//! TDD for rest patterns in destructuring

use std::process::Command;
use std::fs;
use tempfile::NamedTempFile;

fn run_test_file(code: &str) -> Result<String, String> {
    let temp_file = NamedTempFile::new().expect("Failed to create temp file");
    fs::write(temp_file.path(), code).expect("Failed to write test code");
    
    let output = Command::new("cargo")
        .args(&["run", "--quiet", "--bin", "ruchy", "--", "run", temp_file.path().to_str().unwrap()])
        .output()
        .expect("Failed to run ruchy");
    
    if output.status.success() {
        Ok(String::from_utf8_lossy(&output.stdout).to_string())
    } else {
        Err(String::from_utf8_lossy(&output.stderr).to_string())
    }
}

#[test]
fn test_rest_pattern_simple() {
    // GREEN phase - rest patterns now work!
    let code = r#"
let arr = [1, 2, 3, 4, 5]
let [first, ...rest] = arr
println(first)
println(rest)
"#;
    
    let output = run_test_file(code).expect("Rest patterns should work now");
    assert!(output.contains("1"));
    assert!(output.contains("[2, 3, 4, 5]"));
}

#[test]
fn test_rest_pattern_named() {
    // GREEN phase - named rest patterns work!
    let code = r#"
let arr = [1, 2, 3]
let [head, ...tail] = arr
println(head)
println(tail)
"#;
    
    let output = run_test_file(code).expect("Named rest patterns should work now");
    assert!(output.contains("1"));
    assert!(output.contains("[2, 3]"));
}

#[test] 
fn test_rest_pattern_empty() {
    // GREEN phase - rest with single element creates empty array
    let code = r#"
let arr = [42]
let [only, ...empty] = arr
println(only)
println(empty)
"#;
    
    let output = run_test_file(code).expect("Rest patterns with single element should work");
    assert!(output.contains("42"));
    assert!(output.contains("[]"));  // Empty rest becomes empty array
}