use serde::Deserialize;
use serde::Serialize;
use tree_sitter::Parser;
use tree_sitter_graph::ast::File;
use tree_sitter_graph::functions::{Function, Functions};
use tree_sitter_graph::graph::Value;
use tree_sitter_graph::ExecutionConfig;
use tree_sitter_graph::ExecutionError;
use tree_sitter_graph::Identifier;
use tree_sitter_graph::NoCancellation;
use tree_sitter_graph::Variables;

mod text_range;
use text_range::TextRange;

use petgraph::{graph::NodeIndex, visit::EdgeRef, Direction, Graph};

fn main() {
    let scopes = std::fs::read_to_string("src/stag.scm").unwrap();
    let src = r#"
    fn main() {
        let x = 2;
        let a = 5;
        if let _ = z {
            a[x];
        }
    }
    "#;

    let mut parser = Parser::new();
    let language = tree_sitter_rust::language();
    parser.set_language(language).unwrap();
    let tree = parser.parse(src.as_bytes(), None).unwrap();

    let file = File::from_str(language, &scopes).unwrap();

    let mut functions = Functions::stdlib();
    functions.add(Identifier::from("scope"), ScopeShorthand);
    functions.add(Identifier::from("def"), DefShorthand);
    functions.add(Identifier::from("ref"), RefShortHand);
    functions.add(Identifier::from("cover"), CoverRanges);
    functions.add(Identifier::from("range"), NodeRange);

    let mut globals = Variables::new();
    globals
        .add(Identifier::from("filename"), "test.rs".into())
        .map_err(|_| ExecutionError::DuplicateVariable("filename".into()))
        .unwrap();

    let config = ExecutionConfig::new(&functions, &globals);

    let graph = file.execute(&tree, &src, &config, &NoCancellation).unwrap();

    let mut sg = ScopeGraph::new(tree.root_node().range().into());

    sg = build_scope_graph(graph, sg);

    println!("{:#?}", sg);

    for e in sg
        .graph
        .raw_edges()
        .iter()
        .filter(|e| e.weight == EdgeKind::RefToDef)
    {
        println!("{:?} -> {:?}", e.source(), e.target());
    }
}

fn range_to_value(value: &tree_sitter::Range) -> Value {
    let start = Value::from(vec![
        Value::from(value.start_byte as u32),
        Value::from(value.start_point.row as u32),
        Value::from(value.start_point.column as u32),
    ]);
    let end = Value::from(vec![
        Value::from(value.end_byte as u32),
        Value::from(value.end_point.row as u32),
        Value::from(value.end_point.column as u32),
    ]);
    Value::from(vec![start, end])
}

fn value_to_range(value: &Value) -> tree_sitter::Range {
    let range = value.as_list().unwrap();
    let start = range[0].as_list().unwrap();
    let end = range[1].as_list().unwrap();
    tree_sitter::Range {
        start_byte: start[0].as_integer().unwrap() as usize,
        start_point: tree_sitter::Point {
            row: start[1].as_integer().unwrap() as usize,
            column: start[2].as_integer().unwrap() as usize,
        },
        end_byte: end[0].as_integer().unwrap() as usize,
        end_point: tree_sitter::Point {
            row: end[1].as_integer().unwrap() as usize,
            column: end[2].as_integer().unwrap() as usize,
        },
    }
}

fn is_string_attr(node: &tree_sitter_graph::graph::GraphNode, key: &str, value: &str) -> bool {
    matches!(node.attributes.get(&Identifier::from(key)).and_then(|v| v.as_str().ok()), Some(v) if v == value)
}

fn is_scope(node: &tree_sitter_graph::graph::GraphNode) -> bool {
    is_string_attr(node, "kind", "scope")
}

fn is_import(node: &tree_sitter_graph::graph::GraphNode) -> bool {
    is_string_attr(node, "kind", "import")
}

fn is_def(node: &tree_sitter_graph::graph::GraphNode) -> bool {
    is_string_attr(node, "kind", "def")
}

fn is_ref(node: &tree_sitter_graph::graph::GraphNode) -> bool {
    is_string_attr(node, "kind", "ref")
}

pub struct ScopeShorthand;

#[allow(unused_must_use)]
impl Function for ScopeShorthand {
    fn call(
        &self,
        graph: &mut tree_sitter_graph::graph::Graph,
        _source: &str,
        parameters: &mut dyn tree_sitter_graph::functions::Parameters,
    ) -> Result<tree_sitter_graph::graph::Value, ExecutionError> {
        let target_range = parameters.param()?;
        if target_range.as_list().is_err() {
            return Err(ExecutionError::ExpectedList(format!(
                "`scope` expects list"
            )));
        }
        parameters.finish()?;

        let graph_node = graph.add_graph_node();
        graph[graph_node]
            .attributes
            .add::<String>(Identifier::from("kind"), "scope".into());
        graph[graph_node]
            .attributes
            .add(Identifier::from("range"), target_range);

        Ok(tree_sitter_graph::graph::Value::GraphNode(graph_node))
    }
}

pub struct DefShorthand;

#[allow(unused_must_use)]
impl Function for DefShorthand {
    fn call(
        &self,
        graph: &mut tree_sitter_graph::graph::Graph,
        source: &str,
        parameters: &mut dyn tree_sitter_graph::functions::Parameters,
    ) -> Result<tree_sitter_graph::graph::Value, ExecutionError> {
        let target_node = parameters.param()?.into_syntax_node_ref()?;
        let ts_node = graph[target_node];
        let symbol = parameters
            .param()
            .and_then(|p| p.as_str().map(ToOwned::to_owned))
            .ok();
        parameters.finish()?;

        let graph_node = graph.add_graph_node();
        graph[graph_node]
            .attributes
            .add::<String>(Identifier::from("kind"), "def".into());
        graph[graph_node]
            .attributes
            .add::<String>(Identifier::from("scope"), "local".into());

        if let Some(s) = symbol {
            graph[graph_node]
                .attributes
                .add::<String>(Identifier::from("symbol"), s.into());
        }
        graph[graph_node].attributes.add::<String>(
            Identifier::from("text"),
            source[ts_node.byte_range()].to_string().into(),
        );
        graph[graph_node]
            .attributes
            .add(Identifier::from("range"), range_to_value(&ts_node.range()));
        graph[graph_node]
            .attributes
            .add::<tree_sitter_graph::graph::SyntaxNodeRef>(
                Identifier::from("target"),
                target_node.into(),
            );

        Ok(tree_sitter_graph::graph::Value::GraphNode(graph_node))
    }
}

pub struct RefShortHand;

#[allow(unused_must_use)]
impl Function for RefShortHand {
    fn call(
        &self,
        graph: &mut tree_sitter_graph::graph::Graph,
        source: &str,
        parameters: &mut dyn tree_sitter_graph::functions::Parameters,
    ) -> Result<tree_sitter_graph::graph::Value, ExecutionError> {
        let target_node = parameters.param()?.into_syntax_node_ref()?;
        let ts_node = graph[target_node];
        parameters.finish()?;

        let graph_node = graph.add_graph_node();
        graph[graph_node]
            .attributes
            .add::<String>(Identifier::from("kind"), "ref".into());
        graph[graph_node].attributes.add::<String>(
            Identifier::from("text"),
            source[ts_node.byte_range()].to_string().into(),
        );
        graph[graph_node]
            .attributes
            .add(Identifier::from("range"), range_to_value(&ts_node.range()));
        graph[graph_node]
            .attributes
            .add::<tree_sitter_graph::graph::SyntaxNodeRef>(
                Identifier::from("target"),
                target_node.into(),
            );

        Ok(tree_sitter_graph::graph::Value::GraphNode(graph_node))
    }
}

pub struct CoverRanges;

impl Function for CoverRanges {
    fn call(
        &self,
        graph: &mut tree_sitter_graph::graph::Graph,
        _source: &str,
        parameters: &mut dyn tree_sitter_graph::functions::Parameters,
    ) -> Result<tree_sitter_graph::graph::Value, ExecutionError> {
        let p1 = parameters.param()?;
        let p2 = parameters.param()?;

        match (p1.is_null(), p2.is_null()) {
            (true, true) => panic!("all nulls"),
            (false, true) => return Ok(range_to_value(&graph[p1.into_syntax_node_ref()?].range())),
            (true, false) => return Ok(range_to_value(&graph[p2.into_syntax_node_ref()?].range())),
            (false, false) => {
                let node_a = p1.into_syntax_node_ref()?;
                let node_b = p2.into_syntax_node_ref()?;
                let ts_node_a = graph[node_a];
                let ts_node_b = graph[node_b];

                let mut range = cover(ts_node_a.range(), ts_node_b.range());
                while let Ok(param) = parameters.param() {
                    if !param.is_null() {
                        range = cover(range, graph[param.into_syntax_node_ref()?].range())
                    }
                }

                Ok(range_to_value(&range))
            }
        }
    }
}

fn cover(a: tree_sitter::Range, b: tree_sitter::Range) -> tree_sitter::Range {
    let (start_byte, start_point) = if a.start_point < b.start_point {
        (a.start_byte, a.start_point)
    } else {
        (b.start_byte, b.start_point)
    };
    let (end_byte, end_point) = if a.end_point > b.end_point {
        (a.end_byte, a.end_point)
    } else {
        (b.end_byte, b.end_point)
    };
    tree_sitter::Range {
        start_byte,
        start_point,
        end_byte,
        end_point,
    }
}

pub struct NodeRange;

impl Function for NodeRange {
    fn call(
        &self,
        graph: &mut tree_sitter_graph::graph::Graph,
        _source: &str,
        parameters: &mut dyn tree_sitter_graph::functions::Parameters,
    ) -> Result<tree_sitter_graph::graph::Value, ExecutionError> {
        let target_node = parameters.param()?.into_syntax_node_ref()?;
        let ts_node = graph[target_node];
        Ok(range_to_value(&ts_node.range()))
    }
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub struct LocalDef {
    pub range: TextRange,
    pub text: String,
    pub symbol: Option<String>,
}

impl LocalDef {
    /// Initialize a new definition
    pub fn new(range: TextRange, text: String, symbol: Option<String>) -> Self {
        Self {
            range,
            text,
            symbol,
        }
    }

    pub fn name<'a>(&self, buffer: &'a [u8]) -> &'a [u8] {
        &buffer[self.range.start.byte..self.range.end.byte]
    }
}

#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Hash)]
pub struct LocalImport {
    pub range: TextRange,
    pub text: String,
}

impl LocalImport {
    /// Initialize a new import
    pub fn new(range: TextRange, text: String) -> Self {
        Self { range, text }
    }

    pub fn name<'a>(&self, buffer: &'a [u8]) -> &'a [u8] {
        &buffer[self.range.start.byte..self.range.end.byte]
    }
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Reference {
    pub range: TextRange,
    pub text: String,
    pub symbol: Option<String>,
}

impl Reference {
    /// Initialize a new reference
    pub fn new(range: TextRange, text: String, symbol: Option<String>) -> Self {
        Self {
            range,
            text,
            symbol,
        }
    }
}

#[derive(Debug, Clone, Copy, Serialize, Deserialize)]
pub struct LocalScope {
    pub range: TextRange,
}

impl LocalScope {
    pub fn new(range: TextRange) -> Self {
        Self { range }
    }
}

pub struct ScopeStack<'a> {
    pub scope_graph: &'a ScopeGraph,
    pub start: Option<NodeIndex<u32>>,
}

impl<'a> Iterator for ScopeStack<'a> {
    type Item = NodeIndex<u32>;
    fn next(&mut self) -> Option<Self::Item> {
        if let Some(start) = self.start {
            let parent = self
                .scope_graph
                .graph
                .edges_directed(start, Direction::Outgoing)
                .find(|edge| *edge.weight() == EdgeKind::ScopeToScope)
                .map(|edge| edge.target());
            let original = start;
            self.start = parent;
            Some(original)
        } else {
            None
        }
    }
}

/// The type of a node in the ScopeGraph
#[derive(Serialize, Deserialize, Debug, Clone)]
pub enum NodeKind {
    /// A scope node
    Scope(LocalScope),

    /// A definition node
    Def(LocalDef),

    /// An import node
    Import(LocalImport),

    /// A reference node
    Ref(Reference),
}

impl NodeKind {
    /// Construct a scope node from a range
    pub fn scope(range: TextRange) -> Self {
        Self::Scope(LocalScope::new(range))
    }

    /// Produce the range spanned by this node
    pub fn range(&self) -> TextRange {
        match self {
            Self::Scope(l) => l.range,
            Self::Def(d) => d.range,
            Self::Ref(r) => r.range,
            Self::Import(i) => i.range,
        }
    }
}

/// Describes the relation between two nodes in the ScopeGraph
#[derive(Serialize, Deserialize, PartialEq, Eq, Copy, Clone, Debug)]
pub enum EdgeKind {
    /// The edge weight from a nested scope to its parent scope
    ScopeToScope,

    /// The edge weight from a definition to its definition scope
    DefToScope,

    /// The edge weight from an import to its definition scope
    ImportToScope,

    /// The edge weight from a reference to its definition
    RefToDef,

    /// The edge weight from a reference to its import
    RefToImport,
}

/// A graph representation of scopes and names in a single syntax tree
#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct ScopeGraph {
    /// The raw graph
    pub graph: Graph<NodeKind, EdgeKind>,

    // Graphs do not have the concept of a `root`, but lexical scopes follow the syntax
    // tree, and as a result, have a "root" node. The root_idx points to a scope node that
    // encompasses the entire file: the file-global scope.
    root_idx: NodeIndex,
}

impl ScopeGraph {
    pub fn new(range: TextRange) -> Self {
        let mut graph = Graph::new();
        let root_idx = graph.add_node(NodeKind::scope(range));
        Self { graph, root_idx }
    }

    pub fn get_node(&self, node_idx: NodeIndex) -> Option<&NodeKind> {
        self.graph.node_weight(node_idx)
    }

    /// Insert a local scope into the scope-graph
    pub fn insert_local_scope(&mut self, new: LocalScope) {
        if let Some(parent_scope) = self.scope_by_range(new.range, self.root_idx) {
            let new_scope = NodeKind::Scope(new);
            let new_idx = self.graph.add_node(new_scope);
            self.graph
                .add_edge(new_idx, parent_scope, EdgeKind::ScopeToScope);
        }
    }

    /// Insert a def into the scope-graph
    pub fn insert_local_def(&mut self, new: LocalDef) {
        if let Some(defining_scope) = self.scope_by_range(new.range, self.root_idx) {
            let new_def = NodeKind::Def(new);
            let new_idx = self.graph.add_node(new_def);
            self.graph
                .add_edge(new_idx, defining_scope, EdgeKind::DefToScope);
        }
    }

    /// Insert a def into the scope-graph, at the parent scope of the defining scope
    pub fn insert_hoisted_def(&mut self, new: LocalDef) {
        if let Some(defining_scope) = self.scope_by_range(new.range, self.root_idx) {
            let new_def = NodeKind::Def(new);
            let new_idx = self.graph.add_node(new_def);

            // if the parent scope exists, insert this def there, if not,
            // insert into the defining scope
            let target_scope = self.parent_scope(defining_scope).unwrap_or(defining_scope);

            self.graph
                .add_edge(new_idx, target_scope, EdgeKind::DefToScope);
        }
    }

    /// Insert a def into the scope-graph, at the root scope
    pub fn insert_global_def(&mut self, new: LocalDef) {
        let new_def = NodeKind::Def(new);
        let new_idx = self.graph.add_node(new_def);
        self.graph
            .add_edge(new_idx, self.root_idx, EdgeKind::DefToScope);
    }

    /// Insert an import into the scope-graph
    pub fn insert_local_import(&mut self, new: LocalImport) {
        if let Some(defining_scope) = self.scope_by_range(new.range, self.root_idx) {
            let new_imp = NodeKind::Import(new);
            let new_idx = self.graph.add_node(new_imp);
            self.graph
                .add_edge(new_idx, defining_scope, EdgeKind::ImportToScope);
        }
    }

    /// Insert a ref into the scope-graph
    pub fn insert_ref(&mut self, new: Reference) {
        let mut possible_defs = vec![];
        let mut possible_imports = vec![];
        if let Some(local_scope_idx) = self.scope_by_range(new.range, self.root_idx) {
            // traverse the scopes from the current-scope to the root-scope
            for scope in self.scope_stack(local_scope_idx) {
                // find candidate definitions in each scope
                for local_def in self
                    .graph
                    .edges_directed(scope, Direction::Incoming)
                    .filter(|edge| *edge.weight() == EdgeKind::DefToScope)
                    .map(|edge| edge.source())
                {
                    if let NodeKind::Def(def) = &self.graph[local_def] {
                        if new.text == def.text {
                            match (def.symbol.as_ref(), new.symbol.as_ref()) {
                                // both contain symbols, but they don't belong to the same namepspace
                                (Some(d), Some(r)) if d != r => {}

                                // in all other cases, form an edge from the ref to def.
                                // an empty symbol belongs to all namespaces:
                                // * (None, None)
                                // * (None, Some(_))
                                // * (Some(_), None)
                                // * (Some(_), Some(_)) if def.namespace == ref.namespace
                                _ => {
                                    possible_defs.push(local_def);
                                }
                            };
                        }
                    }
                }

                // find candidate imports in each scope
                for local_import in self
                    .graph
                    .edges_directed(scope, Direction::Incoming)
                    .filter(|edge| *edge.weight() == EdgeKind::ImportToScope)
                    .map(|edge| edge.source())
                {
                    if let NodeKind::Import(import) = &self.graph[local_import] {
                        if new.text == import.text {
                            possible_imports.push(local_import);
                        }
                    }
                }
            }
        }

        if !possible_defs.is_empty() || !possible_imports.is_empty() {
            let new_ref = NodeKind::Ref(new);
            let ref_idx = self.graph.add_node(new_ref);
            for def_idx in possible_defs {
                self.graph.add_edge(ref_idx, def_idx, EdgeKind::RefToDef);
            }
            for imp_idx in possible_imports {
                self.graph.add_edge(ref_idx, imp_idx, EdgeKind::RefToImport);
            }
        }
    }

    fn scope_stack(&self, start: NodeIndex) -> ScopeStack<'_> {
        ScopeStack {
            scope_graph: self,
            start: Some(start),
        }
    }

    // The smallest scope that encompasses `range`. Start at `start` and narrow down if possible.
    fn scope_by_range(&self, range: TextRange, start: NodeIndex) -> Option<NodeIndex> {
        let target_range = self.graph[start].range();
        if target_range.contains(&range) {
            let mut child_scopes = self
                .graph
                .edges_directed(start, Direction::Incoming)
                .filter(|edge| *edge.weight() == EdgeKind::ScopeToScope)
                .map(|edge| edge.source())
                .collect::<Vec<_>>();

            child_scopes.sort_by_key(|s| self.graph[*s].range());
            let target_child_scope = child_scopes.binary_search_by(|x| {
                if self.graph[*x].range().contains(&range) {
                    std::cmp::Ordering::Equal
                } else {
                    self.graph[*x].range().cmp(&range)
                }
            });

            if let Some(t) = target_child_scope
                .ok()
                .and_then(|idx| child_scopes.get(idx))
                .and_then(|s| self.scope_by_range(range, *s))
            {
                return Some(t);
            } else {
                return Some(start);
            }
        }
        None
    }

    // Produce the parent scope of a given scope
    fn parent_scope(&self, start: NodeIndex) -> Option<NodeIndex> {
        if matches!(self.graph[start], NodeKind::Scope(_)) {
            return self
                .graph
                .edges_directed(start, Direction::Outgoing)
                .filter(|edge| *edge.weight() == EdgeKind::ScopeToScope)
                .map(|edge| edge.target())
                .next();
        }
        None
    }

    /// Produce a list of interesting ranges: ranges of defs and refs
    pub fn hoverable_ranges(&self) -> Box<dyn Iterator<Item = TextRange> + '_> {
        let iterator =
            self.graph
                .node_indices()
                .filter_map(|node_idx| match &self.graph[node_idx] {
                    NodeKind::Scope(_) => None,
                    NodeKind::Def(d) => Some(d.range),
                    NodeKind::Ref(r) => Some(r.range),
                    NodeKind::Import(i) => Some(i.range),
                });
        Box::new(iterator)
    }

    /// Produce possible definitions for a reference
    pub fn definitions(
        &self,
        reference_node: NodeIndex,
    ) -> Box<dyn Iterator<Item = NodeIndex> + '_> {
        let iterator = self
            .graph
            .edges_directed(reference_node, Direction::Outgoing)
            .filter(|edge| *edge.weight() == EdgeKind::RefToDef)
            .map(|edge| edge.target());
        Box::new(iterator)
    }

    /// Produce possible imports for a reference
    pub fn imports(&self, reference_node: NodeIndex) -> Box<dyn Iterator<Item = NodeIndex> + '_> {
        let iterator = self
            .graph
            .edges_directed(reference_node, Direction::Outgoing)
            .filter(|edge| *edge.weight() == EdgeKind::RefToImport)
            .map(|edge| edge.target());
        Box::new(iterator)
    }

    /// Produce possible references for a definition/import node
    pub fn references(
        &self,
        definition_node: NodeIndex,
    ) -> Box<dyn Iterator<Item = NodeIndex> + '_> {
        let iterator = self
            .graph
            .edges_directed(definition_node, Direction::Incoming)
            .filter(|edge| {
                *edge.weight() == EdgeKind::RefToDef || *edge.weight() == EdgeKind::RefToImport
            })
            .map(|edge| edge.source());
        Box::new(iterator)
    }

    pub fn node_by_range(&self, start_byte: usize, end_byte: usize) -> Option<NodeIndex> {
        self.graph
            .node_indices()
            .filter(|&idx| self.is_definition(idx) || self.is_reference(idx) || self.is_import(idx))
            .find(|&idx| {
                let node = self.graph[idx].range();
                start_byte >= node.start.byte && end_byte <= node.end.byte
            })
    }

    /// The "value" of a definition is loosely characterized as
    ///
    /// - the body of a function block
    /// - the body of a class
    /// - the parameters list defining generic types
    /// - the RHS of a value
    ///
    /// The heuristic used here is
    ///  - the smallest scope-node that encompasses the definition_node
    ///  - or the largest scope-node on the same line as the to the definition_node
    pub fn value_of_definition(&self, def_idx: NodeIndex) -> Option<NodeIndex> {
        let smallest_scope_node = self
            .scope_by_range(self.graph[def_idx].range(), self.root_idx)
            .filter(|&idx| {
                self.graph[idx].range().start.line == self.graph[def_idx].range().start.line
            });
        let largest_adjacent_node = self
            .graph
            .node_indices()
            .filter(|&idx| match self.graph[idx] {
                NodeKind::Scope(scope) => {
                    scope.range.start.line == self.graph[def_idx].range().start.line
                }
                _ => false,
            })
            .max_by_key(|idx| self.graph[*idx].range().size());

        smallest_scope_node.or(largest_adjacent_node)
    }

    pub fn node_by_position(&self, line: usize, column: usize) -> Option<NodeIndex> {
        self.graph
            .node_indices()
            .filter(|&idx| self.is_definition(idx) || self.is_reference(idx))
            .find(|&idx| {
                let node = self.graph[idx].range();
                node.start.line == line
                    && node.end.line == line
                    && node.start.column <= column
                    && node.end.column >= column
            })
    }

    #[cfg(test)]
    pub fn find_node_by_name(&self, src: &[u8], name: &[u8]) -> Option<NodeIndex> {
        self.graph.node_indices().find(|idx| {
            matches!(
                    &self.graph[*idx],
                    NodeKind::Def(d) if d.name(src) == name)
        })
    }

    pub fn is_definition(&self, node_idx: NodeIndex) -> bool {
        matches!(self.graph[node_idx], NodeKind::Def(_))
    }

    pub fn is_reference(&self, node_idx: NodeIndex) -> bool {
        matches!(self.graph[node_idx], NodeKind::Ref(_))
    }

    pub fn is_scope(&self, node_idx: NodeIndex) -> bool {
        matches!(self.graph[node_idx], NodeKind::Scope(_))
    }

    pub fn is_import(&self, node_idx: NodeIndex) -> bool {
        matches!(self.graph[node_idx], NodeKind::Import(_))
    }
}

fn build_scope_graph(
    tsg: tree_sitter_graph::graph::Graph,
    mut scope_graph: ScopeGraph,
) -> ScopeGraph {
    let nodes = tsg.iter_nodes().collect::<Vec<_>>();
    for node in nodes
        .iter()
        .map(|node_ref| &tsg[*node_ref])
        .filter(|node| is_scope(node))
    {
        let range = value_to_range(node.attributes.get(&Identifier::from("range")).unwrap());
        let scope = LocalScope::new(range.into());
        scope_graph.insert_local_scope(scope);
    }

    for node in nodes
        .iter()
        .map(|node_ref| &tsg[*node_ref])
        .filter(|node| is_import(node))
    {
        let range = value_to_range(node.attributes.get(&Identifier::from("range")).unwrap());
        let text = node
            .attributes
            .get(&Identifier::from("text"))
            .and_then(|id| id.clone().into_string().ok())
            .expect("import without text");
        let import = LocalImport::new(range.into(), text);
        scope_graph.insert_local_import(import);
    }

    for node in nodes
        .iter()
        .map(|node_ref| &tsg[*node_ref])
        .filter(|node| is_def(node))
    {
        let range = value_to_range(node.attributes.get(&Identifier::from("range")).unwrap());
        let symbol = node
            .attributes
            .get(&Identifier::from("symbol"))
            .and_then(|id| id.clone().into_string().ok());
        let text = node
            .attributes
            .get(&Identifier::from("text"))
            .and_then(|id| id.clone().into_string().ok())
            .expect("def without text");
        let local_def = LocalDef::new(range.into(), text, symbol);

        // TODO: fix scoping here
        scope_graph.insert_local_def(local_def);
    }

    for node in nodes
        .iter()
        .map(|node_ref| &tsg[*node_ref])
        .filter(|node| is_ref(node))
    {
        let range = value_to_range(node.attributes.get(&Identifier::from("range")).unwrap());
        let symbol = node
            .attributes
            .get(&Identifier::from("symbol"))
            .and_then(|id| id.clone().into_string().ok());
        let text = node
            .attributes
            .get(&Identifier::from("text"))
            .and_then(|id| id.clone().into_string().ok())
            .expect("ref without text");
        let ref_ = Reference::new(range.into(), text, symbol);

        scope_graph.insert_ref(ref_);
    }

    scope_graph
}