#!/bin/zsh

# WordPress Plugin Fatal Error Diagnostic Script
#
# Purpose: Systematically test individual plugins to isolate fatal error issues
# Setup: chmod +x plugin-memory.sh (make executable - only needed once)
# Usage: ./plugin-memory.sh (run from WordPress root directory)
#
# What it does:
# 1. Auto-detects site URL using wp-cli (wp option get home)
# 2. Auto-detects all currently active plugins using wp-cli
# 3. Tests each plugin individually by deactivating it
# 4. Clears debug log and makes a site request
# 5. Checks for fatal memory errors in wp-content/debug.log
# 6. Reactivates the plugin and moves to the next one
# 7. Saves detailed output to timestamped log file
#
# Key Features:
# - Fully automatic detection (site URL + active plugins)
# - Configurable skip list for critical plugins
# - macOS/zsh compatible (uses zsh array syntax)
# - Interactive mode - stops when culprit is found
# - Logging to both terminal and file
#
# Output: plugin_memory_test_YYYYMMDD_HHMMSS.txt with full test results

set -e  # Exit on any error

# Create output file with timestamp
OUTPUT_FILE="plugin_memory_test_$(date +%Y%m%d_%H%M%S).txt"

# Function to output to both terminal and file
output() {
    echo "$@" | tee -a "$OUTPUT_FILE"
}

# Configuration
LOG_FILE="wp-content/debug.log"

# Colours for output (only for terminal)
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Colour

# Plugins to skip (add plugin names here that should never be tested)
# Example: critical security plugins, backup plugins, etc.
SKIP_PLUGINS="wordfence akismet updraftplus"

# Function to print coloured output
print_status() {
    local colour=$1
    local message=$2
    echo -e "${colour}${message}${NC}" | tee -a "$OUTPUT_FILE"
}

# Initialize output file
echo "WordPress Plugin Memory Error Testing Script Output" > "$OUTPUT_FILE"
echo "Generated: $(date)" >> "$OUTPUT_FILE"
echo "========================================" >> "$OUTPUT_FILE"

# Check if we're in a WordPress directory
if [[ ! -f "wp-config.php" ]]; then
    print_status $RED "Error: This script must be run from the WordPress root directory"
    exit 1
fi

print_status $YELLOW "Starting WordPress plugin memory error testing..."
output "Output will be saved to: $OUTPUT_FILE"

# Check wp-cli availability first
if ! command -v wp &> /dev/null; then
    print_status $RED "Error: wp-cli is not installed or not in PATH"
    print_status $YELLOW "Please install wp-cli: https://wp-cli.org/"
    exit 1
fi

# Auto-detect site URL using wp-cli
output "Detecting site URL..."
SITE_URL=$(wp option get home 2>/dev/null)
if [[ -z "$SITE_URL" ]]; then
    print_status $RED "Error: Could not retrieve site URL"
    print_status $YELLOW "Make sure wp-cli is working: wp option get home"
    exit 1
fi

print_status $YELLOW "Site URL: $SITE_URL"
print_status $YELLOW "Log file: $LOG_FILE"
output ""

# Auto-detect active plugins using wp-cli
output "Detecting active plugins..."

# Get list of active plugins
PLUGINS=$(wp plugin list --status=active --field=name 2>/dev/null)
if [[ -z "$PLUGINS" ]]; then
    print_status $RED "Error: Could not retrieve active plugins list"
    print_status $YELLOW "Make sure wp-cli is working: wp plugin list"
    exit 1
fi

# Convert to array and filter out skipped plugins
plugins_array=()
skip_array=(${=SKIP_PLUGINS})

# Convert newline-separated plugin list to array
while IFS= read -r plugin; do
    [[ -n "$plugin" ]] || continue  # Skip empty lines

    # Check if plugin should be skipped
    skip_plugin=false
    for skip in "${skip_array[@]}"; do
        if [[ "$plugin" == "$skip" ]]; then
            output "⏭️  Skipping plugin: $plugin (in skip list)"
            skip_plugin=true
            break
        fi
    done

    if [[ "$skip_plugin" == false ]]; then
        plugins_array+=("$plugin")
    fi
done <<< "$PLUGINS"

# Display detected plugins
output "Found ${#plugins_array[@]} active plugins to test:"
for plugin in "${plugins_array[@]}"; do
    output "  - $plugin"
done
output ""

# Explain what we're looking for
print_status $YELLOW "🔍 What this script detects:"
output "  • Fatal memory errors: 'Allowed memory size of X bytes exhausted'"
output "  • PHP fatal errors: 'PHP Fatal error' messages"
output "  • Memory-related crashes that prevent site loading"
output ""
output "✅ Success criteria: Site loads without fatal errors when plugin is deactivated"
output "❌ Problem identified: Fatal errors disappear when specific plugin is deactivated"
output ""

# Pre-check: Verify there's actually a fatal error to solve
print_status $YELLOW "🔬 Pre-check: Testing site with all plugins active..."
output "Clearing debug log..."
rm "$LOG_FILE" 2>/dev/null && touch "$LOG_FILE"

output "Making test request to site..."
if curl -s --max-time 10 --connect-timeout 5 --insecure "$SITE_URL" > /dev/null 2>&1; then
    output "Site request successful"
    
    # Wait for logs to be written
    sleep 1
    
    # Check for fatal errors
    if ! grep -q "Fatal error" "$LOG_FILE" 2>/dev/null; then
        print_status $GREEN "✅ No fatal errors found!"
        output ""
        output "The site is currently working fine with all plugins active."
        output "This script is designed to isolate plugins causing fatal errors."
        output ""
        print_status $YELLOW "Possible reasons:"
        output "  • The issue has already been resolved"
        output "  • The error only occurs under specific conditions"
        output "  • The error is intermittent"
        output "  • The error is theme-related, not plugin-related"
        output ""
        output "If you're still experiencing issues, try:"
        output "  • Access different pages of your site"
        output "  • Check wp-content/debug.log manually"
        output "  • Use other diagnostic scripts in this directory"
        output ""
        output "Full output saved to: $OUTPUT_FILE"
        exit 0
    else
        print_status $RED "❌ Fatal errors detected!"
        output "Error details:"
        grep "Fatal error" "$LOG_FILE" 2>/dev/null | head -3 | while read -r error_line; do
            output "  $error_line"
        done
        output ""
        print_status $YELLOW "Proceeding with plugin isolation testing..."
        output ""
    fi
else
    print_status $RED "⚠️  Could not reach site - proceeding with testing anyway"
    output "This might indicate a severe error that prevents site loading"
    output ""
fi

for plugin in "${plugins_array[@]}"; do
    output "Testing plugin: $plugin"

    # Deactivate plugin (removed timeout - this was causing the hangs)
    output "  → Deactivating plugin..."
    if wp plugin deactivate "$plugin" --quiet 2>/dev/null; then
        output "  → Plugin deactivated successfully"

        # Clear log file (using method that works on macOS)
        output "  → Clearing log file..."
        rm "$LOG_FILE" 2>/dev/null && touch "$LOG_FILE"
        output "  → Log file cleared successfully"

        # Wait a moment for any pending operations
        output "  → Waiting 2 seconds for changes to take effect..."
        sleep 2
        output "  → Wait complete"

        # Make request to site
        output "  → Making request to site ($SITE_URL)..."
        output "  → Running: curl -s --max-time 10 --connect-timeout 5 --insecure $SITE_URL"

        if curl -s --max-time 10 --connect-timeout 5 --insecure "$SITE_URL" > /dev/null 2>&1; then
            output "  → Site request successful"

            # Wait a moment for logs to be written
            sleep 1

            # Check for fatal errors in log
            output "  → Checking log file for fatal errors..."
            output "  → Searching for pattern: 'Fatal error' in $LOG_FILE"
            if ! grep -q "Fatal error" "$LOG_FILE" 2>/dev/null; then
                print_status $GREEN "✅ Fatal error GONE when $plugin is deactivated. This is the culprit!"

                # Ask if user wants to stop here
                print_status $YELLOW "Found the problematic plugin: $plugin"
                echo "Would you like to stop testing here? (y/n): "
                read -r response
                output "User response: $response"
                if [[ "$response" =~ ^[Yy]$ ]]; then
                    print_status $YELLOW "Testing stopped at user request"
                    output "Plugin causing issues: $plugin"
                    # Reactivate the plugin before exiting
                    output "Reactivating problematic plugin..."
                    wp plugin activate "$plugin" --quiet 2>/dev/null
                    output "Full output saved to: $OUTPUT_FILE"
                    exit 0
                fi
            else
                print_status $RED "❌ Fatal error still present with $plugin deactivated"
                output "  → Error details:"
                grep "Fatal error" "$LOG_FILE" 2>/dev/null | head -2 | while read -r error_line; do
                    output "    $error_line"
                done
            fi
        else
            print_status $YELLOW "⚠️  Could not reach site or request failed"
        fi

        # Reactivate plugin (removed timeout)
        output "  → Reactivating plugin..."
        if wp plugin activate "$plugin" --quiet 2>/dev/null; then
            output "  → Plugin reactivated successfully"
        else
            print_status $RED "Warning: Could not reactivate plugin '$plugin'"
        fi
    else
        print_status $RED "Error: Could not deactivate plugin '$plugin'"
    fi

    output "---------------------------------"
done

print_status $YELLOW "Testing complete!"
output "Full output saved to: $OUTPUT_FILE"