#!/bin/bash

# Linux Fan Diagnostic Script
# Monitors CPU usage, temperature, and processes every 200ms
# Usage: ./fan_diagnostic.sh [duration_in_seconds]

# Default duration: 60 seconds (can be overridden by argument)
DURATION=${1:-60}
INTERVAL_MS=200  # milliseconds
TIMESTAMP=$(date +%Y%m%d_%H%M%S)
LOG_FILE="fan_diagnostic_${TIMESTAMP}.log"
SPIKE_LOG="fan_spikes_${TIMESTAMP}.log"

# Thresholds for spike detection
CPU_SPIKE_THRESHOLD=50  # CPU usage above 50%
TEMP_SPIKE_THRESHOLD=70  # Temperature above 70°C
TEMP_INCREASE_THRESHOLD=5  # Temperature increase of 5°C or more

# Baseline values
PREV_TEMP=0
BASELINE_CPU=0
SAMPLE_COUNT=0

echo "==================================" | tee -a "$LOG_FILE"
echo "Linux Fan Diagnostic Script" | tee -a "$LOG_FILE"
echo "Started: $(date)" | tee -a "$LOG_FILE"
echo "Duration: ${DURATION}s | Interval: ${INTERVAL_MS}ms" | tee -a "$LOG_FILE"
echo "Main log: $LOG_FILE" | tee -a "$LOG_FILE"
echo "Spike log: $SPIKE_LOG" | tee -a "$LOG_FILE"
echo "==================================" | tee -a "$LOG_FILE"
echo "" | tee -a "$LOG_FILE"

# Initialize spike log
echo "==================================" > "$SPIKE_LOG"
echo "CPU & TEMPERATURE SPIKE LOG" >> "$SPIKE_LOG"
echo "Started: $(date)" >> "$SPIKE_LOG"
echo "CPU Spike Threshold: ${CPU_SPIKE_THRESHOLD}%" >> "$SPIKE_LOG"
echo "Temp Spike Threshold: ${TEMP_SPIKE_THRESHOLD}°C" >> "$SPIKE_LOG"
echo "Temp Increase Threshold: ${TEMP_INCREASE_THRESHOLD}°C" >> "$SPIKE_LOG"
echo "==================================" >> "$SPIKE_LOG"
echo "" >> "$SPIKE_LOG"

# System Information
echo "=== SYSTEM INFORMATION ===" >> "$LOG_FILE"
echo "Hostname: $(hostname)" >> "$LOG_FILE"
echo "Kernel: $(uname -r)" >> "$LOG_FILE"
echo "CPU Model: $(lscpu | grep 'Model name' | cut -d':' -f2 | xargs)" >> "$LOG_FILE"
echo "CPU Cores: $(nproc)" >> "$LOG_FILE"
echo "" >> "$LOG_FILE"

# Installed packages that might affect CPU/Fan
echo "=== INSTALLED SOFTWARE ===" >> "$LOG_FILE"
if command -v docker &> /dev/null; then
    echo "Docker version: $(docker --version)" >> "$LOG_FILE"
    echo "Docker containers:" >> "$LOG_FILE"
    docker ps -a >> "$LOG_FILE" 2>&1
    echo "" >> "$LOG_FILE"
fi

if command -v snap &> /dev/null; then
    echo "Snap packages:" >> "$LOG_FILE"
    snap list >> "$LOG_FILE" 2>&1
    echo "" >> "$LOG_FILE"
fi

echo "Recently installed packages (apt):" >> "$LOG_FILE"
if [ -f /var/log/apt/history.log ]; then
    grep -A 2 "Install:" /var/log/apt/history.log | tail -20 >> "$LOG_FILE"
fi
echo "" >> "$LOG_FILE"

# Temperature sensors available
echo "=== TEMPERATURE SENSORS ===" >> "$LOG_FILE"
if command -v sensors &> /dev/null; then
    sensors >> "$LOG_FILE" 2>&1
else
    echo "lm-sensors not installed. Install with: sudo apt install lm-sensors" >> "$LOG_FILE"
fi
echo "" >> "$LOG_FILE"

# Monitoring loop
echo "=== MONITORING DATA ===" >> "$LOG_FILE"
echo "Starting monitoring for ${DURATION} seconds..." | tee -a "$LOG_FILE"

START_TIME=$(date +%s)
END_TIME=$((START_TIME + DURATION))
SAMPLE=0
SPIKE_COUNT=0

while [ $(date +%s) -lt $END_TIME ]; do
    SAMPLE=$((SAMPLE + 1))
    TIMESTAMP_SAMPLE=$(date +"%Y-%m-%d %H:%M:%S.%3N")
    
    echo "--- Sample #${SAMPLE} at ${TIMESTAMP_SAMPLE} ---" >> "$LOG_FILE"
    
    # CPU Temperature
    TEMP_C=0
    if [ -f /sys/class/thermal/thermal_zone0/temp ]; then
        TEMP=$(cat /sys/class/thermal/thermal_zone0/temp)
        TEMP_C=$((TEMP / 1000))
        echo "CPU Temp: ${TEMP_C}°C" >> "$LOG_FILE"
    fi
    
    # Overall CPU usage
    CPU_USAGE=$(top -bn1 | grep "Cpu(s)" | sed "s/.*, *\([0-9.]*\)%* id.*/\1/" | awk '{print 100 - $1}')
    CPU_USAGE_INT=$(echo "$CPU_USAGE" | cut -d'.' -f1)
    echo "CPU Usage: ${CPU_USAGE}%" >> "$LOG_FILE"
    
    # Top 5 CPU consuming processes
    TOP_PROCESSES=$(ps aux --sort=-%cpu | head -6 | tail -5)
    echo "Top CPU processes:" >> "$LOG_FILE"
    echo "$TOP_PROCESSES" >> "$LOG_FILE"
    
    # Docker containers CPU usage (if docker is running)
    DOCKER_STATS=""
    if command -v docker &> /dev/null && docker ps -q &> /dev/null; then
        DOCKER_STATS=$(docker stats --no-stream --format "table {{.Name}}\t{{.CPUPerc}}\t{{.MemUsage}}" 2>&1)
        echo "Docker container stats:" >> "$LOG_FILE"
        echo "$DOCKER_STATS" >> "$LOG_FILE"
    fi
    
    # Fan speed (if available)
    FAN_INFO=""
    if command -v sensors &> /dev/null; then
        FAN_INFO=$(sensors | grep -i "fan")
        if [ ! -z "$FAN_INFO" ]; then
            echo "Fan: $FAN_INFO" >> "$LOG_FILE"
        fi
    fi
    
    echo "" >> "$LOG_FILE"
    
    # SPIKE DETECTION
    SPIKE_DETECTED=0
    SPIKE_REASONS=""
    
    # Check CPU spike
    if [ ! -z "$CPU_USAGE_INT" ] && [ "$CPU_USAGE_INT" -gt "$CPU_SPIKE_THRESHOLD" ]; then
        SPIKE_DETECTED=1
        SPIKE_REASONS="${SPIKE_REASONS}CPU usage high (${CPU_USAGE}% > ${CPU_SPIKE_THRESHOLD}%); "
    fi
    
    # Check temperature spike
    if [ "$TEMP_C" -gt "$TEMP_SPIKE_THRESHOLD" ]; then
        SPIKE_DETECTED=1
        SPIKE_REASONS="${SPIKE_REASONS}High temperature (${TEMP_C}°C > ${TEMP_SPIKE_THRESHOLD}°C); "
    fi
    
    # Check temperature increase
    if [ "$PREV_TEMP" -gt 0 ]; then
        TEMP_DIFF=$((TEMP_C - PREV_TEMP))
        if [ "$TEMP_DIFF" -ge "$TEMP_INCREASE_THRESHOLD" ]; then
            SPIKE_DETECTED=1
            SPIKE_REASONS="${SPIKE_REASONS}Temperature jump (+${TEMP_DIFF}°C); "
        fi
    fi
    
    # Log spike if detected
    if [ "$SPIKE_DETECTED" -eq 1 ]; then
        SPIKE_COUNT=$((SPIKE_COUNT + 1))
        
        echo "╔═══════════════════════════════════════════════════════════════" >> "$SPIKE_LOG"
        echo "║ SPIKE #${SPIKE_COUNT} DETECTED at ${TIMESTAMP_SAMPLE}" >> "$SPIKE_LOG"
        echo "╠═══════════════════════════════════════════════════════════════" >> "$SPIKE_LOG"
        echo "║ Reason: ${SPIKE_REASONS}" >> "$SPIKE_LOG"
        echo "║ CPU Usage: ${CPU_USAGE}%" >> "$SPIKE_LOG"
        echo "║ CPU Temp: ${TEMP_C}°C (Previous: ${PREV_TEMP}°C)" >> "$SPIKE_LOG"
        
        if [ ! -z "$FAN_INFO" ]; then
            echo "║ Fan Status: ${FAN_INFO}" >> "$SPIKE_LOG"
        fi
        
        echo "╠═══════════════════════════════════════════════════════════════" >> "$SPIKE_LOG"
        echo "║ TOP CPU PROCESSES:" >> "$SPIKE_LOG"
        echo "╠═══════════════════════════════════════════════════════════════" >> "$SPIKE_LOG"
        echo "$TOP_PROCESSES" | while IFS= read -r line; do
            echo "║ $line" >> "$SPIKE_LOG"
        done
        
        if [ ! -z "$DOCKER_STATS" ]; then
            echo "╠═══════════════════════════════════════════════════════════════" >> "$SPIKE_LOG"
            echo "║ DOCKER CONTAINERS:" >> "$SPIKE_LOG"
            echo "╠═══════════════════════════════════════════════════════════════" >> "$SPIKE_LOG"
            echo "$DOCKER_STATS" | while IFS= read -r line; do
                echo "║ $line" >> "$SPIKE_LOG"
            done
        fi
        
        echo "╚═══════════════════════════════════════════════════════════════" >> "$SPIKE_LOG"
        echo "" >> "$SPIKE_LOG"
        
        printf "\r⚠ SPIKE #%d detected! " "$SPIKE_COUNT"
    fi
    
    # Update baseline and previous values
    PREV_TEMP=$TEMP_C
    if [ "$SAMPLE" -le 10 ] && [ ! -z "$CPU_USAGE_INT" ]; then
        BASELINE_CPU=$((BASELINE_CPU + CPU_USAGE_INT))
        if [ "$SAMPLE" -eq 10 ]; then
            BASELINE_CPU=$((BASELINE_CPU / 10))
        fi
    fi
    
    # Progress indicator
    CURRENT_TIME=$(date +%s)
    ELAPSED=$((CURRENT_TIME - START_TIME))
    PROGRESS=$((ELAPSED * 100 / DURATION))
    printf "\rProgress: %d%% (Sample #%d, %ds/%ds, Spikes: %d)    " "$PROGRESS" "$SAMPLE" "$ELAPSED" "$DURATION" "$SPIKE_COUNT"
    
    sleep 0.2
done

echo "" | tee -a "$LOG_FILE"
echo "==================================" | tee -a "$LOG_FILE" | tee -a "$SPIKE_LOG"
echo "Monitoring completed: $(date)" | tee -a "$LOG_FILE" | tee -a "$SPIKE_LOG"
echo "Total samples: ${SAMPLE}" | tee -a "$LOG_FILE"
echo "Total spikes detected: ${SPIKE_COUNT}" | tee -a "$LOG_FILE" | tee -a "$SPIKE_LOG"
echo "Main log: $LOG_FILE" | tee -a "$LOG_FILE"
echo "Spike log: $SPIKE_LOG" | tee -a "$LOG_FILE"
echo "==================================" | tee -a "$LOG_FILE" | tee -a "$SPIKE_LOG"
echo ""
echo "✓ Monitoring complete!"
echo "  📊 Full log: $LOG_FILE"
echo "  ⚠️  Spike log: $SPIKE_LOG"
echo ""
echo "Quick analysis commands:"
echo "  cat $SPIKE_LOG | less"
echo "  grep 'SPIKE #' $SPIKE_LOG"