#!/bin/bash
# =============================================================================
# WOOO AIOps - SignOz 備份腳本 (ClickHouse + SQLite)
# 版本: 1.1.0
# 建立日期: 2026-04-05
# 2026-04-05 Claude Code: 新增 SignOz 分散式追蹤備份 — 首席架構師備份審計
# 2026-04-05 Claude Code: v1.1 修正 tar pipeline exit code 處理 + || true
# =============================================================================

set -euo pipefail

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

SERVICE="signoz"
LOCAL_REPO="${BACKUP_BASE}/signoz"
DUMP_DIR="/tmp/signoz-backup-$$"

cleanup() {
    # 確保 collector 已重啟
    docker start signoz-otel-collector 2>/dev/null || true
    rm -rf "${DUMP_DIR}"
}

backup_volume() {
    local volume_name="$1"
    local output_file="$2"
    local extra_exclude="${3:-}"
    log_info "備份 volume: ${volume_name}"
    # 使用 || true 處理 tar 備份運行中 volume 的 exit 1 警告
    if [ -n "${extra_exclude}" ]; then
        docker run --rm -v "${volume_name}:/data" alpine tar czf - "${extra_exclude}" /data 2>/dev/null > "${output_file}" || true
    else
        docker run --rm -v "${volume_name}:/data" alpine tar czf - /data 2>/dev/null > "${output_file}" || true
    fi
    if [ -s "${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=$(date +%s)
    log_info "========== 開始 SignOz 備份 =========="
    mkdir -p "${DUMP_DIR}"

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

    # Step 1: 停止 OTEL Collector 確保數據一致性
    log_info "暫停 signoz-otel-collector 以確保數據一致性..."
    docker stop signoz-otel-collector 2>/dev/null || log_warn "signoz-otel-collector 未在運行，繼續"
    docker stop signoz-telemetrystore-migrator 2>/dev/null || true

    # Step 2: 備份 ClickHouse volume (排除 tmp 目錄降低體積)
    backup_volume "signoz-clickhouse" "${DUMP_DIR}/clickhouse_${timestamp}.tar.gz" "--exclude=/data/tmp" || {
        log_error "ClickHouse volume 備份失敗"
        cleanup
        notify_clawbot "failed" "${SERVICE}" "SignOz ClickHouse 備份失敗"
        exit 1
    }

    # Step 3: 備份 SQLite volume (SignOz metadata)
    backup_volume "signoz-sqlite" "${DUMP_DIR}/sqlite_${timestamp}.tar.gz" || {
        log_warn "SQLite volume 備份失敗，繼續..."
    }

    # Step 4: 重啟 Collector
    log_info "重啟 signoz-otel-collector..."
    docker start signoz-otel-collector 2>/dev/null || log_warn "signoz-otel-collector 重啟失敗"

    # 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 "${RESTIC_PASSWORD_FILE}" 2>&1 || {
            log_error "Restic 倉庫初始化失敗"
            rm -rf "${DUMP_DIR}"
            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}"

    rm -rf "${DUMP_DIR}"

    local end_time=$(date +%s)
    local duration=$((end_time - start_time))
    log_success "========== SignOz 備份完成 (${duration}s) =========="
    notify_clawbot "success" "${SERVICE}" "SignOz 備份完成 (ClickHouse+SQLite)" "${duration}"
}

main "$@"