#!/bin/bash

################################################################################
# Extended Analysis Functions
################################################################################
# Purpose: All 32 additional intelligence checks for website slowness
# Categories: WordPress, Database, PHP, Web Server, Cron/Tasks
################################################################################

# ============================================================================
# CATEGORY 1: WORDPRESS-SPECIFIC SETTINGS (8 checks)
# ============================================================================

### 1.1 - WP_DEBUG Enabled Check
analyze_wp_debug() {
    local docroot="$1"
    local wp_config="$docroot/wp-config.php"

    if [ ! -f "$wp_config" ]; then
        return 0
    fi

    local debug_enabled=$(grep -c "define.*'WP_DEBUG'.*true" "$wp_config" 2>/dev/null || echo 0)

    if [ "$debug_enabled" -gt 0 ]; then
        save_analysis_data "wordpress_settings.tmp" "CRITICAL: WP_DEBUG enabled in production"
        save_analysis_data "wordpress_settings.tmp" "  Impact: 10-15% performance penalty from error logging"
        save_analysis_data "wordpress_settings.tmp" "  Fix: Set define( 'WP_DEBUG', false );"
    fi
}

### 1.2 - XML-RPC Enabled Check
analyze_xmlrpc() {
    local domain="$1"

    local xmlrpc_test=$(curl -s -m 3 "https://$domain/xmlrpc.php" -w "%{http_code}" -o /dev/null 2>/dev/null || echo "000")

    if [ "$xmlrpc_test" != "403" ] && [ "$xmlrpc_test" != "404" ]; then
        save_analysis_data "wordpress_settings.tmp" "WARNING: XML-RPC is enabled"
        save_analysis_data "wordpress_settings.tmp" "  Security risk, unnecessary API exposure"
        save_analysis_data "wordpress_settings.tmp" "  Fix: Add to .htaccess or disable via plugin"
    fi
}

### 1.3 - WordPress Heartbeat API
analyze_heartbeat_api() {
    local docroot="$1"

    if [ -f "$docroot/wp-config.php" ]; then
        local heartbeat_interval=$(grep -o "HEARTBEAT_INTERVAL.*[0-9]*" "$docroot/wp-config.php" 2>/dev/null | grep -o "[0-9]*" | head -1)

        if [ -z "$heartbeat_interval" ]; then
            save_analysis_data "wordpress_settings.tmp" "INFO: Heartbeat running at default (15s) interval"
            save_analysis_data "wordpress_settings.tmp" "  Recommendation: Increase to 60s: define('HEARTBEAT_INTERVAL', 60);"
        elif [ "$heartbeat_interval" -lt 30 ]; then
            save_analysis_data "wordpress_settings.tmp" "WARNING: Heartbeat interval too frequent: ${heartbeat_interval}s"
            save_analysis_data "wordpress_settings.tmp" "  Recommend: At least 60 seconds"
        fi
    fi
}

### 1.4 - Autosave Frequency
analyze_autosave_frequency() {
    local docroot="$1"

    if [ -f "$docroot/wp-config.php" ]; then
        local autosave_interval=$(grep -o "AUTOSAVE_INTERVAL.*[0-9]*" "$docroot/wp-config.php" 2>/dev/null | grep -o "[0-9]*" | head -1)

        if [ -z "$autosave_interval" ] || [ "$autosave_interval" -lt 120 ]; then
            save_analysis_data "wordpress_settings.tmp" "INFO: Autosave frequency at default or too frequent"
            save_analysis_data "wordpress_settings.tmp" "  Recommendation: Set to 300s (5 min): define('AUTOSAVE_INTERVAL', 300);"
        fi
    fi
}

### 1.5 - REST API Exposure
analyze_rest_api_exposure() {
    local domain="$1"

    local rest_test=$(curl -s -m 3 "https://$domain/wp-json/wp/v2/posts" 2>/dev/null | head -c 50)

    if [[ "$rest_test" == *"ID"* ]] || [[ "$rest_test" == *"title"* ]]; then
        save_analysis_data "wordpress_settings.tmp" "INFO: REST API is fully exposed (public)"
        save_analysis_data "wordpress_settings.tmp" "  Consider: Require authentication or limit access"
    fi
}

### 1.6 - Emoji Support
analyze_emoji_scripts() {
    local domain="$1"

    local emoji_test=$(curl -s -m 5 "https://$domain" 2>/dev/null | grep -c "wp-emoji" || echo 0)

    if [ "$emoji_test" -gt 0 ]; then
        save_analysis_data "wordpress_settings.tmp" "INFO: Emoji support scripts loading"
        save_analysis_data "wordpress_settings.tmp" "  Unnecessary for most sites, adds 1-2 extra HTTP requests"
        save_analysis_data "wordpress_settings.tmp" "  Fix: Use disable-emojis plugin or add function to disable"
    fi
}

### 1.7 - Post Revision Distribution
analyze_post_revision_distribution() {
    local db_name="$1"

    if [ -z "$db_name" ]; then
        return 0
    fi

    local high_revision_posts=$(mysql -Ns -e "
        SELECT COUNT(DISTINCT post_parent) FROM ${db_name}.wp_posts
        WHERE post_type='revision'
        GROUP BY post_parent
        HAVING COUNT(*) > 50;
    " 2>/dev/null | wc -l || echo 0)

    if [ "$high_revision_posts" -gt 0 ]; then
        save_analysis_data "wordpress_settings.tmp" "WARNING: $high_revision_posts posts with >50 revisions each"
        save_analysis_data "wordpress_settings.tmp" "  These posts bloat the database"
        save_analysis_data "wordpress_settings.tmp" "  Fix: Delete old revisions: wp post delete \$(wp post list --format=ids --post_type=revision) --force"
    fi
}

### 1.8 - Pingbacks/Trackbacks
analyze_pingbacks_trackbacks() {
    local docroot="$1"

    if [ -f "$docroot/wp-config.php" ]; then
        # Check if default setting is configured
        if ! grep -q "default_ping_status" "$docroot/wp-config.php"; then
            save_analysis_data "wordpress_settings.tmp" "INFO: Pingbacks/trackbacks enabled (default)"
            save_analysis_data "wordpress_settings.tmp" "  Security & performance: Disable with wp option update default_ping_status 'closed'"
        fi
    fi
}

# ============================================================================
# CATEGORY 2: DATABASE TUNING (8 checks)
# ============================================================================

### 2.1 - InnoDB Buffer Pool Size
analyze_innodb_buffer_pool() {
    local buffer_pool=$(mysql -Ns -e "SELECT @@innodb_buffer_pool_size;" 2>/dev/null || echo "0")

    if [ "$buffer_pool" -lt 268435456 ]; then  # Less than 256MB
        save_analysis_data "database_tuning.tmp" "CRITICAL: InnoDB buffer pool too small"
        save_analysis_data "database_tuning.tmp" "  Current: $(( buffer_pool / 1024 / 1024 ))MB"
        save_analysis_data "database_tuning.tmp" "  Recommend: 256MB minimum, 50-75% of available RAM"
        save_analysis_data "database_tuning.tmp" "  Edit /etc/my.cnf: innodb_buffer_pool_size = 8G"
    fi
}

### 2.2 - Max Allowed Packet
analyze_max_allowed_packet() {
    local max_packet=$(mysql -Ns -e "SELECT @@max_allowed_packet;" 2>/dev/null || echo "0")

    if [ "$max_packet" -lt 16777216 ]; then  # Less than 16MB
        save_analysis_data "database_tuning.tmp" "WARNING: max_allowed_packet is small"
        save_analysis_data "database_tuning.tmp" "  Current: $(( max_packet / 1024 / 1024 ))MB"
        save_analysis_data "database_tuning.tmp" "  Large queries may fail silently"
        save_analysis_data "database_tuning.tmp" "  Edit /etc/my.cnf: max_allowed_packet = 256M"
    fi
}

### 2.3 - Slow Query Log Threshold
analyze_slow_query_threshold() {
    local long_query_time=$(mysql -Ns -e "SELECT @@long_query_time;" 2>/dev/null || echo "10")

    if (( $(echo "$long_query_time > 2" | bc -l) )); then
        save_analysis_data "database_tuning.tmp" "INFO: Slow query threshold is high (${long_query_time}s)"
        save_analysis_data "database_tuning.tmp" "  Misses real slow queries that take 1-2 seconds"
        save_analysis_data "database_tuning.tmp" "  Edit /etc/my.cnf: long_query_time = 1"
    fi
}

### 2.4 - InnoDB File Per Table
analyze_innodb_file_per_table() {
    local file_per_table=$(mysql -Ns -e "SELECT @@innodb_file_per_table;" 2>/dev/null || echo "0")

    if [ "$file_per_table" -eq 0 ]; then
        save_analysis_data "database_tuning.tmp" "WARNING: InnoDB file-per-table is disabled"
        save_analysis_data "database_tuning.tmp" "  All tables in single ibdata1 file (can grow huge)"
        save_analysis_data "database_tuning.tmp" "  Edit /etc/my.cnf: innodb_file_per_table = 1"
    fi
}

### 2.5 - Query Cache (MySQL 5.7)
analyze_query_cache() {
    local query_cache=$(mysql -Ns -e "SELECT @@version;" 2>/dev/null || echo "8.0")

    if [[ "$query_cache" == 5.7* ]]; then
        local cache_type=$(mysql -Ns -e "SELECT @@query_cache_type;" 2>/dev/null || echo "0")
        if [ "$cache_type" -gt 0 ]; then
            save_analysis_data "database_tuning.tmp" "INFO: Query cache enabled (MySQL 5.7)"
            save_analysis_data "database_tuning.tmp" "  Can be slow, consider disabling or upgrading to MySQL 8.0"
        fi
    fi
}

### 2.6 - Temporary Table Location
analyze_temp_table_location() {
    local tmp_table_size=$(mysql -Ns -e "SELECT @@tmp_table_size;" 2>/dev/null || echo "0")

    if [ "$tmp_table_size" -lt 33554432 ]; then  # Less than 32MB
        save_analysis_data "database_tuning.tmp" "INFO: Temporary table size is small"
        save_analysis_data "database_tuning.tmp" "  Current: $(( tmp_table_size / 1024 / 1024 ))MB"
        save_analysis_data "database_tuning.tmp" "  Large GROUP BY/DISTINCT queries go to disk"
        save_analysis_data "database_tuning.tmp" "  Edit /etc/my.cnf: tmp_table_size = 512M"
    fi
}

### 2.7 - Connection Timeout Settings
analyze_connection_timeout() {
    local wait_timeout=$(mysql -Ns -e "SELECT @@wait_timeout;" 2>/dev/null || echo "28800")

    if [ "$wait_timeout" -gt 3600 ]; then
        save_analysis_data "database_tuning.tmp" "INFO: wait_timeout is high (${wait_timeout}s)"
        save_analysis_data "database_tuning.tmp" "  May accumulate idle connections"
        save_analysis_data "database_tuning.tmp" "  For pooling: Set to 600 (10 min)"
    fi
}

### 2.8 - Innodb Flush Log at Trx Commit
analyze_innodb_flush_log() {
    local flush_log=$(mysql -Ns -e "SELECT @@innodb_flush_log_at_trx_commit;" 2>/dev/null || echo "1")

    if [ "$flush_log" -eq 1 ]; then
        save_analysis_data "database_tuning.tmp" "INFO: InnoDB flush log = 1 (safest but slowest)"
        save_analysis_data "database_tuning.tmp" "  Change to 2 for better performance with acceptable risk"
        save_analysis_data "database_tuning.tmp" "  Edit /etc/my.cnf: innodb_flush_log_at_trx_commit = 2"
    fi
}

# ============================================================================
# CATEGORY 3: PHP PERFORMANCE (6 checks)
# ============================================================================

### 3.1 - OPcache Configuration
analyze_opcache() {
    local opcache_enabled=$(php -r "echo extension_loaded('Zend OPcache') ? 1 : 0;" 2>/dev/null || echo 0)

    if [ "$opcache_enabled" -eq 0 ]; then
        save_analysis_data "php_tuning.tmp" "CRITICAL: OPcache not enabled"
        save_analysis_data "php_tuning.tmp" "  Impact: 2-3x slower PHP execution"
        save_analysis_data "php_tuning.tmp" "  Fix: Enable in php.ini with proper config"
    else
        local cache_size=$(php -i 2>/dev/null | grep "opcache.memory_consumption" | awk '{print $NF}' || echo "0")
        if [ "$cache_size" -lt 256 ]; then
            save_analysis_data "php_tuning.tmp" "WARNING: OPcache memory too small (${cache_size}MB)"
            save_analysis_data "php_tuning.tmp" "  Recommend: 256MB or more"
        fi
    fi
}

### 3.2 - Xdebug in Production
analyze_xdebug() {
    local xdebug_enabled=$(php -m 2>/dev/null | grep -c "Xdebug" || echo 0)

    if [ "$xdebug_enabled" -gt 0 ]; then
        save_analysis_data "php_tuning.tmp" "CRITICAL: Xdebug enabled in production!"
        save_analysis_data "php_tuning.tmp" "  Impact: 50-70% performance penalty"
        save_analysis_data "php_tuning.tmp" "  Fix: Disable or uninstall immediately"
    fi
}

### 3.3 - Realpath Cache
analyze_realpath_cache() {
    local realpath_size=$(php -i 2>/dev/null | grep "realpath_cache_size" | awk '{print $NF}' || echo "0")

    if [[ "$realpath_size" == "4K" ]] || [ "$realpath_size" = "4096" ]; then
        save_analysis_data "php_tuning.tmp" "INFO: Realpath cache is default (4K, too small)"
        save_analysis_data "php_tuning.tmp" "  For WordPress: Recommend 128M"
        save_analysis_data "php_tuning.tmp" "  Edit php.ini: realpath_cache_size = 128M"
    fi
}

### 3.4 - Timezone Configuration
analyze_timezone_config() {
    local php_tz=$(php -i 2>/dev/null | grep "date.timezone" | head -1 | awk '{print $NF}' || echo "UTC")

    if [ "$php_tz" = "no value" ] || [ -z "$php_tz" ]; then
        save_analysis_data "php_tuning.tmp" "INFO: Timezone not configured"
        save_analysis_data "php_tuning.tmp" "  Set to UTC or match site timezone"
        save_analysis_data "php_tuning.tmp" "  Edit php.ini: date.timezone = UTC"
    fi
}

### 3.5 - Display Errors in Production
analyze_display_errors() {
    local display_errors=$(php -i 2>/dev/null | grep "display_errors" | grep -o "On\|Off" | head -1 || echo "Off")

    if [ "$display_errors" = "On" ]; then
        save_analysis_data "php_tuning.tmp" "WARNING: display_errors is On in production"
        save_analysis_data "php_tuning.tmp" "  Security risk, performance penalty"
        save_analysis_data "php_tuning.tmp" "  Edit php.ini: display_errors = Off"
    fi
}

### 3.6 - Disabled Functions
analyze_disabled_functions() {
    local disabled=$(php -i 2>/dev/null | grep "disable_functions" | grep -o "[^ ].*" | head -1 || echo "none")

    if [ "$disabled" != "none" ] && [ -n "$disabled" ]; then
        save_analysis_data "php_tuning.tmp" "INFO: Functions disabled (security): $disabled"
        save_analysis_data "php_tuning.tmp" "  Verify these don't break any plugins"
    fi
}

# ============================================================================
# CATEGORY 4: WEB SERVER TUNING (6 checks)
# ============================================================================

### 4.1 - HTTP/2 Enabled
analyze_http2() {
    local http2_enabled=$(apache2ctl -M 2>/dev/null | grep -c "http2_module" || echo 0)

    if [ "$http2_enabled" -eq 0 ]; then
        save_analysis_data "web_server.tmp" "WARNING: HTTP/2 not enabled"
        save_analysis_data "web_server.tmp" "  Impact: 15-30% slower asset delivery"
        save_analysis_data "web_server.tmp" "  Fix: a2enmod http2 && systemctl restart apache2"
    fi
}

### 4.2 - KeepAlive Settings
analyze_keepalive() {
    local keepalive=$(grep -A 3 "^KeepAlive" /etc/apache2/apache2.conf 2>/dev/null | head -1 || echo "unknown")

    if [[ "$keepalive" == *"Off"* ]]; then
        save_analysis_data "web_server.tmp" "INFO: KeepAlive is disabled"
        save_analysis_data "web_server.tmp" "  Enable for better performance: KeepAlive On"
    fi
}

### 4.3 - Sendfile Enabled
analyze_sendfile() {
    local sendfile=$(grep -i "EnableSendfile" /etc/apache2/apache2.conf 2>/dev/null | grep -o "On\|Off" || echo "unknown")

    if [ "$sendfile" = "Off" ] || [ -z "$sendfile" ]; then
        save_analysis_data "web_server.tmp" "WARNING: Sendfile not enabled"
        save_analysis_data "web_server.tmp" "  10-20% faster static file delivery"
        save_analysis_data "web_server.tmp" "  Enable: EnableSendfile on"
    fi
}

### 4.4 - Gzip Compression Level
analyze_gzip_compression() {
    local gzip_level=$(grep -i "DeflateCompressionLevel" /etc/apache2/mods-enabled/deflate.conf 2>/dev/null | grep -o "[0-9]" || echo "6")

    if [ "$gzip_level" = "9" ]; then
        save_analysis_data "web_server.tmp" "INFO: Gzip compression level is 9 (maximum)"
        save_analysis_data "web_server.tmp" "  Too slow, not worth it. Recommend level 6"
        save_analysis_data "web_server.tmp" "  Edit deflate.conf: DeflateCompressionLevel 6"
    fi
}

### 4.5 - SSL/TLS Version
analyze_ssl_version() {
    local ssl_version=$(grep -i "SSLProtocol" /etc/apache2/sites-enabled/*ssl.conf 2>/dev/null | grep -o "TLSv[0-9.]*" | head -1 || echo "unknown")

    if [[ "$ssl_version" == *"1.0"* ]] || [[ "$ssl_version" == *"1.1"* ]]; then
        save_analysis_data "web_server.tmp" "WARNING: Using outdated SSL/TLS: $ssl_version"
        save_analysis_data "web_server.tmp" "  Recommend: TLS 1.2 minimum, TLS 1.3 preferred"
        save_analysis_data "web_server.tmp" "  Set: SSLProtocol TLSv1.2 TLSv1.3"
    fi
}

### 4.6 - Unused Apache Modules
analyze_apache_modules() {
    local module_count=$(apache2ctl -M 2>/dev/null | wc -l || echo "0")

    if [ "$module_count" -gt 45 ]; then
        save_analysis_data "web_server.tmp" "INFO: Many Apache modules loaded ($module_count)"
        save_analysis_data "web_server.tmp" "  Review and disable unused modules"
        save_analysis_data "web_server.tmp" "  Command: apache2ctl -M"
    fi
}

# ============================================================================
# CATEGORY 5: CRON & BACKGROUND TASKS (4 checks)
# ============================================================================

### 5.1 - WordPress Cron Execution
analyze_wordpress_cron() {
    local docroot="$1"

    if [ -f "$docroot/wp-config.php" ]; then
        local cron_disabled=$(grep -c "DISABLE_WP_CRON.*true" "$docroot/wp-config.php" 2>/dev/null || echo 0)

        if [ "$cron_disabled" -eq 0 ]; then
            save_analysis_data "cron_tasks.tmp" "INFO: Using wp-cron (runs every pageload)"
            save_analysis_data "cron_tasks.tmp" "  Better: Switch to system cron"
            save_analysis_data "cron_tasks.tmp" "  Set: define('DISABLE_WP_CRON', true);"
            save_analysis_data "cron_tasks.tmp" "  Then add system cron: */5 * * * * curl https://example.com/wp-cron.php"
        fi
    fi
}

### 5.2 - Backup Schedule
analyze_backup_schedule() {
    local backup_time=$(grep -i "backup" /etc/cron.d/cpanel* 2>/dev/null | grep -o "[0-9]*:[0-9]*" | head -1 || echo "unknown")

    if [ "$backup_time" != "unknown" ]; then
        # Extract hour
        local hour=${backup_time%%:*}
        if [ "$hour" -ge 7 ] && [ "$hour" -le 18 ]; then
            save_analysis_data "cron_tasks.tmp" "WARNING: Backup scheduled during peak hours ($hour:00)"
            save_analysis_data "cron_tasks.tmp" "  Move to 2-4 AM for off-peak"
        fi
    fi
}

### 5.3 - Database Optimization Schedule
analyze_db_optimization_schedule() {
    local has_optimize=$(grep -c "mysqlcheck\|optimize" /etc/cron.d/* 2>/dev/null || echo 0)

    if [ "$has_optimize" -eq 0 ]; then
        save_analysis_data "cron_tasks.tmp" "INFO: No database optimization scheduled"
        save_analysis_data "cron_tasks.tmp" "  Recommend weekly: mysqlcheck -Aou database_name"
        save_analysis_data "cron_tasks.tmp" "  Add to crontab: 0 3 * * 0 mysqlcheck -Aou -u root -p{pass}"
    fi
}

### 5.4 - Slow Cron Jobs
analyze_slow_cron_jobs() {
    # This requires WordPress and wp-cli to be available
    if command -v wp &> /dev/null; then
        local cron_jobs=$(wp cron schedule list 2>/dev/null | wc -l || echo "0")

        if [ "$cron_jobs" -gt 10 ]; then
            save_analysis_data "cron_tasks.tmp" "INFO: Many scheduled cron jobs ($cron_jobs)"
            save_analysis_data "cron_tasks.tmp" "  Review with: wp cron schedule list"
            save_analysis_data "cron_tasks.tmp" "  Disable unnecessary ones for better performance"
        fi
    fi
}

# ============================================================================
# ADDITIONAL HIGH-VALUE CHECKS
# ============================================================================

### Missing Critical Indexes
analyze_missing_critical_indexes() {
    local db_name="$1"

    if [ -z "$db_name" ]; then
        return 0
    fi

    # Check for common missing indexes
    local missing_indexes=""

    # Check wp_postmeta meta_key index
    local meta_key_index=$(mysql -Ns -e "
        SELECT COUNT(*) FROM information_schema.STATISTICS
        WHERE TABLE_SCHEMA='${db_name}'
        AND TABLE_NAME='wp_postmeta'
        AND COLUMN_NAME='meta_key';
    " 2>/dev/null || echo "0")

    if [ "$meta_key_index" -eq 0 ]; then
        missing_indexes+="wp_postmeta(meta_key) "
    fi

    # Check wp_posts post_type index
    local post_type_index=$(mysql -Ns -e "
        SELECT COUNT(*) FROM information_schema.STATISTICS
        WHERE TABLE_SCHEMA='${db_name}'
        AND TABLE_NAME='wp_posts'
        AND COLUMN_NAME='post_type';
    " 2>/dev/null || echo "0")

    if [ "$post_type_index" -eq 0 ]; then
        missing_indexes+="wp_posts(post_type) "
    fi

    if [ -n "$missing_indexes" ]; then
        save_analysis_data "database_tuning.tmp" "CRITICAL: Missing critical indexes"
        save_analysis_data "database_tuning.tmp" "  Missing: $missing_indexes"
        save_analysis_data "database_tuning.tmp" "  Add: ALTER TABLE table_name ADD INDEX (column_name);"
    fi
}

### Database to Memory Ratio
analyze_database_memory_ratio() {
    local db_name="$1"

    if [ -z "$db_name" ]; then
        return 0
    fi

    local db_size=$(mysql -Ns -e "
        SELECT ROUND(SUM(data_length + index_length) / 1024 / 1024)
        FROM information_schema.tables
        WHERE table_schema='${db_name}';
    " 2>/dev/null || echo "0")

    local system_memory=$(free -m | awk 'NR==2{print $2}')

    if [ "$db_size" -gt 0 ] && [ "$system_memory" -gt 0 ]; then
        if [ "$db_size" -gt "$system_memory" ]; then
            save_analysis_data "database_tuning.tmp" "CRITICAL: Database (${db_size}MB) larger than available RAM (${system_memory}MB)"
            save_analysis_data "database_tuning.tmp" "  This causes heavy disk I/O"
            save_analysis_data "database_tuning.tmp" "  Solutions: Increase RAM, optimize DB, or split database"
        fi
    fi
}

################################################################################
# EXPORT ALL FUNCTIONS
################################################################################

export -f analyze_wp_debug
export -f analyze_xmlrpc
export -f analyze_heartbeat_api
export -f analyze_autosave_frequency
export -f analyze_rest_api_exposure
export -f analyze_emoji_scripts
export -f analyze_post_revision_distribution
export -f analyze_pingbacks_trackbacks
export -f analyze_innodb_buffer_pool
export -f analyze_max_allowed_packet
export -f analyze_slow_query_threshold
export -f analyze_innodb_file_per_table
export -f analyze_query_cache
export -f analyze_temp_table_location
export -f analyze_connection_timeout
export -f analyze_innodb_flush_log
export -f analyze_opcache
export -f analyze_xdebug
export -f analyze_realpath_cache
export -f analyze_timezone_config
export -f analyze_display_errors
export -f analyze_disabled_functions
export -f analyze_http2
export -f analyze_keepalive
export -f analyze_sendfile
export -f analyze_gzip_compression
export -f analyze_ssl_version
export -f analyze_apache_modules
export -f analyze_wordpress_cron
################################################################################
# PHASE 4: ADVANCED DATABASE & ISSUE PATTERN DETECTION (Tier 1 Quick Wins)
################################################################################

# ============================================================================
# PHASE 4 DATABASE CHECKS (6 quick wins)
# ============================================================================

### P4.1 - Table Engine Mismatch
analyze_table_engine_mismatch() {
    # Check if tables use inconsistent storage engines
    local engines=$(mysql -e "SELECT DISTINCT ENGINE FROM information_schema.TABLES WHERE TABLE_SCHEMA=DATABASE() 2>/dev/null" 2>/dev/null | grep -v ENGINE | sort -u)

    if [ ! -z "$engines" ] && [ "$(echo "$engines" | wc -l)" -gt 1 ]; then
        save_analysis_data "database_advanced.tmp" "WARNING: Mixed storage engines detected"
        save_analysis_data "database_advanced.tmp" "  Engines: $(echo $engines | tr '\n' ', ')"
        save_analysis_data "database_advanced.tmp" "  Recommendation: Convert all tables to InnoDB"
    fi
}

### P4.2 - Table Statistics Age
analyze_table_statistics_age() {
    # Check if table statistics are stale (MySQL 5.7+)
    local stale_count=$(mysql -e "SELECT COUNT(*) FROM mysql.innodb_table_stats WHERE STAT_MODIFIED < DATE_SUB(NOW(), INTERVAL 30 DAY)" 2>/dev/null | tail -1 || echo 0)

    if [ "$stale_count" -gt 0 ]; then
        save_analysis_data "database_advanced.tmp" "INFO: Found $stale_count tables with stale statistics"
        save_analysis_data "database_advanced.tmp" "  Fix: Run ANALYZE TABLE on each table"
        save_analysis_data "database_advanced.tmp" "  Or: wp db optimize (WordPress)"
    fi
}

### P4.3 - Index Cardinality Analysis
analyze_index_cardinality() {
    # Check for indexes with poor selectivity
    local poor_indexes=$(mysql -e "SELECT TABLE_NAME, INDEX_NAME FROM information_schema.STATISTICS WHERE TABLE_SCHEMA=DATABASE() AND SEQ_IN_INDEX=1 AND CARDINALITY IS NOT NULL AND CARDINALITY / (SELECT TABLE_ROWS FROM information_schema.TABLES t WHERE t.TABLE_SCHEMA=information_schema.STATISTICS.TABLE_SCHEMA AND t.TABLE_NAME=information_schema.STATISTICS.TABLE_NAME) > 0.95 LIMIT 5" 2>/dev/null | grep -v TABLE_NAME | head -5)

    if [ ! -z "$poor_indexes" ]; then
        save_analysis_data "database_advanced.tmp" "WARNING: Found indexes with poor cardinality (high selectivity)"
        save_analysis_data "database_advanced.tmp" "  These indexes may not be used by optimizer"
        save_analysis_data "database_advanced.tmp" "  Review and consider dropping unused indexes"
    fi
}

### P4.4 - Query Cache Memory Waste
analyze_query_cache_memory_waste() {
    # Check query cache fragmentation (MySQL 5.7)
    local qcache_info=$(mysql -e "SHOW STATUS LIKE 'Qcache%'" 2>/dev/null)

    if echo "$qcache_info" | grep -q "Qcache_free_blocks"; then
        local free_blocks=$(echo "$qcache_info" | grep "Qcache_free_blocks" | awk '{print $2}')
        local total_blocks=$(echo "$qcache_info" | grep "Qcache_total_blocks" | awk '{print $2}')

        if [ "$total_blocks" -gt 0 ]; then
            local fragmentation=$((free_blocks * 100 / total_blocks))
            if [ "$fragmentation" -gt 30 ]; then
                save_analysis_data "database_advanced.tmp" "INFO: Query cache fragmentation at ${fragmentation}%"
                save_analysis_data "database_advanced.tmp" "  Consider: FLUSH QUERY CACHE; or redesign query strategy"
            fi
        fi
    fi
}

### P4.5 - Replication Lag Check
analyze_replication_lag() {
    # Check if database is replica and has lag
    local slave_status=$(mysql -e "SHOW SLAVE STATUS\G 2>/dev/null" | grep "Seconds_Behind_Master" | awk '{print $NF}')

    if [ ! -z "$slave_status" ] && [ "$slave_status" != "NULL" ] && [ "$slave_status" -gt 10 ]; then
        save_analysis_data "database_advanced.tmp" "WARNING: Database replication lag detected: ${slave_status} seconds"
        save_analysis_data "database_advanced.tmp" "  Impact: Read queries on replica are stale"
        save_analysis_data "database_advanced.tmp" "  Solution: Optimize master, increase replica resources"
    fi
}

### P4.6 - Table Size Growth Tracking
analyze_table_size_growth() {
    # Identify rapidly growing tables (potential logging tables)
    local large_tables=$(mysql -e "SELECT TABLE_NAME, ROUND(((data_length+index_length)/1024/1024),2) as size_mb FROM information_schema.TABLES WHERE TABLE_SCHEMA=DATABASE() ORDER BY size_mb DESC LIMIT 5" 2>/dev/null | grep -v TABLE_NAME)

    if [ ! -z "$large_tables" ]; then
        local largest=$(echo "$large_tables" | head -1 | awk '{print $1, $2}')
        if echo "$largest" | awk '{exit ($2 > 1000) ? 0 : 1}'; then
            save_analysis_data "database_advanced.tmp" "WARNING: Large table detected: $largest MB"
            save_analysis_data "database_advanced.tmp" "  If this is wp_postmeta or wp_options, consider archiving old data"
        fi
    fi
}

# ============================================================================
# PHASE 4 SYSTEM & ERROR PATTERN CHECKS (6 quick wins)
# ============================================================================

### P4.7 - Timeout Error Detection
analyze_timeout_errors() {
    # Count timeout errors in recent logs
    local error_log=$(find /var/log -name "error.log" -o -name "php-fpm.log" 2>/dev/null | head -1)

    if [ -f "$error_log" ]; then
        local timeout_count=$(tail -1000 "$error_log" 2>/dev/null | grep -ci "timeout\|timed out" || echo 0)

        if [ "$timeout_count" -gt 10 ]; then
            save_analysis_data "error_patterns.tmp" "WARNING: Found $timeout_count timeout errors in recent logs"
            save_analysis_data "error_patterns.tmp" "  Impact: Customers experiencing connection/processing failures"
            save_analysis_data "error_patterns.tmp" "  Solutions: Increase timeouts, optimize code, add resources"
        fi
    fi
}

### P4.8 - Memory Exhaustion Attempts
analyze_memory_exhaustion_attempts() {
    # Detect PHP memory limit hits
    local error_log=$(find /var/log -name "error.log" -o -name "php-fpm.log" 2>/dev/null | head -1)

    if [ -f "$error_log" ]; then
        local memory_count=$(tail -1000 "$error_log" 2>/dev/null | grep -ci "allowed memory\|memory.*exhausted" || echo 0)

        if [ "$memory_count" -gt 0 ]; then
            save_analysis_data "error_patterns.tmp" "CRITICAL: PHP hitting memory limits ($memory_count times in logs)"
            save_analysis_data "error_patterns.tmp" "  Impact: Some requests failing with fatal error"
            save_analysis_data "error_patterns.tmp" "  Fix: Increase memory_limit in php.ini"
        fi
    fi
}

### P4.9 - Disk Inode Usage
analyze_disk_inode_usage() {
    # Check filesystem inode exhaustion (causes performance degradation)
    local inode_usage=$(df -i / 2>/dev/null | tail -1 | awk '{print int($5)}' || echo 0)

    if [ "$inode_usage" -gt 80 ]; then
        save_analysis_data "system_resources.tmp" "WARNING: Disk inode usage at ${inode_usage}%"
        save_analysis_data "system_resources.tmp" "  Impact: Filesystem performance degrades, may prevent new files"
        save_analysis_data "system_resources.tmp" "  Fix: Delete old logs, temporary files, or backups"
    fi
}

### P4.10 - Zombie Process Detection
analyze_zombie_processes() {
    # Count zombie/defunct processes
    local zombie_count=$(ps aux 2>/dev/null | grep -c " <defunct>" || echo 0)

    if [ "$zombie_count" -gt 5 ]; then
        save_analysis_data "system_resources.tmp" "WARNING: Found $zombie_count zombie processes"
        save_analysis_data "system_resources.tmp" "  Impact: Wastes process table entries, resource leak"
        save_analysis_data "system_resources.tmp" "  Fix: Restart PHP-FPM or MySQL to clean up"
    fi
}

### P4.11 - Swap Usage Detection (Critical)
analyze_swap_usage_phase4() {
    # Check if system is using swap (massive performance killer)
    local swap_used=$(free 2>/dev/null | grep Swap | awk '{print $3}' || echo 0)

    if [ "$swap_used" -gt 0 ]; then
        save_analysis_data "system_resources.tmp" "CRITICAL: System using swap ($swap_used KB)"
        save_analysis_data "system_resources.tmp" "  Impact: 50-100x SLOWER than RAM access"
        save_analysis_data "system_resources.tmp" "  Emergency: Upgrade RAM or reduce memory usage immediately"
    fi
}

### P4.12 - Load Average Trending
analyze_load_average_trend() {
    # Detect increasing load trend (early warning)
    local load_1=$(uptime 2>/dev/null | grep -oP 'load average: \K[^,]+' | head -1)
    local load_5=$(uptime 2>/dev/null | grep -oP 'load average: \K[^,]+' | tail -2 | head -1)

    if [ ! -z "$load_1" ] && [ ! -z "$load_5" ]; then
        local ratio=$(echo "scale=2; $load_1 / $load_5" | bc 2>/dev/null || echo 1)

        if (( $(echo "$ratio > 1.2" | bc -l) )); then
            save_analysis_data "system_resources.tmp" "INFO: Load average trending upward (1min: $load_1, 5min: $load_5)"
            save_analysis_data "system_resources.tmp" "  Early warning: Monitor for increasing problems"
        fi
    fi
}

################################################################################
# EXPORT ALL PHASE 4 FUNCTIONS
################################################################################

export -f analyze_backup_schedule
export -f analyze_db_optimization_schedule
export -f analyze_slow_cron_jobs
export -f analyze_missing_critical_indexes
export -f analyze_database_memory_ratio
export -f analyze_table_engine_mismatch
export -f analyze_table_statistics_age
export -f analyze_index_cardinality
export -f analyze_query_cache_memory_waste
export -f analyze_replication_lag
export -f analyze_table_size_growth
export -f analyze_timeout_errors
export -f analyze_memory_exhaustion_attempts
export -f analyze_disk_inode_usage
export -f analyze_zombie_processes
export -f analyze_swap_usage_phase4
export -f analyze_load_average_trend