#!/bin/bash

# Health Check Script for mobile.dispo24.de
# Usage: /usr/local/bin/health-check.sh [--fix] [--restart]
# Run as root

set -euo pipefail

# ============================================
# CONFIGURATION
# ============================================
readonly SCRIPT_VERSION="1.1"
readonly PM2_USER="toto"
readonly API_ENDPOINT="http://localhost:8031/v1/test"
readonly DISK_THRESHOLD=80
readonly LOG_FILE="/var/log/health-check.log"

# Colors
readonly GREEN='\033[0;32m'
readonly RED='\033[0;31m'
readonly YELLOW='\033[1;33m'
readonly NC='\033[0m'

# Parse arguments
FIX_MODE=0
RESTART_MODE=0
for arg in "$@"; do
    case "$arg" in
        --fix)     FIX_MODE=1 ;;
        --restart) RESTART_MODE=1 ;;
        *)         echo "Unknown argument: $arg"; echo "Usage: $0 [--fix] [--restart]"; exit 1 ;;
    esac
done

# Counters
ISSUES=0
FIXED=0

# Log buffer - only write if there are issues
LOG_BUFFER=""

# ============================================
# HELPER FUNCTIONS
# ============================================
log_ok() {
    echo -e "${GREEN}✓ $1${NC}"
}

log_error() {
    local msg="$1"
    echo -e "${RED}❌ $msg${NC}"
    LOG_BUFFER+="[$(date '+%Y-%m-%d %H:%M:%S')] ERROR: $msg\n"
    ISSUES=$((ISSUES+1))
}

log_warn() {
    local msg="$1"
    echo -e "${YELLOW}⚠ $msg${NC}"
    LOG_BUFFER+="[$(date '+%Y-%m-%d %H:%M:%S')] WARN: $msg\n"
}

log_fixed() {
    local msg="$1"
    echo -e "${GREEN}🔧 $msg${NC}"
    LOG_BUFFER+="[$(date '+%Y-%m-%d %H:%M:%S')] FIXED: $msg\n"
    FIXED=$((FIXED+1))
}

write_log() {
    if [[ $ISSUES -gt 0 || $RESTART_MODE -eq 1 ]]; then
        {
            echo "========================================"
            echo "Health Check Report - $(date '+%Y-%m-%d %H:%M:%S')"
            [[ $FIX_MODE -eq 1 ]] && echo "Mode: AUTO-FIX"
            [[ $RESTART_MODE -eq 1 ]] && echo "Mode: FORCED RESTART"
            echo "========================================"
            echo -e "$LOG_BUFFER"
            echo "Summary: $ISSUES issue(s) found, $FIXED fixed"
            echo ""
        } >> "$LOG_FILE"
    fi
}

# ============================================
# FORCED RESTART (--restart)
# ============================================
if [[ $RESTART_MODE -eq 1 ]]; then
    echo "================================"
    echo -e "${RED}⚠ FORCED RESTART OF ALL SERVICES${NC}"
    echo "Time: $(date '+%Y-%m-%d %H:%M:%S')"
    echo "================================"
    echo ""
    LOG_BUFFER+="[$(date '+%Y-%m-%d %H:%M:%S')] FORCED RESTART initiated\n"

    echo "=== Restarting PM2 ==="
    if sudo -u "$PM2_USER" pm2 restart all 2>&1; then
        log_fixed "PM2 processes restarted"
    else
        log_error "Failed to restart PM2 processes"
    fi
    echo ""

    echo "=== Restarting MongoDB ==="
    if systemctl restart mongod.service; then
        log_fixed "MongoDB restarted"
    else
        log_error "Failed to restart MongoDB"
    fi
    echo ""

    echo "=== Restarting Redis ==="
    if systemctl restart redis-server.service; then
        log_fixed "Redis restarted"
    else
        log_error "Failed to restart Redis"
    fi
    echo ""

    echo "=== Restarting Apache ==="
    if systemctl restart apache2.service; then
        log_fixed "Apache restarted"
    else
        log_error "Failed to restart Apache"
    fi
    echo ""

    # Wait for services to settle
    echo "Waiting for services to stabilize..."
    sleep 5

    # Verify API after restart
    echo "=== Verifying API ==="
    HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" --max-time 10 "$API_ENDPOINT" 2>/dev/null || echo "000")
    if [[ "$HTTP_CODE" =~ ^(200|201|204)$ ]]; then
        log_ok "API responding (HTTP $HTTP_CODE)"
    else
        log_error "API not responding after restart (HTTP $HTTP_CODE)"
    fi
    echo ""

    write_log

    echo "================================"
    if [[ $ISSUES -eq 0 ]]; then
        log_ok "ALL SERVICES RESTARTED SUCCESSFULLY"
        exit 0
    else
        echo -e "${RED}❌ $ISSUES ISSUE(S) DURING RESTART${NC}"
        echo -e "${YELLOW}Log written to: $LOG_FILE${NC}"
        exit 1
    fi
fi

# ============================================
# HEADER
# ============================================
echo "================================"
echo "SERVICE HEALTH CHECK v${SCRIPT_VERSION}"
[[ $FIX_MODE -eq 1 ]] && echo "Mode: AUTO-FIX ENABLED"
echo "Time: $(date '+%Y-%m-%d %H:%M:%S')"
echo "================================"
echo ""

# ============================================
# 1. PM2 STATUS
# ============================================
echo "=== PM2 Processes ==="
if PM2_OUTPUT=$(sudo -u "$PM2_USER" pm2 jlist 2>&1); then
    if echo "$PM2_OUTPUT" | jq -e '.[] | select(.pm2_env.status != "online")' &>/dev/null; then
        log_error "Some PM2 processes are not online"
        
        if [[ $FIX_MODE -eq 1 ]]; then
            log_warn "Attempting to restart stopped PM2 processes..."
            if sudo -u "$PM2_USER" pm2 restart all 2>&1; then
                sleep 3
                log_fixed "PM2 processes restarted"
            else
                log_error "Failed to restart PM2 processes"
            fi
        fi
    else
        log_ok "All PM2 processes online"
    fi
else
    log_error "Cannot query PM2 status"
fi

sudo -u "$PM2_USER" pm2 list 2>/dev/null || true
echo ""

# ============================================
# 2. MONGODB STATUS
# ============================================
echo "=== MongoDB ==="
if systemctl is-active --quiet mongod.service; then
    log_ok "mongod.service is ACTIVE"
else
    log_error "mongod.service is NOT RUNNING"
    
    if [[ $FIX_MODE -eq 1 ]]; then
        log_warn "Attempting to start MongoDB..."
        if systemctl start mongod.service; then
            sleep 2
            log_fixed "MongoDB started successfully"
        else
            log_error "Failed to start MongoDB"
        fi
    fi
fi
echo ""

# ============================================
# 3. REDIS STATUS
# ============================================
echo "=== Redis ==="
if systemctl is-active --quiet redis-server.service; then
    log_ok "redis-server.service is ACTIVE"
else
    log_error "redis-server.service is NOT RUNNING"
    
    if [[ $FIX_MODE -eq 1 ]]; then
        log_warn "Attempting to start Redis..."
        if systemctl start redis-server.service; then
            sleep 2
            log_fixed "Redis started successfully"
        else
            log_error "Failed to start Redis"
        fi
    fi
fi
echo ""

# ============================================
# 4. APACHE STATUS
# ============================================
echo "=== Apache ==="
if systemctl is-active --quiet apache2.service; then
    log_ok "apache2.service is ACTIVE"
else
    log_error "apache2.service is NOT RUNNING"
    
    if [[ $FIX_MODE -eq 1 ]]; then
        log_warn "Attempting to start Apache..."
        if systemctl start apache2.service; then
            sleep 2
            log_fixed "Apache started successfully"
        else
            log_error "Failed to start Apache"
        fi
    fi
fi
echo ""

# ============================================
# 5. API ENDPOINT TEST
# ============================================
echo "=== API Endpoint Test ==="
HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" --max-time 5 "$API_ENDPOINT" 2>/dev/null || echo "000")

if [[ "$HTTP_CODE" =~ ^(200|201|204)$ ]]; then
    log_ok "API responding (HTTP $HTTP_CODE)"
else
    log_error "API not responding properly (HTTP $HTTP_CODE)"
    
    if [[ $FIX_MODE -eq 1 && "$HTTP_CODE" == "000" ]]; then
        log_warn "API unreachable - restarting PM2..."
        sudo -u "$PM2_USER" pm2 restart all 2>&1 && sleep 3
        
        HTTP_CODE=$(curl -s -o /dev/null -w "%{http_code}" --max-time 5 "$API_ENDPOINT" 2>/dev/null || echo "000")
        [[ "$HTTP_CODE" =~ ^(200|201|204)$ ]] && log_fixed "API recovered after restart"
    fi
fi
echo ""

# ============================================
# 6. DISK SPACE
# ============================================
echo "=== Disk Space ==="
DISK_USAGE=$(df -h / | awk 'NR==2 {print $5}' | sed 's/%//')
if [[ "$DISK_USAGE" -lt "$DISK_THRESHOLD" ]]; then
    log_ok "Disk usage: ${DISK_USAGE}%"
else
    log_error "Disk usage HIGH: ${DISK_USAGE}%"
fi
echo ""

# ============================================
# WRITE LOG & SUMMARY
# ============================================
write_log

echo "================================"
if [[ $ISSUES -eq 0 ]]; then
    log_ok "ALL SYSTEMS OK"
    exit 0
else
    echo -e "${RED}❌ $ISSUES ISSUE(S) FOUND${NC}"
    [[ $FIX_MODE -eq 1 ]] && echo -e "${GREEN}🔧 $FIXED ISSUE(S) AUTO-FIXED${NC}"
    echo -e "${YELLOW}Log written to: $LOG_FILE${NC}"
    exit 1
fi