#!/data/data/com.termux/files/usr/bin/env bash
# ===============================================
# Termux Battery Daemon + On-demand TUI
# Features: Background daemon, trend graph, degradation alerts,
# Smart charging advice, and notifications.
# ===============================================

PID_FILE="$PREFIX/tmp/battery.pid"
LOG_FILE="$PREFIX/tmp/battery.log"
HISTORY_FILE="$PREFIX/tmp/battery_history.csv"
CHECK_INTERVAL=60
MAX_TEMP=45
LOW_BATTERY=20
HIGH_DRAIN=800000

mkdir -p "$PREFIX/tmp"

# ANSI colors
RED="\033[1;31m"
GREEN="\033[1;32m"
CYAN="\033[1;36m"
MAGENTA="\033[1;35m"
YELLOW="\033[1;33m"
RESET="\033[0m"

notify() {
    termux-notification --title "$1" --content "$2"
}

get_battery() {
    termux-battery-status
}

log() {
    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1" >> "$LOG_FILE"
}

# ===============================================
# Analyze battery and create alerts
# ===============================================
analyze() {
    local health="$1"
    local temp="$2"
    local percent="$3"
    local status="$4"
    local current="$5"
    local alerts=()

    # 1. Health alert
    [[ "$health" != "GOOD" ]] && alerts+=("Health=$health")
    # 2. Temperature alert
    (( $(echo "$temp >= $MAX_TEMP" | bc -l) )) && alerts+=("Temp=${temp}C")
    # 3. Low battery alert
    (( percent <= LOW_BATTERY )) && alerts+=("Low=${percent}%")
    # 4. High current / drain alert
    if [[ "$status" == "DISCHARGING" ]] && (( current >= HIGH_DRAIN )); then
        alerts+=("High Drain=$(echo "$current/1000000" | bc)A")
    fi

    # 5. Degradation alert
    if [ -f "$HISTORY_FILE" ]; then
        last_percent=$(tail -n1 "$HISTORY_FILE" | awk -F, '{print $2}')
        if [ -n "$last_percent" ]; then
            degradation=$(echo "$last_percent - $percent" | bc)
            if (( $(echo "$degradation > 10" | bc -l) )); then
                alerts+=("Battery degrading")
            fi
        fi
    fi

    echo "${alerts[@]}"
}

# ===============================================
# Battery trend graph
# ===============================================
battery_graph() {
    local history=("$@")
    local bar=""
    for p in "${history[@]}"; do
        if (( p > 75 )); then bar+="${GREEN}#" ;
        elif (( p > 50 )); then bar+="${CYAN}#" ;
        elif (( p > 25 )); then bar+="${YELLOW}-" ;
        else bar+="${RED}-" ;
        fi
    done
    echo -e "$bar${RESET}"
}

# ===============================================
# Smart advice
# ===============================================
battery_advice() {
    local percent="$1"
    local health="$2"
    if [[ "$health" != "GOOD" ]]; then
        echo "Check battery health!"
    elif (( percent < 40 )); then
        echo "Charge now"
    elif (( percent > 80 )); then
        echo "Unplug"
    else
        echo "Optimal"
    fi
}

# ===============================================
# Draw TUI dashboard
# ===============================================
draw_status() {
    local status="$1"
    local health="$2"
    local percent="$3"
    local temp="$4"
    local volt="$5"
    local current="$6"
    local uptime="$7"
    local trend="$8"
    local alerts="$9"

    tput civis
    tput clear
    echo -e "${CYAN}============== Termux Battery Dashboard ==============${RESET}"
    echo -e "${MAGENTA}Status       :${RESET} $status"
    echo -e "${MAGENTA}Health       :${RESET} $health"
    echo -e "${MAGENTA}Level        :${RESET} $percent%"
    echo -e "${MAGENTA}Temperature  :${RESET} ${temp}C"
    echo -e "${MAGENTA}Voltage      :${RESET} ${volt} mV"
    echo -e "${MAGENTA}Current      :${RESET} $(echo "$current/1000000" | bc) A"
    echo -e "${MAGENTA}Device Uptime:${RESET} $uptime"
    echo -e "${MAGENTA}Battery Trend:${RESET} $trend"
    echo -e "${MAGENTA}Recommended :${RESET} $(battery_advice $percent $health)"
    [[ -n "$alerts" ]] && echo -e "${RED}ALERTS: $alerts${RESET}" || echo -e "${GREEN}Battery OK${RESET}"
    echo -e "${CYAN}=======================================================${RESET}"
    tput cnorm
}

# ===============================================
# Daemon: Background collection
# ===============================================
daemon() {
    notify "Battery Daemon" "Started"
    log "Daemon started"
    battery_history=()

    [ ! -f "$HISTORY_FILE" ] && echo "timestamp,percent,voltage,temperature,current" > "$HISTORY_FILE"

    while true; do
        data=$(get_battery)
        health=$(echo "$data" | jq -r '.health')
        temp=$(echo "$data" | jq -r '.temperature')
        percent=$(echo "$data" | jq -r '.percentage')
        status_b=$(echo "$data" | jq -r '.status')
        volt=$(echo "$data" | jq -r '.voltage')
        current=$(echo "$data" | jq -r '.current')

        echo "$(date +%s),$percent,$volt,$temp,$current" >> "$HISTORY_FILE"

        battery_history+=("$percent")
        [ "${#battery_history[@]}" -gt 20 ] && battery_history=("${battery_history[@]: -20}")

        alerts=$(analyze "$health" "$temp" "$percent" "$status_b" "$current")
        uptime_sec=0
        [ -f "$PID_FILE" ] && uptime_sec=$(( $(date +%s) - $(stat -c %Y "$PID_FILE") ))
        uptime_str=$(printf '%dh %dm %ds' $((uptime_sec/3600)) $((uptime_sec%3600/60)) $((uptime_sec%60)))
        trend=$(battery_graph "${battery_history[@]}")

        [[ -n "$alerts" ]] && log "$alerts" && notify "Battery Alert" "$alerts" || log "OK $percent% $temp C"

        sleep "$CHECK_INTERVAL"
    done
}

# ===============================================
# CLI Commands
# ===============================================
start() {
    if [ -f "$PID_FILE" ]; then
        echo "Battery daemon already running"
        exit 1
    fi
    daemon &         # run in background
    echo $! > "$PID_FILE"
    echo "Battery daemon started in background"
}

stop() {
    if [ ! -f "$PID_FILE" ]; then
        echo "Battery daemon not running"
        exit 1
    fi
    kill $(cat "$PID_FILE") 2>/dev/null
    rm "$PID_FILE"
    echo "Battery daemon stopped"
}

status() {
    if [ ! -f "$HISTORY_FILE" ]; then
        echo "No battery data collected yet. Start the daemon first."
        exit 1
    fi
    mapfile -t history < <(tail -n20 "$HISTORY_FILE" | awk -F, '{print $2}')
    last_entry=$(tail -n1 "$HISTORY_FILE")
    percent=$(echo "$last_entry" | awk -F, '{print $2}')
    volt=$(echo "$last_entry" | awk -F, '{print $3}')
    temp=$(echo "$last_entry" | awk -F, '{print $4}')
    current=$(echo "$last_entry" | awk -F, '{print $5}')
    status_b="UNKNOWN"
    health="GOOD"
    uptime_sec=0
    [ -f "$PID_FILE" ] && uptime_sec=$(( $(date +%s) - $(stat -c %Y "$PID_FILE") ))
    uptime_str=$(printf '%dh %dm %ds' $((uptime_sec/3600)) $((uptime_sec%3600/60)) $((uptime_sec%60)))
    alerts=$(analyze "$health" "$temp" "$percent" "$status_b" "$current")
    trend=$(battery_graph "${history[@]}")
    draw_status "$status_b" "$health" "$percent" "$temp" "$volt" "$current" "$uptime_str" "$trend" "$alerts"
}

logs() {
    tail -f "$LOG_FILE"
}

case "$1" in
    start) start ;;
    stop) stop ;;
    status) status ;;
    logs) logs ;;
    *) echo "Usage: battery start|stop|status|logs" ;;
esac