// hippocampus — memory storage, retrieval, and consolidation
//
// The graph-structured memory system: nodes, relations, queries,
// similarity scoring, spectral analysis, and neuroscience-inspired
// consolidation (spaced repetition, interference detection, schema
// assimilation).
//
// Tool implementations are typed functions that take &Store or &mut Store.
// The tools/memory.rs layer handles JSON parsing and RPC routing.

pub mod memory;
pub mod store;
pub mod graph;
pub mod local;
pub mod lookups;
pub mod query;
pub mod spectral;
pub mod neuro;
pub mod counters;
pub mod transcript;

use std::cell::RefCell;
use std::path::PathBuf;
use std::sync::{Arc, OnceLock};
use anyhow::{Context, Result};
use crate::hippocampus::store::Store;

pub use local::{LinkInfo, JournalEntry};

// ── Store access ───────────────────────────────────────────────

/// Daemon's store (eager init) or client's fallback local store.
static STORE_ACCESS: OnceLock<Option<Arc<crate::Mutex<Store>>>> = OnceLock::new();

// Client's socket connection (thread-local for lock-free access).
thread_local! {
    static SOCKET_CONN: RefCell<Option<SocketConn>> = const { RefCell::new(None) };
}

/// How we access the memory store.
pub enum StoreAccess {
    Daemon(Arc<crate::Mutex<Store>>),  // Direct store access
    Client,                             // Socket to daemon (in thread-local)
    None(String),                       // Error: couldn't get access
}

/// Set the global store handle. Call once at daemon startup (eager init).
pub fn set_store(store: Arc<crate::Mutex<Store>>) {
    STORE_ACCESS.set(Some(store)).ok();
}

/// Get store access: daemon's store, socket, or local fallback.
pub fn access() -> StoreAccess {
    // Daemon: already set via set_store()
    if let Some(Some(store)) = STORE_ACCESS.get() {
        return StoreAccess::Daemon(store.clone());
    }

    // Client: check if socket already cached in thread-local
    let have_socket = SOCKET_CONN.with(|cell| cell.borrow().is_some());
    if have_socket {
        return StoreAccess::Client;
    }

    // No socket cached, try connecting
    if let Ok(conn) = SocketConn::connect() {
        SOCKET_CONN.with(|cell| *cell.borrow_mut() = Some(conn));
        return StoreAccess::Client;
    }

    // Socket failed - try local store as fallback (cached in STORE_ACCESS)
    let store_opt = STORE_ACCESS.get_or_init(|| {
        Store::load().ok().map(|s| Arc::new(crate::Mutex::new(s)))
    });

    match store_opt {
        Some(store) => StoreAccess::Daemon(store.clone()),
        None => StoreAccess::None("could not connect to daemon or open store locally".into()),
    }
}

pub fn socket_path() -> PathBuf {
    dirs::home_dir()
        .unwrap_or_default()
        .join(".consciousness/mcp.sock")
}

struct SocketConn {
    reader: std::io::BufReader<std::os::unix::net::UnixStream>,
    writer: std::io::BufWriter<std::os::unix::net::UnixStream>,
    next_id: u64,
}

impl SocketConn {
    fn connect() -> Result<Self> {
        use std::os::unix::net::UnixStream;
        use std::io::{BufRead, BufReader, BufWriter, Write};

        let path = socket_path();
        let stream = UnixStream::connect(&path)?;
        let mut reader = BufReader::new(stream.try_clone()?);
        let mut writer = BufWriter::new(stream);

        // Initialize MCP connection
        let init = serde_json::json!({"jsonrpc": "2.0", "id": 1, "method": "initialize",
            "params": {"protocolVersion": "2024-11-05", "capabilities": {},
                       "clientInfo": {"name": "forward", "version": "0.1"}}});
        writeln!(writer, "{}", init)?;
        writer.flush()?;
        let mut buf = String::new();
        reader.read_line(&mut buf)?;

        Ok(Self { reader, writer, next_id: 1 })
    }

    fn call(&mut self, tool_name: &str, args: &serde_json::Value) -> Result<String> {
        use std::io::{BufRead, Write};

        self.next_id += 1;
        let call = serde_json::json!({"jsonrpc": "2.0", "id": self.next_id, "method": "tools/call",
            "params": {"name": tool_name, "arguments": args}});
        writeln!(self.writer, "{}", call)?;
        self.writer.flush()?;

        let mut buf = String::new();
        self.reader.read_line(&mut buf)?;

        let resp: serde_json::Value = serde_json::from_str(&buf)?;
        if let Some(err) = resp.get("error") {
            anyhow::bail!("daemon error: {}", err);
        }
        let result = resp.get("result").cloned().unwrap_or(serde_json::json!({}));
        let text = result.get("content")
            .and_then(|c| c.as_array())
            .and_then(|arr| arr.first())
            .and_then(|c| c.get("text"))
            .and_then(|t| t.as_str())
            .unwrap_or("");
        Ok(text.to_string())
    }
}

/// Forward a tool call to the daemon via socket.
/// Only valid when access() returns Client.
pub fn memory_rpc(tool_name: &str, args: serde_json::Value) -> Result<String> {
    SOCKET_CONN.with(|cell| {
        let mut conn = cell.borrow_mut();
        let conn = conn.as_mut().expect("access() returned Client but SOCKET_CONN is None");
        conn.call(tool_name, &args)
    })
}

// ── Helpers ────────────────────────────────────────────────────

fn get_str<'a>(args: &'a serde_json::Value, name: &'a str) -> Result<&'a str> {
    args.get(name).and_then(|v| v.as_str()).context(format!("{} is required", name))
}

fn get_f64(args: &serde_json::Value, name: &str) -> Result<f64> {
    args.get(name).and_then(|v| v.as_f64()).context(format!("{} is required", name))
}

/// Get provenance from agent state, or "manual".
async fn get_provenance(agent: &Option<std::sync::Arc<crate::agent::Agent>>) -> String {
    match agent {
        Some(a) => a.state.lock().await.provenance.clone(),
        None => "manual".to_string(),
    }
}

// ── Macro for generating tool wrappers ─────────────────────────
//
// memory_tool!(name, mut, arg1: [str], arg2: [Option<bool>])
//   - mut/ref for store mutability
//   - generates jsonargs_* (internal, JSON args) and public typed API

macro_rules! memory_tool {
    // ── Helper rules (must come first) ─────────────────────────────

    // Extract from JSON
    (@extract $args:ident, $name:ident, str) => {
        get_str($args, stringify!($name))?
    };
    (@extract $args:ident, $name:ident, f32) => {
        get_f64($args, stringify!($name))? as f32
    };
    (@extract $args:ident, $name:ident, Vec<String>) => {
        $args.get(stringify!($name))
            .and_then(|v| v.as_array())
            .map(|arr| arr.iter().filter_map(|v| v.as_str().map(String::from)).collect::<Vec<_>>())
            .unwrap_or_default()
    };
    (@extract $args:ident, $name:ident, Option<&str>) => {
        $args.get(stringify!($name)).and_then(|v| v.as_str())
    };
    (@extract $args:ident, $name:ident, Option<bool>) => {
        $args.get(stringify!($name)).and_then(|v| v.as_bool())
    };
    (@extract $args:ident, $name:ident, Option<u64>) => {
        $args.get(stringify!($name)).and_then(|v| v.as_u64())
    };
    (@extract $args:ident, $name:ident, Option<i64>) => {
        $args.get(stringify!($name)).and_then(|v| v.as_i64())
    };
    (@extract $args:ident, $name:ident, Option<usize>) => {
        $args.get(stringify!($name)).and_then(|v| v.as_u64()).map(|v| v as usize)
    };
    (@extract $args:ident, $name:ident, Option<u32>) => {
        $args.get(stringify!($name)).and_then(|v| v.as_u64()).map(|v| v as u32)
    };
    (@extract $args:ident, $name:ident, Option<f64>) => {
        $args.get(stringify!($name)).and_then(|v| v.as_f64())
    };

    // Parameter types for function signatures
    (@param_type str) => { &str };
    (@param_type f32) => { f32 };
    (@param_type Vec<String>) => { Vec<String> };
    (@param_type Option<&str>) => { Option<&str> };
    (@param_type Option<bool>) => { Option<bool> };
    (@param_type Option<u64>) => { Option<u64> };
    (@param_type Option<i64>) => { Option<i64> };
    (@param_type Option<usize>) => { Option<usize> };
    (@param_type Option<u32>) => { Option<u32> };
    (@param_type Option<f64>) => { Option<f64> };

    // Serialize result for jsonargs
    (@serialize $t:ty, $result:expr) => { serde_json::to_string(&$result)? };

    // Deserialize RPC response
    (@deserialize $t:ty, $json:expr) => { serde_json::from_str(&$json).map_err(|e| anyhow::anyhow!("{}", e)) };

    // Serialize to JSON for RPC
    (@insert_json $map:ident, $name:ident, str) => {
        $map.insert(stringify!($name).into(), serde_json::json!($name));
    };
    (@insert_json $map:ident, $name:ident, f32) => {
        $map.insert(stringify!($name).into(), serde_json::json!($name));
    };
    (@insert_json $map:ident, $name:ident, Vec<String>) => {
        $map.insert(stringify!($name).into(), serde_json::json!($name));
    };
    (@insert_json $map:ident, $name:ident, Option<&str>) => {
        if let Some(v) = $name { $map.insert(stringify!($name).into(), serde_json::json!(v)); }
    };
    (@insert_json $map:ident, $name:ident, Option<bool>) => {
        if let Some(v) = $name { $map.insert(stringify!($name).into(), serde_json::json!(v)); }
    };
    (@insert_json $map:ident, $name:ident, Option<u64>) => {
        if let Some(v) = $name { $map.insert(stringify!($name).into(), serde_json::json!(v)); }
    };
    (@insert_json $map:ident, $name:ident, Option<i64>) => {
        if let Some(v) = $name { $map.insert(stringify!($name).into(), serde_json::json!(v)); }
    };
    (@insert_json $map:ident, $name:ident, Option<usize>) => {
        if let Some(v) = $name { $map.insert(stringify!($name).into(), serde_json::json!(v)); }
    };
    (@insert_json $map:ident, $name:ident, Option<u32>) => {
        if let Some(v) = $name { $map.insert(stringify!($name).into(), serde_json::json!(v)); }
    };
    (@insert_json $map:ident, $name:ident, Option<f64>) => {
        if let Some(v) = $name { $map.insert(stringify!($name).into(), serde_json::json!(v)); }
    };

    // Call hippocampus with appropriate mutability
    (@call mut, $name:ident, $store:ident, $prov:expr $(, $arg:expr)*) => {
        local::$name(&mut $store, $prov $(, $arg)*)
    };
    (@call ref, $name:ident, $store:ident, $prov:expr $(, $arg:expr)*) => {
        local::$name(&$store, $prov $(, $arg)*)
    };

    // ── Main rules ─────────────────────────────────────────────────

    // Shorthand: mut/ref without return type defaults to String
    ($name:ident, $m:ident $(, $($arg:ident : [$($typ:tt)+]),* $(,)?)?) => {
        memory_tool!($name, $m -> String $(, $($arg : [$($typ)+]),*)?);
    };

    // Full form with return type
    ($name:ident, $m:ident -> $ret:ty $(, $($arg:ident : [$($typ:tt)+]),* $(,)?)?) => {
        paste::paste! {
            pub async fn $name(agent: Option<&crate::agent::Agent> $($(, $arg: memory_tool!(@param_type $($typ)+))*)?) -> Result<$ret> {
                let prov = match agent {
                    Some(a) => a.state.lock().await.provenance.clone(),
                    None => "manual".to_string(),
                };

                match access() {
                    StoreAccess::Daemon(arc) => {
                        #[allow(unused_mut)]
                        let mut store = arc.lock().await;
                        memory_tool!(@call $m, $name, store, &prov $($(, $arg)*)?)
                    }
                    StoreAccess::Client => {
                        #[allow(unused_mut)]
                        let mut map = serde_json::Map::new();
                        $($(memory_tool!(@insert_json map, $arg, $($typ)+);)*)?
                        let json = memory_rpc(stringify!($name), serde_json::Value::Object(map))?;
                        memory_tool!(@deserialize $ret, json)
                    }
                    StoreAccess::None(err) => anyhow::bail!("{}", err),
                }
            }
        }
    };
}

// ── Memory tools ───────────────────────────────────────────────

memory_tool!(memory_render, ref, key: [str], raw: [Option<bool>]);
memory_tool!(memory_write, mut, key: [str], content: [str]);
memory_tool!(memory_search, ref, keys: [Vec<String>], max_hops: [Option<u32>], edge_decay: [Option<f64>], min_activation: [Option<f64>], limit: [Option<usize>]);
memory_tool!(memory_link_set, mut, source: [str], target: [str], strength: [f32]);
memory_tool!(memory_link_add, mut, source: [str], target: [str]);
memory_tool!(memory_delete, mut, key: [str]);
memory_tool!(memory_history, ref, key: [str], full: [Option<bool>]);
memory_tool!(memory_weight_set, mut, key: [str], weight: [f32]);
memory_tool!(memory_rename, mut, old_key: [str], new_key: [str]);
memory_tool!(memory_supersede, mut, old_key: [str], new_key: [str], reason: [Option<&str>]);
memory_tool!(memory_query, ref, query: [str], format: [Option<&str>]);
memory_tool!(memory_links, ref -> Vec<LinkInfo>, key: [str]);

// ── Journal tools ──────────────────────────────────────────────

memory_tool!(journal_tail, ref -> Vec<JournalEntry>, count: [Option<u64>], level: [Option<u64>], after: [Option<&str>]);
memory_tool!(journal_new, mut, name: [str], title: [str], body: [str], level: [Option<i64>]);
memory_tool!(journal_update, mut, body: [str], level: [Option<i64>]);

// ── Graph tools ───────────────────────────────────────────────

memory_tool!(graph_topology, ref);
memory_tool!(graph_health, ref);
memory_tool!(graph_communities, ref, top_n: [Option<usize>], min_size: [Option<usize>]);
memory_tool!(graph_normalize_strengths, mut, apply: [Option<bool>]);
memory_tool!(graph_link_impact, ref, source: [str], target: [str]);
memory_tool!(graph_hubs, ref, count: [Option<usize>]);
memory_tool!(graph_trace, ref, key: [str]);