openbao 0.10.0

//! Shared OpenBao response envelopes.

use core::fmt;

use secrecy::SecretString;
use serde::de::Error as DeError;
use serde::{
    Deserialize, Deserializer, Serialize,
    de::{IgnoredAny, MapAccess, SeqAccess, Visitor},
};

use std::collections::BTreeMap;

use crate::{Error, Result, path::validate_endpoint_path};

const MAX_API_ERRORS: usize = 16;
/// Maximum number of strings accepted by the crate's bounded list helpers.
pub const MAX_RESPONSE_STRINGS: usize = 4096;

/// Empty JSON payload used for endpoints that do not require a body.
#[derive(Clone, Copy, Debug, Default, Deserialize, Serialize)]
pub struct Empty {}

/// Shared accessor trait for OpenBao list responses.
///
/// OpenBao commonly returns list endpoints as a primary `keys`, `policies`,
/// or `roles` string array. Concrete response structs keep their documented
/// field names; this trait provides common read-only ergonomics across them.
pub trait ListEntries {
    /// Returns the primary list entries.
    fn entries(&self) -> &[String];

    /// Returns an iterator over the primary list entries.
    fn iter(&self) -> core::slice::Iter<'_, String> {
        self.entries().iter()
    }

    /// Returns the number of primary entries.
    fn len(&self) -> usize {
        self.entries().len()
    }

    /// Returns true when the primary entry list is empty.
    fn is_empty(&self) -> bool {
        self.entries().is_empty()
    }

    /// Returns true when the primary entry list contains `entry`.
    fn contains(&self, entry: &str) -> bool {
        self.entries().iter().any(|candidate| candidate == entry)
    }
}

/// Shared pagination options for non-secret OpenBao string-list endpoints.
///
/// This type is intentionally not used for token accessors, lease IDs, or
/// other secret-bearing list values. Those endpoints keep dedicated helpers so
/// secret-specific handling is not erased by generic list ergonomics.
#[derive(Clone, Debug, Default, Eq, PartialEq)]
pub struct ListPageOptions {
    after: Option<String>,
    limit: Option<u64>,
}

impl ListPageOptions {
    /// Creates empty pagination options.
    #[must_use]
    pub fn new() -> Self {
        Self::default()
    }

    /// Sets the OpenBao `after` cursor.
    ///
    /// The cursor is validated as an endpoint path fragment so it cannot inject
    /// query strings, fragments, relative segments, empty segments, or control
    /// characters.
    pub fn after(mut self, after: impl AsRef<str>) -> Result<Self> {
        let segments = validate_endpoint_path(after.as_ref())?;
        if segments.is_empty() {
            return Err(Error::InvalidPath(
                "pagination cursor must not be empty".into(),
            ));
        }
        self.after = Some(segments.join("/"));
        Ok(self)
    }

    /// Sets the OpenBao `limit` value.
    ///
    /// The bound matches [`MAX_RESPONSE_STRINGS`], the maximum string-list
    /// allocation this crate accepts while decoding list responses.
    pub fn limit(mut self, limit: u64) -> Result<Self> {
        if limit == 0 {
            return Err(Error::InvalidParameter(
                "pagination limit must be greater than zero".into(),
            ));
        }
        if limit > MAX_RESPONSE_STRINGS as u64 {
            return Err(Error::InvalidParameter(
                "pagination limit exceeds maximum allowed value".into(),
            ));
        }
        self.limit = Some(limit);
        Ok(self)
    }

    /// Returns the validated `after` cursor.
    #[must_use]
    pub fn after_cursor(&self) -> Option<&str> {
        self.after.as_deref()
    }

    /// Returns the requested page size.
    #[must_use]
    pub fn limit_value(&self) -> Option<u64> {
        self.limit
    }

    pub(crate) fn from_after_limit(after: Option<&str>, limit: Option<u64>) -> Result<Self> {
        let mut options = Self::new();
        if let Some(after) = after {
            options = options.after(after)?;
        }
        if let Some(limit) = limit {
            options = options.limit(limit)?;
        }
        Ok(options)
    }

    pub(crate) fn query_pairs(&self) -> Vec<(&'static str, String)> {
        let mut query = Vec::new();
        if let Some(after) = self.after.as_ref() {
            query.push(("after", after.clone()));
        }
        if let Some(limit) = self.limit {
            query.push(("limit", limit.to_string()));
        }
        query
    }
}

/// Standard OpenBao response envelope for endpoints that return `data`.
#[derive(Clone, Deserialize)]
pub struct ResponseEnvelope<T> {
    /// Endpoint-specific response data.
    pub data: T,
    /// Lease identifier, when the endpoint returns one.
    #[serde(default = "empty_secret")]
    pub lease_id: SecretString,
    /// Lease duration in seconds.
    #[serde(default)]
    pub lease_duration: u64,
    /// Whether the lease is renewable.
    #[serde(default)]
    pub renewable: bool,
    /// Warnings emitted by OpenBao.
    #[serde(default, deserialize_with = "deserialize_optional_bounded_string_vec")]
    pub warnings: Option<Vec<String>>,
    /// Response wrapping metadata, when OpenBao returns a wrapped response.
    #[serde(default)]
    pub wrap_info: Option<WrapInfo>,
}

impl<T: fmt::Debug> fmt::Debug for ResponseEnvelope<T> {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        formatter
            .debug_struct("ResponseEnvelope")
            .field("data", &self.data)
            .field("lease_id", &"<redacted>")
            .field("lease_duration", &self.lease_duration)
            .field("renewable", &self.renewable)
            .field("warnings", &self.warnings)
            .field("wrap_info", &self.wrap_info)
            .finish()
    }
}

/// Metadata for a response-wrapping token.
#[derive(Clone, Deserialize)]
pub struct WrapInfo {
    /// Wrapping token. Treat as secret material.
    pub token: SecretString,
    /// Token accessor, when returned. Treat as secret material.
    #[serde(default)]
    pub accessor: Option<SecretString>,
    /// Wrapping token TTL in seconds.
    #[serde(default)]
    pub ttl: u64,
    /// Wrapped response creation time.
    #[serde(default)]
    pub creation_time: Option<String>,
    /// Wrapped response creation path.
    #[serde(default)]
    pub creation_path: Option<String>,
}

impl fmt::Debug for WrapInfo {
    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        formatter
            .debug_struct("WrapInfo")
            .field("token", &"<redacted>")
            .field("accessor", &self.accessor.as_ref().map(|_| "<redacted>"))
            .field("ttl", &self.ttl)
            .field("creation_time", &self.creation_time)
            .field("creation_path", &self.creation_path)
            .finish()
    }
}

fn empty_secret() -> SecretString {
    SecretString::from(String::new())
}

/// Deserializes a bounded vector of strings.
///
/// Custom plugin wrappers can use this with serde field attributes to apply
/// the same allocation bound used by built-in OpenBao list responses:
///
/// ```rust
/// # use serde::Deserialize;
/// #[derive(Deserialize)]
/// struct PluginList {
///     #[serde(default, deserialize_with = "openbao::deserialize_bounded_string_vec")]
///     keys: Vec<String>,
/// }
/// ```
pub fn deserialize_bounded_string_vec<'de, D>(
    deserializer: D,
) -> core::result::Result<Vec<String>, D::Error>
where
    D: Deserializer<'de>,
{
    deserializer.deserialize_seq(BoundedStringListVisitor::<MAX_RESPONSE_STRINGS>)
}

pub(crate) fn deserialize_optional_bounded_string_vec<'de, D>(
    deserializer: D,
) -> core::result::Result<Option<Vec<String>>, D::Error>
where
    D: Deserializer<'de>,
{
    Option::<BoundedStringList>::deserialize(deserializer).map(|value| value.map(|value| value.0))
}

#[allow(dead_code)]
pub(crate) fn deserialize_bounded_string_map<'de, D>(
    deserializer: D,
) -> core::result::Result<BTreeMap<String, String>, D::Error>
where
    D: Deserializer<'de>,
{
    deserializer.deserialize_map(BoundedStringMapVisitor::<MAX_RESPONSE_STRINGS>)
}

#[allow(dead_code)]
pub(crate) fn deserialize_optional_bounded_string_map<'de, D>(
    deserializer: D,
) -> core::result::Result<Option<BTreeMap<String, String>>, D::Error>
where
    D: Deserializer<'de>,
{
    Option::<BoundedStringMap>::deserialize(deserializer).map(|value| value.map(|value| value.0))
}

#[allow(dead_code)]
pub(crate) fn deserialize_bounded_string_map_or_default<'de, D>(
    deserializer: D,
) -> core::result::Result<BTreeMap<String, String>, D::Error>
where
    D: Deserializer<'de>,
{
    Ok(Option::<BoundedStringMap>::deserialize(deserializer)?
        .map(|value| value.0)
        .unwrap_or_default())
}

/// Bounded string list for custom plugin responses.
///
/// Use this when a deployment-specific plugin returns a string array and you
/// want the same item limit used by built-in list helpers.
#[derive(Clone, Debug, Default, Deserialize, Eq, PartialEq, Serialize)]
pub struct BoundedStringList(
    #[serde(deserialize_with = "deserialize_bounded_string_vec")] Vec<String>,
);

impl BoundedStringList {
    /// Builds a bounded list from caller-provided values.
    ///
    /// This enforces the same maximum item count that deserialization applies
    /// to OpenBao responses.
    pub fn try_new(values: Vec<String>) -> Result<Self> {
        if values.len() > MAX_RESPONSE_STRINGS {
            return Err(Error::InvalidParameter(
                "OpenBao string list exceeds item limit".into(),
            ));
        }
        Ok(Self(values))
    }

    /// Returns the bounded list entries.
    #[must_use]
    pub fn as_slice(&self) -> &[String] {
        &self.0
    }

    /// Consumes the wrapper and returns the inner vector.
    #[must_use]
    pub fn into_vec(self) -> Vec<String> {
        self.0
    }
}

impl ListEntries for BoundedStringList {
    fn entries(&self) -> &[String] {
        self.as_slice()
    }
}

#[derive(Deserialize)]
#[allow(dead_code)]
struct BoundedStringMap(
    #[serde(deserialize_with = "deserialize_bounded_string_map")] BTreeMap<String, String>,
);

#[allow(dead_code)]
pub(crate) fn deserialize_bounded_secret_string_vec<'de, D>(
    deserializer: D,
) -> core::result::Result<Vec<SecretString>, D::Error>
where
    D: Deserializer<'de>,
{
    deserializer.deserialize_seq(BoundedSecretStringListVisitor::<MAX_RESPONSE_STRINGS>)
}

struct BoundedStringListVisitor<const MAX: usize>;

impl<'de, const MAX: usize> Visitor<'de> for BoundedStringListVisitor<MAX> {
    type Value = Vec<String>;

    fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(formatter, "a list of at most {MAX} strings")
    }

    fn visit_seq<A>(self, mut seq: A) -> core::result::Result<Self::Value, A::Error>
    where
        A: SeqAccess<'de>,
    {
        let mut values = Vec::new();
        while values.len() < MAX {
            let Some(value) = seq.next_element::<String>()? else {
                return Ok(values);
            };
            values.push(value);
        }
        if seq.next_element::<IgnoredAny>()?.is_some() {
            return Err(A::Error::custom("OpenBao string list exceeds item limit"));
        }
        Ok(values)
    }
}

#[allow(dead_code)]
struct BoundedStringMapVisitor<const MAX: usize>;

impl<'de, const MAX: usize> Visitor<'de> for BoundedStringMapVisitor<MAX> {
    type Value = BTreeMap<String, String>;

    fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(formatter, "a map of at most {MAX} string pairs")
    }

    fn visit_map<A>(self, mut map: A) -> core::result::Result<Self::Value, A::Error>
    where
        A: MapAccess<'de>,
    {
        let mut values = BTreeMap::new();
        while values.len() < MAX {
            let Some((key, value)) = map.next_entry::<String, String>()? else {
                return Ok(values);
            };
            values.insert(key, value);
        }
        if map.next_entry::<IgnoredAny, IgnoredAny>()?.is_some() {
            return Err(A::Error::custom("OpenBao string map exceeds item limit"));
        }
        Ok(values)
    }
}

#[allow(dead_code)]
struct BoundedSecretStringListVisitor<const MAX: usize>;

impl<'de, const MAX: usize> Visitor<'de> for BoundedSecretStringListVisitor<MAX> {
    type Value = Vec<SecretString>;

    fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(formatter, "a list of at most {MAX} secret strings")
    }

    fn visit_seq<A>(self, mut seq: A) -> core::result::Result<Self::Value, A::Error>
    where
        A: SeqAccess<'de>,
    {
        let mut values = Vec::new();
        while values.len() < MAX {
            let Some(value) = seq.next_element::<String>()? else {
                return Ok(values);
            };
            values.push(SecretString::from(value));
        }
        if seq.next_element::<IgnoredAny>()?.is_some() {
            return Err(A::Error::custom(
                "OpenBao secret string list exceeds item limit",
            ));
        }
        Ok(values)
    }
}

#[derive(Debug, Deserialize)]
pub(crate) struct ErrorEnvelope {
    #[serde(default, deserialize_with = "deserialize_error_list")]
    pub(crate) errors: Vec<String>,
}

fn deserialize_error_list<'de, D>(deserializer: D) -> core::result::Result<Vec<String>, D::Error>
where
    D: Deserializer<'de>,
{
    deserializer.deserialize_seq(ErrorListVisitor)
}

struct ErrorListVisitor;

impl<'de> Visitor<'de> for ErrorListVisitor {
    type Value = Vec<String>;

    fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
        formatter.write_str("a bounded list of OpenBao API errors")
    }

    fn visit_seq<A>(self, mut seq: A) -> core::result::Result<Self::Value, A::Error>
    where
        A: SeqAccess<'de>,
    {
        let mut errors = Vec::with_capacity(seq.size_hint().unwrap_or(0).min(MAX_API_ERRORS));
        while errors.len() < MAX_API_ERRORS {
            let Some(error) = seq.next_element::<String>()? else {
                return Ok(errors);
            };
            errors.push(error);
        }
        while seq.next_element::<IgnoredAny>()?.is_some() {}
        Ok(errors)
    }
}

#[cfg(test)]
mod tests {
    #![allow(clippy::panic)]

    use secrecy::SecretString;

    use super::{BoundedStringList, ListEntries, ListPageOptions, ResponseEnvelope};

    #[test]
    fn response_debug_redacts_lease_id() {
        let envelope = ResponseEnvelope {
            data: "ok",
            lease_id: SecretString::from("secret-lease"),
            lease_duration: 30,
            renewable: true,
            warnings: None,
            wrap_info: None,
        };

        let debug = format!("{envelope:?}");
        assert!(debug.contains("<redacted>"));
        assert!(!debug.contains("secret-lease"));
    }

    #[test]
    fn response_debug_redacts_wrap_info() {
        let envelope = ResponseEnvelope {
            data: "ok",
            lease_id: SecretString::from(""),
            lease_duration: 0,
            renewable: false,
            warnings: None,
            wrap_info: Some(super::WrapInfo {
                token: SecretString::from("wrap-token"),
                accessor: Some(SecretString::from("wrap-accessor")),
                ttl: 60,
                creation_time: None,
                creation_path: None,
            }),
        };

        let debug = format!("{envelope:?}");
        assert!(debug.contains("<redacted>"));
        assert!(!debug.contains("wrap-token"));
        assert!(!debug.contains("wrap-accessor"));
    }

    #[test]
    fn error_envelope_caps_error_count() {
        let json = format!(
            r#"{{"errors":[{}]}}"#,
            (0..32)
                .map(|index| format!(r#""error-{index}""#))
                .collect::<Vec<_>>()
                .join(",")
        );

        let envelope: super::ErrorEnvelope =
            serde_json::from_str(&json).unwrap_or_else(|error| panic!("{error}"));
        assert_eq!(envelope.errors.len(), 16);
        assert_eq!(envelope.errors[15], "error-15");
    }

    #[test]
    fn response_warnings_are_bounded() {
        let mut warnings = Vec::new();
        for index in 0..=super::MAX_RESPONSE_STRINGS {
            warnings.push(format!("warning-{index}"));
        }
        let value = serde_json::json!({ "data": "ok", "warnings": warnings });
        let error = match serde_json::from_value::<ResponseEnvelope<String>>(value) {
            Ok(_) => panic!("oversized warning list unexpectedly decoded"),
            Err(error) => error,
        };
        assert!(error.to_string().contains("exceeds item limit"));
    }

    #[test]
    fn bounded_string_list_is_public_list_wrapper() {
        let list: BoundedStringList =
            serde_json::from_str(r#"["alpha","beta"]"#).unwrap_or_else(|error| panic!("{error}"));

        assert_eq!(list.entries(), ["alpha", "beta"]);
        assert!(list.contains("beta"));
        assert_eq!(list.into_vec(), ["alpha".to_owned(), "beta".to_owned()]);

        let mut values = Vec::new();
        for index in 0..=super::MAX_RESPONSE_STRINGS {
            values.push(format!("value-{index}"));
        }
        assert!(BoundedStringList::try_new(values).is_err());
    }

    #[test]
    fn list_page_options_validate_and_build_query() {
        let options = ListPageOptions::new()
            .after("team/app")
            .unwrap_or_else(|error| panic!("{error}"))
            .limit(10)
            .unwrap_or_else(|error| panic!("{error}"));
        assert_eq!(options.after_cursor(), Some("team/app"));
        assert_eq!(options.limit_value(), Some(10));
        assert_eq!(
            options.query_pairs(),
            vec![("after", "team/app".to_owned()), ("limit", "10".to_owned())]
        );

        assert!(ListPageOptions::new().after("../secret").is_err());
        assert!(ListPageOptions::new().after("").is_err());
        assert!(ListPageOptions::new().limit(0).is_err());
        assert!(
            ListPageOptions::new()
                .limit(super::MAX_RESPONSE_STRINGS as u64 + 1)
                .is_err()
        );
    }

    #[test]
    #[cfg(all(feature = "kv2", feature = "ssh", feature = "sys"))]
    fn list_entries_trait_covers_common_primary_fields() {
        let kv = crate::secrets::kv2::Kv2List {
            keys: vec!["app/".to_owned(), "db".to_owned()],
        };
        let ssh = crate::secrets::ssh::SshRoleList {
            roles: vec!["admin".to_owned()],
        };
        let policies = crate::sys::PolicyList {
            policies: vec!["default".to_owned()],
        };

        assert_eq!(kv.len(), 2);
        assert!(kv.contains("db"));
        assert_eq!(ssh.entries(), ["admin"]);
        assert_eq!(policies.iter().next().map(String::as_str), Some("default"));
    }
}