#!/bin/bash

# send_test_email.sh - Send test emails via SMTP to MailHog
# Usage: ./send_test_email.sh [OPTIONS]

set -e

# Default values
SMTP_HOST="localhost"
SMTP_PORT="1025"
TO="test@recipient.local"
FROM="test@sender.local"
SUBJECT="Test Email from MailHog Skill"
BODY="This is a test email sent via the MailHog skill script."
HTML=false
ATTACHMENT=""
VERBOSE=false

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Print colored output
print_info() {
    echo -e "${BLUE}[INFO]${NC} $1"
}

print_success() {
    echo -e "${GREEN}[SUCCESS]${NC} $1"
}

print_warning() {
    echo -e "${YELLOW}[WARNING]${NC} $1"
}

print_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

# Show usage information
show_usage() {
    cat << EOF
Send Test Email Script

Usage: $0 [OPTIONS]

OPTIONS:
    -h, --help              Show this help message
    -t, --to EMAIL          Recipient email address (default: test@recipient.local)
    -f, --from EMAIL        Sender email address (default: test@sender.local)
    -s, --subject SUBJECT   Email subject (default: "Test Email from MailHog Skill")
    -b, --body TEXT         Email body text (default: simple test message)
    --html                  Send as HTML email
    --attachment FILE       Attach file to email
    --smtp-host HOST        SMTP server host (default: localhost)
    --smtp-port PORT        SMTP server port (default: 1025)
    -v, --verbose           Enable verbose output
    --template TEMPLATE     Use predefined template (welcome, notification, reset)
    --multiple COUNT        Send multiple emails (for testing)

TEMPLATES:
    welcome     - Welcome email template
    notification - Notification email template
    reset       - Password reset email template
    bulk        - Bulk email test template

EXAMPLES:
    # Send simple test email
    $0 --to user@test.local --subject "Welcome!"

    # Send HTML email with template
    $0 --html --template welcome --to newuser@test.local

    # Send multiple emails for load testing
    $0 --multiple 100 --subject "Load Test"

    # Send email with attachment
    $0 --attachment ./test.pdf --to recipient@test.local

EOF
}

# Email templates
get_template_content() {
    local template="$1"
    local to="$2"

    case "$template" in
        "welcome")
            echo "<h1>Welcome to Our Service!</h1>
<p>Hello $to,</p>
<p>Thank you for signing up for our service. We're excited to have you on board!</p>
<p>Here's what you can do next:</p>
<ul>
    <li>Complete your profile</li>
    <li>Explore our features</li>
    <li>Connect with other users</li>
</ul>
<p>Best regards,<br>The Team</p>"
            echo "Welcome to Our Service!"
            ;;
        "notification")
            echo "<h2>Important Notification</h1>
<p>Hello $to,</p>
<p>You have an important notification that requires your attention.</p>
<div style='background-color: #f8f9fa; padding: 15px; border-left: 4px solid #007bff;'>
    <strong>Action Required:</strong> Please review your account settings.
</div>
<p>Thank you for your prompt attention to this matter.</p>"
            echo "Important Notification"
            ;;
        "reset")
            echo "<h1>Password Reset Request</h1>
<p>Hello $to,</p>
<p>You requested a password reset for your account. Click the link below to reset your password:</p>
<p><a href='https://example.com/reset?token=abc123' style='background-color: #007bff; color: white; padding: 10px 20px; text-decoration: none; border-radius: 4px;'>Reset Password</a></p>
<p>If you didn't request this reset, please ignore this email. The link will expire in 1 hour.</p>
<p>Best regards,<br>Support Team</p>"
            echo "Password Reset Request"
            ;;
        "bulk")
            echo "<h2>Bulk Communication</h1>
<p>This is a test email for bulk communication testing.</p>
<p>Message ID: $(date +%s)</p>
<p>Timestamp: $(date)</p>"
            echo "Bulk Communication Test"
            ;;
        *)
            print_error "Unknown template: $template"
            exit 1
            ;;
    esac
}

# Parse command line arguments
while [[ $# -gt 0 ]]; do
    case $1 in
        -h|--help)
            show_usage
            exit 0
            ;;
        -t|--to)
            TO="$2"
            shift 2
            ;;
        -f|--from)
            FROM="$2"
            shift 2
            ;;
        -s|--subject)
            SUBJECT="$2"
            shift 2
            ;;
        -b|--body)
            BODY="$2"
            shift 2
            ;;
        --html)
            HTML=true
            shift
            ;;
        --attachment)
            ATTACHMENT="$2"
            if [[ ! -f "$ATTACHMENT" ]]; then
                print_error "Attachment file not found: $ATTACHMENT"
                exit 1
            fi
            shift 2
            ;;
        --smtp-host)
            SMTP_HOST="$2"
            shift 2
            ;;
        --smtp-port)
            SMTP_PORT="$2"
            shift 2
            ;;
        -v|--verbose)
            VERBOSE=true
            shift
            ;;
        --template)
            TEMPLATE="$2"
            shift 2
            ;;
        --multiple)
            MULTIPLE="$2"
            shift 2
            ;;
        *)
            print_error "Unknown option: $1"
            show_usage
            exit 1
            ;;
    esac
done

# Check if netcat is available
check_dependencies() {
    local missing_deps=()

    if ! command -v nc >/dev/null 2>&1 && ! command -v telnet >/dev/null 2>&1; then
        missing_deps+=("nc or telnet")
    fi

    if [[ ${#missing_deps[@]} -gt 0 ]]; then
        print_error "Missing required dependencies: ${missing_deps[*]}"
        print_info "Install missing dependencies and try again."
        exit 1
    fi
}

# Test SMTP connection
test_smtp_connection() {
    print_info "Testing SMTP connection to $SMTP_HOST:$SMTP_PORT..."

    if command -v nc >/dev/null 2>&1; then
        if echo "" | nc -w 5 "$SMTP_HOST" "$SMTP_PORT" >/dev/null 2>&1; then
            print_success "SMTP connection successful"
            return 0
        else
            print_error "Failed to connect to SMTP server"
            return 1
        fi
    elif command -v telnet >/dev/null 2>&1; then
        timeout 5 telnet "$SMTP_HOST" "$SMTP_PORT" </dev/null >/dev/null 2>&1
        if [[ $? -eq 0 ]]; then
            print_success "SMTP connection successful"
            return 0
        else
            print_error "Failed to connect to SMTP server"
            return 1
        fi
    fi
}

# Create temporary file for email
create_email_file() {
    local temp_file=$(mktemp)
    local boundary="MAILHOG-$(date +%s%N)"

    cat << EOF > "$temp_file"
From: $FROM
To: $TO
Subject: $SUBJECT
Date: $(date -R)
MIME-Version: 1.0
EOF

    if [[ -n "$ATTACHMENT" ]]; then
        echo "Content-Type: multipart/mixed; boundary=\"$boundary\"" >> "$temp_file"
        echo "" >> "$temp_file"
        echo "--$boundary" >> "$temp_file"

        if [[ "$HTML" == true ]]; then
            echo "Content-Type: text/html; charset=UTF-8" >> "$temp_file"
            echo "Content-Transfer-Encoding: 7bit" >> "$temp_file"
        else
            echo "Content-Type: text/plain; charset=UTF-8" >> "$temp_file"
            echo "Content-Transfer-Encoding: 7bit" >> "$temp_file"
        fi
        echo "" >> "$temp_file"
        echo "$BODY" >> "$temp_file"
        echo "" >> "$temp_file"
        echo "--$boundary" >> "$temp_file"

        # Add attachment
        local attachment_name=$(basename "$ATTACHMENT")
        echo "Content-Type: application/octet-stream" >> "$temp_file"
        echo "Content-Transfer-Encoding: base64" >> "$temp_file"
        echo "Content-Disposition: attachment; filename=\"$attachment_name\"" >> "$temp_file"
        echo "" >> "$temp_file"
        base64 "$ATTACHMENT" >> "$temp_file"
        echo "" >> "$temp_file"
        echo "--$boundary--" >> "$temp_file"
    else
        if [[ "$HTML" == true ]]; then
            echo "Content-Type: text/html; charset=UTF-8" >> "$temp_file"
            echo "Content-Transfer-Encoding: 7bit" >> "$temp_file"
        else
            echo "Content-Type: text/plain; charset=UTF-8" >> "$temp_file"
        fi
        echo "" >> "$temp_file"
        echo "$BODY" >> "$temp_file"
    fi

    echo "$temp_file"
}

# Send email using SMTP
send_email_smtp() {
    local email_file="$1"

    if [[ "$VERBOSE" == true ]]; then
        print_info "Sending email with the following content:"
        cat "$email_file"
        echo ""
    fi

    # Connect to SMTP and send email
    (
        echo "EHLO mailhog-test.local"
        echo "MAIL FROM:<$FROM>"
        echo "RCPT TO:<$TO>"
        echo "DATA"
        cat "$email_file"
        echo "."
        echo "QUIT"
    ) | nc "$SMTP_HOST" "$SMTP_PORT" 2>/dev/null

    if [[ $? -eq 0 ]]; then
        print_success "Email sent successfully"
        return 0
    else
        print_error "Failed to send email"
        return 1
    fi
}

# Send email using Python if available
send_email_python() {
    local email_file="$1"

    if command -v python3 >/dev/null 2>&1; then
        python3 << EOF
import smtplib
import ssl
from email import message_from_file

try:
    with open('$email_file', 'r') as f:
        msg = message_from_file(f)

    # Convert to string for sending
    email_string = msg.as_string()

    # Connect to SMTP server
    server = smtplib.SMTP('$SMTP_HOST', $SMTP_PORT)
    server.set_debuglevel(1 if '$VERBOSE' == 'true' else 0)

    # Send email
    server.sendmail('$FROM', ['$TO'], email_string)
    server.quit()

    print("Email sent successfully via Python")
except Exception as e:
    print(f"Failed to send email via Python: {e}")
    exit(1)
EOF
        return $?
    else
        return 1
    fi
}

# Send multiple emails for testing
send_multiple_emails() {
    local count="$1"
    local success_count=0
    local failed_count=0

    print_info "Sending $count emails..."

    for ((i=1; i<=count; i++)); do
        local temp_subject="$SUBJECT - #$i"
        local temp_body="This is test email #$i\n\nSent at: $(date)"

        if [[ "$HTML" == true ]]; then
            temp_body="<h2>This is test email #$i</h2><p>Sent at: $(date)</p>"
        fi

        local temp_file=$(mktemp)

        cat << EOF > "$temp_file"
From: $FROM
To: $TO
Subject: $temp_subject
Date: $(date -R)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8

$temp_body
EOF

        if send_email_smtp "$temp_file"; then
            ((success_count++))
        else
            ((failed_count++))
        fi

        rm -f "$temp_file"

        # Progress indicator
        if [[ $((i % 10)) -eq 0 ]]; then
            print_info "Sent $i/$count emails..."
        fi

        # Small delay to avoid overwhelming the server
        sleep 0.1
    done

    print_success "Email sending complete: $success_count successful, $failed_count failed"
}

# Check MailHog for the sent email
verify_email_received() {
    local max_attempts=10
    local attempt=1

    print_info "Verifying email was received by MailHog..."

    while [[ $attempt -le $max_attempts ]]; do
        local response=$(curl -s "http://localhost:8025/api/v1/messages?limit=1" 2>/dev/null)

        if [[ $? -eq 0 ]] && echo "$response" | grep -q "\"total\":1"; then
            print_success "Email verified in MailHog"

            if [[ "$VERBOSE" == true ]]; then
                echo "$response" | jq '.'
            fi

            return 0
        fi

        sleep 1
        ((attempt++))
    done

    print_warning "Email not found in MailHog after verification attempts"
    return 1
}

# Main execution
main() {
    print_info "MailHog Test Email Sender"

    # Check dependencies
    check_dependencies

    # Apply template if specified
    if [[ -n "$TEMPLATE" ]]; then
        if [[ "$VERBOSE" == true ]]; then
            print_info "Using template: $TEMPLATE"
        fi

        local template_result=$(get_template_content "$TEMPLATE" "$TO")
        BODY=$(echo "$template_result" | sed -n '1p')
        SUBJECT=$(echo "$template_result" | sed -n '2p')
        HTML=true
    fi

    # Test SMTP connection
    test_smtp_connection

    # Send multiple emails if requested
    if [[ -n "$MULTIPLE" ]]; then
        send_multiple_emails "$MULTIPLE"
        exit 0
    fi

    # Create email file
    local email_file=$(create_email_file)

    # Send email
    print_info "Sending email to $TO from $FROM via $SMTP_HOST:$SMTP_PORT..."

    if ! send_email_smtp "$email_file"; then
        # Fallback to Python if netcat fails
        if send_email_python "$email_file"; then
            print_success "Email sent successfully via Python fallback"
        else
            print_error "All email sending methods failed"
            rm -f "$email_file"
            exit 1
        fi
    fi

    # Clean up
    rm -f "$email_file"

    # Verify email was received (only if running on same host as MailHog)
    if [[ "$SMTP_HOST" == "localhost" ]] || [[ "$SMTP_HOST" == "127.0.0.1" ]]; then
        verify_email_received
    fi

    print_success "Test email sending completed successfully"
}

# Run main function
main "$@"