#!/bin/bash
# =============================================================================
# Aula 12 - Victoria Metrics (Observabilidade)
# =============================================================================
#
# Este script instala o stack de monitoramento via Helm:
#   1. Victoria Metrics (coleta + storage de métricas)
#   2. Grafana (dashboards)
#   3. Alertas pré-configurados
#
# Pré-requisitos:
#   - Cluster Kubernetes (aula-08)
#   - kubectl e helm instalados
#
# =============================================================================

set -e

RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
CYAN='\033[0;36m'
NC='\033[0m'

log_info() { echo -e "${BLUE}[INFO]${NC} $1"; }
log_success() { echo -e "${GREEN}[OK]${NC} $1"; }
log_warn() { echo -e "${YELLOW}[WARN]${NC} $1"; }
log_error() { echo -e "${RED}[ERROR]${NC} $1"; }

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

# =============================================================================
# VERIFICAR PRÉ-REQUISITOS
# =============================================================================

log_info "Verificando pré-requisitos..."

if ! command -v kubectl &> /dev/null; then
    log_error "kubectl não encontrado"
    exit 1
fi

if ! command -v helm &> /dev/null; then
    log_error "helm não encontrado"
    exit 1
fi

if ! kubectl cluster-info &> /dev/null; then
    log_error "Não foi possível conectar ao cluster"
    exit 1
fi

log_success "Pré-requisitos verificados"

# =============================================================================
# CARREGAR CONFIGURAÇÃO
# =============================================================================

if [[ -f "$ENV_FILE" ]]; then
    source "$ENV_FILE"
fi

# Herdar domínio da aula-10 ou aula-11
for ENV_SRC in "${SCRIPT_DIR}/../aula-11/.env" "${SCRIPT_DIR}/../aula-10/.env"; do
    if [[ -f "$ENV_SRC" && -z "$DOMAIN" ]]; then
        source "$ENV_SRC"
    fi
done

# =============================================================================
# COLETAR CONFIGURAÇÃO
# =============================================================================

echo ""
echo -e "${CYAN}═══════════════════════════════════════════════════${NC}"
echo -e "${CYAN}  Victoria Metrics - Observabilidade${NC}"
echo -e "${CYAN}═══════════════════════════════════════════════════${NC}"
echo ""

if [[ -z "$DOMAIN" ]]; then
    read -p "Domínio base (ex: kube.quest): " DOMAIN
fi

if [[ -z "$GRAFANA_HOST" ]]; then
    DEFAULT_GRAFANA="grafana.${DOMAIN}"
    read -p "Hostname do Grafana [${DEFAULT_GRAFANA}]: " GRAFANA_HOST
    GRAFANA_HOST="${GRAFANA_HOST:-$DEFAULT_GRAFANA}"
fi
log_info "Grafana: https://${GRAFANA_HOST}"

# TLS
if [[ -z "$USE_CLOUDFLARE" && -z "$USE_LETSENCRYPT" ]]; then
    echo ""
    echo "Configuração de TLS:"
    echo "  1) Let's Encrypt (recomendado)"
    echo "  2) CloudFlare (proxy)"
    echo "  3) HTTP apenas"
    read -p "Escolha [1-3]: " TLS_CHOICE
    case $TLS_CHOICE in
        1) USE_CLOUDFLARE=false; USE_LETSENCRYPT=true ;;
        2) USE_CLOUDFLARE=true; USE_LETSENCRYPT=false ;;
        *) USE_CLOUDFLARE=false; USE_LETSENCRYPT=false ;;
    esac
fi

# Salvar
cat > "$ENV_FILE" << EOF
# Configuração gerada pelo setup.sh - $(date)
DOMAIN=${DOMAIN}
GRAFANA_HOST=${GRAFANA_HOST}
USE_CLOUDFLARE=${USE_CLOUDFLARE}
USE_LETSENCRYPT=${USE_LETSENCRYPT}
EOF

log_success "Configuração salva"

# =============================================================================
# PREPARAR VALUES COM HOSTNAME DO GRAFANA
# =============================================================================

log_info "Preparando configuração..."

VALUES_FILE="${SCRIPT_DIR}/gitops/apps/victoria-metrics/values.yaml"
TEMP_VALUES=$(mktemp)
sed "s/grafana\.kube\.quest/${GRAFANA_HOST}/g" "$VALUES_FILE" > "$TEMP_VALUES"

# Ajustar TLS no values
if [[ "$USE_LETSENCRYPT" != "true" ]]; then
    # Remover anotação cert-manager se não usa Let's Encrypt
    sed -i.bak '/cert-manager.io\/cluster-issuer/d' "$TEMP_VALUES"
    rm -f "$TEMP_VALUES.bak"
fi

if [[ "$USE_CLOUDFLARE" == "true" || "$USE_LETSENCRYPT" != "true" ]]; then
    # Remover bloco TLS se não usa Let's Encrypt
    sed -i.bak '/tls:/,/- grafana/d' "$TEMP_VALUES"
    rm -f "$TEMP_VALUES.bak"
fi

# =============================================================================
# INSTALAR VIA HELM
# =============================================================================

echo ""
log_info "=== Instalando Victoria Metrics Stack ==="

helm repo add vm https://victoriametrics.github.io/helm-charts/ 2>/dev/null || true
helm repo update vm

kubectl create namespace monitoring 2>/dev/null || true

if helm status monitoring -n monitoring &> /dev/null; then
    log_warn "Já instalado. Atualizando..."
    HELM_CMD="upgrade"
else
    HELM_CMD="install"
fi

helm ${HELM_CMD} monitoring vm/victoria-metrics-k8s-stack \
    --namespace monitoring \
    -f "$TEMP_VALUES" \
    --wait \
    --timeout 10m

rm -f "$TEMP_VALUES"

log_success "Victoria Metrics Stack instalado!"

# =============================================================================
# APLICAR ALERTAS CUSTOMIZADOS
# =============================================================================

if [[ -f "${SCRIPT_DIR}/gitops/apps/victoria-metrics/templates/alerts.yaml" ]]; then
    echo ""
    log_info "Aplicando alertas customizados..."
    kubectl apply -f "${SCRIPT_DIR}/gitops/apps/victoria-metrics/templates/alerts.yaml" -n monitoring 2>/dev/null || true
    log_success "Alertas aplicados"
fi

# =============================================================================
# OBTER SENHA DO GRAFANA
# =============================================================================

echo ""
log_info "Obtendo credenciais do Grafana..."

GRAFANA_PASSWORD=""
for i in {1..30}; do
    GRAFANA_PASSWORD=$(kubectl get secret -n monitoring -l app.kubernetes.io/name=grafana \
        -o jsonpath='{.items[0].data.admin-password}' 2>/dev/null | base64 -d 2>/dev/null)
    if [[ -n "$GRAFANA_PASSWORD" ]]; then break; fi
    sleep 2
done

# =============================================================================
# RESUMO FINAL
# =============================================================================

PROTOCOL="https"
if [[ "$USE_CLOUDFLARE" == "false" && "$USE_LETSENCRYPT" == "false" ]]; then
    PROTOCOL="http"
fi

echo ""
echo -e "${CYAN}═══════════════════════════════════════════════════${NC}"
echo -e "${GREEN}  Victoria Metrics Instalado!${NC}"
echo -e "${CYAN}═══════════════════════════════════════════════════${NC}"
echo ""
echo "Grafana:"
echo "  URL:      ${PROTOCOL}://${GRAFANA_HOST}"
echo "  Username: admin"
echo "  Password: ${GRAFANA_PASSWORD:-'(kubectl get secret -n monitoring -l app.kubernetes.io/name=grafana -o jsonpath=\"{.items[0].data.admin-password}\" | base64 -d)'}"
echo ""
echo "Acesso alternativo (port-forward):"
echo "  kubectl port-forward -n monitoring svc/monitoring-grafana 3000:80"
echo "  open http://localhost:3000"
echo ""
echo "Verificar:"
echo "  kubectl get pods -n monitoring"
echo ""
echo "Desinstalar:"
echo "  ./cleanup.sh"
echo ""
echo -e "${CYAN}═══════════════════════════════════════════════════${NC}"
echo ""

log_info "Status dos pods:"
kubectl get pods -n monitoring