#![cfg(test)]
#![warn(clippy::dbg_macro)]
// See github.com/rtfeldman/roc/issues/800 for discussion of the large_enum_variant check.
#![allow(clippy::large_enum_variant)]
// we actually want to compare against the literal float bits
#![allow(clippy::float_cmp)]

#[macro_use]
extern crate pretty_assertions;

#[macro_use]
extern crate indoc;

/// Used in the with_larger_debug_stack() function, for tests that otherwise
/// run out of stack space in debug builds (but don't in --release builds)
#[allow(dead_code)]
const EXPANDED_STACK_SIZE: usize = 8 * 1024 * 1024;

use test_mono_macros::*;

use roc_can::builtins::builtin_defs_map;
use roc_collections::all::MutMap;
use roc_module::symbol::Symbol;
use roc_mono::ir::Proc;

use roc_mono::ir::ProcLayout;

/// Without this, some tests pass in `cargo test --release` but fail without
/// the --release flag because they run out of stack space. This increases
/// stack size for debug builds only, while leaving the stack space at the default
/// amount for release builds.
#[allow(dead_code)]
#[cfg(debug_assertions)]
pub fn with_larger_debug_stack<F>(run_test: F)
where
    F: FnOnce(),
    F: Send,
    F: 'static,
{
    std::thread::Builder::new()
        .stack_size(EXPANDED_STACK_SIZE)
        .spawn(run_test)
        .expect("Error while spawning expanded dev stack size thread")
        .join()
        .expect("Error while joining expanded dev stack size thread")
}

/// In --release builds, don't increase the stack size. Run the test normally.
/// This way, we find out if any of our tests are blowing the stack even after
/// optimizations in release builds.
#[allow(dead_code)]
#[cfg(not(debug_assertions))]
#[inline(always)]
pub fn with_larger_debug_stack<F>(run_test: F)
where
    F: FnOnce() -> (),
    F: Send,
    F: 'static,
{
    run_test()
}

fn promote_expr_to_module(src: &str) -> String {
    let mut buffer = String::from("app \"test\" provides [ main ] to \"./platform\"\n\nmain =\n");

    for line in src.lines() {
        // indent the body!
        buffer.push_str("    ");
        buffer.push_str(line);
        buffer.push('\n');
    }

    buffer
}

fn compiles_to_ir(test_name: &str, src: &str) {
    use bumpalo::Bump;
    use std::path::{Path, PathBuf};

    let arena = &Bump::new();

    // let stdlib = roc_builtins::unique::uniq_stdlib();
    let stdlib = roc_builtins::std::standard_stdlib();
    let filename = PathBuf::from("Test.roc");
    let src_dir = Path::new("fake/test/path");

    let module_src;
    let temp;
    if src.starts_with("app") {
        // this is already a module
        module_src = src;
    } else {
        // this is an expression, promote it to a module
        temp = promote_expr_to_module(src);
        module_src = &temp;
    }

    let exposed_types = MutMap::default();

    let loaded = roc_load::file::load_and_monomorphize_from_str(
        arena,
        filename,
        module_src,
        &stdlib,
        src_dir,
        exposed_types,
        8,
        builtin_defs_map,
    );

    let mut loaded = match loaded {
        Ok(x) => x,
        Err(roc_load::file::LoadingProblem::FormattedReport(report)) => {
            println!("{}", report);
            panic!();
        }
        Err(e) => panic!("{:?}", e),
    };

    use roc_load::file::MonomorphizedModule;
    let MonomorphizedModule {
        module_id: home,
        procedures,
        exposed_to_host,
        ..
    } = loaded;

    let can_problems = loaded.can_problems.remove(&home).unwrap_or_default();
    let type_problems = loaded.type_problems.remove(&home).unwrap_or_default();
    let mono_problems = loaded.mono_problems.remove(&home).unwrap_or_default();

    if !can_problems.is_empty() {
        println!("Ignoring {} canonicalization problems", can_problems.len());
    }

    assert_eq!(type_problems, Vec::new());
    assert_eq!(mono_problems, Vec::new());

    debug_assert_eq!(exposed_to_host.len(), 1);

    let main_fn_symbol = exposed_to_host.keys().copied().next().unwrap();

    verify_procedures(test_name, procedures, main_fn_symbol);
}

#[cfg(debug_assertions)]
fn verify_procedures(
    test_name: &str,
    procedures: MutMap<(Symbol, ProcLayout<'_>), Proc<'_>>,
    main_fn_symbol: Symbol,
) {
    let index = procedures
        .keys()
        .position(|(s, _)| *s == main_fn_symbol)
        .unwrap();

    let mut procs_string = procedures
        .values()
        .map(|proc| proc.to_pretty(200))
        .collect::<Vec<_>>();

    let main_fn = procs_string.swap_remove(index);

    procs_string.sort();
    procs_string.push(main_fn);

    let result = procs_string.join("\n");

    let path = format!("generated/{}.txt", test_name);
    std::fs::create_dir_all("generated").unwrap();
    std::fs::write(&path, result).unwrap();

    use std::process::Command;
    let is_tracked = Command::new("git")
        .args(&["ls-files", "--error-unmatch", &path])
        .output()
        .unwrap();

    if !is_tracked.status.success() {
        panic!(
            "The file {:?} is not tracked by git. Try using `git add` on it",
            &path
        );
    }

    let has_changes = Command::new("git")
        .args(&["diff", "--color=always", &path])
        .output()
        .unwrap();

    if !has_changes.status.success() {
        eprintln!("`git diff {:?}` failed", &path);
        unreachable!();
    }

    if !has_changes.stdout.is_empty() {
        println!("{}", std::str::from_utf8(&has_changes.stdout).unwrap());
        panic!("Output changed: resolve conflicts and `git add` the file.");
    }
}

// NOTE because the Show instance of module names is different in --release mode,
// these tests would all fail. In the future, when we do interesting optimizations,
// we'll likely want some tests for --release too.
#[cfg(not(debug_assertions))]
fn verify_procedures(
    _expected: &str,
    _procedures: MutMap<(Symbol, ProcLayout<'_>), Proc<'_>>,
    _main_fn_symbol: Symbol,
) {
    // Do nothing
}

#[mono_test]
fn ir_int_literal() {
    r#"
    5
    "#
}

#[mono_test]
fn ir_int_add() {
    r#"
    x = [ 1,2 ]
    5 + 4 + 3 + List.len x
    "#
}

#[mono_test]
fn ir_assignment() {
    r#"
    x = 5

    x
    "#
}

#[mono_test]
fn ir_when_maybe() {
    r#"
    when Just 3 is
        Just n -> n
        Nothing -> 0
    "#
}

#[mono_test]
fn ir_when_these() {
    r#"
    when These 1 2 is
        This x -> x
        That y -> y
        These x _ -> x
    "#
}

#[mono_test]
fn ir_when_record() {
    r#"
    when { x: 1, y: 3.14 } is
        { x } -> x
    "#
}

#[mono_test]
fn ir_plus() {
    r#"
    1 + 2
    "#
}

#[mono_test]
fn ir_round() {
    r#"
    Num.round 3.6
    "#
}

#[mono_test]
fn ir_when_idiv() {
    r#"
    when 1000 // 10 is
        Ok val -> val
        Err _ -> -1
    "#
}

#[mono_test]
fn ir_two_defs() {
    r#"
    x = 3
    y = 4

    x + y
    "#
}

#[mono_test]
fn ir_when_just() {
    r#"
    x : [ Nothing, Just I64 ]
    x = Just 41

    when x is
        Just v -> v + 0x1
        Nothing -> 0x1
    "#
}

#[mono_test]
fn one_element_tag() {
    r#"
    x : [ Pair I64 ]
    x = Pair 2

    x
    "#
}

#[mono_test]
fn guard_pattern_true() {
    r#"
    wrapper = \{} ->
        when 2 is
            2 if False -> 42
            _ -> 0

    wrapper {}
    "#
}

#[mono_test]
fn when_on_record() {
    r#"
    when { x: 0x2 } is
        { x } -> x + 3
    "#
}

#[mono_test]
fn when_nested_maybe() {
    r#"
    Maybe a : [ Nothing, Just a ]

    x : Maybe (Maybe I64)
    x = Just (Just 41)

    when x is
        Just (Just v) -> v + 0x1
        _ -> 0x1
    "#
}

#[mono_test]
fn when_on_two_values() {
    r#"
    when Pair 2 3 is
        Pair 4 3 -> 9
        Pair a b -> a + b
    "#
}

#[mono_test]
fn dict() {
    r#"
    Dict.len Dict.empty
    "#
}

#[mono_test]
fn list_append_closure() {
    r#"
    myFunction = \l -> List.append l 42

    myFunction [ 1, 2 ]
    "#
}

#[mono_test]
fn list_append() {
    // TODO this leaks at the moment
    // ListAppend needs to decrement its arguments
    r#"
    List.append [1] 2
    "#
}

#[mono_test]
fn list_len() {
    r#"
    x = [1,2,3]
    y = [ 1.0 ]

    List.len x + List.len y
    "#
}

#[mono_test]
fn when_joinpoint() {
    r#"
    wrapper = \{} ->
        x : [ Red, White, Blue ]
        x = Blue

        y =
            when x is
                Red -> 1
                White -> 2
                Blue -> 3

        y

    wrapper {}
    "#
}

#[mono_test]
fn simple_if() {
    r#"
    if True then
        1
    else
        2
    "#
}

#[mono_test]
fn if_multi_branch() {
    r#"
    if True then
        1
    else if False then
        2
    else
        3
    "#
}

#[mono_test]
fn when_on_result() {
    r#"
    wrapper = \{} ->
        x : Result I64 I64
        x = Ok 2

        y =
            when x is
                Ok 3 -> 1
                Ok _ -> 2
                Err _ -> 3
        y

    wrapper {}
    "#
}

#[mono_test]
fn let_with_record_pattern() {
    r#"
    { x } = { x: 0x2, y: 3.14 }

    x
    "#
}

#[mono_test]
fn let_with_record_pattern_list() {
    r#"
    { x } = { x: [ 1, 3, 4 ], y: 3.14 }

    x
    "#
}

#[mono_test]
fn if_guard_bind_variable_false() {
    r#"
    wrapper = \{} ->
        when 10 is
            x if x == 5 -> 0
            _ -> 42

    wrapper {}
    "#
}

#[mono_test]
fn alias_variable() {
    r#"
    x = 5
    y = x

    3
    "#
}

#[mono_test]
fn alias_variable_and_return_it() {
    r#"
    x = 5
    y = x

    y
    "#
}

#[mono_test]
fn branch_store_variable() {
    r#"
    when 0 is
        1 -> 12
        a -> a
    "#
}

#[mono_test]
fn list_pass_to_function() {
    r#"
    x : List I64
    x = [1,2,3]

    id : List I64 -> List I64
    id = \y -> List.set y 0 0

    id x
    "#
}

#[mono_test]
fn record_optional_field_let_no_use_default() {
    r#"
    f = \r ->
        { x ? 10, y } = r
        x + y


    f { x: 4, y: 9 }
    "#
}

#[mono_test]
fn record_optional_field_let_use_default() {
    r#"
    f = \r ->
        { x ? 10, y } = r
        x + y


    f { y: 9 }
    "#
}

#[mono_test]
fn record_optional_field_function_no_use_default() {
    r#"
    f = \{ x ? 10, y } -> x + y


    f { x: 4, y: 9 }
    "#
}

#[mono_test]
fn record_optional_field_function_use_default() {
    r#"
    f = \{ x ? 10, y } -> x + y


    f { y: 9 }
    "#
}

#[mono_test]
fn quicksort_help() {
    // do we still need with_larger_debug_stack?
    r#"
    quicksortHelp : List (Num a), I64, I64 -> List (Num a)
    quicksortHelp = \list, low, high ->
        if low < high then
            (Pair partitionIndex partitioned) = Pair 0 []

            partitioned
                |> quicksortHelp low (partitionIndex - 1)
                |> quicksortHelp (partitionIndex + 1) high
        else
            list

    quicksortHelp [] 0 0
    "#
}

#[mono_test]
fn quicksort_swap() {
    indoc!(
        r#"
        app "test" provides [ main ] to "./platform"

        swap = \list ->
            when Pair (List.get list 0) (List.get list 0) is
                Pair (Ok atI) (Ok atJ) ->
                    list
                        |> List.set 0 atJ
                        |> List.set 0 atI

                _ ->
                    []

        main =
            swap [ 1, 2 ]
        "#
    )
}

// #[ignore]
// #[mono_test]
// fn quicksort_partition_help() {
//     indoc!(
//         r#"
//         app "test" provides [ main ] to "./platform"

//         partitionHelp : I64, I64, List (Num a), I64, (Num a) -> [ Pair I64 (List (Num a)) ]
//         partitionHelp = \i, j, list, high, pivot ->
//             if j < high then
//                 when List.get list j is
//                     Ok value ->
//                         if value <= pivot then
//                             partitionHelp (i + 1) (j + 1) (swap (i + 1) j list) high pivot
//                         else
//                             partitionHelp i (j + 1) list high pivot

//                     Err _ ->
//                         Pair i list
//             else
//                 Pair i list

//         main =
//             partitionHelp 0 0 [] 0 0
//         "#
//     )
// }

// #[ignore]
// #[mono_test]
// fn quicksort_full() {
//     indoc!(
//         r#"
//         app "test" provides [ main ] to "./platform"

//         quicksortHelp : List (Num a), I64, I64 -> List (Num a)
//         quicksortHelp = \list, low, high ->
//             if low < high then
//                 (Pair partitionIndex partitioned) = partition low high list

//                 partitioned
//                     |> quicksortHelp low (partitionIndex - 1)
//                     |> quicksortHelp (partitionIndex + 1) high
//             else
//                 list

//         swap : I64, I64, List a -> List a
//         swap = \i, j, list ->
//             when Pair (List.get list i) (List.get list j) is
//                 Pair (Ok atI) (Ok atJ) ->
//                     list
//                         |> List.set i atJ
//                         |> List.set j atI

//                 _ ->
//                     []

//         partition : I64, I64, List (Num a) -> [ Pair I64 (List (Num a)) ]
//         partition = \low, high, initialList ->
//             when List.get initialList high is
//                 Ok pivot ->
//                     when partitionHelp (low - 1) low initialList high pivot is
//                         Pair newI newList ->
//                             Pair (newI + 1) (swap (newI + 1) high newList)

//                 Err _ ->
//                     Pair (low - 1) initialList

//         partitionHelp : I64, I64, List (Num a), I64, (Num a) -> [ Pair I64 (List (Num a)) ]
//         partitionHelp = \i, j, list, high, pivot ->
//             if j < high then
//                 when List.get list j is
//                     Ok value ->
//                         if value <= pivot then
//                             partitionHelp (i + 1) (j + 1) (swap (i + 1) j list) high pivot
//                         else
//                             partitionHelp i (j + 1) list high pivot

//                     Err _ ->
//                         Pair i list
//             else
//                 Pair i list

//         quicksort = \originalList ->
//             n = List.len originalList
//             quicksortHelp originalList 0 (n - 1)

//         main =
//             quicksort [1,2,3]
//         "#
//     )
// }

#[mono_test]
fn factorial() {
    r#"
    factorial = \n, accum ->
        when n is
            0 ->
                accum

            _ ->
                factorial (n - 1) (n * accum)

    factorial 10 1
    "#
}

#[mono_test]
fn is_nil() {
    r#"
    ConsList a : [ Cons a (ConsList a), Nil ]

    isNil : ConsList a -> Bool
    isNil = \list ->
        when list is
            Nil -> True
            Cons _ _ -> False

    isNil (Cons 0x2 Nil)
    "#
}

#[mono_test]
#[ignore]
fn has_none() {
    r#"
    Maybe a : [ Just a, Nothing ]
    ConsList a : [ Cons a (ConsList a), Nil ]

    hasNone : ConsList (Maybe a) -> Bool
    hasNone = \list ->
        when list is
            Nil -> False
            Cons Nothing _ -> True
            Cons (Just _) xs -> hasNone xs

    hasNone (Cons (Just 3) Nil)
    "#
}

#[mono_test]
fn mk_pair_of() {
    indoc!(
        r#"
        app "test" provides [ main ] to "./platform"

        mkPairOf = \x -> Pair x x

        main =
            mkPairOf [1,2,3]
        "#
    )
}

#[mono_test]
fn fst() {
    indoc!(
        r#"
        app "test" provides [ main ] to "./platform"

        fst = \x, _ -> x

        main =
            fst [1,2,3] [3,2,1]
        "#
    )
}

#[mono_test]
fn list_cannot_update_inplace() {
    indoc!(
        r#"
        app "test" provides [ main ] to "./platform"

        x : List I64
        x = [1,2,3]

        add : List I64 -> List I64
        add = \y -> List.set y 0 0

        main =
            List.len (add x) + List.len x
        "#
    )
}

#[mono_test]
fn list_get() {
    r#"
    wrapper = \{} ->
        List.get [1,2,3] 0

    wrapper {}
    "#
}

#[mono_test]
fn peano() {
    r#"
    Peano : [ S Peano, Z ]

    three : Peano
    three = S (S (S Z))

    three
    "#
}

#[mono_test]
fn peano1() {
    r#"
    Peano : [ S Peano, Z ]

    three : Peano
    three = S (S (S Z))

    when three is
        Z -> 0
        S _ -> 1
    "#
}

#[mono_test]
fn peano2() {
    r#"
    Peano : [ S Peano, Z ]

    three : Peano
    three = S (S (S Z))

    when three is
        S (S _) -> 1
        S (_) -> 0
        Z -> 0
    "#
}

#[mono_test]
fn optional_when() {
    r#"
    f = \r ->
        when r is
            { x: Blue, y ? 3 } -> y
            { x: Red, y ? 5 } -> y

    a = f { x: Blue, y: 7 }
    b = f { x: Blue }
    c = f { x: Red, y: 11 }
    d = f { x: Red }

    a * b * c * d
    "#
}

#[mono_test]
fn nested_pattern_match() {
    r#"
    Maybe a : [ Nothing, Just a ]

    x : Maybe (Maybe I64)
    x = Just (Just 41)

    when x is
        Just (Just v) -> v + 0x1
        _ -> 0x1
    "#
}

#[mono_test]
#[ignore]
fn linked_list_length_twice() {
    r#"
    LinkedList a : [ Nil, Cons a (LinkedList a) ]

    nil : LinkedList I64
    nil = Nil

    length : LinkedList a -> I64
    length = \list ->
        when list is
            Nil -> 0
            Cons _ rest -> 1 + length rest

    length nil + length nil
    "#
}

#[mono_test]
fn rigids() {
    indoc!(
        r#"
        app "test" provides [ main ] to "./platform"

        swap : Nat, Nat, List a -> List a
        swap = \i, j, list ->
            when Pair (List.get list i) (List.get list j) is
                Pair (Ok atI) (Ok atJ) ->
                    foo = atJ

                    list
                        |> List.set i foo
                        |> List.set j atI

                _ ->
                    []

        main =
            swap 0 0 [0x1]
        "#
    )
}

#[mono_test]
fn let_x_in_x() {
    r#"
    x = 5

    answer =
        1337

    unused =
        nested = 17
        nested

    answer
    "#
}

#[mono_test]
fn let_x_in_x_indirect() {
    r#"
    x = 5

    answer =
        1337

    unused =
        nested = 17

        i = 1

        nested

    { answer, unused }.answer
    "#
}

#[mono_test]
fn nested_closure() {
    indoc!(
        r#"
        app "test" provides [ main ] to "./platform"

        foo = \{} ->
            x = 42
            f = \{} -> x
            f

        main =
            f = foo {}
            f {}
        "#
    )
}

#[mono_test]
fn closure_in_list() {
    indoc!(
        r#"
        app "test" provides [ main ] to "./platform"
    
        foo = \{} ->
            x = 41
    
            f = \{} -> x
    
            [ f ]
    
        main =
            items = foo {}
    
            List.len items
        "#
    )
}

#[ignore]
#[mono_test]
fn somehow_drops_definitions() {
    indoc!(
        r#"
        app "test" provides [ main ] to "./platform"

        one : I64 
        one = 1

        two : I64
        two = 2

        increment : I64 -> I64
        increment = \x -> x + one

        double : I64 -> I64
        double = \x -> x * two

        apply : (a -> a), a -> a
        apply = \f, x -> f x

        main =
            apply (if True then increment else double) 42
        "#
    )
}

#[mono_test]
fn specialize_closures() {
    indoc!(
        r#"
        app "test" provides [ main ] to "./platform"


        apply : (a -> a), a -> a
        apply = \f, x -> f x

        main =
            one : I64 
            one = 1

            two : I64
            two = 2

            b : Bool
            b = True

            increment : I64 -> I64
            increment = \x -> x + one

            double : I64 -> I64
            double = \x -> if b then x * two else x

            apply (if True then increment else double) 42
        "#
    )
}

#[mono_test]
fn specialize_lowlevel() {
    indoc!(
        r#"
         app "test" provides [ main ] to "./platform"

         apply : (a -> a), a -> a
         apply = \f, x -> f x

         main =
             one : I64
             one = 1

             two : I64
             two = 2

             increment : I64 -> I64
             increment = \x -> x + one

             double : I64 -> I64
             double = \x -> x * two

             (if True then increment else double) 42
         "#
    )
}

// #[ignore]
// #[mono_test]
// fn static_str_closure() {
//     indoc!(
//         r#"
//         app "test" provides [ main ] to "./platform"

//         main : Str
//         main =
//             x = "long string that is malloced"

//             f : {} -> Str
//             f = (\_ -> x)

//             f {}
//         "#
//     )
// }