peeker 1.1.0

use anyhow::Result;
use serde::Serialize;
use tree_sitter::{Node, Parser, Tree};

use crate::languages::{LanguageConfig, get_language_config};

#[derive(Debug, Clone, Serialize, Default)]
pub struct CodeStructure {
    pub imports: Vec<Import>,
    pub structs: Vec<StructDef>,
    pub functions: Vec<FunctionDef>,
    pub traits: Vec<TraitDef>,
    pub enums: Vec<EnumDef>,
}

impl CodeStructure {
    pub fn exports_only(&self) -> CodeStructure {
        CodeStructure {
            imports: self.imports.clone(),
            structs: self
                .structs
                .iter()
                .filter(|s| s.is_public)
                .cloned()
                .collect(),
            functions: self
                .functions
                .iter()
                .filter(|f| f.is_public)
                .cloned()
                .collect(),
            traits: self
                .traits
                .iter()
                .filter(|t| t.is_public)
                .cloned()
                .collect(),
            enums: self.enums.iter().filter(|e| e.is_public).cloned().collect(),
        }
    }
}

#[derive(Debug, Clone, Serialize)]
pub struct Import {
    pub name: String,
    pub line: usize,
}

#[derive(Debug, Clone, Serialize)]
pub struct StructDef {
    pub name: String,
    pub is_public: bool,
    pub start_line: usize,
    pub end_line: usize,
    pub fields: Vec<FieldDef>,
}

#[derive(Debug, Clone, Serialize)]
pub struct FieldDef {
    pub name: String,
    pub type_name: String,
    pub is_public: bool,
}

#[derive(Debug, Clone, Serialize)]
pub struct FunctionDef {
    pub name: String,
    pub is_public: bool,
    pub is_async: bool,
    pub params: Vec<String>,
    pub return_type: Option<String>,
    pub start_line: usize,
    pub end_line: usize,
}

#[derive(Debug, Clone, Serialize)]
pub struct TraitDef {
    pub name: String,
    pub is_public: bool,
    pub start_line: usize,
    pub end_line: usize,
}

#[derive(Debug, Clone, Serialize)]
pub struct EnumDef {
    pub name: String,
    pub is_public: bool,
    pub start_line: usize,
    pub end_line: usize,
    pub variants: Vec<String>,
}

pub fn parse_file(source: &str, extension: &str) -> Result<CodeStructure> {
    let config = get_language_config(extension)?;

    let mut parser = Parser::new();
    parser.set_language(&config.language)?;

    let tree = parser
        .parse(source, None)
        .ok_or_else(|| anyhow::anyhow!("Failed to parse file"))?;

    extract_structure(&tree, source, &config)
}

fn extract_structure(tree: &Tree, source: &str, config: &LanguageConfig) -> Result<CodeStructure> {
    let mut structure = CodeStructure::default();
    let root = tree.root_node();

    extract_from_node(root, source, config, &mut structure);

    Ok(structure)
}

fn extract_from_node(
    node: Node,
    source: &str,
    config: &LanguageConfig,
    structure: &mut CodeStructure,
) {
    let kind = node.kind();

    // Check for imports
    if config.import_kinds.contains(&kind) {
        if let Some(import) = extract_import(node, source, config) {
            structure.imports.push(import);
        }
    }

    // Check for structs/classes
    if config.struct_kinds.contains(&kind) {
        if let Some(struct_def) = extract_struct(node, source, config) {
            structure.structs.push(struct_def);
        }
    }

    // Check for functions
    if config.function_kinds.contains(&kind) {
        if let Some(func_def) = extract_function(node, source, config) {
            structure.functions.push(func_def);
        }
    }

    // Check for traits/interfaces
    if config.trait_kinds.contains(&kind) {
        if let Some(trait_def) = extract_trait(node, source, config) {
            structure.traits.push(trait_def);
        }
    }

    // Check for enums
    if config.enum_kinds.contains(&kind) {
        if let Some(enum_def) = extract_enum(node, source, config) {
            structure.enums.push(enum_def);
        }
    }

    // Recurse into children
    let mut cursor = node.walk();
    for child in node.children(&mut cursor) {
        extract_from_node(child, source, config, structure);
    }
}

fn extract_import(node: Node, source: &str, _config: &LanguageConfig) -> Option<Import> {
    let text = node.utf8_text(source.as_bytes()).ok()?;
    let line = node.start_position().row + 1;

    // Clean up the import text
    let name = text.lines().next().unwrap_or(text).trim().to_string();

    Some(Import { name, line })
}

fn extract_struct(node: Node, source: &str, config: &LanguageConfig) -> Option<StructDef> {
    let name = find_child_by_field(node, "name")
        .and_then(|n| n.utf8_text(source.as_bytes()).ok())
        .map(|s| s.to_string())?;

    let is_public = check_visibility(node, source, config);
    let start_line = node.start_position().row + 1;
    let end_line = node.end_position().row + 1;

    let fields = extract_fields(node, source, config);

    Some(StructDef {
        name,
        is_public,
        start_line,
        end_line,
        fields,
    })
}

fn extract_fields(node: Node, source: &str, config: &LanguageConfig) -> Vec<FieldDef> {
    let mut fields = Vec::new();
    let mut cursor = node.walk();

    for child in node.children(&mut cursor) {
        if config.field_kinds.contains(&child.kind()) {
            if let Some(field) = extract_single_field(child, source, config) {
                fields.push(field);
            }
        }
        // Also check nested children (e.g., field_declaration_list)
        let mut inner_cursor = child.walk();
        for inner in child.children(&mut inner_cursor) {
            if config.field_kinds.contains(&inner.kind()) {
                if let Some(field) = extract_single_field(inner, source, config) {
                    fields.push(field);
                }
            }
        }
    }

    fields
}

fn extract_single_field(node: Node, source: &str, config: &LanguageConfig) -> Option<FieldDef> {
    let name = find_child_by_field(node, "name")
        .and_then(|n| n.utf8_text(source.as_bytes()).ok())
        .map(|s| s.to_string())?;

    let type_name = find_child_by_field(node, "type")
        .and_then(|n| n.utf8_text(source.as_bytes()).ok())
        .map(|s| s.to_string())
        .unwrap_or_else(|| "unknown".to_string());

    let is_public = check_visibility(node, source, config);

    Some(FieldDef {
        name,
        type_name,
        is_public,
    })
}

fn extract_function(node: Node, source: &str, config: &LanguageConfig) -> Option<FunctionDef> {
    let name = find_child_by_field(node, "name")
        .and_then(|n| n.utf8_text(source.as_bytes()).ok())
        .map(|s| s.to_string())?;

    let is_public = check_visibility(node, source, config);
    let is_async = check_async(node, source);
    let start_line = node.start_position().row + 1;
    let end_line = node.end_position().row + 1;

    let params = extract_parameters(node, source, config);
    let return_type = extract_return_type(node, source, config);

    Some(FunctionDef {
        name,
        is_public,
        is_async,
        params,
        return_type,
        start_line,
        end_line,
    })
}

fn extract_parameters(node: Node, source: &str, config: &LanguageConfig) -> Vec<String> {
    let mut params = Vec::new();

    if let Some(params_node) = find_child_by_field(node, "parameters") {
        let mut cursor = params_node.walk();
        for child in params_node.children(&mut cursor) {
            if config.param_kinds.contains(&child.kind()) {
                // Try to get parameter name
                if let Some(name_node) = find_child_by_field(child, "pattern")
                    .or_else(|| find_child_by_field(child, "name"))
                {
                    if let Ok(name) = name_node.utf8_text(source.as_bytes()) {
                        // Try to get type
                        let type_str = find_child_by_field(child, "type")
                            .and_then(|t| t.utf8_text(source.as_bytes()).ok())
                            .map(|t| format!(": {}", t))
                            .unwrap_or_default();
                        params.push(format!("{}{}", name, type_str));
                    }
                } else if let Ok(text) = child.utf8_text(source.as_bytes()) {
                    // Fallback: use full text
                    let text = text.trim();
                    if !text.is_empty() && text != "," {
                        params.push(text.to_string());
                    }
                }
            }
        }
    }

    params
}

fn extract_return_type(node: Node, source: &str, _config: &LanguageConfig) -> Option<String> {
    find_child_by_field(node, "return_type")
        .and_then(|n| n.utf8_text(source.as_bytes()).ok())
        .map(|s| s.trim_start_matches("->").trim().to_string())
}

fn extract_trait(node: Node, source: &str, config: &LanguageConfig) -> Option<TraitDef> {
    let name = find_child_by_field(node, "name")
        .and_then(|n| n.utf8_text(source.as_bytes()).ok())
        .map(|s| s.to_string())?;

    let is_public = check_visibility(node, source, config);
    let start_line = node.start_position().row + 1;
    let end_line = node.end_position().row + 1;

    Some(TraitDef {
        name,
        is_public,
        start_line,
        end_line,
    })
}

fn extract_enum(node: Node, source: &str, config: &LanguageConfig) -> Option<EnumDef> {
    let name = find_child_by_field(node, "name")
        .and_then(|n| n.utf8_text(source.as_bytes()).ok())
        .map(|s| s.to_string())?;

    let is_public = check_visibility(node, source, config);
    let start_line = node.start_position().row + 1;
    let end_line = node.end_position().row + 1;

    let variants = extract_enum_variants(node, source, config);

    Some(EnumDef {
        name,
        is_public,
        start_line,
        end_line,
        variants,
    })
}

fn extract_enum_variants(node: Node, source: &str, config: &LanguageConfig) -> Vec<String> {
    let mut variants = Vec::new();
    let mut cursor = node.walk();

    fn collect_variants(
        node: Node,
        source: &str,
        config: &LanguageConfig,
        variants: &mut Vec<String>,
    ) {
        if config.enum_variant_kinds.contains(&node.kind()) {
            if let Some(name_node) = find_child_by_field(node, "name") {
                if let Ok(name) = name_node.utf8_text(source.as_bytes()) {
                    variants.push(name.to_string());
                }
            } else if let Ok(text) = node.utf8_text(source.as_bytes()) {
                // Some languages have simpler variant structures
                let text = text.trim();
                if !text.is_empty() {
                    variants.push(text.to_string());
                }
            }
        }

        let mut cursor = node.walk();
        for child in node.children(&mut cursor) {
            collect_variants(child, source, config, variants);
        }
    }

    for child in node.children(&mut cursor) {
        collect_variants(child, source, config, &mut variants);
    }

    variants
}

fn check_visibility(node: Node, source: &str, config: &LanguageConfig) -> bool {
    // Check for visibility modifier as a child
    let mut cursor = node.walk();
    for child in node.children(&mut cursor) {
        if child.kind() == "visibility_modifier" {
            if let Ok(text) = child.utf8_text(source.as_bytes()) {
                return text.contains("pub");
            }
        }
        // Python: check for decorators or naming conventions
        if child.kind() == "decorator" {
            if let Ok(text) = child.utf8_text(source.as_bytes()) {
                if text.contains("export") || text.contains("public") {
                    return true;
                }
            }
        }
    }

    // TypeScript/JavaScript: check for export keyword
    if let Some(parent) = node.parent() {
        if parent.kind() == "export_statement" {
            return true;
        }
    }

    // Check previous sibling for export
    if let Some(prev) = node.prev_sibling() {
        if prev.kind() == "export" || prev.kind() == "export_statement" {
            return true;
        }
    }

    // Language-specific defaults
    match config.name {
        "python" => {
            // Python: items not starting with _ are considered public
            if let Some(name_node) = find_child_by_field(node, "name") {
                if let Ok(name) = name_node.utf8_text(source.as_bytes()) {
                    return !name.starts_with('_');
                }
            }
            true
        }
        "typescript" | "javascript" => false, // Need explicit export
        _ => false,
    }
}

fn check_async(node: Node, source: &str) -> bool {
    let mut cursor = node.walk();
    for child in node.children(&mut cursor) {
        if child.kind() == "async" {
            return true;
        }
    }

    // Also check the node text for async keyword
    if let Ok(text) = node.utf8_text(source.as_bytes()) {
        return text.trim_start().starts_with("async");
    }

    false
}

fn find_child_by_field<'a>(node: Node<'a>, field_name: &str) -> Option<Node<'a>> {
    node.child_by_field_name(field_name)
}