#![cfg(test)]

use std::cell::RefCell;
use std::rc::Rc;

use crate::symbol_table::SymbolTable;
use crate::scope_resolution::ScopeResolver;
use crate::reduced_ast::reduce;
use crate::eval::State;

fn evaluate_all_outputs(input: &str) -> Vec<Result<String, String>> {
  let symbol_table = Rc::new(RefCell::new(SymbolTable::new()));
  let mut state = State::new(symbol_table);
  let mut ast = crate::util::quick_ast(input);
  state.symbol_table_handle.borrow_mut().add_top_level_symbols(&ast).unwrap();
  {
  let t = &state.symbol_table_handle.borrow();
  let mut scope_resolver = crate::scope_resolution::ScopeResolver::new(&t);
  let _ = scope_resolver.resolve(&mut ast);
  }

  let reduced = reduce(&ast, &state.symbol_table_handle.borrow());
  let all_output = state.evaluate(reduced, true);
  all_output
}

macro_rules! test_in_fresh_env {
  ($string:expr, $correct:expr) => {
    {
      let all_output = evaluate_all_outputs($string);
      let ref output = all_output.last().unwrap();
      assert_eq!(**output, Ok($correct.to_string()));
    }
  }
}

#[test]
fn test_basic_eval() {
  test_in_fresh_env!("1 + 2", "3");
  test_in_fresh_env!("let mut a = 1; a = 2", "Unit");
  /*
     test_in_fresh_env!("let mut a = 1; a = 2; a", "2");
     test_in_fresh_env!(r#"("a", 1 + 2)"#, r#"("a", 3)"#);
     */
}

#[test]
fn op_eval() {
  test_in_fresh_env!("- 13", "-13");
  test_in_fresh_env!("10 - 2", "8");
}

#[test]
fn function_eval() {
  test_in_fresh_env!("fn oi(x) { x + 1 }; oi(4)", "5");
  test_in_fresh_env!("fn oi(x) { x + 1 }; oi(1+2)", "4");
}

#[test]
fn scopes() {
  let scope_ok = r#"
    let a = 20
    fn haha() {
      let a = 10
      a
    }
    haha()
    "#;
    test_in_fresh_env!(scope_ok, "10");
    let scope_ok = r#"
    let a = 20
    fn haha() {
      let a = 10
      a
    }
    a
    "#;
    test_in_fresh_env!(scope_ok, "20");
}

#[test]
fn if_is_patterns() {
  let source = r#"
type Option<T> = Some(T) | None
let x = Option::Some(9); if x is Option::Some(q) then { q } else { 0 }"#;
  test_in_fresh_env!(source, "9");

  let source = r#"
type Option<T> = Some(T) | None
let x = Option::None; if x is Option::Some(q) then { q } else { 0 }"#;
  test_in_fresh_env!(source, "0");
}

#[test]
fn full_if_matching() {
  let source = r#"
type Option<T> = Some(T) | None
let a = Option::None
if a { is Option::None -> 4, is Option::Some(x) -> x }
"#;
test_in_fresh_env!(source, "4");

let source = r#"
type Option<T> = Some(T) | None
let a = Option::Some(99)
if a { is Option::None -> 4, is Option::Some(x) -> x }
"#;
test_in_fresh_env!(source, "99");

let source = r#"
let a = 10
if a { is 10 -> "x", is 4 -> "y" }
"#;
test_in_fresh_env!(source, "\"x\"");

let source = r#"
let a = 10
if a { is 15 -> "x", is 10 -> "y" }
"#;
test_in_fresh_env!(source, "\"y\"");
}

#[test]
fn string_pattern() {
  let source = r#"
let a = "foo"
if a { is "foo" -> "x", is _ -> "y" }
"#;
test_in_fresh_env!(source, "\"x\"");
}

#[test]
fn boolean_pattern() {
  let source = r#"
let a = true
if a { 
  is true -> "x",
  is false -> "y"
}
"#;
test_in_fresh_env!(source, "\"x\"");
}

#[test]
fn boolean_pattern_2() {
  let source = r#"
let a = false
if a { is true -> "x", is false -> "y" }
"#;
test_in_fresh_env!(source, "\"y\"");
}

#[test]
fn ignore_pattern() {
  let source = r#"
type Option<T> = Some(T) | None
if Option::Some(10) {
  is _ -> "hella"
}
"#;
test_in_fresh_env!(source, "\"hella\"");
}

#[test]
fn tuple_pattern() {
  let source = r#"
if (1, 2) {
  is (1, x) -> x,
  is _ -> 99
}
"#;
test_in_fresh_env!(source, 2);
}


#[test]
fn tuple_pattern_2() {
  let source = r#"
if (1, 2) {
  is (10, x) -> x,
  is (y, x) -> x + y
}
"#;
test_in_fresh_env!(source, 3);
}

#[test]
fn tuple_pattern_3() {
  let source = r#"
if (1, 5) {
  is (10, x) -> x,
  is (1, x) -> x
}
"#;
test_in_fresh_env!(source, 5);
}

#[test]
fn tuple_pattern_4() {
  let source = r#"
if (1, 5) {
  is (10, x) -> x,
  is (1, x) -> x,
}
"#;
test_in_fresh_env!(source, 5);
}

#[test]
fn  prim_obj_pattern() {
  let source = r#"
type Stuff = Mulch(Nat) | Jugs(Nat, String) | Mardok
let a = Stuff::Mulch(20)
let b = Stuff::Jugs(1, "haha")
let c = Stuff::Mardok

let x = if a {
  is Stuff::Mulch(20) -> "x",
  is _ -> "ERR"
}

let y = if b {
  is Stuff::Mulch(n) -> "ERR",
  is Stuff::Jugs(2, _) -> "ERR",
  is Stuff::Jugs(1, s) -> s,
  is _ -> "ERR",
}

let z = if c {
  is Stuff::Jugs(_, _) -> "ERR",
  is Stuff::Mardok -> "NIGH",
  is _ -> "ERR",
}

(x, y, z)
"#;
test_in_fresh_env!(source, r#"("x", "haha", "NIGH")"#);
}

#[test]
fn basic_lambda_syntax() {
  let source = r#"
let q = \(x, y) { x * y }
let x = q(5,2)
let y = \(m, n, o) { m + n + o }(1,2,3)
(x, y)
  "#;
test_in_fresh_env!(source, r"(10, 6)");
}

#[test]
fn lambda_syntax_2() {
  let source = r#"
fn milta() {
  \(x) { x + 33 }
}
milta()(10)
  "#;
  test_in_fresh_env!(source, "43");
  }