similarity-core 0.5.2

#![allow(clippy::io_other_error)]

use crate::generic_parser_config::GenericParserConfig;
use crate::language_parser::{GenericFunctionDef, GenericTypeDef, Language, LanguageParser};
use crate::tree::TreeNode;
use std::error::Error;
use std::rc::Rc;
use tree_sitter::{Node, Parser};

pub struct GenericTreeSitterParser {
    parser: Parser,
    config: GenericParserConfig,
}

impl GenericTreeSitterParser {
    /// Create a new generic parser with the given tree-sitter language and configuration
    pub fn new(
        language: tree_sitter::Language,
        config: GenericParserConfig,
    ) -> Result<Self, Box<dyn Error + Send + Sync>> {
        let mut parser = Parser::new();
        parser.set_language(&language).map_err(|e| {
            Box::new(std::io::Error::new(
                std::io::ErrorKind::Other,
                format!("Failed to set language: {:?}", e),
            )) as Box<dyn Error + Send + Sync>
        })?;

        Ok(Self { parser, config })
    }

    /// Create from a pre-configured language
    pub fn from_language_name(language_name: &str) -> Result<Self, Box<dyn Error + Send + Sync>> {
        let (language, config) = match language_name {
            "go" => (tree_sitter_go::LANGUAGE.into(), GenericParserConfig::go()),
            "java" => (tree_sitter_java::LANGUAGE.into(), GenericParserConfig::java()),
            "c" => (tree_sitter_c::LANGUAGE.into(), GenericParserConfig::c()),
            "cpp" | "c++" => (tree_sitter_cpp::LANGUAGE.into(), GenericParserConfig::cpp()),
            "csharp" | "cs" => {
                (tree_sitter_c_sharp::LANGUAGE.into(), GenericParserConfig::csharp())
            }
            "ruby" | "rb" => (tree_sitter_ruby::LANGUAGE.into(), GenericParserConfig::ruby()),
            _ => {
                return Err(Box::new(std::io::Error::new(
                    std::io::ErrorKind::InvalidInput,
                    format!("Unsupported language: {}", language_name),
                )) as Box<dyn Error + Send + Sync>)
            }
        };

        Self::new(language, config)
    }

    fn convert_node(&self, node: Node, source: &str, id_counter: &mut usize) -> TreeNode {
        let current_id = *id_counter;
        *id_counter += 1;

        let label = node.kind().to_string();
        let value = if self.config.value_nodes.contains(&node.kind().to_string()) {
            node.utf8_text(source.as_bytes()).unwrap_or("").to_string()
        } else {
            "".to_string()
        };

        let mut tree_node = TreeNode::new(label, value, current_id);

        for child in node.children(&mut node.walk()) {
            let child_node = self.convert_node(child, source, id_counter);
            tree_node.add_child(Rc::new(child_node));
        }

        tree_node
    }

    fn extract_functions_from_node(
        &self,
        node: Node,
        source: &str,
        functions: &mut Vec<GenericFunctionDef>,
        class_name: Option<&str>,
    ) {
        let node_kind = node.kind();

        // Skip anonymous class bodies in Java
        if self.config.language == "java" && node_kind == "object_creation_expression" {
            // Skip the class_body of anonymous classes
            return;
        }

        // Check if this is a function node
        if self.config.function_nodes.contains(&node_kind.to_string()) {
            if let Some(func_def) = self.extract_function_definition(node, source, class_name) {
                functions.push(func_def);
            }
        }

        // Check if this is a type/class node
        if self.config.type_nodes.contains(&node_kind.to_string()) {
            // Extract class name for nested functions
            let new_class_name = node
                .child_by_field_name(&self.config.field_mappings.name_field)
                .and_then(|n| n.utf8_text(source.as_bytes()).ok())
                .unwrap_or("");

            // Recursively extract methods from class
            for child in node.children(&mut node.walk()) {
                self.extract_functions_from_node(child, source, functions, Some(new_class_name));
            }
            return; // Don't continue normal traversal for type nodes
        }

        // Continue searching in children
        for child in node.children(&mut node.walk()) {
            self.extract_functions_from_node(child, source, functions, class_name);
        }
    }

    fn extract_function_definition(
        &self,
        node: Node,
        source: &str,
        class_name: Option<&str>,
    ) -> Option<GenericFunctionDef> {
        // Extract the function name first, which might require special handling
        let name_string = if (self.config.language == "c" || self.config.language == "cpp")
            && node.kind() == "function_definition"
        {
            // In C/C++, the declarator contains both name and parameters
            let declarator = node.child_by_field_name("declarator")?;

            match declarator.kind() {
                "function_declarator" => declarator
                    .child_by_field_name("declarator")
                    .and_then(|n| n.utf8_text(source.as_bytes()).ok())
                    .map(String::from)?,
                "pointer_declarator" => {
                    // Handle functions returning pointers
                    let func_decl = declarator
                        .children(&mut declarator.walk())
                        .find(|n| n.kind() == "function_declarator")?;
                    func_decl
                        .child_by_field_name("declarator")
                        .and_then(|n| n.utf8_text(source.as_bytes()).ok())
                        .map(String::from)?
                }
                _ => {
                    // Simple function without parameters
                    declarator.utf8_text(source.as_bytes()).ok().map(String::from)?
                }
            }
        } else if self.config.language == "csharp" {
            // Special handling for C# methods
            match node.kind() {
                "operator_declaration" => {
                    // For operators, construct name as "operator <symbol>"
                    let operator_symbol = node
                        .child_by_field_name("operator")
                        .and_then(|n| n.utf8_text(source.as_bytes()).ok())?;
                    format!("operator {}", operator_symbol)
                }
                "destructor_declaration" => {
                    // For destructors, add ~ prefix
                    let class_name = node
                        .child_by_field_name("name")
                        .and_then(|n| n.utf8_text(source.as_bytes()).ok())?;
                    format!("~{}", class_name)
                }
                _ => {
                    // Standard C# methods
                    let name_node =
                        node.child_by_field_name(&self.config.field_mappings.name_field)?;
                    name_node.utf8_text(source.as_bytes()).ok().map(String::from)?
                }
            }
        } else if self.config.language == "elixir" && node.kind() == "call" {
            // Special handling for Elixir functions
            // The function name is in the arguments field (first call node)
            // For Elixir def/defp, arguments is the second child (index 1)
            let name_result = node
                .child(1)
                .filter(|n| n.kind() == "arguments")
                .and_then(|args| args.child(0))
                .and_then(|call_node| {
                    if call_node.kind() == "call" {
                        // Get the target of the inner call (the function name)
                        call_node.child_by_field_name("target")
                    } else {
                        None
                    }
                })
                .and_then(|n| n.utf8_text(source.as_bytes()).ok())
                .map(String::from);
            name_result?
        } else {
            // For other languages, use the standard field mapping
            let name_node = node.child_by_field_name(&self.config.field_mappings.name_field)?;
            name_node.utf8_text(source.as_bytes()).ok().map(String::from)?
        };

        // Extract parameters - special handling for C/C++
        let params_node = if (self.config.language == "c" || self.config.language == "cpp")
            && node.kind() == "function_definition"
        {
            let declarator = node.child_by_field_name("declarator")?;
            match declarator.kind() {
                "function_declarator" => declarator.child_by_field_name("parameters"),
                "pointer_declarator" => declarator
                    .children(&mut declarator.walk())
                    .find(|n| n.kind() == "function_declarator")
                    .and_then(|n| n.child_by_field_name("parameters")),
                _ => None,
            }
        } else {
            node.child_by_field_name(&self.config.field_mappings.params_field)
        };

        let body_node = node.child_by_field_name(&self.config.field_mappings.body_field);

        let params = self.extract_parameters(params_node, source);
        let decorators = self.extract_decorators(node, source);
        let is_async = self.is_async_function(node, source);
        let is_generator = self.is_generator_function(node, source);

        Some(GenericFunctionDef {
            name: name_string,
            start_line: node.start_position().row as u32 + 1,
            end_line: node.end_position().row as u32 + 1,
            body_start_line: body_node.map(|n| n.start_position().row as u32 + 1).unwrap_or(0),
            body_end_line: body_node.map(|n| n.end_position().row as u32 + 1).unwrap_or(0),
            parameters: params,
            is_method: class_name.is_some(),
            class_name: class_name.map(String::from),
            is_async,
            is_generator,
            decorators,
        })
    }

    fn extract_parameters(&self, params_node: Option<Node>, source: &str) -> Vec<String> {
        let Some(node) = params_node else {
            return Vec::new();
        };

        let mut params = Vec::new();
        let mut cursor = node.walk();

        for child in node.children(&mut cursor) {
            if self.config.value_nodes.contains(&child.kind().to_string()) {
                if let Ok(param_text) = child.utf8_text(source.as_bytes()) {
                    params.push(param_text.to_string());
                }
            } else if let Some(name_child) =
                child.child_by_field_name(&self.config.field_mappings.name_field)
            {
                if let Ok(param_text) = name_child.utf8_text(source.as_bytes()) {
                    params.push(param_text.to_string());
                }
            }
        }

        params
    }

    fn extract_decorators(&self, node: Node, source: &str) -> Vec<String> {
        let mut decorators = Vec::new();

        if let Some(decorator_field) = &self.config.field_mappings.decorator_field {
            // Look for decorator nodes
            if let Some(parent) = node.parent() {
                let mut cursor = parent.walk();
                for child in parent.children(&mut cursor) {
                    if child.kind() == decorator_field
                        && child.end_position().row < node.start_position().row
                    {
                        if let Ok(decorator_text) = child.utf8_text(source.as_bytes()) {
                            decorators.push(decorator_text.trim_start_matches('@').to_string());
                        }
                    }
                }
            }
        }

        decorators
    }

    fn is_async_function(&self, node: Node, source: &str) -> bool {
        // Check if the function definition contains async keyword
        if let Ok(text) = node.utf8_text(source.as_bytes()) {
            return text.starts_with("async ");
        }
        false
    }

    fn is_generator_function(&self, node: Node, source: &str) -> bool {
        // Check if function body contains yield
        if let Some(body) = node.child_by_field_name(&self.config.field_mappings.body_field) {
            if let Ok(body_text) = body.utf8_text(source.as_bytes()) {
                return body_text.contains("yield");
            }
        }
        false
    }

    fn extract_types_from_node(&self, node: Node, source: &str, types: &mut Vec<GenericTypeDef>) {
        let node_kind = node.kind();

        // Check if this is a type node
        if self.config.type_nodes.contains(&node_kind.to_string()) {
            if let Some(type_def) = self.extract_type_definition(node, source) {
                types.push(type_def);
            }
        }

        // Continue searching in children
        for child in node.children(&mut node.walk()) {
            self.extract_types_from_node(child, source, types);
        }
    }

    fn extract_type_definition(&self, node: Node, source: &str) -> Option<GenericTypeDef> {
        // Special handling for Go's type_declaration
        let (name, actual_type_node) = if node.kind() == "type_declaration"
            && self.config.language == "go"
        {
            // In Go, type_declaration -> type_spec -> actual type
            let type_spec = node
                .child_by_field_name("spec")
                .or_else(|| node.children(&mut node.walk()).find(|n| n.kind() == "type_spec"))?;

            let name_node = type_spec.child_by_field_name("name").or_else(|| {
                type_spec.children(&mut type_spec.walk()).find(|n| n.kind() == "type_identifier")
            })?;
            let name = name_node.utf8_text(source.as_bytes()).ok()?;

            // Get the actual type (struct_type, interface_type, etc.)
            let actual_type = type_spec
                .child_by_field_name("type")
                .or_else(|| type_spec.children(&mut type_spec.walk()).nth(1))?;

            (name, actual_type)
        } else if node.kind() == "type_definition" && self.config.language == "c" {
            // In C, type_definition has a declarator field
            let declarator = node.child_by_field_name("declarator")?;
            let name = declarator.utf8_text(source.as_bytes()).ok()?;

            // Get the actual type from the type field
            let actual_type = node.child_by_field_name("type").unwrap_or(node);

            (name, actual_type)
        } else {
            // For other languages, use the standard field mapping
            let name_node = node.child_by_field_name(&self.config.field_mappings.name_field)?;
            let name = name_node.utf8_text(source.as_bytes()).ok()?;
            (name, node)
        };

        Some(GenericTypeDef {
            name: name.to_string(),
            kind: actual_type_node.kind().to_string(),
            start_line: node.start_position().row as u32 + 1,
            end_line: node.end_position().row as u32 + 1,
            fields: Vec::new(), // TODO: Extract fields based on language
        })
    }
}

impl LanguageParser for GenericTreeSitterParser {
    fn parse(
        &mut self,
        source: &str,
        _filename: &str,
    ) -> Result<Rc<TreeNode>, Box<dyn Error + Send + Sync>> {
        let tree = self.parser.parse(source, None).ok_or_else(|| {
            Box::new(std::io::Error::new(std::io::ErrorKind::InvalidData, "Failed to parse source"))
                as Box<dyn Error + Send + Sync>
        })?;

        let root_node = tree.root_node();
        let mut id_counter = 0;
        Ok(Rc::new(self.convert_node(root_node, source, &mut id_counter)))
    }

    fn extract_functions(
        &mut self,
        source: &str,
        _filename: &str,
    ) -> Result<Vec<GenericFunctionDef>, Box<dyn Error + Send + Sync>> {
        let tree = self.parser.parse(source, None).ok_or_else(|| {
            Box::new(std::io::Error::new(std::io::ErrorKind::InvalidData, "Failed to parse source"))
                as Box<dyn Error + Send + Sync>
        })?;

        let root_node = tree.root_node();
        let mut functions = Vec::new();
        self.extract_functions_from_node(root_node, source, &mut functions, None);
        Ok(functions)
    }

    fn extract_types(
        &mut self,
        source: &str,
        _filename: &str,
    ) -> Result<Vec<GenericTypeDef>, Box<dyn Error + Send + Sync>> {
        let tree = self.parser.parse(source, None).ok_or_else(|| {
            Box::new(std::io::Error::new(std::io::ErrorKind::InvalidData, "Failed to parse source"))
                as Box<dyn Error + Send + Sync>
        })?;

        let root_node = tree.root_node();
        let mut types = Vec::new();
        self.extract_types_from_node(root_node, source, &mut types);
        Ok(types)
    }

    fn language(&self) -> Language {
        match self.config.language.as_str() {
            "python" => Language::Python,
            "rust" => Language::Rust,
            "javascript" | "typescript" => Language::TypeScript,
            "go" => Language::Go,
            "java" => Language::Java,
            "c" => Language::C,
            "cpp" => Language::Cpp,
            "csharp" => Language::CSharp,
            "ruby" => Language::Ruby,
            "php" => Language::Php,
            _ => Language::Unknown,
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_generic_parser_with_go() {
        let mut parser = GenericTreeSitterParser::from_language_name("go").unwrap();

        let source = r#"
package main

func hello(name string) string {
    return "Hello, " + name + "!"
}

type Greeter struct {}

func (g *Greeter) greet(name string) string {
    return "Hi, " + name + "!"
}
"#;

        let functions = parser.extract_functions(source, "test.go").unwrap();
        assert_eq!(functions.len(), 2);
        assert_eq!(functions[0].name, "hello");
        assert_eq!(functions[1].name, "greet");
    }

    #[test]
    fn test_generic_parser_with_java() {
        let mut parser = GenericTreeSitterParser::from_language_name("java").unwrap();

        let source = r#"
public class Calculator {
    public int add(int a, int b) {
        return a + b;
    }
    
    public int multiply(int x, int y) {
        return x * y;
    }
}
"#;

        let functions = parser.extract_functions(source, "Test.java").unwrap();
        assert_eq!(functions.len(), 2);
        assert_eq!(functions[0].name, "add");
        assert_eq!(functions[1].name, "multiply");
    }
}