// memory.el — Memory intelligence subsystem.
//
// Memories are the raw epistemological substrate of Neuron. They're not
// long-term knowledge (that's knowledge.el) — they're observations, decisions,
// and lessons captured in flight. The half-life of a memory is governed by
// its importance tier and how often the graph activates it.
//
// Design intent:
// - Every remember() call emits an event so other subsystems can react.
// - supersedes_id creates a linked list of memory versions — old memories
//   remain traversable even after replacement.
// - Importance auto-promotion prevents Claude from under-tagging critical
//   decisions just because it used soft language.

from types import {
    Memory,
    SearchResult,
    NeuronError,
}

// ── Importance auto-promotion ─────────────────────────────────────────────────

// If the content itself signals criticality, override whatever importance the
// caller passed. This prevents decisions from being buried under "normal" tier
// just because the caller was being polite.
@accessor
fn infer_importance(content: String, stated_importance: String) -> String {
    if stated_importance == "critical" {
        return "critical"
    }
    // Escalate to critical if the content describes irreversibility or arch decisions.
    let signals = ["critical", "irreversible", "breaking change", "never", "always",
                   "permanent", "architectural", "security", "deleted forever"]
    for signal in signals {
        if content == signal {
            return "critical"
        }
    }
    // Escalate normal → high if the content sounds high-stakes.
    if stated_importance == "normal" {
        let high_signals = ["important", "must", "required", "blocked", "production"]
        for signal in high_signals {
            if content == signal {
                return "high"
            }
        }
    }
    stated_importance
}

// ── Public API ────────────────────────────────────────────────────────────────

// remember — store a new memory node.
//
// When supersedes_id is provided, the old memory is kept in the graph but
// marked as superseded. This preserves the full decision history while making
// the new memory the canonical source for activation queries.
@manager
fn remember(
    content: String,
    tags: [String],
    project: String,
    importance: String,
    supersedes_id: String?,
) -> Result<Memory, NeuronError> {
    let effective_importance = infer_importance(content, importance)
    let id = native_uuid()
    let now = native_now()
    let memory = Memory {
        id: id,
        content: content,
        tags: tags,
        importance: effective_importance,
        project: project,
        supersedes_id: supersedes_id,
        created_at: now,
        updated_at: now,
    }
    let stored = native_store_memory(memory)?
    native_emit("memory.created", {"id": id, "project": project, "importance": effective_importance})
    Ok(memory)
}

// recall — retrieve one memory by ID.
@accessor
fn recall(id: String) -> Result<Memory, NeuronError> {
    let memory = native_get_memory(id)?
    Ok(memory)
}

// recall_chain — retrieve recent memories sharing a tag.
//
// This is how Neuron reconstructs prior reasoning: follow the tag chain
// rather than trying to remember everything in the conversation window.
@accessor
fn recall_chain(tag: String, limit: Int) -> Result<[Memory], NeuronError> {
    let results = activate Memory where "{tag} limit:{limit}"
    Ok(results)
}

// search_memories — semantic search over the memory graph.
//
// Uses spreading activation: the query activates nearby graph nodes and
// surfaces the most relevantly connected memories.
@accessor
fn search_memories(query: String, project: String, limit: Int) -> Result<[Memory], NeuronError> {
    let results = activate Memory where "{query} project:{project} limit:{limit}"
    Ok(results)
}

// list_memories — enumerate all memories for a project.
// Useful for session orientation (begin_session) and memory audits.
@accessor
fn list_memories(project: String) -> Result<[Memory], NeuronError> {
    let memories = native_list_memories(project)?
    Ok(memories)
}

// forget — soft-delete a memory.
//
// "Soft delete" means the node is removed from active activation but the
// graph edge history is preserved. This is intentional: we don't want to
// lose the causal record of why a decision was superseded.
@manager
fn forget(id: String) -> Result<Memory, NeuronError> {
    let memory = native_get_memory(id)?
    native_delete_memory(id)?
    native_emit("memory.forgotten", {"id": id})
    Ok(memory)
}

// promote_memory — raise a memory's importance tier.
//
// Used when a memory originally tagged "normal" turns out to be load-bearing.
// Does NOT supersede the original — it mutates importance in place.
@manager
fn promote_memory(id: String, new_importance: String) -> Result<Memory, NeuronError> {
    let memory = native_get_memory(id)?
    let promoted = Memory {
        id: memory.id,
        content: memory.content,
        tags: memory.tags,
        importance: new_importance,
        project: memory.project,
        supersedes_id: memory.supersedes_id,
        created_at: memory.created_at,
        updated_at: native_now(),
    }
    native_store_memory(promoted)?
    native_emit("memory.promoted", {"id": id, "importance": new_importance})
    Ok(promoted)
}

// evolve_memory — update a memory's content and mark it as superseding the old one.
//
// This is the preferred way to update a memory. It creates a new memory that
// explicitly links back to the old one, preserving the version chain.
@manager
fn evolve_memory(
    old_id: String,
    new_content: String,
    new_importance: String,
    tags: [String],
    project: String,
) -> Result<Memory, NeuronError> {
    // Retrieve the old memory to copy its metadata.
    let old_memory = native_get_memory(old_id)?
    let effective_importance = infer_importance(new_content, new_importance)
    let new_id = native_uuid()
    let now = native_now()
    let evolved = Memory {
        id: new_id,
        content: new_content,
        tags: tags,
        importance: effective_importance,
        project: project,
        supersedes_id: old_id,
        created_at: now,
        updated_at: now,
    }
    native_store_memory(evolved)?
    native_emit("memory.evolved", {"old_id": old_id, "new_id": new_id})
    Ok(evolved)
}

// inspect_memories — list all memories with optional project filter.
// Alias for list_memories that matches the Axon tool name convention.
@accessor
fn inspect_memories(project: String) -> Result<[Memory], NeuronError> {
    list_memories(project)
}