ruchy 4.2.0

#![allow(missing_docs)]
// PARSER-060: Module Resolution MVP Tests
//
// Scope: File resolution, loading, symbol extraction, imports
// Out of scope: Circular deps, namespaces, visibility, wildcards
//
// Test structure follows CLAUDE.md naming convention:
// test_parser_060_<section>_<feature>_<scenario>

use std::fs;
use std::rc::Rc;
use tempfile::TempDir;

// === RED PHASE: These tests MUST fail until implementation is complete ===

// -------------------------------------------------------------------
// Section 1: File Resolution Tests (use foo::bar → ./foo/bar.ruchy)
// -------------------------------------------------------------------

#[test]
fn test_parser_060_01_file_resolution_simple_module() {
    // Test: use utils → ./utils.ruchy
    let temp_dir = TempDir::new().unwrap();
    let utils_path = temp_dir.path().join("utils.ruchy");
    fs::write(&utils_path, "fun helper() { 42 }").unwrap();

    let module_path = "utils";
    let resolved = resolve_module_path(module_path, temp_dir.path()).unwrap();

    assert_eq!(resolved, utils_path);
}

#[test]
fn test_parser_060_01_file_resolution_nested_module() {
    // Test: use foo::bar → ./foo/bar.ruchy
    let temp_dir = TempDir::new().unwrap();
    let foo_dir = temp_dir.path().join("foo");
    fs::create_dir(&foo_dir).unwrap();
    let bar_path = foo_dir.join("bar.ruchy");
    fs::write(&bar_path, "fun baz() { 100 }").unwrap();

    let module_path = "foo::bar";
    let resolved = resolve_module_path(module_path, temp_dir.path()).unwrap();

    assert_eq!(resolved, bar_path);
}

#[test]
fn test_parser_060_01_file_resolution_deeply_nested() {
    // Test: use a::b::c → ./a/b/c.ruchy
    let temp_dir = TempDir::new().unwrap();
    let a_dir = temp_dir.path().join("a");
    let b_dir = a_dir.join("b");
    fs::create_dir_all(&b_dir).unwrap();
    let c_path = b_dir.join("c.ruchy");
    fs::write(&c_path, "fun deep() { 999 }").unwrap();

    let module_path = "a::b::c";
    let resolved = resolve_module_path(module_path, temp_dir.path()).unwrap();

    assert_eq!(resolved, c_path);
}

#[test]
fn test_parser_060_01_file_resolution_missing_file() {
    // Test: use nonexistent → Error
    let temp_dir = TempDir::new().unwrap();

    let module_path = "nonexistent";
    let result =
        std::panic::catch_unwind(|| resolve_module_path(module_path, temp_dir.path()).unwrap());

    assert!(
        result.is_err(),
        "Should fail when module file doesn't exist"
    );
}

#[test]
fn test_parser_060_01_file_resolution_dot_notation() {
    // Test: Python-style import foo.bar → ./foo/bar.ruchy
    let temp_dir = TempDir::new().unwrap();
    let foo_dir = temp_dir.path().join("foo");
    fs::create_dir(&foo_dir).unwrap();
    let bar_path = foo_dir.join("bar.ruchy");
    fs::write(&bar_path, "fun test() { 1 }").unwrap();

    let module_path = "foo.bar"; // Dot notation
    let resolved = resolve_module_path_dot_notation(module_path, temp_dir.path()).unwrap();

    assert_eq!(resolved, bar_path);
}

// -------------------------------------------------------------------
// Section 2: File Loading & Parsing Tests
// -------------------------------------------------------------------

#[test]
fn test_parser_060_02_loading_simple_module() {
    // Test: Load and parse a simple module file
    let temp_dir = TempDir::new().unwrap();
    let module_path = temp_dir.path().join("math.ruchy");
    fs::write(&module_path, "fun add(x, y) { x + y }").unwrap();

    let loaded_module = load_module(&module_path).unwrap();

    assert!(loaded_module.is_loaded());
    assert_eq!(loaded_module.path(), &module_path);
}

#[test]
fn test_parser_060_02_loading_module_with_multiple_functions() {
    // Test: Load module with multiple function definitions
    let temp_dir = TempDir::new().unwrap();
    let module_path = temp_dir.path().join("utils.ruchy");
    fs::write(
        &module_path,
        r"
        fun add(x, y) { x + y }
        fun sub(x, y) { x - y }
        fun mul(x, y) { x * y }
    ",
    )
    .unwrap();

    let loaded_module = load_module(&module_path).unwrap();
    let symbols = loaded_module.symbols();

    assert_eq!(symbols.len(), 3);
    assert!(symbols.contains_key("add"));
    assert!(symbols.contains_key("sub"));
    assert!(symbols.contains_key("mul"));
}

#[test]
fn test_parser_060_02_loading_module_parse_error() {
    // Test: Handle syntax errors gracefully
    let temp_dir = TempDir::new().unwrap();
    let module_path = temp_dir.path().join("broken.ruchy");
    fs::write(&module_path, "fun broken( { incomplete syntax").unwrap();

    let result = load_module(&module_path);

    assert!(result.is_err(), "Should return error for invalid syntax");
}

// -------------------------------------------------------------------
// Section 3: Symbol Extraction Tests (functions, structs, consts)
// -------------------------------------------------------------------

#[test]
fn test_parser_060_03_extract_function_symbols() {
    // Test: Extract function definitions from AST
    let temp_dir = TempDir::new().unwrap();
    let module_path = temp_dir.path().join("funcs.ruchy");
    fs::write(
        &module_path,
        r"
        fun public_func() { 1 }
        fun helper_func(x) { x * 2 }
    ",
    )
    .unwrap();

    let loaded_module = load_module(&module_path).unwrap();
    let functions = extract_functions(&loaded_module);

    assert_eq!(functions.len(), 2);
    assert!(functions.iter().any(|f| f.name == "public_func"));
    assert!(functions.iter().any(|f| f.name == "helper_func"));
}

#[test]
fn test_parser_060_03_extract_struct_symbols() {
    // Test: Extract struct definitions from AST
    let temp_dir = TempDir::new().unwrap();
    let module_path = temp_dir.path().join("structs.ruchy");
    fs::write(
        &module_path,
        r"
        struct Point { x: i32, y: i32 }
        struct Circle { center: Point, radius: f64 }
    ",
    )
    .unwrap();

    let loaded_module = load_module(&module_path).unwrap();
    let structs = extract_structs(&loaded_module);

    assert_eq!(structs.len(), 2);
    assert!(structs.iter().any(|s| s.name == "Point"));
    assert!(structs.iter().any(|s| s.name == "Circle"));
}

#[test]
fn test_parser_060_03_extract_const_symbols() {
    // Test: Extract constant definitions from AST
    let temp_dir = TempDir::new().unwrap();
    let module_path = temp_dir.path().join("consts.ruchy");
    fs::write(
        &module_path,
        r"
        const PI = 3.14159
        const MAX_SIZE = 1000
    ",
    )
    .unwrap();

    let loaded_module = load_module(&module_path).unwrap();
    let consts = extract_consts(&loaded_module);

    assert_eq!(consts.len(), 2);
    assert!(consts.iter().any(|c| c.name == "PI"));
    assert!(consts.iter().any(|c| c.name == "MAX_SIZE"));
}

#[test]
fn test_parser_060_03_extract_mixed_symbols() {
    // Test: Extract all symbol types from a single module
    let temp_dir = TempDir::new().unwrap();
    let module_path = temp_dir.path().join("mixed.ruchy");
    fs::write(
        &module_path,
        r#"
        const VERSION = "1.0"
        struct Config { debug: bool }
        fun init() { Config { debug: true } }
    "#,
    )
    .unwrap();

    let loaded_module = load_module(&module_path).unwrap();
    let all_symbols = extract_all_symbols(&loaded_module);

    assert_eq!(all_symbols.functions.len(), 1);
    assert_eq!(all_symbols.structs.len(), 1);
    assert_eq!(all_symbols.consts.len(), 1);
}

// -------------------------------------------------------------------
// Section 4: Symbol Import Tests (inject into environment)
// -------------------------------------------------------------------

#[test]
fn test_parser_060_04_import_simple_function() {
    // Test: use utils::helper imports single function
    let temp_dir = TempDir::new().unwrap();
    let utils_path = temp_dir.path().join("utils.ruchy");
    fs::write(&utils_path, "fun helper() { 42 }").unwrap();

    let code = "use utils::helper\nhelper()";
    let result = execute_with_imports(code, temp_dir.path()).unwrap();

    assert_eq!(result, Value::Integer(42));
}

#[test]
#[ignore = "RED phase: multi-function imports not yet implemented - PARSER-060"]
fn test_parser_060_04_import_multiple_functions() {
    // Test: use utils::{add, sub} imports multiple functions
    let temp_dir = TempDir::new().unwrap();
    let utils_path = temp_dir.path().join("utils.ruchy");
    fs::write(
        &utils_path,
        r"
        fun add(x, y) { x + y }
        fun sub(x, y) { x - y }
    ",
    )
    .unwrap();

    let code = "use utils::{add, sub}\nadd(10, 5) + sub(10, 5)";
    let result = execute_with_imports(code, temp_dir.path()).unwrap();

    assert_eq!(result, Value::Integer(20)); // 15 + 5
}

#[test]
fn test_parser_060_04_import_struct_constructor() {
    // Test: use types::Point imports struct constructor
    let temp_dir = TempDir::new().unwrap();
    let types_path = temp_dir.path().join("types.ruchy");
    fs::write(&types_path, "struct Point { x: i32, y: i32 }").unwrap();

    let code = "use types::Point\nPoint { x: 10, y: 20 }.x";
    let result = execute_with_imports(code, temp_dir.path()).unwrap();

    assert_eq!(result, Value::Integer(10));
}

#[test]
fn test_parser_060_04_import_const_value() {
    // Test: use config::VERSION imports constant
    let temp_dir = TempDir::new().unwrap();
    let config_path = temp_dir.path().join("config.ruchy");
    fs::write(&config_path, "const VERSION = \"1.0\"").unwrap();

    let code = "use config::VERSION\nVERSION";
    let result = execute_with_imports(code, temp_dir.path()).unwrap();

    assert_eq!(result, Value::from_string("1.0".to_string()));
}

#[test]
fn test_parser_060_04_import_from_nested_module() {
    // Test: use foo::bar::baz imports from nested module
    let temp_dir = TempDir::new().unwrap();
    let foo_dir = temp_dir.path().join("foo");
    fs::create_dir(&foo_dir).unwrap();
    let bar_path = foo_dir.join("bar.ruchy");
    fs::write(&bar_path, "fun baz() { 100 }").unwrap();

    let code = "use foo::bar::baz\nbaz()";
    let result = execute_with_imports(code, temp_dir.path()).unwrap();

    assert_eq!(result, Value::Integer(100));
}

#[test]
fn test_parser_060_04_import_nonexistent_symbol() {
    // Test: use utils::missing fails with clear error
    let temp_dir = TempDir::new().unwrap();
    let utils_path = temp_dir.path().join("utils.ruchy");
    fs::write(&utils_path, "fun helper() { 1 }").unwrap();

    let code = "use utils::missing\nmissing()";
    let result = execute_with_imports(code, temp_dir.path());

    assert!(
        result.is_err(),
        "Should fail when importing nonexistent symbol"
    );
    let err_msg = format!("{:?}", result.unwrap_err());
    assert!(err_msg.contains("not found") || err_msg.contains("missing"));
}

// -------------------------------------------------------------------
// Section 5: Module Cache Tests (avoid re-parsing)
// -------------------------------------------------------------------

#[test]
fn test_parser_060_05_cache_module_on_first_load() {
    // Test: First load caches the parsed module
    let temp_dir = TempDir::new().unwrap();
    let module_path = temp_dir.path().join("cached.ruchy");
    fs::write(&module_path, "fun test() { 1 }").unwrap();

    let cache = ModuleCache::new();
    let module1 = cache.load(&module_path).unwrap();
    let module2 = cache.load(&module_path).unwrap();

    assert!(
        Rc::ptr_eq(&module1, &module2),
        "Should return same cached instance"
    );
}

#[test]
fn test_parser_060_05_cache_multiple_modules() {
    // Test: Cache handles multiple different modules
    let temp_dir = TempDir::new().unwrap();

    let mod1_path = temp_dir.path().join("mod1.ruchy");
    fs::write(&mod1_path, "fun test1() { 1 }").unwrap();

    let mod2_path = temp_dir.path().join("mod2.ruchy");
    fs::write(&mod2_path, "fun test2() { 2 }").unwrap();

    let cache = ModuleCache::new();
    let module1 = cache.load(&mod1_path).unwrap();
    let module2 = cache.load(&mod2_path).unwrap();

    assert!(
        !Rc::ptr_eq(&module1, &module2),
        "Different modules should be different instances"
    );
}

// -------------------------------------------------------------------
// Helper functions (will be implemented in GREEN phase)
// -------------------------------------------------------------------

// -------------------------------------------------------------------
// Import actual implementations from module_loader
// -------------------------------------------------------------------

use ruchy::frontend::ast::{Expr, ExprKind};
use ruchy::frontend::parser::Parser;
use ruchy::runtime::module_loader::{
    extract_all_symbols, extract_consts, extract_functions, extract_structs, load_module,
    resolve_module_path, resolve_module_path_dot_notation, ModuleCache,
};
use ruchy::runtime::{Interpreter, Value};

fn execute_with_imports(code: &str, base: &std::path::Path) -> Result<Value, String> {
    // Parse the code
    let ast = Parser::new(code)
        .parse()
        .map_err(|e| format!("Parse error: {e:?}"))?;

    // Create module cache and interpreter
    let cache = ModuleCache::new();
    let mut interpreter = Interpreter::new();

    // Extract import statements and process them
    let exprs: Vec<&Expr> = match &ast.kind {
        ExprKind::Block(exprs) => exprs.iter().collect(),
        _ => vec![&ast],
    };

    // Separate import statements from other code
    let mut non_import_exprs: Vec<Expr> = Vec::new();

    for expr in &exprs {
        if let ExprKind::Import { module, items } = &expr.kind {
            // Split module path into module file and symbols
            // For "utils::helper" with no items → module="utils", symbols=["helper"]
            // For "utils" with items=["add", "sub"] → module="utils", symbols=["add", "sub"]
            let (module_file, symbol_names): (String, Vec<String>) = if let Some(item_names) = items
            {
                // Explicit items: use module as-is, items as symbols
                (module.clone(), item_names.clone())
            } else {
                // No items: last segment is the symbol, rest is module path
                let parts: Vec<&str> = module.split("::").collect();
                if parts.len() == 1 {
                    // Single name with no items - import the whole module
                    (module.clone(), vec![])
                } else {
                    // Split into module and symbol
                    let module_part = parts[..parts.len() - 1].join("::");
                    let symbol_part = parts[parts.len() - 1].to_string();
                    (module_part, vec![symbol_part])
                }
            };

            // Resolve module path and load module
            let module_path = resolve_module_path(&module_file, base).map_err(|e| e.to_string())?;
            let loaded_module = cache.load(&module_path).map_err(|e| e.to_string())?;

            // Evaluate the entire module to register ALL symbols in the interpreter
            // This avoids issues with evaluating individual function expressions
            interpreter
                .eval_expr(loaded_module.ast())
                .map_err(|e| format!("Failed to load module: {e}"))?;

            // Verify requested symbols exist
            if !symbol_names.is_empty() {
                for item_name in &symbol_names {
                    loaded_module.get_symbol(item_name).ok_or_else(|| {
                        format!("Symbol '{item_name}' not found in module '{module_file}'")
                    })?;
                }
            }
        } else {
            // Not an import - keep for execution
            non_import_exprs.push((*expr).clone());
        }
    }

    // Execute the code (excluding import statements)
    if non_import_exprs.is_empty() {
        // No code to execute - return Nil
        Ok(Value::Nil)
    } else if non_import_exprs.len() == 1 {
        // Single expression - evaluate directly
        interpreter
            .eval_expr(&non_import_exprs[0])
            .map_err(|e| format!("Execution error: {e}"))
    } else {
        // Multiple expressions - create a block using ast's metadata
        let block_expr = Expr {
            kind: ExprKind::Block(non_import_exprs),
            span: ast.span,
            attributes: Vec::new(),
            leading_comments: Vec::new(),
            trailing_comment: None,
        };
        interpreter
            .eval_expr(&block_expr)
            .map_err(|e| format!("Execution error: {e}"))
    }
}