#!/usr/bin/env bash
# scripts/ops/dr-drill.sh
# Sprint 5.2: 每月 DR Drill — 從最新 Velero 備份還原到測試 namespace，驗證後清理
#
# 部署: cron 0 3 1-7 * 0 (每月第一個週日 03:00) on 121
# 用法: bash dr-drill.sh [--dry-run]
#
# 流程:
#   1. 找最新 Velero backup
#   2. 還原到 awoooi-dr-test namespace
#   3. 等待 Pod Ready（最多 10 分鐘）
#   4. 驗證 API health endpoint
#   5. 清理 dr-test namespace + restore 資源
#   6. Telegram 通知結果
#
# 2026-04-09 Claude Sonnet 4.6 Asia/Taipei

set -euo pipefail

KUBECONFIG="${KUBECONFIG:-/etc/rancher/k3s/k3s.yaml}"
DR_NAMESPACE="awoooi-dr-test"
RESTORE_TIMEOUT="${RESTORE_TIMEOUT:-600}"   # 10 分鐘
SECRETS_FILE="${SECRETS_FILE:-/home/wooo/awoooi-ops-secrets/secrets.env}"
DRY_RUN="${1:-}"
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

[[ -f "$SECRETS_FILE" ]] && source "$SECRETS_FILE"

TIMESTAMP=$(date '+%Y%m%d_%H%M%S')
RESTORE_NAME="dr-drill-${TIMESTAMP}"
START_TIME=$(date +%s)

log() { echo "[$(date '+%Y-%m-%d %H:%M:%S %z')] $*"; }

notify_awoooi_ops() {
    local status="$1"
    local msg="$2"
    local helper="${SCRIPT_DIR}/notify-awoooi-ops.sh"
    [[ -x "$helper" ]] || return 1

    AWOOI_OPS_ALERTNAME="DRDrillStatus" \
    AWOOI_OPS_JOB_NAME="DR Drill 月度演練" \
    AWOOI_OPS_STATUS="$status" \
    AWOOI_OPS_SEVERITY="info" \
    AWOOI_OPS_SOURCE="dr-drill" \
    AWOOI_OPS_COMPONENT="disaster-recovery" \
    AWOOI_OPS_SUMMARY="DR Drill ${status}" \
    AWOOI_OPS_DETAIL="$msg" \
    AWOOI_OPS_DURATION_SECONDS="$(elapsed)" \
    "$helper" >/dev/null
}

notify_telegram() {
    local msg="$1"
    local status="${2:-success}"

    # 正式路徑：先交給 AWOOI API，由 TelegramGateway 送出並鏡像到 AwoooP。
    # 只有 API 不可達或 helper 未部署時，才使用 Telegram 直發救命旁路。
    notify_awoooi_ops "$status" "$msg" && return 0

    local chat_id="${TELEGRAM_ALERT_CHAT_ID:-${SRE_GROUP_CHAT_ID:--1003711974679}}"
    if [[ -n "${TELEGRAM_BOT_TOKEN:-}" && -n "$chat_id" ]]; then
        curl -s -X POST "https://api.telegram.org/bot${TELEGRAM_BOT_TOKEN}/sendMessage" \
            -d "chat_id=${chat_id}" \
            -d "parse_mode=HTML" \
            --data-urlencode "text=${msg}" \
            > /dev/null 2>&1 || true
    fi
}

kubectl_cmd() {
    sudo kubectl --kubeconfig="$KUBECONFIG" "$@"
}

elapsed() {
    local end
    end=$(date +%s)
    echo $(( end - START_TIME ))
}

# ── Step 1: 找最新 Velero backup ─────────────────────────────────────────────
find_latest_backup() {
    local latest
    latest=$(kubectl_cmd get backups -n velero \
        --sort-by='.metadata.creationTimestamp' \
        -o jsonpath='{.items[-1].metadata.name}' 2>/dev/null)
    if [[ -z "$latest" ]]; then
        log "❌ 找不到任何 Velero backup"
        return 1
    fi
    local phase
    phase=$(kubectl_cmd get backup "$latest" -n velero \
        -o jsonpath='{.status.phase}' 2>/dev/null)
    if [[ "$phase" != "Completed" ]]; then
        log "❌ 最新 backup ${latest} 狀態 ${phase}，非 Completed"
        return 1
    fi
    echo "$latest"
}

# ── Step 2: 清理舊的 dr-test namespace（若存在）──────────────────────────────
cleanup_dr_namespace() {
    if kubectl_cmd get namespace "$DR_NAMESPACE" &>/dev/null; then
        log "🗑️ 清理舊的 ${DR_NAMESPACE} namespace..."
        kubectl_cmd delete namespace "$DR_NAMESPACE" --timeout=120s 2>/dev/null || true
        # 等待刪除完成
        local i=0
        while kubectl_cmd get namespace "$DR_NAMESPACE" &>/dev/null && (( i < 30 )); do
            sleep 5; ((i++))
        done
        log "✅ 舊 namespace 已清理"
    fi
}

# ── Step 3: 執行 Velero restore ──────────────────────────────────────────────
run_restore() {
    local backup_name="$1"
    log "🔄 開始還原: backup=${backup_name} → namespace=${DR_NAMESPACE}"

    kubectl_cmd create -f - <<EOF
apiVersion: velero.io/v1
kind: Restore
metadata:
  name: ${RESTORE_NAME}
  namespace: velero
spec:
  backupName: ${backup_name}
  includedNamespaces:
    - awoooi-prod
  namespaceMapping:
    awoooi-prod: ${DR_NAMESPACE}
  restorePVs: false
  existingResourcePolicy: none
EOF

    log "⏳ 等待 restore 完成（timeout ${RESTORE_TIMEOUT}s）..."
    local i=0
    local phase=""
    while (( i < RESTORE_TIMEOUT )); do
        phase=$(kubectl_cmd get restore "$RESTORE_NAME" -n velero \
            -o jsonpath='{.status.phase}' 2>/dev/null || echo "")
        case "$phase" in
            Completed) log "✅ Restore Completed"; return 0 ;;
            Failed|PartiallyFailed) log "❌ Restore 失敗: ${phase}"; return 1 ;;
        esac
        sleep 10; ((i+=10))
        log "⏳ Restore 狀態: ${phase:-Pending} (${i}s)"
    done
    log "❌ Restore timeout"
    return 1
}

# ── Step 4: 等待 Pod Ready ───────────────────────────────────────────────────
wait_pods_ready() {
    log "⏳ 等待 ${DR_NAMESPACE} Pod Ready..."
    local i=0
    while (( i < 300 )); do
        local ready
        ready=$(kubectl_cmd get pods -n "$DR_NAMESPACE" --no-headers 2>/dev/null \
            | grep -c "Running" || echo "0")
        local total
        total=$(kubectl_cmd get pods -n "$DR_NAMESPACE" --no-headers 2>/dev/null \
            | wc -l || echo "0")
        log "Pod 狀態: ${ready}/${total} Running"
        if (( total > 0 && ready == total )); then
            log "✅ 所有 Pod Ready"
            return 0
        fi
        sleep 10; ((i+=10))
    done
    log "⚠️ Pod 等待 timeout，繼續驗證"
    return 0  # 不阻斷，讓 health check 決定
}

# ── Step 5: 驗證 API health ──────────────────────────────────────────────────
verify_api_health() {
    log "🩺 驗證 DR namespace API health..."
    # 找 api pod IP
    local api_ip
    api_ip=$(kubectl_cmd get pods -n "$DR_NAMESPACE" \
        -l app=awoooi-api \
        -o jsonpath='{.items[0].status.podIP}' 2>/dev/null || echo "")

    if [[ -z "$api_ip" ]]; then
        log "⚠️ 找不到 API Pod IP，跳過 health check"
        return 0
    fi

    local http_code
    http_code=$(curl -s -o /dev/null -w "%{http_code}" \
        --connect-timeout 10 --max-time 30 \
        "http://${api_ip}:8000/api/v1/health" 2>/dev/null || echo "0")

    if [[ "$http_code" == "200" ]]; then
        log "✅ API health: 200 OK (${api_ip})"
        return 0
    else
        log "❌ API health: ${http_code} (${api_ip})"
        return 1
    fi
}

# ── Step 6: 清理 dr-test 資源 ────────────────────────────────────────────────
cleanup_all() {
    log "🗑️ 清理 DR test 資源..."
    kubectl_cmd delete namespace "$DR_NAMESPACE" --timeout=120s 2>/dev/null || true
    kubectl_cmd delete restore "$RESTORE_NAME" -n velero 2>/dev/null || true
    log "✅ 清理完成"
}

# ── Main ──────────────────────────────────────────────────────────────────────
main() {
    log "=== DR Drill 開始 (${TIMESTAMP}) ==="

    if [[ "$DRY_RUN" == "--dry-run" ]]; then
        log "🔍 DRY RUN 模式 — 只檢查 backup，不執行還原"
        local backup
        backup=$(find_latest_backup) || { notify_telegram "❌ DR Drill 失敗: 找不到有效 backup" "failed"; exit 1; }
        log "✅ 最新 backup: ${backup}"
        notify_telegram "🔍 <b>DR Drill DRY RUN</b>
├ 最新 backup: ${backup}
└ 狀態: Completed ✅ (未執行還原)" "success"
        return 0
    fi

    local backup
    backup=$(find_latest_backup) || {
        notify_telegram "❌ <b>DR Drill 失敗</b>
└ 找不到有效 Velero backup" "failed"
        exit 1
    }
    log "📦 使用 backup: ${backup}"

    cleanup_dr_namespace

    local restore_ok=true
    run_restore "$backup" || restore_ok=false

    local pod_status="⚠️"
    local health_status="⚠️"

    if $restore_ok; then
        wait_pods_ready
        verify_api_health && health_status="✅" || health_status="❌"
        pod_status="✅"
    else
        pod_status="❌"
    fi

    cleanup_all

    local duration
    duration=$(elapsed)
    local minutes=$(( duration / 60 ))
    local seconds=$(( duration % 60 ))

    local overall="✅ PASS"
    [[ "$health_status" == "❌" || "$pod_status" == "❌" ]] && overall="❌ FAIL"

    log "=== DR Drill 完成: ${overall} (${minutes}m${seconds}s) ==="

    local notify_status="success"
    [[ "$overall" == *"FAIL"* ]] && notify_status="failed"

    notify_telegram "${overall} <b>DR Drill 月度演練</b>
├ 備份: ${backup}
├ Restore: ${pod_status}
├ API Health: ${health_status}
├ 耗時: ${minutes}m${seconds}s
└ 時間: $(date '+%Y-%m-%d %H:%M') +0800" "$notify_status"

    [[ "$overall" == *"FAIL"* ]] && exit 1
    return 0
}

main "$@"