#!/bin/bash
# =============================================
# restore-k8s-apps.sh — k8s-native replacement for restore-myapps.sh
# Restores: n8n, Odoo, Mautic, Nextcloud, Frappe/ERPNext (all live in k3s)
#
# Contract mirrors restore-myapps.sh exactly, so wiring into app.py's
# restore_start route is a pure path swap:
#   - Expects to be run from inside an already-extracted backup directory
#     (SCRIPT_DIR = the script's own directory), i.e. app.py's existing
#     "tar -xzf backup --strip-components=1 && cp restore-*.sh <session> &&
#     cd <session> && bash restore-*.sh --apps X" flow works unchanged —
#     only the two script filenames/paths need to change on the Python side.
#   - Same --apps flag: comma-separated subset of frappe,odoo,nextcloud,mautic,n8n
#     (omit = restore all found in the backup).
#
# Restore order per app (migration-status.md §5 — never populate a PVC
# that's still mounted by a running consumer; always populate-then-deploy):
#   1. kubectl apply the Secret + manifests (idempotent — creates if missing,
#      updates in place if present; this is also the DR-onto-fresh-cluster path
#      for anything that isn't a PVC, which pre-exists there already this session)
#   2. Scale the app Deployment to 0 and wait for the pod to terminate
#   3. Populate the app-data PVC via a short-lived loader pod + kubectl exec
#      (never raw filesystem/PVC-path access)
#   4. Scale the app Deployment back up
#   5. Restore the DB via pg_restore/mysql (SQL-level, never a raw datadir copy)
#      against the DB Deployment, which stays running throughout
#
# NOT included this session (explicitly deferred, see backup-migration-plan.md §5):
#   - Cross-cluster / disaster-recovery restore. This script assumes the target
#     cluster/namespaces/PVCs already exist (same-cluster restore-in-place).
#     A fresh-cluster bootstrap + PVC-from-scratch path is future work.
# =============================================

set -uo pipefail

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

APPS_FILTER="all"
VALID_APPS="frappe odoo nextcloud mautic n8n"

while [[ $# -gt 0 ]]; do
    case "$1" in
        --apps)
            APPS_FILTER="$2"
            shift 2
            ;;
        *)
            shift
            ;;
    esac
done

if [ "$APPS_FILTER" != "all" ]; then
    APPS_FILTER=$(echo "$APPS_FILTER" | tr -d '[:space:]' | tr '[:upper:]' '[:lower:]')
    IFS=',' read -ra _APP_CHECK <<< "$APPS_FILTER"
    for _a in "${_APP_CHECK[@]}"; do
        if [[ " $VALID_APPS " != *" $_a "* ]]; then
            echo "❌ Unknown app '$_a' in --apps. Valid options: $VALID_APPS"
            exit 1
        fi
    done
fi

app_selected() {
    local app="$1"
    [ "$APPS_FILTER" = "all" ] && return 0
    [[ ",$APPS_FILTER," == *",${app},"* ]]
}

# --------------------------------------------------
# Per-app metadata table (same shape as backup-k8s-apps.sh)
# --------------------------------------------------
declare -A NS=(          [n8n]=n8n            [odoo]=odoo            [mautic]=mautic         [nextcloud]=nextcloud         [frappe]=erpnext )
declare -A APP_DEPLOY=(  [n8n]=n8n            [odoo]=odoo            [mautic]=mautic         [nextcloud]=nextcloud         [frappe]=erpnext-web )
declare -A DB_DEPLOY=(   [n8n]=n8n-postgres   [odoo]=odoo-postgres   [mautic]=mautic-mariadb [nextcloud]=nextcloud-postgres [frappe]=erpnext-mariadb )
declare -A DB_ENGINE=(   [n8n]=postgres       [odoo]=postgres        [mautic]=mariadb        [nextcloud]=postgres          [frappe]=mariadb )
declare -A DB_NAME=(     [n8n]=n8n            [odoo]=odoo            [mautic]=mautic         [nextcloud]=nextcloud         [frappe]=DYNAMIC )
declare -A PVC_NAME=(    [n8n]=n8n-data       [odoo]=odoo-data       [mautic]=mautic-app-data [nextcloud]=nextcloud-app-data [frappe]=erpnext-sites )
declare -A PVC_PATH=(    [n8n]="/home/node/.n8n" [odoo]="/var/lib/odoo" [mautic]="/var/www/html" [nextcloud]="/var/www/html" [frappe]="/home/frappe/frappe-bench/sites" )
declare -A SECRET_NAME=( [n8n]=n8n-secrets    [odoo]=odoo-secrets    [mautic]=mautic-secrets [nextcloud]=nextcloud-secrets [frappe]=erpnext-secrets )
declare -A DB_USER_KEY=( [n8n]=DB_POSTGRESDB_USER [odoo]=POSTGRES_USER [mautic]=MYSQL_USER [nextcloud]=POSTGRES_USER [frappe]="" )
declare -A DB_PASS_KEY=( [n8n]=DB_POSTGRESDB_PASSWORD [odoo]=POSTGRES_PASSWORD [mautic]=MYSQL_ROOT_PASSWORD [nextcloud]=POSTGRES_PASSWORD [frappe]=MARIADB_ROOT_PASSWORD )
declare -A DOMAIN=(      [n8n]="n8nwf.nav.ovh" [odoo]="odooo.nav.ovh" [mautic]="mautics.nav.ovh" [nextcloud]="next.cloud.nav.ovh" [frappe]="erpnext.navitrends.ovh" )

ALL_APPS="n8n odoo mautic nextcloud frappe"
LOADER_IMAGE="alpine:3.20"

echo "========================================="
echo "🔄 k8s Restore — SAME-CLUSTER MODE"
echo "   Backup dir: $SCRIPT_DIR"
if [ "$APPS_FILTER" = "all" ]; then
    echo "   Apps:       ALL (found in backup)"
else
    echo "   Apps:       $APPS_FILTER"
fi
echo "========================================="

check_resources() {
    local avail_mb avail_gb
    avail_mb=$(free -m | awk '/^Mem:/{print $7}')
    avail_gb=$(df -BG / | awk 'NR==2{gsub("G","",$4); print $4}')
    if [ "$avail_mb" -lt 1536 ] || [ "$avail_gb" -lt 10 ]; then
        echo "   ❌ Resource safety threshold hit (RAM=${avail_mb}MB, Disk=${avail_gb}GB) — aborting."
        exit 1
    fi
}

RESTORED_APPS=()
FAILED_APPS=()

check_resources

for app in $ALL_APPS; do
    app_selected "$app" || continue

    if [ ! -d "$SCRIPT_DIR/$app" ]; then
        echo ""
        echo "   ⏭️  $app — not present in this backup, skipping"
        continue
    fi

    ns="${NS[$app]}"
    app_deploy="${APP_DEPLOY[$app]}"
    db_deploy="${DB_DEPLOY[$app]}"
    db_engine="${DB_ENGINE[$app]}"
    db_name="${DB_NAME[$app]}"
    pvc_name="${PVC_NAME[$app]}"
    pvc_path="${PVC_PATH[$app]}"
    secret_name="${SECRET_NAME[$app]}"
    db_user_key="${DB_USER_KEY[$app]}"
    db_pass_key="${DB_PASS_KEY[$app]}"
    APP_DIR="$SCRIPT_DIR/$app"

    echo ""
    echo "-----------------------------------------"
    echo "🔧 [$app] namespace=$ns"
    echo "-----------------------------------------"

    app_ok=true

    # ---- 1. Secret + manifests (apply — idempotent) ----
    if [ -f "$APP_DIR/secret.yaml" ]; then
        echo -n "   🔑 Applying Secret ... "
        kubectl apply -f "$APP_DIR/secret.yaml" &>/dev/null && echo "✅" || { echo "⚠️  FAILED"; app_ok=false; }
    fi
    if [ -f "$APP_DIR/manifests.yaml" ]; then
        echo -n "   📄 Applying manifests ... "
        kubectl apply -f "$APP_DIR/manifests.yaml" &>/dev/null && echo "✅" || { echo "⚠️  FAILED"; app_ok=false; }
    fi

    # ---- 2. Scale app down ----
    prior_replicas=$(kubectl get deployment "$app_deploy" -n "$ns" -o jsonpath='{.spec.replicas}' 2>/dev/null || echo 1)
    [ -z "$prior_replicas" ] && prior_replicas=1
    echo -n "   ⏸️  Scaling $app_deploy to 0 ... "
    kubectl scale deployment "$app_deploy" -n "$ns" --replicas=0 &>/dev/null \
        && kubectl wait --for=delete pod -l app="$app" -n "$ns" --timeout=90s &>/dev/null
    echo "✅"

    # ---- 3. Restore PVC data via loader pod ----
    if [ -f "$APP_DIR/pvc-data.tar.gz" ]; then
        if kubectl get pvc "$pvc_name" -n "$ns" &>/dev/null; then
            loader="${app}-restore-loader"
            echo -n "   📦 Populating PVC $pvc_name via loader pod ... "
            kubectl run "$loader" -n "$ns" --image="$LOADER_IMAGE" --restart=Never \
                --overrides="{\"spec\":{\"containers\":[{\"name\":\"loader\",\"image\":\"${LOADER_IMAGE}\",\"command\":[\"sleep\",\"3600\"],\"volumeMounts\":[{\"name\":\"data\",\"mountPath\":\"/restore\"}]}],\"volumes\":[{\"name\":\"data\",\"persistentVolumeClaim\":{\"claimName\":\"${pvc_name}\"}}]}}" \
                &>/dev/null
            kubectl wait --for=condition=Ready "pod/$loader" -n "$ns" --timeout=60s &>/dev/null

            kubectl exec -n "$ns" "$loader" -- sh -c 'rm -rf /restore/* /restore/.[!.]* /restore/..?* 2>/dev/null; true' &>/dev/null
            if kubectl exec -i -n "$ns" "$loader" -- tar xzf - -C /restore < "$APP_DIR/pvc-data.tar.gz" &>"$APP_DIR/restore-pvc.err"; then
                echo "✅"
                rm -f "$APP_DIR/restore-pvc.err"
            else
                echo "⚠️  FAILED (see $APP_DIR/restore-pvc.err)"
                app_ok=false
            fi
            kubectl delete pod "$loader" -n "$ns" --wait=false &>/dev/null
        else
            echo "   ⚠️  PVC '$pvc_name' does not exist in this cluster — skipping PVC restore"
            echo "       (fresh-cluster/DR provisioning of PVCs from manifests is not yet implemented)"
            app_ok=false
        fi
    else
        echo "   ⏭️  No pvc-data.tar.gz in backup — skipping PVC restore"
    fi

    # ---- 4. Scale app back up ----
    echo -n "   ▶️  Scaling $app_deploy back to $prior_replicas ... "
    kubectl scale deployment "$app_deploy" -n "$ns" --replicas="$prior_replicas" &>/dev/null && echo "✅" || echo "⚠️  FAILED"

    # ---- 5. DB restore (SQL-level, never raw datadir copy) ----
    if [ -f "$APP_DIR/db-dump.sql.gz" ]; then
        echo -n "   💾 Restoring DB ($db_engine) ... "
        case "$db_engine" in
            postgres)
                db_user=$(kubectl get secret "$secret_name" -n "$ns" -o jsonpath="{.data.${db_user_key}}" 2>/dev/null | base64 -d)
                db_pass=$(kubectl get secret "$secret_name" -n "$ns" -o jsonpath="{.data.${db_pass_key}}" 2>/dev/null | base64 -d)
                if [ -n "$db_user" ] && [ -n "$db_pass" ]; then
                    kubectl exec -n "$ns" "deploy/${db_deploy}" -- env PGPASSWORD="$db_pass" \
                        psql -U "$db_user" -d postgres -c "DROP DATABASE IF EXISTS \"$db_name\";" &>/dev/null
                    kubectl exec -n "$ns" "deploy/${db_deploy}" -- env PGPASSWORD="$db_pass" \
                        createdb -U "$db_user" "$db_name" &>/dev/null
                    if gunzip -c "$APP_DIR/db-dump.sql.gz" | \
                        kubectl exec -i -n "$ns" "deploy/${db_deploy}" -- env PGPASSWORD="$db_pass" \
                        psql -U "$db_user" -d "$db_name" &>"$APP_DIR/restore-db.err"; then
                        echo "✅"
                        rm -f "$APP_DIR/restore-db.err"
                    else
                        echo "⚠️  FAILED (see $APP_DIR/restore-db.err)"
                        app_ok=false
                    fi
                else
                    echo "⚠️  could not read DB credentials from (restored) secret"
                    app_ok=false
                fi
                ;;
            mariadb)
                if [ "$db_name" = "DYNAMIC" ]; then
                    db_name=$(cat "$APP_DIR/db-name.txt" 2>/dev/null)
                fi
                db_pass=$(kubectl get secret "$secret_name" -n "$ns" -o jsonpath="{.data.${db_pass_key}}" 2>/dev/null | base64 -d)
                if [ -n "$db_name" ] && [ -n "$db_pass" ]; then
                    kubectl exec -n "$ns" "deploy/${db_deploy}" -- env MYSQL_PWD="$db_pass" \
                        mysql -uroot -e "DROP DATABASE IF EXISTS \`$db_name\`;" &>/dev/null
                    if gunzip -c "$APP_DIR/db-dump.sql.gz" | \
                        kubectl exec -i -n "$ns" "deploy/${db_deploy}" -- env MYSQL_PWD="$db_pass" \
                        mysql -uroot &>"$APP_DIR/restore-db.err"; then
                        echo "✅ (db=$db_name)"
                        rm -f "$APP_DIR/restore-db.err"
                    else
                        echo "⚠️  FAILED (see $APP_DIR/restore-db.err)"
                        app_ok=false
                    fi
                else
                    echo "⚠️  could not determine DB name/credentials"
                    app_ok=false
                fi
                ;;
        esac
    else
        echo "   ⏭️  No db-dump.sql.gz in backup — skipping DB restore"
    fi

    if [ "$app_ok" = true ]; then
        RESTORED_APPS+=("$app")
    else
        FAILED_APPS+=("$app")
    fi

    check_resources
done

# --------------------------------------------------
# Summary
# --------------------------------------------------
echo ""
echo "========================================="
echo "✅ RESTORE COMPLETE"
echo "========================================="
for app in "${RESTORED_APPS[@]:-}"; do
    [ -z "$app" ] && continue
    echo "  ${app} → https://${DOMAIN[$app]}"
done
if [ "${#FAILED_APPS[@]}" -gt 0 ]; then
    echo ""
    echo "  ⚠️  Had failures: ${FAILED_APPS[*]} — check the .err files under each app's backup dir"
fi
echo "========================================="