#!/bin/bash

GREEN='\033[32m'
YELLOW='\033[33m'
RED='\033[31m'
RESET='\033[0m'

OVERALL=0

set_warning() {
    [ "$OVERALL" -lt 1 ] && OVERALL=1
}

set_danger() {
    OVERALL=2
}

echo
echo "Pi Health"
echo "────────────────────────────"

# CPU
CPU=$(top -bn1 | awk '/Cpu\(s\)/ {printf "%.1f", 100 - $8}')
printf "CPU:        "

if awk "BEGIN {exit !($CPU >= 90)}"; then
    printf "${RED}%s%%${RESET}\n" "$CPU"
    set_danger
elif awk "BEGIN {exit !($CPU >= 70)}"; then
    printf "${YELLOW}%s%%${RESET}\n" "$CPU"
    set_warning
else
    printf "${GREEN}%s%%${RESET}\n" "$CPU"
fi

# RAM
read -r TOTAL USED <<< "$(free -m | awk '/^Mem:/ {print $2, $2-$4-$6}')"
RAM_PCT=$(awk "BEGIN {printf \"%.1f\", ($USED/$TOTAL)*100}")

printf "RAM:        "

if awk "BEGIN {exit !($RAM_PCT >= 85)}"; then
    printf "${RED}%s%%${RESET}" "$RAM_PCT"
    set_danger
elif awk "BEGIN {exit !($RAM_PCT >= 70)}"; then
    printf "${YELLOW}%s%%${RESET}" "$RAM_PCT"
    set_warning
else
    printf "${GREEN}%s%%${RESET}" "$RAM_PCT"
fi

printf " (%s / %s MB)\n" "$USED" "$TOTAL"

# Swap
read -r SWAP_TOTAL SWAP_USED <<< "$(free -m | awk '/^Swap:/ {print $2, $3}')"

if [ "$SWAP_TOTAL" -gt 0 ]; then
    SWAP_PCT=$(awk "BEGIN {printf \"%.1f\", ($SWAP_USED/$SWAP_TOTAL)*100}")
else
    SWAP_PCT=0
fi

printf "Swap:       "

if awk "BEGIN {exit !($SWAP_PCT >= 30)}"; then
    printf "${RED}%s%%${RESET}" "$SWAP_PCT"
    set_danger
elif awk "BEGIN {exit !($SWAP_PCT >= 10)}"; then
    printf "${YELLOW}%s%%${RESET}" "$SWAP_PCT"
    set_warning
else
    printf "${GREEN}%s%%${RESET}" "$SWAP_PCT"
fi

printf " (%s / %s MB)\n" "$SWAP_USED" "$SWAP_TOTAL"

# Load average
read -r LOAD1 LOAD5 LOAD15 <<< "$(awk '{print $1, $2, $3}' /proc/loadavg)"
CORES=$(nproc)
LOAD_PER_CORE=$(awk "BEGIN {printf \"%.2f\", $LOAD1/$CORES}")

printf "Load:       "

if awk "BEGIN {exit !($LOAD_PER_CORE >= 1)}"; then
    printf "${RED}HIGH${RESET}"
    set_danger
elif awk "BEGIN {exit !($LOAD_PER_CORE >= 0.625)}"; then
    printf "${YELLOW}ELEVATED${RESET}"
    set_warning
else
    printf "${GREEN}NORMAL${RESET}"
fi

printf " (%s / %s / %s)\n" "$LOAD1" "$LOAD5" "$LOAD15"

# Temperature
TEMP=$(vcgencmd measure_temp | sed "s/temp=//;s/'C//")

printf "Temp:       "

if awk "BEGIN {exit !($TEMP >= 75)}"; then
    printf "${RED}%s°C${RESET}\n" "$TEMP"
    set_danger
elif awk "BEGIN {exit !($TEMP >= 65)}"; then
    printf "${YELLOW}%s°C${RESET}\n" "$TEMP"
    set_warning
else
    printf "${GREEN}%s°C${RESET}\n" "$TEMP"
fi

# Disk
DISK=$(df / | awk 'NR==2 {gsub("%",""); print $5}')

printf "Disk:       "

if [ "$DISK" -ge 85 ]; then
    printf "${RED}%s%%${RESET}\n" "$DISK"
    set_danger
elif [ "$DISK" -ge 70 ]; then
    printf "${YELLOW}%s%%${RESET}\n" "$DISK"
    set_warning
else
    printf "${GREEN}%s%%${RESET}\n" "$DISK"
fi

# Wi-Fi
WIFI=$(iw dev wlan0 link | awk '/signal:/ {print $2}')

printf "Wi-Fi:      "

if [ -z "$WIFI" ]; then
    printf "${RED}DISCONNECTED${RESET}\n"
    set_danger
elif [ "$WIFI" -ge -60 ]; then
    printf "${GREEN}EXCELLENT${RESET}\n"
elif [ "$WIFI" -ge -67 ]; then
    printf "${GREEN}GOOD${RESET}\n"
elif [ "$WIFI" -ge -75 ]; then
    printf "${YELLOW}FAIR${RESET}\n"
    set_warning
elif [ "$WIFI" -ge -80 ]; then
    printf "${YELLOW}WEAK${RESET}\n"
    set_warning
else
    printf "${RED}POOR${RESET}\n"
    set_danger
fi

# Throttling / power state
THROTTLED=$(vcgencmd get_throttled | cut -d= -f2)
THROTTLED_DEC=$((THROTTLED))

CURRENT_UNDERVOLTAGE=$((THROTTLED_DEC & 0x1))
CURRENT_FREQ_CAP=$((THROTTLED_DEC & 0x2))
CURRENT_THROTTLED=$((THROTTLED_DEC & 0x4))
CURRENT_SOFT_TEMP=$((THROTTLED_DEC & 0x8))

HIST_UNDERVOLTAGE=$((THROTTLED_DEC & 0x10000))
HIST_FREQ_CAP=$((THROTTLED_DEC & 0x20000))
HIST_THROTTLED=$((THROTTLED_DEC & 0x40000))
HIST_SOFT_TEMP=$((THROTTLED_DEC & 0x80000))

# Power
printf "Power:      "

if [ "$CURRENT_UNDERVOLTAGE" -ne 0 ]; then
    printf "${RED}DANGER — Under-voltage NOW${RESET}\n"
    set_danger
elif [ "$HIST_UNDERVOLTAGE" -ne 0 ]; then
    printf "${YELLOW}WARNING — Under-voltage occurred${RESET}\n"
    set_warning
else
    printf "${GREEN}OK — No issues detected${RESET}\n"
fi

# Thermal / throttling
printf "Thermal:    "

if [ "$CURRENT_THROTTLED" -ne 0 ] || [ "$CURRENT_SOFT_TEMP" -ne 0 ] || [ "$CURRENT_FREQ_CAP" -ne 0 ]; then
    printf "${RED}DANGER — Throttling NOW${RESET}\n"
    set_danger
elif [ "$HIST_THROTTLED" -ne 0 ] || [ "$HIST_SOFT_TEMP" -ne 0 ] || [ "$HIST_FREQ_CAP" -ne 0 ]; then
    printf "${YELLOW}WARNING — Throttling occurred${RESET}\n"
    set_warning
else
    printf "${GREEN}OK — No throttling${RESET}\n"
fi

# Uptime — always green
UPTIME=$(uptime -p | sed \
    -e 's/up //' \
    -e 's/ days\?/d/' \
    -e 's/ hours\?/h/' \
    -e 's/ minutes\?/m/' \
    -e 's/,//g')

printf "Uptime:     ${GREEN}%s${RESET}\n" "$UPTIME"

echo "────────────────────────────"

printf "Overall:    "

if [ "$OVERALL" -eq 2 ]; then
    printf "${RED}DANGER${RESET}\n"
elif [ "$OVERALL" -eq 1 ]; then
    printf "${YELLOW}WARNING${RESET}\n"
else
    printf "${GREEN}HEALTHY${RESET}\n"
fi

echo