#!/bin/bash
# =============================================================================
# WOOO AIOps - Monitoring 備份腳本 (Prometheus + Grafana + Alertmanager)
# 版本: 1.1.0
# 建立日期: 2026-04-05
# 2026-04-05 Claude Code: 新增監控數據備份 — 首席架構師備份審計
# 2026-04-05 Claude Code: v1.1 修正 Prometheus 1.1GB volume tar pipeline exit code 處理
# =============================================================================

set -euo pipefail

source "$(dirname "$0")/common.sh"

SERVICE="monitoring"
LOCAL_REPO="${BACKUP_BASE}/monitoring"
DUMP_DIR="/tmp/monitoring-backup-$$"
MONITORING_CONFIG_DIR="/home/wooo/monitoring"

cleanup() {
    rm -rf "${DUMP_DIR}"
}

backup_volume() {
    local volume_name="$1"
    local output_file="$2"
    log_info "備份 volume: ${volume_name}"
    # 注意: tar 備份大型 volume 時可能 exit 1 (因 mmap/lock files 被修改)
    # 使用 || true 避免因 warning 導致失敗，但仍驗證檔案大小
    docker run --rm -v "${volume_name}:/data" alpine tar czf - /data 2>/dev/null > "${output_file}" || true
    if [ -s "${output_file}" ]; then
        local size=$(du -h "${output_file}" | cut -f1)
        log_success "  Volume ${volume_name} 備份完成 (${size})"
        return 0
    else
        log_error "  Volume ${volume_name} 備份失敗 (空檔案)"
        return 1
    fi
}

main() {
    local start_time=$(date +%s)
    log_info "========== 開始 Monitoring 備份 =========="
    mkdir -p "${DUMP_DIR}"

    local timestamp=$(date "+%Y%m%d_%H%M%S")
    local any_failed=0

    # Step 1: 備份 Prometheus volume (TSDB 數據，約 1GB+)
    backup_volume "monitoring_prometheus_data" "${DUMP_DIR}/prometheus_${timestamp}.tar.gz" || {
        notify_clawbot "failed" "${SERVICE}" "Prometheus volume 備份失敗"
        cleanup
        exit 1
    }

    # Step 2: 備份 Grafana volume (dashboards/alerts 設定)
    backup_volume "monitoring_grafana_data" "${DUMP_DIR}/grafana_${timestamp}.tar.gz" || {
        log_warn "Grafana volume 備份失敗，繼續..."
        any_failed=1
    }

    # Step 3: 備份 Alertmanager volume (靜默/路由設定)
    backup_volume "monitoring_alertmanager_data" "${DUMP_DIR}/alertmanager_${timestamp}.tar.gz" || {
        log_warn "Alertmanager volume 備份失敗，繼續..."
        any_failed=1
    }

    # Step 4: 備份 monitoring 設定檔目錄
    log_info "備份 monitoring 設定檔 (${MONITORING_CONFIG_DIR})"
    if [ -d "${MONITORING_CONFIG_DIR}" ]; then
        tar czf "${DUMP_DIR}/monitoring-configs_${timestamp}.tar.gz" -C "$(dirname ${MONITORING_CONFIG_DIR})" "$(basename ${MONITORING_CONFIG_DIR})" 2>/dev/null || true
        if [ -s "${DUMP_DIR}/monitoring-configs_${timestamp}.tar.gz" ]; then
            log_success "設定檔備份完成"
        else
            log_warn "設定檔備份失敗或為空"
        fi
    else
        log_warn "monitoring 設定目錄不存在: ${MONITORING_CONFIG_DIR}"
    fi

    # Step 5: 初始化 Restic 倉庫
    if [ ! -d "${LOCAL_REPO}/data" ]; then
        log_info "初始化 Restic 倉庫: ${LOCAL_REPO}"
        restic -r "${LOCAL_REPO}" init --password-file "${RESTIC_PASSWORD_FILE}" 2>&1 || {
            log_error "Restic 倉庫初始化失敗"
            cleanup
            exit 1
        }
    fi

    # Step 6: Restic 備份
    log_info "建立 Restic 備份..."
    local tags=$(build_tags "${SERVICE}")
    restic -r "${LOCAL_REPO}" backup "${DUMP_DIR}"         --password-file "${RESTIC_PASSWORD_FILE}"         ${tags} 2>&1

    local snapshot_id=$(restic -r "${LOCAL_REPO}" snapshots --latest 1 --json --password-file "${RESTIC_PASSWORD_FILE}" 2>/dev/null | grep -oP '"short_id":"\K[^"]+' | head -1)
    log_success "Restic 備份完成: ${snapshot_id}"

    # Step 7: GFS 清理
    cleanup_old_backups "${LOCAL_REPO}"

    cleanup

    local end_time=$(date +%s)
    local duration=$((end_time - start_time))
    log_success "========== Monitoring 備份完成 (${duration}s) =========="
    notify_clawbot "success" "${SERVICE}" "Monitoring 備份完成 (Prometheus+Grafana+Alertmanager)" "${duration}"
}

main "$@"