magellan 3.2.0

//! Call node operations for CodeGraph
//!
//! Handles call node CRUD operations and CALLS/CALLER edge management.

use anyhow::Result;
use sqlitegraph::{
    BackendDirection, EdgeSpec, GraphBackend, NeighborQuery, NodeId, NodeSpec, SnapshotId,
};
use std::collections::HashMap;
use std::path::PathBuf;
use std::sync::Arc;

use crate::graph::schema::CallNode;
use crate::ingest::c::CParser;
use crate::ingest::cpp::CppParser;
use crate::ingest::java::JavaParser;
use crate::ingest::javascript::JavaScriptParser;
use crate::ingest::pool;
use crate::ingest::python::PythonParser;
use crate::ingest::typescript::TypeScriptParser;
use crate::ingest::{detect::Language, detect_language, Parser, SymbolFact, SymbolKind};
use crate::references::CallFact;

/// Call operations for CodeGraph
pub struct CallOps {
    pub backend: Arc<dyn GraphBackend>,
}

impl CallOps {
    /// Delete all Call nodes that belong to a specific file path.
    ///
    /// Determinism: collects candidate entity IDs, sorts ascending, deletes in that order.
    pub fn delete_calls_in_file(&self, path: &str) -> Result<usize> {
        let entity_ids = self.backend.entity_ids()?;

        let mut to_delete: Vec<i64> = Vec::new();
        for entity_id in entity_ids {
            let snapshot = SnapshotId::current();
            let node = match self.backend.get_node(snapshot, entity_id) {
                Ok(n) => n,
                Err(_) => continue,
            };

            if node.kind != "Call" {
                continue;
            }

            let call_node: CallNode = match serde_json::from_value(node.data) {
                Ok(value) => value,
                Err(_) => continue,
            };

            if call_node.file == path {
                to_delete.push(entity_id);
            }
        }

        to_delete.sort_unstable();

        for id in &to_delete {
            self.backend.delete_entity(*id)?;
        }

        Ok(to_delete.len())
    }
    /// Index calls for a file into the graph
    ///
    /// # Behavior
    /// 1. Parse symbols from source
    /// 2. Extract function calls (caller → callee)
    /// 3. Insert Call nodes
    /// 4. Create CALLER edges from caller Symbol to Call node
    /// 5. Create CALLS edges from Call node to callee Symbol
    ///
    /// # Arguments
    /// * `path` - File path
    /// * `source` - File contents as bytes
    /// * `symbol_ids` - Map of symbol names to their node IDs (ALL symbols in database)
    pub fn index_calls(
        &self,
        path: &str,
        source: &[u8],
        symbol_ids: &HashMap<String, i64>,
    ) -> Result<usize> {
        let path_buf = PathBuf::from(path);
        let language = detect_language(&path_buf);

        // Build symbol facts from persisted symbols to enable cross-file call matching.
        // This iterates through ALL symbols in the database, not just the current file.
        // Also build stable symbol_id lookup map: (file_path, symbol_name) -> stable_symbol_id
        let mut symbol_facts = Vec::new();
        let mut current_file_facts = Vec::new();
        let mut stable_symbol_ids: HashMap<(String, String), Option<String>> = HashMap::new();

        // Iterate over ALL symbols from all files to enable cross-file call resolution
        for symbol_id in symbol_ids.values() {
            let snapshot = SnapshotId::current();
            let node = match self.backend.get_node(snapshot, *symbol_id) {
                Ok(value) => value,
                Err(_) => continue,
            };

            if node.kind != "Symbol" {
                continue;
            }

            // Extract SymbolNode to get stable symbol_id
            let symbol_node: Option<crate::graph::schema::SymbolNode> =
                serde_json::from_value(node.data.clone()).ok();

            let stable_id = symbol_node.as_ref().and_then(|n| n.symbol_id.clone());

            let symbol_fact = match self.symbol_fact_from_node(&node) {
                Some(value) => value,
                None => continue,
            };

            // Build stable symbol_id lookup key: (file_path, symbol_name)
            if let Some(ref name) = symbol_fact.name {
                let key = (
                    symbol_fact.file_path.to_string_lossy().to_string(),
                    name.clone(),
                );
                stable_symbol_ids.insert(key, stable_id);
            }

            if node.file_path.as_deref() == Some(path) {
                current_file_facts.push(symbol_fact);
            } else {
                // Symbols from other files - enables cross-file call resolution
                symbol_facts.push(symbol_fact);
            }
        }

        // Combine: other files first, then current file
        // Current file symbols are added last to take precedence for same-name symbols
        symbol_facts.extend(current_file_facts);

        // Extract calls using parser pool (was creating fresh parsers per file)
        let calls = match language {
            Some(Language::Rust) => pool::with_parser_opt(Language::Rust, |opt_parser| {
                let parser = opt_parser
                    .take()
                    .expect("Parser pool corruption: parser was None"); // M-UNWRAP: thread-local parser pool guarantees initialized parser
                let mut wrapper = Parser::from_parser(parser);
                let result = wrapper.extract_calls(path_buf.clone(), source, &symbol_facts);
                *opt_parser = Some(wrapper.parser);
                result
            })?,
            Some(Language::Python) => pool::with_parser_opt(Language::Python, |opt_parser| {
                let parser = opt_parser
                    .take()
                    .expect("Parser pool corruption: parser was None"); // M-UNWRAP: thread-local parser pool guarantees initialized parser
                let mut wrapper = PythonParser::from_parser(parser);
                let result = wrapper.extract_calls(path_buf.clone(), source, &symbol_facts);
                *opt_parser = Some(wrapper.parser);
                result
            })?,
            Some(Language::C) => pool::with_parser_opt(Language::C, |opt_parser| {
                let parser = opt_parser
                    .take()
                    .expect("Parser pool corruption: parser was None"); // M-UNWRAP: thread-local parser pool guarantees initialized parser
                let mut wrapper = CParser::from_parser(parser);
                let result = wrapper.extract_calls(path_buf.clone(), source, &symbol_facts);
                *opt_parser = Some(wrapper.parser);
                result
            })?,
            Some(Language::Cpp) => pool::with_parser_opt(Language::Cpp, |opt_parser| {
                let parser = opt_parser
                    .take()
                    .expect("Parser pool corruption: parser was None"); // M-UNWRAP: thread-local parser pool guarantees initialized parser
                let mut wrapper = CppParser::from_parser(parser);
                let result = wrapper.extract_calls(path_buf.clone(), source, &symbol_facts);
                *opt_parser = Some(wrapper.parser);
                result
            })?,
            Some(Language::Java) => pool::with_parser_opt(Language::Java, |opt_parser| {
                let parser = opt_parser
                    .take()
                    .expect("Parser pool corruption: parser was None"); // M-UNWRAP: thread-local parser pool guarantees initialized parser
                let mut wrapper = JavaParser::from_parser(parser);
                let result = wrapper.extract_calls(path_buf.clone(), source, &symbol_facts);
                *opt_parser = Some(wrapper.parser);
                result
            })?,
            Some(Language::JavaScript) => {
                pool::with_parser_opt(Language::JavaScript, |opt_parser| {
                    let parser = opt_parser
                        .take()
                        .expect("Parser pool corruption: parser was None"); // M-UNWRAP: thread-local parser pool guarantees initialized parser
                    let mut wrapper = JavaScriptParser::from_parser(parser);
                    let result = wrapper.extract_calls(path_buf.clone(), source, &symbol_facts);
                    *opt_parser = Some(wrapper.parser);
                    result
                })?
            }
            Some(Language::TypeScript) => {
                pool::with_parser_opt(Language::TypeScript, |opt_parser| {
                    let parser = opt_parser
                        .take()
                        .expect("Parser pool corruption: parser was None"); // M-UNWRAP: thread-local parser pool guarantees initialized parser
                    let mut wrapper = TypeScriptParser::from_parser(parser);
                    let result = wrapper.extract_calls(path_buf.clone(), source, &symbol_facts);
                    *opt_parser = Some(wrapper.parser);
                    result
                })?
            }
            None => Vec::new(),
        };

        let call_count = calls.len();

        // Build a name-only fallback map for cross-file call resolution.
        //
        // After Phase 11 (FQN changes), symbol_ids uses FQNs as keys (e.g., "crate::module::function"),
        // but CallFact uses simple names (e.g., "function"). This enables fallback to simple name
        // matching for cross-file calls where the FQN might not match exactly.
        //
        // For example:
        // - CallFact.callee might be "render" (simple name from widget.render())
        // - Symbol might be stored as "Widget::render" (FQN)
        // - This fallback enables matching "render" to "Widget::render"
        let mut name_to_ids: HashMap<String, Vec<i64>> = HashMap::new();
        for (fqn, &id) in symbol_ids.iter() {
            // Extract simple name from FQN (after last :: or .)
            let simple_name = fqn.split("::").last().unwrap_or(fqn.as_str());
            let simple_name = simple_name.split('.').next_back().unwrap_or(simple_name);
            name_to_ids
                .entry(simple_name.to_string())
                .or_default()
                .push(id);
        }

        // Insert call nodes and edges
        for mut call in calls {
            // Look up stable symbol_ids for caller and callee
            let caller_key = (
                call.file_path.to_string_lossy().to_string(),
                call.caller.clone(),
            );
            let callee_key = (
                call.file_path.to_string_lossy().to_string(),
                call.callee.clone(),
            );

            call.caller_symbol_id = stable_symbol_ids.get(&caller_key).and_then(|id| id.clone());
            call.callee_symbol_id = stable_symbol_ids.get(&callee_key).and_then(|id| id.clone());

            // Resolve callee symbol_id with fallback to simple name
            // This enables cross-file call resolution when:
            // 1. The callee is in a different file
            // 2. The FQN doesn't exactly match (e.g., method calls)
            let callee_symbol_id = symbol_ids.get(&call.callee).or_else(|| {
                // Fallback: try simple name lookup for cross-file calls
                // For method calls like widget.render(), call.callee is "render"
                // but the symbol might be stored as "Widget::render"
                name_to_ids.get(&call.callee).and_then(|ids| ids.first())
            });

            // Resolve caller symbol_id - always in current file, so FQN should work
            let caller_symbol_id = symbol_ids.get(&call.caller);

            // Insert call node regardless of symbol resolution
            let call_id = self.insert_call_node(&call)?;

            // Create CALLER edge if caller symbol found
            if let Some(&caller_id) = caller_symbol_id {
                self.insert_caller_edge(NodeId::from(caller_id), call_id)?;
            }

            // Create CALLS edge if callee symbol found
            if let Some(&callee_id) = callee_symbol_id {
                self.insert_calls_edge(call_id, NodeId::from(callee_id))?;
            }
        }

        Ok(call_count)
    }

    /// Query all calls FROM a specific symbol (forward call graph)
    ///
    /// # Arguments
    /// * `symbol_id` - Node ID of the caller symbol
    ///
    /// # Returns
    /// Vector of CallFact for all calls from this symbol
    pub fn calls_from_symbol(&mut self, symbol_id: i64) -> Result<Vec<CallFact>> {
        // Query outgoing CALLER edges from caller to Call nodes
        let snapshot = SnapshotId::current();
        let neighbor_ids = self.backend.neighbors(
            snapshot,
            symbol_id,
            NeighborQuery {
                direction: BackendDirection::Outgoing,
                edge_type: Some("CALLER".to_string()),
            },
        )?;

        let mut calls = Vec::new();
        for call_node_id in neighbor_ids {
            if let Ok(Some(call)) = self.call_fact_from_node(call_node_id) {
                calls.push(call);
            }
        }

        Ok(calls)
    }

    /// Query all calls TO a specific symbol (reverse call graph)
    ///
    /// # Arguments
    /// * `symbol_id` - Node ID of the callee symbol
    ///
    /// # Returns
    /// Vector of CallFact for all calls to this symbol
    pub fn callers_of_symbol(&mut self, symbol_id: i64) -> Result<Vec<CallFact>> {
        // Query incoming CALLS edges to callee
        let snapshot = SnapshotId::current();
        let neighbor_ids = self.backend.neighbors(
            snapshot,
            symbol_id,
            NeighborQuery {
                direction: BackendDirection::Incoming,
                edge_type: Some("CALLS".to_string()),
            },
        )?;

        let mut calls = Vec::new();
        for call_node_id in neighbor_ids {
            if let Ok(Some(call)) = self.call_fact_from_node(call_node_id) {
                calls.push(call);
            }
        }

        Ok(calls)
    }

    /// Insert a call node from CallFact
    fn insert_call_node(&self, call: &CallFact) -> Result<NodeId> {
        let call_node = CallNode {
            file: call.file_path.to_string_lossy().to_string(),
            caller: call.caller.clone(),
            callee: call.callee.clone(),
            caller_symbol_id: call.caller_symbol_id.clone(),
            callee_symbol_id: call.callee_symbol_id.clone(),
            byte_start: call.byte_start as u64,
            byte_end: call.byte_end as u64,
            start_line: call.start_line as u64,
            start_col: call.start_col as u64,
            end_line: call.end_line as u64,
            end_col: call.end_col as u64,
        };

        let node_spec = NodeSpec {
            kind: "Call".to_string(),
            name: format!("{} calls {}", call.caller, call.callee),
            file_path: Some(call.file_path.to_string_lossy().to_string()),
            data: serde_json::to_value(call_node)?,
        };

        let id = self.backend.insert_node(node_spec)?;
        Ok(NodeId::from(id))
    }

    /// Insert CALLS edge from call node to callee symbol
    fn insert_calls_edge(&self, call_id: NodeId, callee_id: NodeId) -> Result<()> {
        let edge_spec = EdgeSpec {
            from: call_id.as_i64(),
            to: callee_id.as_i64(),
            edge_type: "CALLS".to_string(),
            data: serde_json::json!({}),
        };

        self.backend.insert_edge(edge_spec)?;
        Ok(())
    }

    /// Insert CALLER edge from caller symbol to call node
    fn insert_caller_edge(&self, caller_id: NodeId, call_id: NodeId) -> Result<()> {
        let edge_spec = EdgeSpec {
            from: caller_id.as_i64(),
            to: call_id.as_i64(),
            edge_type: "CALLER".to_string(),
            data: serde_json::json!({}),
        };

        self.backend.insert_edge(edge_spec)?;
        Ok(())
    }

    /// Convert a call node to CallFact
    fn call_fact_from_node(&self, node_id: i64) -> Result<Option<CallFact>> {
        let snapshot = SnapshotId::current();
        let node = self.backend.get_node(snapshot, node_id)?;

        let call_node: Option<CallNode> = serde_json::from_value(node.data).ok();

        let call_node = match call_node {
            Some(n) => n,
            None => return Ok(None),
        };

        Ok(Some(CallFact {
            file_path: PathBuf::from(&call_node.file),
            caller: call_node.caller,
            callee: call_node.callee,
            caller_symbol_id: call_node.caller_symbol_id,
            callee_symbol_id: call_node.callee_symbol_id,
            byte_start: call_node.byte_start as usize,
            byte_end: call_node.byte_end as usize,
            start_line: call_node.start_line as usize,
            start_col: call_node.start_col as usize,
            end_line: call_node.end_line as usize,
            end_col: call_node.end_col as usize,
        }))
    }

    fn symbol_fact_from_node(&self, node: &sqlitegraph::GraphEntity) -> Option<SymbolFact> {
        let symbol_node: crate::graph::schema::SymbolNode =
            serde_json::from_value(node.data.clone()).ok()?;

        let file_path = node.file_path.as_deref()?;

        let kind = match symbol_node.kind.as_str() {
            "Function" => SymbolKind::Function,
            "Method" => SymbolKind::Method,
            "Class" => SymbolKind::Class,
            "Interface" => SymbolKind::Interface,
            "Enum" => SymbolKind::Enum,
            "Module" => SymbolKind::Module,
            "Union" => SymbolKind::Union,
            "Namespace" => SymbolKind::Namespace,
            "TypeAlias" => SymbolKind::TypeAlias,
            "Unknown" => SymbolKind::Unknown,
            _ => SymbolKind::Unknown,
        };

        let normalized_kind = symbol_node
            .kind_normalized
            .clone()
            .unwrap_or_else(|| kind.normalized_key().to_string());

        Some(SymbolFact {
            file_path: PathBuf::from(file_path),
            kind,
            kind_normalized: normalized_kind,
            name: symbol_node.name.clone(),
            fqn: symbol_node.name,
            canonical_fqn: None,
            display_fqn: None,
            byte_start: symbol_node.byte_start,
            byte_end: symbol_node.byte_end,
            start_line: symbol_node.start_line,
            start_col: symbol_node.start_col,
            end_line: symbol_node.end_line,
            end_col: symbol_node.end_col,
        })
    }
}