oharness-core 0.1.0

//! Event schema (§4.7). The JSONL format is the source of truth for trajectory files.

use crate::capabilities::LlmCapabilities;
use crate::completion::{CompletionRequest, CompletionResponse, StopReason, Usage};
use crate::context::NamespaceError;
use crate::ids::{RunId, SpanId};
use crate::task::Task;
use crate::MetadataMap;
use serde::{Deserialize, Serialize};
use serde_json::Value;
use time::OffsetDateTime;

/// Semver-tagged schema version. Additive changes bump minor; breaking changes bump
/// major (and become v2+). See §19.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct SchemaVersion {
    pub major: u16,
    pub minor: u16,
}

impl SchemaVersion {
    pub const CURRENT: SchemaVersion = SchemaVersion { major: 1, minor: 0 };
}

impl std::fmt::Display for SchemaVersion {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{}.{}", self.major, self.minor)
    }
}

impl Serialize for SchemaVersion {
    fn serialize<S: serde::Serializer>(&self, s: S) -> Result<S::Ok, S::Error> {
        s.serialize_str(&self.to_string())
    }
}

impl<'de> Deserialize<'de> for SchemaVersion {
    fn deserialize<D: serde::Deserializer<'de>>(d: D) -> Result<Self, D::Error> {
        let s = String::deserialize(d)?;
        let (maj, min) = s
            .split_once('.')
            .ok_or_else(|| serde::de::Error::custom("schema version must be `MAJOR.MINOR`"))?;
        let major = maj.parse().map_err(serde::de::Error::custom)?;
        let minor = min.parse().map_err(serde::de::Error::custom)?;
        Ok(SchemaVersion { major, minor })
    }
}

#[cfg(feature = "schemars-export")]
impl schemars::JsonSchema for SchemaVersion {
    fn schema_name() -> String {
        "SchemaVersion".into()
    }
    fn json_schema(_: &mut schemars::r#gen::SchemaGenerator) -> schemars::schema::Schema {
        // Serialized as "MAJOR.MINOR" (see Serialize / Deserialize
        // above). Pin the pattern so schema consumers reject malformed
        // values rather than accepting any string.
        schemars::schema::SchemaObject {
            instance_type: Some(schemars::schema::InstanceType::String.into()),
            string: Some(Box::new(schemars::schema::StringValidation {
                pattern: Some(r"^\d+\.\d+$".into()),
                ..Default::default()
            })),
            ..Default::default()
        }
        .into()
    }
}

/// Top-level event envelope. Every event — lifecycle, LLM, tool, memory, etc. — is
/// wrapped in this struct. Spans are represented by two events sharing a `span_id`.
#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct Event {
    pub v: SchemaVersion,
    pub seq: u64,
    pub run_id: RunId,
    #[serde(
        default,
        skip_serializing_if = "Option::is_none",
        with = "time::serde::rfc3339::option"
    )]
    #[cfg_attr(feature = "schemars-export", schemars(with = "Option<String>"))]
    pub timestamp: Option<OffsetDateTime>,
    pub span_id: SpanId,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub parent: Option<u64>,
    /// Flattens `type` and `payload` fields into the envelope. Unknown types deserialize
    /// as `EventKind::Unknown` carrying the raw payload — a forward-compat contract.
    #[serde(flatten)]
    pub kind: EventKind,
    #[serde(default, skip_serializing_if = "Vec::is_empty")]
    pub redactions: Vec<String>,
}

impl Event {
    pub fn new(seq: u64, run_id: RunId, span_id: impl Into<SpanId>, kind: EventKind) -> Self {
        Self {
            v: SchemaVersion::CURRENT,
            seq,
            run_id,
            timestamp: Some(OffsetDateTime::now_utc()),
            span_id: span_id.into(),
            parent: None,
            kind,
            redactions: Vec::new(),
        }
    }

    pub fn with_parent(mut self, parent: u64) -> Self {
        self.parent = Some(parent);
        self
    }
}

/// Discriminated event catalog. `type` field is the serde tag; `payload` holds the
/// variant's data. New variants are additive per schema versioning rules.
#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
#[serde(tag = "type", content = "payload", rename_all = "snake_case")]
#[non_exhaustive]
pub enum EventKind {
    #[serde(rename = "meta")]
    Meta(MetaPayload),

    #[serde(rename = "run.started")]
    RunStarted(RunStartedPayload),
    #[serde(rename = "run.finished")]
    RunFinished(RunFinishedPayload),

    #[serde(rename = "turn.started")]
    TurnStarted(TurnPayload),
    #[serde(rename = "turn.finished")]
    TurnFinished(TurnFinishedPayload),
    #[serde(rename = "turn.revised")]
    TurnRevised(TurnRevisedPayload),

    #[serde(rename = "llm.request")]
    LlmRequest(LlmRequestPayload),
    #[serde(rename = "llm.response")]
    LlmResponse(LlmResponsePayload),
    #[serde(rename = "llm.stream.chunk")]
    LlmStreamChunk(Value),
    #[serde(rename = "llm.retry")]
    LlmRetry(LlmRetryPayload),
    #[serde(rename = "llm.failed")]
    LlmFailed(LlmFailedPayload),

    #[serde(rename = "tool.call.started")]
    ToolCallStarted(ToolCallStartedPayload),
    #[serde(rename = "tool.call.finished")]
    ToolCallFinished(ToolCallFinishedPayload),
    #[serde(rename = "tool.call.failed")]
    ToolCallFailed(ToolCallFailedPayload),
    #[serde(rename = "tool.approval.requested")]
    ToolApprovalRequested(Value),
    #[serde(rename = "tool.approval.decided")]
    ToolApprovalDecided(Value),

    #[serde(rename = "memory.evicted")]
    MemoryEvicted(Value),
    #[serde(rename = "memory.summarized")]
    MemorySummarized(Value),
    #[serde(rename = "memory.retrieved")]
    MemoryRetrieved(Value),

    #[serde(rename = "budget.exceeded")]
    BudgetExceeded(Value),

    #[serde(rename = "policy.input.checked")]
    PolicyInputChecked(Value),
    #[serde(rename = "policy.output.checked")]
    PolicyOutputChecked(Value),
    #[serde(rename = "policy.blocked")]
    PolicyBlocked(Value),

    #[serde(rename = "planner.proposed")]
    PlannerProposed(Value),
    #[serde(rename = "planner.revised")]
    PlannerRevised(Value),
    #[serde(rename = "planner.committed")]
    PlannerCommitted(Value),

    #[serde(rename = "critic.assessed")]
    CriticAssessed(Value),
    #[serde(rename = "critic.rejected")]
    CriticRejected(Value),
    #[serde(rename = "critic.revised")]
    CriticRevised(Value),
    #[serde(rename = "critic.failed")]
    CriticFailed(Value),

    #[serde(rename = "reflection.generated")]
    ReflectionGenerated(Value),
    #[serde(rename = "reflection.injected")]
    ReflectionInjected(Value),

    #[serde(rename = "human.interrupt")]
    HumanInterrupt(Value),
    #[serde(rename = "human.inject")]
    HumanInject(Value),

    #[serde(rename = "user.simulated.message")]
    UserSimulatedMessage(Value),
    #[serde(rename = "user.simulated.ended")]
    UserSimulatedEnded(Value),

    /// Escape hatch for user-defined events. Namespace MUST NOT start with a built-in
    /// category prefix. Construct via `EventKind::user_log`.
    #[serde(rename = "user.log")]
    UserLog(UserLogPayload),

    /// Forward-compat fallback: unknown event type preserved verbatim.
    #[serde(other)]
    Unknown,
}

/// Namespaces reserved for built-in categories — `user.log` namespaces may not collide.
pub const RESERVED_NAMESPACE_PREFIXES: &[&str] = &[
    "run.",
    "turn.",
    "llm.",
    "tool.",
    "memory.",
    "budget.",
    "policy.",
    "planner.",
    "critic.",
    "reflection.",
    "human.",
    "user.simulated.",
    "meta.",
];

impl EventKind {
    /// Construct a `user.log` event. Returns an error if the namespace is empty or
    /// collides with a built-in category prefix.
    pub fn user_log(namespace: impl Into<String>, data: Value) -> Result<Self, NamespaceError> {
        let namespace = namespace.into();
        if namespace.is_empty() {
            return Err(NamespaceError::Empty);
        }
        // A namespace collides if it equals or is prefixed by a reserved category.
        for reserved in RESERVED_NAMESPACE_PREFIXES {
            let bare = reserved.trim_end_matches('.');
            if namespace == bare || namespace.starts_with(reserved) {
                return Err(NamespaceError::BuiltinCollision(namespace));
            }
        }
        Ok(EventKind::UserLog(UserLogPayload { namespace, data }))
    }
}

// -- payload structs ----------------------------------------------------------

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct MetaPayload {
    pub schema_version: SchemaVersion,
    pub harness_version: String,
    pub task_snapshot: Task,
    pub llm_capabilities: LlmCapabilities,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct RunStartedPayload {
    #[serde(default, skip_serializing_if = "MetadataMap::is_empty")]
    pub extra: MetadataMap,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct RunFinishedPayload {
    pub termination: String,
    pub turns: u32,
    pub tool_calls: u32,
    #[serde(default, skip_serializing_if = "MetadataMap::is_empty")]
    pub extra: MetadataMap,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct TurnPayload {
    pub turn_index: u32,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct TurnFinishedPayload {
    pub turn_index: u32,
    pub stop_reason: StopReason,
    pub usage: Usage,
    pub tool_calls: u32,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct TurnRevisedPayload {
    pub original_seq: u64,
    pub replacement_seq: u64,
    pub reason: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct LlmRequestPayload {
    pub request: CompletionRequest,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub provider: Option<String>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct LlmResponsePayload {
    pub response: CompletionResponse,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct LlmRetryPayload {
    pub attempt: u32,
    pub reason: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct LlmFailedPayload {
    pub reason: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct ToolCallStartedPayload {
    pub tool_name: String,
    pub tool_use_id: String,
    pub input: Value,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct ToolCallFinishedPayload {
    pub tool_name: String,
    pub tool_use_id: String,
    pub output: Value,
    #[serde(default)]
    pub truncated: bool,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct ToolCallFailedPayload {
    pub tool_name: String,
    pub tool_use_id: String,
    pub reason: String,
    #[serde(default)]
    pub recoverable: bool,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[cfg_attr(feature = "schemars-export", derive(schemars::JsonSchema))]
pub struct UserLogPayload {
    pub namespace: String,
    #[serde(flatten)]
    pub data: Value,
}

/// Shim alias so callers that want to pattern-match on `EventPayload::X` can import
/// the payload types through one re-export. (Not strictly needed; kept for ergonomics.)
pub type EventPayload = Value;

/// Errors encountered constructing events (currently: namespace collisions).
pub type EventConstructionError = NamespaceError;

#[cfg(test)]
mod tests {
    use super::*;
    use crate::ids::ModelId;
    use crate::message::{Content, Message};
    use serde_json::json;

    fn sample_request() -> CompletionRequest {
        CompletionRequest {
            messages: vec![Message::Assistant {
                content: vec![
                    Content::text("Let me look around."),
                    Content::ToolUse {
                        id: "tu_1".into(),
                        name: "fs_list".into(),
                        input: json!({"path": "."}),
                    },
                ],
                stop_reason: Some(StopReason::ToolUse),
                meta: MetadataMap::new(),
            }],
            tools: Vec::new(),
            system: None,
            max_tokens: Some(1024),
            temperature: None,
            stop_sequences: Vec::new(),
            cache_hints: Default::default(),
            extensions: MetadataMap::new(),
        }
    }

    #[test]
    fn llm_request_event_round_trips_through_jsonl() {
        let req = sample_request();
        let event = Event::new(
            42,
            RunId::new(),
            SpanId::from("span_1"),
            EventKind::LlmRequest(LlmRequestPayload {
                request: req,
                provider: Some("anthropic".into()),
            }),
        );
        let bytes = serde_json::to_vec(&event).expect("serialize");
        let back: Event = serde_json::from_slice(&bytes).expect("deserialize");
        assert_eq!(back.seq, 42);
        match back.kind {
            EventKind::LlmRequest(p) => {
                assert_eq!(p.provider.as_deref(), Some("anthropic"));
                assert_eq!(p.request.messages.len(), 1);
            }
            other => panic!("expected LlmRequest, got {other:?}"),
        }
    }

    #[test]
    fn llm_response_event_round_trips_through_jsonl() {
        let response = CompletionResponse {
            id: "msg_1".into(),
            model: ModelId::new("claude-sonnet-4-5"),
            content: vec![Content::text("Hello world")],
            stop_reason: StopReason::EndTurn,
            usage: Usage {
                tokens_input: 25,
                tokens_output: 15,
                ..Default::default()
            },
        };
        let event = Event::new(
            7,
            RunId::new(),
            SpanId::from("span_2"),
            EventKind::LlmResponse(LlmResponsePayload { response }),
        );
        let bytes = serde_json::to_vec(&event).expect("serialize");
        let back: Event = serde_json::from_slice(&bytes).expect("deserialize");
        match back.kind {
            EventKind::LlmResponse(p) => {
                assert_eq!(p.response.id, "msg_1");
                assert_eq!(p.response.content.len(), 1);
                assert!(matches!(
                    &p.response.content[0],
                    Content::Text { text } if text == "Hello world"
                ));
            }
            other => panic!("expected LlmResponse, got {other:?}"),
        }
    }
}