#!/usr/bin/env bash
# Option A logical backup for CoulombCore CNPG clusters (RAILIANCE-WP-0015-T03).
# pg_dump -Fc → age → Nextcloud WebDAV; records last-success ConfigMap.
set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
PLATFORM_REPO="${PLATFORM_REPO:-$HOME/railiance-platform}"
COMMON_SH="${PLATFORM_REPO}/lib/railiance-backup-common.sh"

NAMESPACE="${CNPG_NAMESPACE:-databases}"
BACKUP_ROOT="${BACKUP_DIR:-$HOME/.cache/railiance/backups/cnpg}"
DRY_RUN="${RAILIANCE_BACKUP_DRY_RUN:-1}"
STATUS_CM="${CNPG_OPTION_A_STATUS_CM:-cnpg-option-a-status}"
CLUSTERS_FILTER="${CNPG_BACKUP_CLUSTERS:-}"
UPDATE_STATUS="${CNPG_UPDATE_STATUS_CM:-1}"

# cluster|db1,db2,...  (skip template/postgres system DB)
DEFAULT_TARGETS=(
  "apps-pg|apps_meta,core_hub,core_hub_staging,vergabe_db"
  "gitea-db|gitea"
  "net-kingdom-pg|interhub,privacyidea_db"
  "state-hub-db|state_hub"
)

if [[ ! -f "$COMMON_SH" ]]; then
  echo "ERROR: missing ${COMMON_SH}" >&2
  exit 1
fi
# shellcheck source=/dev/null
source "$COMMON_SH"

railiance_backup_require_tools

if [[ "$DRY_RUN" != "1" ]]; then
  railiance_backup_require_openbao_lane
fi

primary_pod() {
  local cluster="$1"
  kubectl get pods -n "$NAMESPACE" \
    -l "cnpg.io/cluster=${cluster},role=primary" \
    -o jsonpath='{.items[0].metadata.name}' 2>/dev/null || true
}

dump_db() {
  local cluster="$1" pod="$2" db="$3" out="$4"
  kubectl exec -n "$NAMESPACE" "$pod" -c postgres -- \
    pg_dump -U postgres -d "$db" -Fc --no-owner --no-acl >"$out"
}

record_status_cm() {
  local cluster="$1" ts="$2"
  [[ "$UPDATE_STATUS" == "1" ]] || return 0
  if ! kubectl get ns "$NAMESPACE" >/dev/null 2>&1; then
    echo "WARN: skip status ConfigMap — namespace unreachable" >&2
    return 0
  fi
  if ! kubectl get configmap "$STATUS_CM" -n "$NAMESPACE" >/dev/null 2>&1; then
    kubectl create configmap "$STATUS_CM" -n "$NAMESPACE" \
      --from-literal="${cluster}=${ts}" \
      --from-literal=lane=option-a \
      --from-literal=updated="${ts}" \
      >/dev/null
  else
    kubectl patch configmap "$STATUS_CM" -n "$NAMESPACE" --type merge \
      -p "{\"data\":{\"${cluster}\":\"${ts}\",\"updated\":\"${ts}\",\"lane\":\"option-a\"}}" \
      >/dev/null
  fi
  # label for discovery by cnpg-backup-status
  kubectl label configmap "$STATUS_CM" -n "$NAMESPACE" \
    railiance.apps/backup-lane=option-a --overwrite >/dev/null
}

should_run_cluster() {
  local cluster="$1"
  if [[ -z "$CLUSTERS_FILTER" ]]; then
    return 0
  fi
  [[ ",${CLUSTERS_FILTER}," == *",${cluster},"* ]]
}

TS="$(date -u +%Y%m%dT%H%M%SZ)"
echo "cnpg logical backup (Option A)"
echo "  namespace: ${NAMESPACE}"
echo "  dry-run:  ${DRY_RUN}"
echo "  ts:       ${TS}"
echo

failed=0
succeeded_clusters=()

for entry in "${DEFAULT_TARGETS[@]}"; do
  cluster="${entry%%|*}"
  dbs_csv="${entry#*|}"
  should_run_cluster "$cluster" || continue

  pod="$(primary_pod "$cluster")"
  if [[ -z "$pod" ]]; then
    echo "ERROR: ${cluster}: primary pod not found" >&2
    failed=$((failed + 1))
    continue
  fi

  cluster_dir="${BACKUP_ROOT}/${cluster}"
  mkdir -p "$cluster_dir"
  cluster_ok=1

  echo "${cluster}: primary=${pod}"
  IFS=',' read -r -a dbs <<<"$dbs_csv"
  for db in "${dbs[@]}"; do
    plain="${cluster_dir}/${cluster}-${db}-${TS}.dump"
    aged="${plain}.age"
    echo "  dump ${db} → $(basename "$plain")"
    if ! dump_db "$cluster" "$pod" "$db" "$plain"; then
      echo "  ERROR: pg_dump failed for ${cluster}/${db}" >&2
      cluster_ok=0
      failed=$((failed + 1))
      continue
    fi
    railiance_backup_encrypt "$plain" "$aged"
    echo "  ok: age $(basename "$aged") ($(du -h "$aged" | awk '{print $1}'))"
    # drop plaintext after encrypt
    rm -f "$plain"

    if [[ "$DRY_RUN" == "1" ]]; then
      echo "  dry-run: skip upload"
    else
      RAILIANCE_BACKUP_NC_PREFIX="${cluster}"
      railiance_backup_nc_upload "$aged" "${cluster}-${db}-${TS}.dump.age"
      # weekly copy on Sundays (UTC)
      if [[ "$(date -u +%u)" == "7" ]]; then
        railiance_backup_nc_upload "$aged" "${cluster}-${db}-weekly-${TS}.dump.age" || true
      fi
      echo "  ok: uploaded ${cluster}/${cluster}-${db}-${TS}.dump.age"
    fi
    railiance_backup_prune_local "$cluster_dir" "${cluster}-${db}-*.dump.age" 7
  done

  if ((cluster_ok)); then
    railiance_backup_record_success "$cluster_dir" "$TS"
    record_status_cm "$cluster" "$TS"
    succeeded_clusters+=("$cluster")
    echo "  ok: ${cluster} complete"
  fi
  echo
done

if ((failed > 0)); then
  echo "RESULT: failed — ${failed} dump error(s); succeeded: ${succeeded_clusters[*]:-none}"
  exit 1
fi

if ((${#succeeded_clusters[@]} == 0)); then
  echo "RESULT: failed — no clusters selected/ran"
  exit 1
fi

echo "RESULT: ok — clusters: ${succeeded_clusters[*]} (dry-run=${DRY_RUN})"