docs: autoselect version

Define functions that can be used in mdx pages to dinamically choose the
right version according to the documentation page viewed.

Closes #343

Signed-off-by: Francesco Canovai <francesco.canovai@enterprisedb.com>

web/docs/installation.mdx

@@ -6,6 +6,20 @@ sidebar_position: 20
 
 <!-- SPDX-License-Identifier: CC-BY-4.0 -->
 
+import { react } from 'react';
+import CodeBlock from '@theme/CodeBlock';
+import { useCurrentVersion } from '@site/src/hooks/versions';
+
+export function InstallationSnippet() {
+    const latest = useCurrentVersion('latestReleased');
+    return(
+<CodeBlock language="sh" >
+        {`kubectl apply -f \\
+  https://github.com/cloudnative-pg/plugin-barman-cloud/releases/download/v${latest}/manifest.yaml`}
+</CodeBlock>
+    );
+}
+
 :::important
 1. The plugin **must** be installed in the same namespace as the CloudNativePG
    operator (typically `cnpg-system`).
@@ -59,14 +73,7 @@ Both checks are required before proceeding with the installation.
 Install the plugin using `kubectl` by applying the manifest for the latest
 release:
 
-<!-- x-release-please-start-version -->
-
-```sh
-kubectl apply -f \
-  https://github.com/cloudnative-pg/plugin-barman-cloud/releases/download/v0.4.0/manifest.yaml
-```
-
-<!-- x-release-please-end -->
+<InstallationSnippet />
 
 Example output:
 
@@ -114,4 +121,3 @@ following command:
 kubectl apply -f \
   https://raw.githubusercontent.com/cloudnative-pg/plugin-barman-cloud/refs/heads/main/manifest.yaml
 ```
-

web/docs/migration.md

@@ -13,7 +13,7 @@ If you're currently relying on the built-in Barman Cloud integration, you can
 migrate seamlessly to the new **plugin-based architecture** using the Barman
 Cloud Plugin, with **no downtime**. Follow these steps:
 
-- [Install the Barman Cloud Plugin](installation.md)
+- [Install the Barman Cloud Plugin](installation.mdx)
 - Create an `ObjectStore` resource by translating the contents of the
   `.spec.backup.barmanObjectStore` section from your existing `Cluster`
   definition

web/docs/usage.md

@@ -6,7 +6,7 @@ sidebar_position: 30
 
 <!-- SPDX-License-Identifier: CC-BY-4.0 -->
 
-After [installing the plugin](installation.md) in the same namespace as the
+After [installing the plugin](installation.mdx) in the same namespace as the
 CloudNativePG operator, enabling your PostgreSQL cluster to use the Barman
 Cloud Plugin involves just a few steps:
 

web/src/hooks/versions.ts

@@ -0,0 +1,27 @@
+import { useActiveVersion, useLatestVersion, useVersions } from '@docusaurus/plugin-content-docs/client';
+
+
+export function useCurrentVersion(fallback: 'latest' | 'latestReleased' = 'latest') {
+    const version = useActiveVersion('default');
+    if (fallback === 'latestReleased') {
+        return useLatestReleasedVersion();
+    }
+    if (fallback === 'latest') {
+        return version?.name ?? useLatestVersion('default');
+    }
+}
+
+
+export function useLatestReleasedVersion() {
+    const versions = useVersions('default'); // returns all versions, including "current"
+
+    // Filter out "current" to only consider versioned docs
+    const versioned = versions.filter(v => v.name !== 'current');
+
+    // Assuming the latest is the first in the list after sorting by semantic version
+    const latestVersion = versioned.length > 0
+        ? versioned.sort((a, b) => (b.name.localeCompare(a.name, undefined, {numeric: true, sensitivity: 'base'})))[0]
+        : null;
+
+    return latestVersion.name
+}