#!/usr/bin/env bash
#
# Phase 3 Validation: DNS and Email
#
# Validates that RFC 0041 components are deployed and healthy:
# - PowerDNS (responding, DNSSEC enabled)
# - Stalwart (SMTP, IMAP, TLS)
# - DNS records (SPF, DKIM, DMARC)
#
set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

PASSED=0
FAILED=0
WARNINGS=0

# Configuration
DOMAIN="${DOMAIN:-coherence.dev}"

log_info() {
    echo -e "${BLUE}[INFO]${NC} $1"
}

log_pass() {
    echo -e "${GREEN}[PASS]${NC} $1"
    ((PASSED++))
}

log_fail() {
    echo -e "${RED}[FAIL]${NC} $1"
    ((FAILED++))
}

log_warn() {
    echo -e "${YELLOW}[WARN]${NC} $1"
    ((WARNINGS++))
}

check_powerdns() {
    log_info "Checking PowerDNS status..."

    # Check if namespace exists
    if ! kubectl get namespace dns &> /dev/null; then
        log_fail "dns namespace does not exist"
        return
    fi

    # Check pod health
    local ready_pods
    ready_pods=$(kubectl -n dns get pods -l app=powerdns -o json | jq '[.items[] | select(.status.phase == "Running") | select(.status.containerStatuses[]?.ready == true)] | length')

    if [ "$ready_pods" -ge 1 ]; then
        log_pass "PowerDNS has $ready_pods ready pods"
    else
        log_fail "PowerDNS has no ready pods"
        return
    fi

    # Check PowerDNS service
    local svc_ip
    svc_ip=$(kubectl -n dns get svc powerdns -o jsonpath='{.spec.clusterIP}' 2>/dev/null || echo "")

    if [ -n "$svc_ip" ]; then
        log_pass "PowerDNS service exists (ClusterIP: $svc_ip)"
    else
        log_fail "PowerDNS service does not exist"
    fi

    # Check external NLB
    local nlb_hostname
    nlb_hostname=$(kubectl -n dns get svc powerdns-external -o jsonpath='{.status.loadBalancer.ingress[0].hostname}' 2>/dev/null || echo "")

    if [ -n "$nlb_hostname" ]; then
        log_pass "PowerDNS NLB provisioned: $nlb_hostname"
    else
        log_warn "PowerDNS NLB not yet provisioned"
    fi
}

check_dns_resolution() {
    log_info "Checking DNS resolution..."

    # Get NLB hostname
    local nlb_hostname
    nlb_hostname=$(kubectl -n dns get svc powerdns-external -o jsonpath='{.status.loadBalancer.ingress[0].hostname}' 2>/dev/null || echo "")

    if [ -z "$nlb_hostname" ]; then
        log_warn "Cannot test DNS resolution - NLB not provisioned"
        return
    fi

    # Get NLB IP
    local nlb_ip
    nlb_ip=$(dig +short "$nlb_hostname" | head -1 || echo "")

    if [ -z "$nlb_ip" ]; then
        log_warn "Cannot resolve NLB hostname to IP"
        return
    fi

    # Test DNS resolution against PowerDNS
    local dns_response
    dns_response=$(dig @"$nlb_ip" "$DOMAIN" +short 2>/dev/null || echo "")

    if [ -n "$dns_response" ]; then
        log_pass "DNS resolution working: $DOMAIN -> $dns_response"
    else
        log_warn "DNS resolution failed for $DOMAIN (may need NS delegation)"
    fi
}

check_dnssec() {
    log_info "Checking DNSSEC..."

    # Check DNSSEC via public DNS
    local dnssec_response
    dnssec_response=$(dig +dnssec "$DOMAIN" 2>/dev/null | grep -c "ad" || echo "0")

    if [ "$dnssec_response" -gt 0 ]; then
        log_pass "DNSSEC is enabled and validated"
    else
        log_warn "DNSSEC not validated (may need DS record at registrar)"
    fi

    # Check for DNSKEY records
    local dnskey_count
    dnskey_count=$(dig DNSKEY "$DOMAIN" +short 2>/dev/null | wc -l | tr -d ' ')

    if [ "$dnskey_count" -gt 0 ]; then
        log_pass "DNSKEY records present ($dnskey_count keys)"
    else
        log_warn "No DNSKEY records found"
    fi
}

check_stalwart() {
    log_info "Checking Stalwart Mail Server..."

    # Check if namespace exists
    if ! kubectl get namespace email &> /dev/null; then
        log_fail "email namespace does not exist"
        return
    fi

    # Check pod health
    local ready_pods
    ready_pods=$(kubectl -n email get pods -l app=stalwart -o json | jq '[.items[] | select(.status.phase == "Running") | select(.status.containerStatuses[]?.ready == true)] | length')

    if [ "$ready_pods" -ge 1 ]; then
        log_pass "Stalwart has $ready_pods ready pods"
    else
        log_fail "Stalwart has no ready pods"
        return
    fi

    # Check Stalwart services
    local services=("smtp" "submission" "imap")
    for svc in "${services[@]}"; do
        local svc_exists
        svc_exists=$(kubectl -n email get svc stalwart-"$svc" -o name 2>/dev/null || echo "")
        if [ -n "$svc_exists" ]; then
            log_pass "Stalwart $svc service exists"
        else
            log_warn "Stalwart $svc service not found"
        fi
    done
}

check_email_tls() {
    log_info "Checking email TLS..."

    # Get mail server hostname
    local mail_host="mail.$DOMAIN"

    # Check SMTP TLS (port 465)
    if command -v openssl &> /dev/null; then
        local smtp_tls
        smtp_tls=$(echo | timeout 5 openssl s_client -connect "$mail_host":465 2>/dev/null | grep -c "Verify return code: 0" || echo "0")

        if [ "$smtp_tls" -gt 0 ]; then
            log_pass "SMTP TLS working on port 465"
        else
            log_warn "SMTP TLS check failed (may need DNS propagation)"
        fi

        # Check IMAP TLS (port 993)
        local imap_tls
        imap_tls=$(echo | timeout 5 openssl s_client -connect "$mail_host":993 2>/dev/null | grep -c "Verify return code: 0" || echo "0")

        if [ "$imap_tls" -gt 0 ]; then
            log_pass "IMAP TLS working on port 993"
        else
            log_warn "IMAP TLS check failed (may need DNS propagation)"
        fi
    else
        log_warn "openssl not available - skipping TLS checks"
    fi
}

check_email_dns_records() {
    log_info "Checking email DNS records..."

    # Check MX record
    local mx_record
    mx_record=$(dig MX "$DOMAIN" +short 2>/dev/null | head -1 || echo "")

    if [ -n "$mx_record" ]; then
        log_pass "MX record exists: $mx_record"
    else
        log_warn "No MX record found for $DOMAIN"
    fi

    # Check SPF record
    local spf_record
    spf_record=$(dig TXT "$DOMAIN" +short 2>/dev/null | grep "v=spf1" || echo "")

    if [ -n "$spf_record" ]; then
        log_pass "SPF record exists"
    else
        log_warn "No SPF record found"
    fi

    # Check DMARC record
    local dmarc_record
    dmarc_record=$(dig TXT "_dmarc.$DOMAIN" +short 2>/dev/null | grep "v=DMARC1" || echo "")

    if [ -n "$dmarc_record" ]; then
        log_pass "DMARC record exists"
    else
        log_warn "No DMARC record found"
    fi

    # Check DKIM record
    local dkim_record
    dkim_record=$(dig TXT "default._domainkey.$DOMAIN" +short 2>/dev/null | grep "v=DKIM1" || echo "")

    if [ -n "$dkim_record" ]; then
        log_pass "DKIM record exists"
    else
        log_warn "No DKIM record found (check selector name)"
    fi
}

print_summary() {
    echo ""
    echo "========================================"
    echo "Phase 3 Validation Summary"
    echo "========================================"
    echo -e "  ${GREEN}Passed:${NC}   $PASSED"
    echo -e "  ${RED}Failed:${NC}   $FAILED"
    echo -e "  ${YELLOW}Warnings:${NC} $WARNINGS"
    echo "========================================"

    if [ "$FAILED" -gt 0 ]; then
        echo ""
        echo -e "${RED}Phase 3 validation FAILED${NC}"
        echo "Please fix the issues above before proceeding to Phase 4."
        exit 1
    elif [ "$WARNINGS" -gt 0 ]; then
        echo ""
        echo -e "${YELLOW}Phase 3 validation passed with warnings${NC}"
        echo "DNS propagation may take up to 48 hours."
        echo "Review warnings above. You may proceed to Phase 4."
        exit 0
    else
        echo ""
        echo -e "${GREEN}Phase 3 validation PASSED${NC}"
        echo "You may proceed to Phase 4."
        exit 0
    fi
}

main() {
    echo "========================================"
    echo "Phase 3 Validation: DNS and Email"
    echo "========================================"
    echo ""

    check_powerdns
    check_dns_resolution
    check_dnssec
    check_stalwart
    check_email_tls
    check_email_dns_records

    print_summary
}

main "$@"