok=link_ok=True
net_iface=""; net_kind="NET"; net_metric="DOWN"; ip_label="IP4"; ip="NO IP"
wifi_weak_since=None; wifi_weak_active=False
last_net=last_watch=0
watch_state=[]

def cmd(c): bus_write("write_byte_data",OLED,0x00,c)
def oled_init():
    # Seller-native physical 128x32 configuration.
    for c in [0xAE,0xD5,0x80,0xA8,0x1F,0xD3,0x00,0x40,0x8D,0x14,
              0x20,0x00,0xA1,0xC8,0xDA,0x02,0x81,0x7F,0xD9,0xF1,
              0xDB,0x40,0xA4,0xA6,0xAF]:
        cmd(c)

def draw_text_5x7(pix,x,y,text):
    for ch in text:
        code=ord(ch)
        if code<0 or code>255: code=ord("?")
        off=code*5
        if off+5>len(FONT5): code=ord("?"); off=code*5
        for cx in range(5):
            col=FONT5[off+cx]
            for cy in range(7):
                if col & (1<<cy):
                    xx=x+cx; yy=y+cy
                    if 0<=xx<W and 0<=yy<H: pix[xx,yy]=1
        x+=6
        if x>W-6: break

def oled_show(lines_lr, title_zh=False):
    im=Image.new("1",(W,H),0); pix=im.load()
    for row,(left,right) in enumerate(lines_lr[:4]):
        y=row*8
        draw_text_5x7(pix,0,y,left)
        if right:
            draw_text_5x7(pix,max(0,W-len(right)*6),y,right)
    data=[]
    for pg in range(4):
        for x in range(W):
            v=0
            for bit in range(8):
                if pix[x,pg*8+bit]: v|=1<<bit
            data.append(v)
    cmd(0x21);cmd(0);cmd(127);cmd(0x22);cmd(0);cmd(3)
    for i in range(0,len(data),16):
        bus_write("write_i2c_block_data",OLED,0x40,data[i:i+16])


def mcu(reg,val): bus_write("write_byte_data",MCU,reg,val)
_last_rgb=None
def rgb_off():
    global _last_rgb
    if _last_rgb != ("off",):
        mcu(0x07,0x00)  # seller closeRGB(): true OFF
        _last_rgb=("off",)

def set_pi_led(name,off=True):
    base=Path("/sys/class/leds")/name
    try:
        if off:
            (base/"trigger").write_text("none")
            (base/"brightness").write_text("0")
    except Exception as e:
        print(f"board LED {name}: {e}",flush=True)

def apply_dark_mode():
    if DARK_PWR: set_pi_led("PWR",True)
    if DARK_ACT: set_pi_led("ACT",True)

FAN_REG=[0x00,0x04,0x06,0x08,0x09,0x01]
FAN_NAME=["OFF","L1","L2","L3","L4","MAX"]
def fan_target(t):
    if t<FAN_T[0]: return 0
    if t<FAN_T[1]: return 1
    if t<FAN_T[2]: return 2
    if t<FAN_T[3]: return 3
    if t<FAN_T[4]: return 4
    return 5
def update_fan(t):
    global fan_level
    want=fan_target(t); old=fan_level
    if want>fan_level: fan_level=want
    elif want<fan_level:
        boundary = FAN_T[max(0,fan_level-1)] - FAN_HYST
        if t < boundary: fan_level-=1
    if old!=fan_level: mcu(0x08,FAN_REG[fan_level])

def cpu_pct():
    global prev_cpu
    p=list(map(int,Path("/proc/stat").read_text().splitlines()[0].split()[1:9]))
    idle=p[3]+p[4]; total=sum(p)
    if prev_cpu is None: prev_cpu=(idle,total); return 0.0
    di=idle-prev_cpu[0]; dt=total-prev_cpu[1]; prev_cpu=(idle,total)
    return 100.0*(dt-di)/dt if dt else 0.0
def temp_c(): return int(Path("/sys/class/thermal/thermal_zone0/temp").read_text())/1000.0
def mem_pct():
    vals={}
    for l in Path("/proc/meminfo").read_text().splitlines():
        if ":" in l:
            k,v=l.split(":",1); vals[k]=int(v.split()[0])
    return 100*(vals["MemTotal"]-vals["MemAvailable"])/vals["MemTotal"]
def disk_pct():
    d=disk_usage("/"); return 100*d.used/d.total
def _run(args,timeout=2):
    try: return subprocess.check_output(args,text=True,stderr=subprocess.DEVNULL,timeout=timeout).strip()
    except Exception: return ""

def primary_network():
    out=_run(["ip","-4","route","get","1.1.1.1"])
    dev=re.search(r"\bdev\s+(\S+)",out); src=re.search(r"\bsrc\s+(\S+)",out); label="IP4"
    if not dev:
        out=_run(["ip","-6","route","get","2606:4700:4700::1111"])
        dev=re.search(r"\bdev\s+(\S+)",out); src=re.search(r"\bsrc\s+(\S+)",out); label="IP6"
    if not dev: return "","NET","DOWN","IP4","NO IP"
    iface=dev.group(1); ipval=src.group(1) if src else ""
    if Path(f"/sys/class/net/{iface}/wireless").exists():
        kind="WIF"; metric="--"
        try:
            for line in Path("/proc/net/wireless").read_text().splitlines():
                if line.lstrip().startswith(iface+":"):
                    metric=str(int(float(line.split()[3].rstrip(".")))); break
        except Exception: pass
    else:
        kind="ETH"; metric="UP"
        try:
            n=int(Path(f"/sys/class/net/{iface}/speed").read_text().strip())
            metric=f"{n//1000}G" if n>=1000 and n%1000==0 else str(n)
        except Exception: pass
    return iface,kind,metric,label,(ipval or "NO IP")

def get_ip():
    return primary_network()[4]

def internet():
    try:
        s=socket.create_connection(("1.1.1.1",53),0.5);s.close();return True
    except: return False

def load_cfg():
    c=configparser.ConfigParser(); c.read(CFG)
    watches=[]
    if c.has_section("services"):
        for label,target in c["services"].items():
            target=target.strip()
            paused=c.getboolean("service_monitor_disabled",label,fallback=False)
            if target and not target.startswith("#") and not paused:
                watches.append(("service",label.upper(),target))
    if c.has_section("processes"):
        for label,target in c["processes"].items():
            target=target.strip()
            if target and not target.startswith("#"): watches.append(("process",label.upper(),target))
    return c,watches
cfg,watches=load_cfg()

def cf(section,key,default,cast=float):
    try: return cast(cfg.get(section,key))
    except: return default

DEVICE_ID=cf("device","identifier","auto",str).strip()
if not DEVICE_ID or DEVICE_ID.lower()=="auto": DEVICE_ID=socket.gethostname()
DEVICE_NAME=cf("device","name",DEVICE_ID,str).strip() or DEVICE_ID
if DEVICE_NAME.lower()=="auto": DEVICE_NAME=DEVICE_ID
DEVICE_INFO=device_details()

SENSOR_INTERVAL=cf("timing","sensor_interval",1.0)
OLED_REFRESH=cf("timing","oled_refresh_interval",1.0)
PAGE_INTERVAL=cf("timing","page_interval",10.0)
NETWORK_INTERVAL=cf("timing","network_interval",5.0)
SERVICE_INTERVAL=cf("timing","service_interval",5.0)
HEALTH_INTERVAL=cf("timing","health_interval",1.0)

CPU_HIGH=cf("alerts","cpu_high",90.0)
CPU_RECOVER=cf("alerts","cpu_recover",75.0)
CPU_HIGH_SEC=cf("alerts","cpu_high_seconds",30,int)
MEM_HIGH=cf("alerts","memory_high",90.0)
MEM_RECOVER=cf("alerts","memory_recover",85.0)
MEM_HIGH_SEC=cf("alerts","memory_high_seconds",30,int)
TEMP_HIGH=cf("alerts","temp_high",68.0)
TEMP_CRIT=cf("alerts","temp_critical",75.0)
DISK_HIGH=cf("alerts","disk_high",90.0)
DISK_CRIT=cf("alerts","disk_critical",95.0)
WIFI_WEAK=cf("alerts","wifi_weak",-75.0)
WIFI_RECOVER=cf("alerts","wifi_recover",-68.0)
WIFI_WEAK_SECONDS=cf("alerts","wifi_weak_seconds",30.0)

FAN_T=[cf("fan","start",50.0),cf("fan","level2",53.0),cf("fan","level3",56.0),
       cf("fan","level4",59.0),cf("fan","max",62.0)]
FAN_HYST=cf("fan","hysteresis",1.5)
ROW_Y=[cf("display","row1_y",0,int),cf("display","row2_y",8,int),cf("display","row3_y",16,int),cf("display","row4_y",24,int)]
DARK_PWR=cf("dark_mode","pi_pwr_led",True,lambda x: str(x).strip().lower() in ("off","0","false","no"))
DARK_ACT=cf("dark_mode","pi_act_led",True,lambda x: str(x).strip().lower() in ("off","0","false","no"))
RGB_WRITE_DELAY_MS=max(1,cf("led","write_delay_ms",10,int))
WARNING_FLASH=(max(50,cf("led","warning_flash_on_ms",1500,int)),max(50,cf("led","warning_flash_off_ms",1500,int)))
CRITICAL_FLASH=(max(50,cf("led","critical_flash_on_ms",750,int)),max(50,cf("led","critical_flash_off_ms",750,int)))
EMERGENCY_FLASH=(max(50,cf("led","emergency_flash_on_ms",300,int)),max(50,cf("led","emergency_flash_off_ms",300,int)))
NORMAL_MODE=cf("led","normal_mode","off",str).strip().lower()
NORMAL_MODES={"off","solid","flash","flow","breathe","marquee","rainbow","colorful"}
if NORMAL_MODE not in NORMAL_MODES: NORMAL_MODE="off"
NORMAL_COLOR=tuple(max(0,min(255,cf("led",f"normal_{channel}",value,int)))
                   for channel,value in zip(("r","g","b"),(0,0,0)))
NORMAL_FLASH=(max(50,cf("led","normal_flash_on_ms",1000,int)),
              max(50,cf("led","normal_flash_off_ms",1000,int)))
NORMAL_EFFECT_SPEED=max(1,min(3,cf("led","normal_effect_speed",2,int)))
NORMAL_EFFECT_COLOR=cf("led","normal_effect_color","green",str).strip().lower()
RGB_EFFECT_COLORS={"red":0,"green":1,"blue":2,"yellow":3,"purple":4,"cyan":5,"white":6}
if NORMAL_EFFECT_COLOR not in RGB_EFFECT_COLORS: NORMAL_EFFECT_COLOR="green"
RGB_EFFECTS={"flow":0,"breathe":1,"marquee":2,"rainbow":3,"colorful":4}
NORMAL_RGB_MODE={"off":"OFF","solid":"NORMAL_SOLID","flash":"NORMAL_FLASH",
                 **{name:f"NORMAL_{name.upper()}" for name in RGB_EFFECTS}}[NORMAL_MODE]

def rgb_cfg(name,default):
    return tuple(max(0,min(255,cf("led",f"{name}_{channel}",value,int)))
                 for channel,value in zip(("r","g","b"),default))

RGB_GROUP_VALUES={
    "CPU":rgb_cfg("cpu",(255,0,0)),
    "POWER":rgb_cfg("power",(255,40,0)),
    "MEMORY":rgb_cfg("memory",(255,0,255)),
    "STORAGE":rgb_cfg("storage",(255,255,255)),
    "NETWORK":rgb_cfg("network",(0,0,255)),
    "SERVICE":rgb_cfg("service",(0,255,96)),
}
RGB_OBJECT_GROUPS={
    "ROOT_READONLY":"STORAGE",
    "TEMP_CRITICAL":"CPU","TEMP_HIGH":"CPU","SOFT_TEMP_LIMIT":"CPU",
    "THROTTLED":"CPU","FREQ_CAPPED":"CPU","CPU_HIGH":"CPU",
    "POWER_UNDERVOLT":"POWER",
    "MEMORY_HIGH":"MEMORY",
    "DISK_CRITICAL":"STORAGE","DISK_HIGH":"STORAGE",
    "NETWORK_DOWN":"NETWORK","INTERNET_DOWN":"NETWORK","WIFI_WEAK":"NETWORK",
    "SERVICE_DOWN":"SERVICE","PROCESS_DOWN":"SERVICE",
}

def check_watch(w):
    typ,label,target=w
    args=["systemctl","is-active","--quiet",target] if typ=="service" else ["pgrep","-f","--",target]
    try:
        r=subprocess.run(args,stdout=subprocess.DEVNULL,stderr=subprocess.DEVNULL,timeout=2)
        return r.returncode==0
    except (OSError,subprocess.TimeoutExpired):
        return False


def diagnose():
    print("Agent:")
    print(f"version={APP_VERSION} uptime_seconds={uptime_seconds()} config={CFG}")
    print(f"machine_id={DEVICE_ID} machine_name={DEVICE_NAME} hostname={socket.gethostname()}")
    print("loop_errors=UNAVAILABLE i2c_errors=UNAVAILABLE scope=separate_diagnostic_process")
    print("System:")
    print(f"load_average={load_average()} cpu_freq_mhz={cpu_freq_mhz():.0f} root_readonly={root_readonly()}")
    print("Power:")
    power=throttled_state()
    print("throttled="+power["raw"])
    for key in ("under_voltage_now","freq_capped_now","throttled_now","soft_temp_limit_now",
                "under_voltage_occurred","freq_capped_occurred","throttled_occurred","soft_temp_limit_occurred"):
        print(f"{key}={power.get(key,'UNKNOWN')}")
    if "error" in power: print("error="+power["error"])
    iface,kind,metric,label,address=primary_network()
    print("Network:")
    print(f"primary_interface={iface or 'NONE'} kind={kind} metric={metric} signal_percent={wifi_percent(metric) if kind=='WIF' else 'N/A'} ip_label={label} IP={address} internet={internet()}")
    print("I2C:")
    # SMBus receive-byte performs a read only; no register selection or display commands.
    try:
        with SMBus(1) as probe:
            for address,name in ((MCU,"MCU"),(OLED,"OLED")):
                try:
                    probe.read_byte(address)
                    print(f"0x{address:02X} {name}=PRESENT")
                except OSError as e:
                    status="MISSING" if e.errno in (errno.ENXIO,getattr(errno,"EREMOTEIO",121)) else "ERROR"
                    print(f"0x{address:02X} {name}={status} error={e}")
    except OSError as e:
        for address,name in ((MCU,"MCU"),(OLED,"OLED")):
            print(f"0x{address:02X} {name}=ERROR error={e}")
    print("Watches:")
    for w in watches:
        print(f"watch {w[1]}={'UP' if check_watch(w) else 'DOWN'} type={w[0]} target={w[2]}")
    return 0


DISPLAY_PRIORITIES={
    "ROOT_READONLY":100,
    "TEMP_CRITICAL":90,
    "SOFT_TEMP_LIMIT":85,
    "POWER_UNDERVOLT":80,
    "THROTTLED":75,
    "FREQ_CAPPED":70,
    "NETWORK_DOWN":65,
    "INTERNET_DOWN":65,
    "SERVICE_DOWN":60,
    "PROCESS_DOWN":60,
    "DISK_CRITICAL":55,
    "TEMP_HIGH":50,
    "CPU_HIGH":45,
    "MEMORY_HIGH":45,
    "DISK_HIGH":40,
    "WIFI_WEAK":30,
    "NORMAL_HOME":0,
}

def display_priority(request_id):
    return DISPLAY_PRIORITIES[request_id.split("|",1)[0]]

def transition(key,active,on_event,off_event,**fields):
    old=event_state.get(key,False)
    if active!=old:
        event_state[key]=active
        log("WARN" if active else "INFO",on_event if active else off_event,**fields)

def update_active_alerts(cpu,temp,mem,disk,sample_elapsed=0.0):
    global wifi_weak_since,wifi_weak_active
    global cpu_hi,mem_hi
    cpu_hi=cpu_hi+sample_elapsed if cpu>=CPU_HIGH else 0 if cpu<CPU_RECOVER else cpu_hi
    mem_hi=mem_hi+sample_elapsed if mem>=MEM_HIGH else 0 if mem<MEM_RECOVER else mem_hi
    if cpu_hi>=CPU_HIGH_SEC: display.request("CPU_HIGH",1,"CPU LOAD HIGH",f"LOAD {cpu:.1f}%",f"TEMP {temp:.1f}C","CHECK LOAD")
    else: display.clear("CPU_HIGH")
    if temp>=TEMP_CRIT:
        display.request("TEMP_CRITICAL",3,"TEMP CRITICAL",f"TEMP {temp:.1f}C",f"FAN {FAN_NAME[fan_level]}","CHECK COOLING")
        display.clear("TEMP_HIGH")
    elif temp>=TEMP_HIGH:
        display.request("TEMP_HIGH",1,"TEMP HIGH",f"TEMP {temp:.1f}C",f"FAN {FAN_NAME[fan_level]}","CHECK COOLING")
        display.clear("TEMP_CRITICAL")
    else:
        display.clear("TEMP_HIGH"); display.clear("TEMP_CRITICAL")
    if mem_hi>=MEM_HIGH_SEC: display.request("MEMORY_HIGH",1,"MEMORY HIGH",f"USED {mem:.1f}%","CHECK PROCESS","")
    else: display.clear("MEMORY_HIGH")
    if disk>=DISK_CRIT:
        display.request("DISK_CRITICAL",2,"DISK CRITICAL",f"USED {disk:.1f}%","FREE < 5%","CHECK STORAGE")
        display.clear("DISK_HIGH")
    elif disk>=DISK_HIGH:
        display.request("DISK_HIGH",1,"DISK SPACE LOW",f"USED {disk:.1f}%","FREE < 10%","CHECK STORAGE")
        display.clear("DISK_CRITICAL")
    else:
        display.clear("DISK_HIGH"); display.clear("DISK_CRITICAL")
    if not link_ok:
        display.request("NETWORK_DOWN",2,"NETWORK DOWN","NO LAN / WIFI","NO IP ADDRESS","")
        display.clear("INTERNET_DOWN")
    elif not net_ok:
        display.request("INTERNET_DOWN",2,"INTERNET DOWN","LOCAL LINK OK",ip,"")
        display.clear("NETWORK_DOWN")
    else:
        display.clear("NETWORK_DOWN"); display.clear("INTERNET_DOWN")
    for w,ok in zip(watches,watch_state):
        alert_id=("SERVICE_DOWN" if w[0]=="service" else "PROCESS_DOWN")+"|"+w[1]
        if not ok:
            display.request(alert_id,2,"SERVICE DOWN" if w[0]=="service" else "PROCESS DOWN",w[1],"CHECK / RESTART","CRITICAL",{"target":w[2]})
        else: display.clear(alert_id)
    if net_kind=="WIF" and str(net_metric).lstrip("-").isdigit():
        rssi=float(net_metric)
        if not wifi_weak_active:
            if rssi <= WIFI_WEAK:
                if wifi_weak_since is None: wifi_weak_since=time.monotonic()
                if time.monotonic()-wifi_weak_since >= WIFI_WEAK_SECONDS: wifi_weak_active=True
            else: wifi_weak_since=None
        elif rssi >= WIFI_RECOVER:
            wifi_weak_active=False; wifi_weak_since=None
        if wifi_weak_active:
            display.request("WIFI_WEAK",1,"WIFI SIGNAL WEAK",f"RSSI {rssi:.0f} dBm",f"IF {net_iface}","CHECK SIGNAL")
        else: display.clear("WIFI_WEAK")
    else:
        wifi_weak_since=None; wifi_weak_active=False; display.clear("WIFI_WEAK")
    if health.get("under_voltage_now"):
        display.request("POWER_UNDERVOLT",2,"POWER LOW","UNDERVOLTAGE","CHECK POWER","CRITICAL",{"raw":health.get("raw","")})
    else: display.clear("POWER_UNDERVOLT")
    if health.get("throttled_now"):
        display.request("THROTTLED",2,"CPU THROTTLED",f"FREQ {cpu_freq_mhz():.0f}M",health.get("raw",""),"CHECK POWER")
    else: display.clear("THROTTLED")
    if health.get("freq_capped_now"):
        display.request("FREQ_CAPPED",2,"FREQ CAPPED",f"FREQ {cpu_freq_mhz():.0f}M",health.get("raw",""),"CHECK POWER")
    else: display.clear("FREQ_CAPPED")
    if health.get("soft_temp_limit_now"):
        display.request("SOFT_TEMP_LIMIT",2,"SOFT TEMP LIMIT","CPU TEMP LIMITED",health.get("raw",""),"CHECK COOLING")
    else: display.clear("SOFT_TEMP_LIMIT")
    if fs_readonly: display.request("ROOT_READONLY",3,"FILESYSTEM RO","ROOT READ ONLY","CHECK STORAGE","EMERGENCY")
    else: display.clear("ROOT_READONLY")

def rgb_mode_for(request_id,severity):
    if severity<=0: return "OFF"
    alert_type=request_id.split("|",1)[0]
    color=RGB_OBJECT_GROUPS[alert_type]
    level="EMERGENCY" if severity>=3 else "CRITICAL" if severity>=2 else "WARNING"
    return f"{color}_{level}_FLASH"

def rgb_flash(mode,on):
    global _last_rgb
    color=mode.split("_",1)[0]
    channels=RGB_GROUP_VALUES[color]
    state=(mode,bool(on))
    if _last_rgb==state: return
    if not on:
        mcu(0x07,0x00)
    else:
        mcu(0x00,0xff); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
        mcu(0x01,channels[0]); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
        mcu(0x02,channels[1]); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
        mcu(0x03,channels[2])
    _last_rgb=state

def rgb_static(channels,state_name):
    global _last_rgb
    state=(state_name,channels)
    if _last_rgb==state: return
    mcu(0x07,0x00); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
    mcu(0x00,0xff); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
    mcu(0x01,channels[0]); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
    mcu(0x02,channels[1]); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
    mcu(0x03,channels[2])
    _last_rgb=state

def rgb_normal_effect(mode):
    global _last_rgb
    effect_name=mode.removeprefix("NORMAL_").lower()
    state=("effect",effect_name,NORMAL_EFFECT_SPEED,NORMAL_EFFECT_COLOR)
    if _last_rgb==state: return
    # Hardware-calibrated order: speed and color are parameters; the final
    # effect register write commits and starts the selected MCU animation.
    mcu(0x05,NORMAL_EFFECT_SPEED); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
    mcu(0x06,RGB_EFFECT_COLORS[NORMAL_EFFECT_COLOR]); time.sleep(RGB_WRITE_DELAY_MS/1000.0)
    mcu(0x04,RGB_EFFECTS[effect_name])
    _last_rgb=state

def render_home(cpu,temp,mem,disk):
    # 128x32 fixed columns. Both columns are LEFT-aligned.
    # Seller 5x7 font has 6px character pitch; right column starts at x=72.
    im=Image.new("1",(W,H),0); pix=im.load()
    display_ip=ip[:7]+".."+ip[-7:] if ip_label=="IP6" and len(ip)>18 else ip
    left=[
        f"CPU {cpu:.1f}%",
        f"TMP {temp:.1f}C",
        f"DSK {disk:.1f}%",
        ip_label+" "+display_ip,
    ]
    signal=wifi_percent(net_metric) if net_kind=="WIF" else None
    right=[
        f"MEM {mem:.1f}%",
        f"FAN {FAN_NAME[fan_level]}",
        f"WIF {signal}%" if signal is not None else f"{net_kind} {net_metric}",
        "",
    ]
    for row in range(4):
        y=row*8
        draw_text_5x7(pix,0,y,left[row])
        if right[row]:
            draw_text_5x7(pix,72,y,right[row])
    data=[]
    for pg in range(4):
        for x in range(W):
            v=0
            for bit in range(8):
                if pix[x,pg*8+bit]: v|=1<<bit
            data.append(v)
    cmd(0x21);cmd(0);cmd(127);cmd(0x22);cmd(0);cmd(3)
    for i in range(0,len(data),16):
        bus_write("write_i2c_block_data",OLED,0x40,data[i:i+16])


def render_alert(a,index,total):
    oled_show([(a["title"],f"{index}/{total}"),
               (a["l2"],""),(a["l3"],""),(a["l4"],"")])


class DisplayController:
    def __init__(self):
        now=time.monotonic()
        self.lock=threading.RLock()
        self.requests={"NORMAL_HOME":{
            "id":"NORMAL_HOME","priority":0,"severity":0,"rgb_mode":NORMAL_RGB_MODE,
            "title":"","l2":"","l3":"","l4":"","active":True,
            "first_seen":now,"last_changed":now,"metadata":{"home":(0.0,0.0,0.0,0.0)},
        }}
        self.current_owner_id="NORMAL_HOME"
        self.current_priority=0
        self.current_rgb_mode="OFF"
        self.owner_since=now
        self.current_oled_page_id="NORMAL_HOME"
        self.page_started=now
        self.batch_depth=0
        self.stop_event=threading.Event()
        self.rgb_thread=threading.Thread(target=self._rgb_worker,name="rgb",daemon=True)

    def start(self):
        oled_init(); self.refresh(); rgb_off(); self.rgb_thread.start()

    def update_home(self,cpu,temp,mem,disk):
        with self.lock:
            request=self.requests["NORMAL_HOME"]
            values=(cpu,temp,mem,disk)
            if request["metadata"].get("home")!=values:
                request["metadata"]={"home":values}; request["last_changed"]=time.monotonic()

    def request(self,request_id,severity,title,l2="",l3="",l4="",metadata=None):
        now=time.monotonic(); priority=display_priority(request_id)
        request={"id":request_id,"priority":priority,"severity":severity,
                 "rgb_mode":rgb_mode_for(request_id,severity),"title":title[:21],
                 "l2":l2[:21],"l3":l3[:21],"l4":l4[:21],"active":True,
                 "last_changed":now,"metadata":metadata or {}}
        with self.lock:
            current=self.requests.get(request_id)
            if current is None:
                request["first_seen"]=now; self.requests[request_id]=request
                log("WARN","ALERT_ACTIVE",alert=request_id,severity=severity,detail=l2)
            else:
                request["first_seen"]=current["first_seen"]
                changed=any(current.get(k)!=request.get(k) for k in
                            ("priority","severity","rgb_mode","title","l2","l3","l4","metadata"))
                if not changed: request["last_changed"]=current["last_changed"]
                self.requests[request_id]=request
            if self.batch_depth==0:
                self._arbitrate_locked()
                self._sync_rgb_locked()

    def clear(self,request_id):
        if request_id=="NORMAL_HOME": return
        with self.lock:
            if self.requests.pop(request_id,None) is not None:
                log("INFO","ALERT_RECOVERED",alert=request_id)
                if self.batch_depth==0:
                    self._arbitrate_locked()
                    if self.current_oled_page_id not in self.requests:
                        self._show_page_locked(self.current_owner_id)
                    else: self._sync_rgb_locked()

    def begin_update(self):
        with self.lock: self.batch_depth+=1

    def end_update(self):
        with self.lock:
            if self.batch_depth<=0: raise RuntimeError("display update batch imbalance")
            self.batch_depth-=1
            if self.batch_depth==0:
                self._arbitrate_locked()
                if self.current_oled_page_id not in self.requests:
                    self._show_page_locked(self.current_owner_id)
                else: self._sync_rgb_locked()

    def _arbitrate_locked(self):
        current=self.requests.get(self.current_owner_id)
        ordered=sorted(self.requests.values(),key=lambda r:(-r["priority"],r["first_seen"],r["id"]))
        candidate=ordered[0]
        if current is not None and candidate["priority"]<=current["priority"]: return
        self._change_owner_locked(candidate)

    def _change_owner_locked(self,request):
        old=self.current_owner_id
        if request["id"]==old: return
        self.current_owner_id=request["id"]
        self.current_priority=request["priority"]
        self.current_rgb_mode=request["rgb_mode"]
        self.owner_since=time.monotonic()
        log("INFO","DISPLAY_OWNER",old=old,new=request["id"],priority=request["priority"])
        self._show_page_locked(request["id"])

    def _ordered_alerts_locked(self):
        return sorted((r for r in self.requests.values() if r["id"]!="NORMAL_HOME"),
                      key=lambda r:(-r["priority"],r["first_seen"],r["id"]))

    def _show_page_locked(self,page_id):
        alerts=self._ordered_alerts_locked()
        request=self.requests.get(page_id,self.requests["NORMAL_HOME"])
        self.current_oled_page_id=request["id"]
        self.page_started=time.monotonic()
        self._sync_rgb_locked()
        if request["id"]=="NORMAL_HOME":
            render_home(*request["metadata"]["home"])
        else:
            alert_ids=[a["id"] for a in alerts]
            render_alert(request,alert_ids.index(request["id"])+1,len(alerts))

    def _sync_rgb_locked(self):
        # Alert pages show that alert's object color.  HOME keeps the highest-
        # priority active owner visible instead of briefly switching RGB off.
        rgb_request=self.requests.get(self.current_oled_page_id)
        if self.current_oled_page_id=="NORMAL_HOME":
            rgb_request=self.requests.get(self.current_owner_id,self.requests["NORMAL_HOME"])
        if rgb_request is None:
            rgb_request=self.requests["NORMAL_HOME"]
        self.current_rgb_mode=rgb_request["rgb_mode"]

    def refresh(self):
        with self.lock:
            alerts=self._ordered_alerts_locked()
            pages=["NORMAL_HOME"]+[a["id"] for a in alerts]
            if self.current_oled_page_id not in pages:
                self._show_page_locked(self.current_owner_id)
                return
            if len(pages)>1 and time.monotonic()-self.page_started>=PAGE_INTERVAL:
                pos=pages.index(self.current_oled_page_id)
                self._show_page_locked(pages[(pos+1)%len(pages)])
                return
            request=self.requests[self.current_oled_page_id]
            if request["id"]=="NORMAL_HOME": render_home(*request["metadata"]["home"])
            else:
                alert_ids=[a["id"] for a in alerts]
                render_alert(request,alert_ids.index(request["id"])+1,len(alerts))

    def owner_snapshot(self):
        with self.lock: return dict(self.requests[self.current_owner_id])

    def status_snapshot(self):
        with self.lock:
            alerts=self._ordered_alerts_locked()
            return {
                "owner":self.current_owner_id,
                "oled_page":self.current_oled_page_id,
                "rgb_mode":self.current_rgb_mode,
                "alerts":[{k:a[k] for k in ("id","priority","severity","title","l2","l3","l4","first_seen","last_changed")}
                          for a in alerts],
            }

    def _rgb_worker(self):
        previous_error=None; applied_mode="OFF"; applied_flash=False
        flash_on=None; animation_started=time.monotonic()
        while not self.stop_event.is_set():
            try:
                with self.lock: wanted_mode=self.current_rgb_mode
                wanted_flash=wanted_mode.endswith("_FLASH")
                if wanted_mode!=applied_mode:
                    with bus_lock:
                        if wanted_mode=="OFF": rgb_off()
                        elif wanted_mode=="NORMAL_SOLID": rgb_static(NORMAL_COLOR,"normal_solid")
                        elif wanted_mode=="NORMAL_FLASH": rgb_static(NORMAL_COLOR,"normal_flash_on")
                        elif wanted_mode.startswith("NORMAL_"): rgb_normal_effect(wanted_mode)
                        elif wanted_flash:
                            rgb_off()
                            rgb_flash(wanted_mode,True)
                        else: raise ValueError(f"unsupported RGB mode: {wanted_mode}")
                    log("INFO","RGB_MODE",old=applied_mode,new=wanted_mode)
                    applied_mode=wanted_mode; animation_started=time.monotonic()
                    flash_on=True if wanted_mode.endswith("_FLASH") else None
                applied_flash=applied_mode.endswith("_FLASH")
                if applied_flash:
                    elapsed_ms=(time.monotonic()-animation_started)*1000.0
                    if applied_mode=="NORMAL_FLASH": on_ms,off_ms=NORMAL_FLASH
                    elif "_EMERGENCY_" in applied_mode: on_ms,off_ms=EMERGENCY_FLASH
                    elif "_CRITICAL_" in applied_mode: on_ms,off_ms=CRITICAL_FLASH
                    else: on_ms,off_ms=WARNING_FLASH
                    on=elapsed_ms%(on_ms+off_ms)<on_ms
                    if on!=flash_on:
                        with bus_lock:
                            if applied_mode=="NORMAL_FLASH":
                                rgb_static(NORMAL_COLOR,"normal_flash_on") if on else rgb_off()
                            else: rgb_flash(applied_mode,on)
                        flash_on=on
                if previous_error is not None: log("INFO","RGB_RECOVERED")
                previous_error=None
            except Exception as e:
                if repr(e)!=previous_error: log("ERROR","RGB_ERROR",error=repr(e))
                previous_error=repr(e)
            delay=0.04 if applied_flash else 0.25
            self.stop_event.wait(delay)

    def shutdown(self):
        self.stop_event.set()
        if self.rgb_thread.is_alive(): self.rgb_thread.join()
        for name,action in (("rgb",rgb_off),("oled_clear",lambda:oled_show([("","")]*4)),
                            ("oled_off",lambda:cmd(0xAE))):
            try: action()
            except Exception as e: log("ERROR","SHUTDOWN_CLEANUP",step=name,error=repr(e))

def cleanup():
    log("INFO","STOP",loop_errors=agent["loop_errors"],i2c_errors=agent["i2c_errors"])
    if bus is None: return
    display.shutdown()
    for name,action in (("fan",lambda:mcu(0x08,0x00)),("bus_close",bus.close)):
        try: action()
        except Exception as e: log("ERROR","SHUTDOWN_CLEANUP",step=name,error=repr(e))
    try: Path(STATUS_PATH).unlink(missing_ok=True)
    except Exception as e: log("ERROR","SHUTDOWN_CLEANUP",step="status_file",error=repr(e))

def write_status(cpu,temp,mem,disk):
    display_state=display.status_snapshot()
    memory_total,memory_used,memory_available,memory_calculated=memory_usage()
    disk_total,disk_used,disk_free=disk_usage("/")
    signal=wifi_percent(net_metric) if net_kind=="WIF" else None
    state={
        "version":APP_VERSION,"timestamp":int(time.time()),"uptime_seconds":uptime_seconds(),
        "machine":{"id":DEVICE_ID,"name":DEVICE_NAME,"hostname":socket.gethostname()},
        "device":DEVICE_INFO,
        "system":{"load_average":load_average(),"cpu_percent":round(cpu,1),
                  "cpu_freq_mhz":round(cpu_freq_mhz()),"temperature_c":round(temp,1),
                  "memory_percent":round(memory_calculated if memory_total else mem,1),
                  "memory_total_bytes":memory_total,"memory_used_bytes":memory_used,
                  "memory_available_bytes":memory_available,
                  "disk_percent":round(disk,1),"disk_total_bytes":disk_total,
                  "disk_used_bytes":disk_used,"disk_free_bytes":disk_free,
                  "root_readonly":bool(fs_readonly),"fan_level":fan_level,"fan_name":FAN_NAME[fan_level]},
        "power":health,
        "network":{"interface":net_iface,"kind":net_kind,"metric":net_metric,
                   "signal_percent":signal,
                   "ip_label":ip_label,"ip":ip,"link":bool(link_ok),"internet":bool(net_ok)},
        "watches":[{"type":w[0],"name":w[1],"target":w[2],"up":bool(ok)}
                   for w,ok in zip(watches,watch_state)],
        "display":display_state,
        "agent":{"loop_errors":agent["loop_errors"],"i2c_errors":agent["i2c_errors"]},
    }
    path=Path(STATUS_PATH); path.parent.mkdir(mode=0o755,parents=True,exist_ok=True)
    temporary=path.with_suffix(".tmp")
    temporary.write_text(json.dumps(state,ensure_ascii=False,separators=(",",":")))
    temporary.chmod(0o644); temporary.replace(path)

# Dispatch only after all shared checks and configuration have been initialized.
parser=argparse.ArgumentParser()
parser.add_argument("--diagnose",action="store_true")
args=parser.parse_args()
if args.diagnose: raise SystemExit(diagnose())

watch_state=[]
last_sensor=last_render=last_status=0.0
last_net=last_watch=last_health=0.0
health={}; fs_readonly=False
agent={"last_sensor_ok":0.0,"last_network_ok":0.0,"last_watch_ok":0.0,"last_health_ok":0.0,"loop_errors":0,"i2c_errors":0}
event_state={}
history_logged=set()
latest=(0.0,0.0,0.0,0.0)
display=DisplayController()
try:
    bus=SMBus(1)
    FONT5=Path(FONT_PATH).read_bytes()
    display.start(); apply_dark_mode()
    log("INFO","START",version=APP_VERSION,uptime=uptime_seconds())
    while running:
        try:
            now=time.monotonic()
            sample_elapsed=0.0


            # Independent clocks: update data/state only.
            if now-last_sensor >= SENSOR_INTERVAL:
                sample_elapsed=now-last_sensor if last_sensor else 0.0
                c=cpu_pct(); t=temp_c(); m=mem_pct(); d=disk_pct()
                latest=(c,t,m,d); update_fan(t); last_sensor=now; agent["last_sensor_ok"]=now

            if now-last_net >= NETWORK_INTERVAL:
                old_id=(net_iface,ip)
                net_iface,net_kind,net_metric,ip_label,ip=primary_network(); link_ok=ip!="NO IP"; net_ok=internet() if link_ok else False
                new_id=(net_iface,ip)
                if new_id!=old_id:
                    log("INFO","NET_SWITCH",old_if=old_id[0],old_ip=old_id[1],new_if=net_iface,new_ip=ip)
                transition("network_down",not link_ok,"NETWORK_DOWN","NETWORK_RECOVERED",iface=net_iface,ip=ip)
                transition("internet_down",link_ok and not net_ok,"INTERNET_DOWN","INTERNET_RECOVERED",iface=net_iface,ip=ip)
                last_net=now; agent["last_network_ok"]=now

            if now-last_watch >= SERVICE_INTERVAL:
                watch_state=[check_watch(w) for w in watches]
                for w,ok in zip(watches,watch_state):
                    transition("watch:"+w[0]+":"+w[1],not ok,"WATCH_DOWN","WATCH_RECOVERED",name=w[1],target=w[2])
                last_watch=now; agent["last_watch_ok"]=now

            if now-last_health >= HEALTH_INTERVAL:
                power_sample=throttled_state(); fs_readonly=root_readonly()
                transition("power_check", "error" in power_sample,"POWER_CHECK_ERROR","POWER_CHECK_RECOVERED")
                # An unavailable reading is not evidence that an existing fault recovered.
                if "error" not in power_sample: health=power_sample
                transition("undervoltage",health.get("under_voltage_now",False),"POWER_LOW","POWER_RECOVERED",raw=health.get("raw"))
                transition("throttled",health.get("throttled_now",False) or health.get("freq_capped_now",False),"THROTTLED","THROTTLE_RECOVERED",raw=health.get("raw"),freq_mhz=f"{cpu_freq_mhz():.0f}")
                transition("soft_temp",health.get("soft_temp_limit_now",False),"SOFT_TEMP_LIMIT","SOFT_TEMP_RECOVERED",raw=health.get("raw"))
                transition("root_ro",fs_readonly,"FILESYSTEM_RO","FILESYSTEM_RW")
                for k in ("under_voltage_occurred","freq_capped_occurred","throttled_occurred","soft_temp_limit_occurred"):
                    if health.get(k) and k not in history_logged:
                        history_logged.add(k); log("WARN","HISTORY_FLAG",flag=k,raw=health.get("raw"))
                agent["last_health_ok"]=now; last_health=now

            c,t,m,d=latest
            display.update_home(c,t,m,d)
            display.begin_update()
            try: update_active_alerts(c,t,m,d,sample_elapsed)
            finally: display.end_update()
            if now-last_render >= OLED_REFRESH:
                display.refresh()
                last_render=now
            if now-last_status >= 1.0:
                write_status(c,t,m,d); last_status=now

            time.sleep(0.20)
        except Exception as e:
            agent["loop_errors"]+=1; log("ERROR","LOOP_ERROR",count=agent["loop_errors"],error=repr(e)); time.sleep(1)
finally:
    cleanup()