[pve-devel] [PATCH v2 proxmox-backup 02/10] api: add GroupFilter(List) type

["Fabian Grünbichler" <f.gruenbichler@proxmox.com>]

at the API level, this is a simple (wrapped) Vec of Strings with a
verifier function. all users should use the provided helper to get the
actual GroupFilter enum values, which can't be directly used in the API
schema because of restrictions of the api macro.

validation of the schema + parsing into the proper type uses the same fn
intentionally to avoid running out of sync, even if it means compiling
the REs twice.

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
---
this is working around some api limitations
- updated doesn't support a Vec<String> type
- api-macro doesn't support enum with values

the validation fn and the parser/converted use the same code to avoid
getting out of sync, at the expense of parsing potentially expensive REs
twice..

 pbs-api-types/src/jobs.rs | 90 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)

diff --git a/pbs-api-types/src/jobs.rs b/pbs-api-types/src/jobs.rs
index 1526dbc4..94638fe5 100644
--- a/pbs-api-types/src/jobs.rs
+++ b/pbs-api-types/src/jobs.rs
@@ -1,3 +1,7 @@
+use anyhow::format_err;
+use std::str::FromStr;
+
+use regex::Regex;
 use serde::{Deserialize, Serialize};
 
 use proxmox::const_regex;
@@ -7,6 +11,7 @@ use proxmox::api::{api, schema::*};
 use crate::{
     Userid, Authid, REMOTE_ID_SCHEMA, DRIVE_NAME_SCHEMA, MEDIA_POOL_NAME_SCHEMA,
     SINGLE_LINE_COMMENT_SCHEMA, PROXMOX_SAFE_ID_FORMAT, DATASTORE_SCHEMA,
+    BACKUP_GROUP_SCHEMA, BACKUP_TYPE_SCHEMA,
 };
 
 const_regex!{
@@ -319,6 +324,91 @@ pub struct TapeBackupJobStatus {
     pub next_media_label: Option<String>,
 }
 
+#[derive(Clone, Debug)]
+/// Filter for matching `BackupGroup`s, for use with `BackupGroup::filter`.
+pub enum GroupFilter {
+    /// BackupGroup type - either `vm`, `ct`, or `host`.
+    BackupType(String),
+    /// Full identifier of BackupGroup, including type
+    Group(String),
+    /// A regular expression matched against the full identifier of the BackupGroup
+    Regex(Regex),
+}
+
+impl std::str::FromStr for GroupFilter {
+    type Err = anyhow::Error;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s.split_once(":") {
+            Some(("group", value)) => parse_simple_value(value, &BACKUP_GROUP_SCHEMA).map(|_| GroupFilter::Group(value.to_string())),
+            Some(("type", value)) => parse_simple_value(value, &BACKUP_TYPE_SCHEMA).map(|_| GroupFilter::BackupType(value.to_string())),
+            Some(("regex", value)) => Ok(GroupFilter::Regex(Regex::new(value)?)),
+            Some((ty, _value)) => Err(format_err!("expected 'group', 'type' or 'regex' prefix, got '{}'", ty)),
+            None => Err(format_err!("input doesn't match expected format '<group:GROUP||type:<vm|ct|host>|regex:REGEX>'")),
+        }.map_err(|err| format_err!("'{}' - {}", s, err))
+    }
+}
+
+// used for serializing below, caution!
+impl std::fmt::Display for GroupFilter {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            GroupFilter::BackupType(backup_type) => write!(f, "type:{}", backup_type),
+            GroupFilter::Group(backup_group) => write!(f, "group:{}", backup_group),
+            GroupFilter::Regex(regex) => write!(f, "regex:{}", regex.as_str()),
+        }
+    }
+}
+
+impl Serialize for GroupFilter {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.serialize_str(&self.to_string())
+    }
+}
+
+impl<'de> Deserialize<'de> for GroupFilter {
+    fn deserialize<D>(deserializer: D) -> Result<GroupFilter, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        String::deserialize(deserializer).and_then(|string| {
+            GroupFilter::from_str(&string).map_err(serde::de::Error::custom)
+        })
+    }
+}
+
+fn verify_group_filter(input: &str) -> Result<(), anyhow::Error> {
+    GroupFilter::from_str(input).map(|_| ())
+}
+
+pub const GROUP_FILTER_SCHEMA: Schema = StringSchema::new(
+    "Group filter based on group identifier ('group:GROUP'), group type ('type:<vm|ct|host>'), or regex ('regex:RE').")
+    .format(&ApiStringFormat::VerifyFn(verify_group_filter))
+    .type_text("<type:<vm|ct|host>|group:GROUP|regex:RE>")
+    .schema();
+
+#[api(
+    type: Array,
+    description: "List of group filters.",
+    items: {
+        schema: GROUP_FILTER_SCHEMA,
+    },
+)]
+#[derive(Serialize, Deserialize, Clone, UpdaterType)]
+pub struct GroupFilterList(Vec<String>);
+
+impl GroupFilterList {
+    /// converts schema-validated Vec<String> into Vec<GroupFilter>
+    pub fn filters(self) -> Vec<GroupFilter> {
+        self.0.iter()
+             .map(|group_filter| GroupFilter::from_str(group_filter).unwrap())
+             .collect()
+    }
+}
+
 #[api(
     properties: {
         id: {
-- 
2.30.2