#![cfg(test)]

use super::{const_value, create_exported_function_no_locals, default_state};
use crate::{instance::Action, ImportDispatcher, Instance, ValueStack, DEFAULT_IMPORTS};
use bumpalo::{collections::Vec, Bump};
use roc_wasm_module::sections::{Import, ImportDesc};
use roc_wasm_module::{
    opcodes::OpCode, sections::ElementSegment, Export, ExportType, SerialBuffer, Serialize,
    Signature, Value, ValueType, WasmModule,
};

#[test]
fn test_loop() {
    test_loop_help(10, 55);
}

fn test_loop_help(end: i32, expected: i32) {
    let arena = Bump::new();
    let mut module = WasmModule::new(&arena);
    let buf = &mut module.code.bytes;

    // Loop from 0 to end, adding the loop variable to a total
    let var_i = 0;
    let var_total = 1;

    // (local i32 i32)
    buf.push(1); // one group of the given type
    buf.push(2); // two locals in the group
    buf.push(ValueType::I32 as u8);

    // loop <void>
    buf.push(OpCode::LOOP as u8);
    buf.push(ValueType::VOID as u8);

    //   local.get $i
    buf.push(OpCode::GETLOCAL as u8);
    buf.encode_u32(var_i);

    //   i32.const 1
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(1);

    //   i32.add
    buf.push(OpCode::I32ADD as u8);

    //   local.tee $i
    buf.push(OpCode::TEELOCAL as u8);
    buf.encode_u32(var_i);

    //   local.get $total
    buf.push(OpCode::GETLOCAL as u8);
    buf.encode_u32(var_total);

    //   i32.add
    buf.push(OpCode::I32ADD as u8);

    //   local.set $total
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(var_total);

    //   local.get $i
    buf.push(OpCode::GETLOCAL as u8);
    buf.encode_u32(var_i);

    //   i32.const $end
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(end);

    //   i32.lt_s
    buf.push(OpCode::I32LTS as u8);

    //   br_if 0
    buf.push(OpCode::BRIF as u8);
    buf.encode_u32(0);

    // end
    buf.push(OpCode::END as u8);

    // local.get $total
    buf.push(OpCode::GETLOCAL as u8);
    buf.encode_u32(var_total);

    // end function
    buf.push(OpCode::END as u8);

    let mut state = default_state(&arena);
    state
        .call_stack
        .push_frame(
            0,
            0,
            &[],
            &mut state.value_stack,
            &module.code.bytes,
            &mut state.program_counter,
        )
        .unwrap();

    while let Ok(Action::Continue) = state.execute_next_instruction(&module) {}

    assert_eq!(state.value_stack.pop_i32(), Ok(expected));
}

#[test]
fn test_if_else() {
    test_if_else_help(0, 222);
    test_if_else_help(1, 111);
    test_if_else_help(-123, 111);
}

fn test_if_else_help(condition: i32, expected: i32) {
    let arena = Bump::new();
    let mut module = WasmModule::new(&arena);
    let buf = &mut module.code.bytes;

    buf.push(1); // one group of the given type
    buf.push(1); // one local in the group
    buf.push(ValueType::I32 as u8);

    // i32.const <condition>
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(condition);

    // if <blocktype>
    buf.push(OpCode::IF as u8);
    buf.push(ValueType::VOID as u8);

    // i32.const 111
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(111);

    // local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    // else
    buf.push(OpCode::ELSE as u8);

    // i32.const 222
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(222);

    // local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    // end
    buf.push(OpCode::END as u8);

    // local.get 0
    buf.push(OpCode::GETLOCAL as u8);
    buf.encode_u32(0);

    // end function
    buf.push(OpCode::END as u8);

    let mut state = default_state(&arena);
    state
        .call_stack
        .push_frame(
            0,
            0,
            &[],
            &mut state.value_stack,
            &module.code.bytes,
            &mut state.program_counter,
        )
        .unwrap();

    while let Ok(Action::Continue) = state.execute_next_instruction(&module) {}

    assert_eq!(state.value_stack.pop_i32(), Ok(expected));
}

#[test]
fn test_br() {
    let arena = Bump::new();
    let mut state = default_state(&arena);
    let mut module = WasmModule::new(&arena);
    let buf = &mut module.code.bytes;

    // (local i32)
    buf.encode_u32(1);
    buf.encode_u32(1);
    buf.push(ValueType::I32 as u8);

    // i32.const 111
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(111);

    // local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    // block  ;; label = @1
    buf.push(OpCode::BLOCK as u8);
    buf.push(ValueType::VOID);

    //     block  ;; label = @2
    buf.push(OpCode::BLOCK as u8);
    buf.push(ValueType::VOID);

    //     block  ;; label = @3
    buf.push(OpCode::BLOCK as u8);
    buf.push(ValueType::VOID);

    //         br 2 (;@1;)
    buf.push(OpCode::BR as u8);
    buf.encode_u32(2);

    //         i32.const 444
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(444);

    //         local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    //     end
    buf.push(OpCode::END as u8);

    //     i32.const 333
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(333);

    //     local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    //     end
    buf.push(OpCode::END as u8);

    //     i32.const 222
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(222);

    //     local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    // end
    buf.push(OpCode::END as u8);

    // local.get 0)
    buf.push(OpCode::GETLOCAL as u8);
    buf.encode_u32(0);

    buf.push(OpCode::END as u8);

    state
        .call_stack
        .push_frame(
            0,
            0,
            &[],
            &mut state.value_stack,
            &module.code.bytes,
            &mut state.program_counter,
        )
        .unwrap();

    while let Ok(Action::Continue) = state.execute_next_instruction(&module) {}

    assert_eq!(state.value_stack.pop(), Value::I32(111))
}

#[test]
fn test_br_if() {
    test_br_if_help(0, 222);
    test_br_if_help(1, 111);
}

fn test_br_if_help(condition: i32, expected: i32) {
    let arena = Bump::new();
    let mut state = default_state(&arena);
    let mut module = WasmModule::new(&arena);
    let buf = &mut module.code.bytes;

    // (local i32)
    buf.encode_u32(1);
    buf.encode_u32(1);
    buf.push(ValueType::I32 as u8);

    // i32.const 111
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(111);

    // local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    // block  ;; label = @1
    buf.push(OpCode::BLOCK as u8);
    buf.push(ValueType::VOID);

    //     block  ;; label = @2
    buf.push(OpCode::BLOCK as u8);
    buf.push(ValueType::VOID);

    //     block  ;; label = @3
    buf.push(OpCode::BLOCK as u8);
    buf.push(ValueType::VOID);

    //         i32.const <condition>
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(condition);

    //         br_if 2 (;@1;)
    buf.push(OpCode::BRIF as u8);
    buf.encode_u32(2);

    //         i32.const 444
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(444);

    //         local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    //     end
    buf.push(OpCode::END as u8);

    //     i32.const 333
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(333);

    //     local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    //     end
    buf.push(OpCode::END as u8);

    //     i32.const 222
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(222);

    //     local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    // end
    buf.push(OpCode::END as u8);

    // local.get 0)
    buf.push(OpCode::GETLOCAL as u8);
    buf.encode_u32(0);

    buf.push(OpCode::END as u8);

    state
        .call_stack
        .push_frame(
            0,
            0,
            &[],
            &mut state.value_stack,
            &module.code.bytes,
            &mut state.program_counter,
        )
        .unwrap();

    while let Ok(Action::Continue) = state.execute_next_instruction(&module) {}

    assert_eq!(state.value_stack.pop(), Value::I32(expected))
}

#[test]
fn test_br_table() {
    test_br_table_help(0, 333);
    test_br_table_help(1, 222);
    test_br_table_help(2, 111);
}

fn test_br_table_help(condition: i32, expected: i32) {
    let arena = Bump::new();
    let mut state = default_state(&arena);
    let mut module = WasmModule::new(&arena);
    let buf = &mut module.code.bytes;

    // (local i32)
    buf.encode_u32(1);
    buf.encode_u32(1);
    buf.push(ValueType::I32 as u8);

    // i32.const 111
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(111);

    // local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    // block  ;; label = @1
    buf.push(OpCode::BLOCK as u8);
    buf.push(ValueType::VOID);

    //     block  ;; label = @2
    buf.push(OpCode::BLOCK as u8);
    buf.push(ValueType::VOID);

    //     block  ;; label = @3
    buf.push(OpCode::BLOCK as u8);
    buf.push(ValueType::VOID);

    //         i32.const <condition>
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(condition);

    //         br_table 0 1 2 (;@1;)
    buf.push(OpCode::BRTABLE as u8);
    buf.encode_u32(2); // number of non-fallback branches
    buf.encode_u32(0);
    buf.encode_u32(1);
    buf.encode_u32(2);

    //     end
    buf.push(OpCode::END as u8);

    //         i32.const 333
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(333);

    //         local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    //         br 1
    buf.push(OpCode::BR as u8);
    buf.encode_u32(1);

    //     end
    buf.push(OpCode::END as u8);

    //     i32.const 222
    buf.push(OpCode::I32CONST as u8);
    buf.encode_i32(222);

    //     local.set 0
    buf.push(OpCode::SETLOCAL as u8);
    buf.encode_u32(0);

    //         br 0
    buf.push(OpCode::BR as u8);
    buf.encode_u32(0);

    //     end
    buf.push(OpCode::END as u8);

    // local.get 0)
    buf.push(OpCode::GETLOCAL as u8);
    buf.encode_u32(0);

    buf.push(OpCode::END as u8);

    println!("{:02x?}", buf);

    state
        .call_stack
        .push_frame(
            0,
            0,
            &[],
            &mut state.value_stack,
            &module.code.bytes,
            &mut state.program_counter,
        )
        .unwrap();

    while let Ok(Action::Continue) = state.execute_next_instruction(&module) {}

    assert_eq!(state.value_stack.pop(), Value::I32(expected))
}

struct TestDispatcher {
    internal_state: i32,
}

impl ImportDispatcher for TestDispatcher {
    fn dispatch(
        &mut self,
        module_name: &str,
        function_name: &str,
        arguments: &[Value],
        _memory: &mut [u8],
    ) -> Option<Value> {
        assert_eq!(module_name, "env");
        assert_eq!(function_name, "increment_state");
        assert_eq!(arguments.len(), 1);
        let val = arguments[0].expect_i32().unwrap();
        self.internal_state += val;
        dbg!(val, self.internal_state);
        Some(Value::I32(self.internal_state))
    }
}

#[test]
fn test_call_import() {
    let arena = Bump::new();
    let mut module = WasmModule::new(&arena);
    let start_fn_name = "test";

    // User-provided non-Wasm code, with state
    let import_dispatcher = TestDispatcher {
        internal_state: 100,
    };

    // Function 0 is the import
    module.import.imports.push(Import {
        module: "env",
        name: "increment_state",
        description: ImportDesc::Func { signature_index: 0 },
    });
    module.types.insert(Signature {
        param_types: bumpalo::vec![in &arena; ValueType::I32],
        ret_type: Some(ValueType::I32),
    });

    // Function 1, which calls the import
    module.code.function_count = 1;
    let func0_offset = module.code.bytes.len() as u32;
    module.code.function_offsets.push(func0_offset);
    module.add_function_signature(Signature {
        param_types: Vec::new_in(&arena),
        ret_type: Some(ValueType::I32),
    });
    module.export.append(Export {
        name: start_fn_name,
        ty: ExportType::Func,
        index: 1,
    });
    [
        0, // no locals
        OpCode::I32CONST as u8,
        11, // argument to increment_state
        OpCode::CALL as u8,
        0, // function 0
        OpCode::I32CONST as u8,
        12, // argument to increment_state
        OpCode::CALL as u8,
        0, // function 0
        OpCode::I32ADD as u8,
        OpCode::END as u8,
    ]
    .serialize(&mut module.code.bytes);

    if false {
        let mut buf = Vec::new_in(&arena);
        module.serialize(&mut buf);
        let filename = "/tmp/roc/call-return.wasm";
        std::fs::write(filename, buf).unwrap();
        println!("Wrote to {}", filename);
    }

    let mut inst = Instance::for_module(&arena, &module, import_dispatcher, true).unwrap();

    let return_val = inst
        .call_export(&module, start_fn_name, [])
        .unwrap()
        .unwrap();

    assert_eq!(return_val, Value::I32(234));
}

#[test]
fn test_call_return_no_args() {
    let arena = Bump::new();
    let mut module = WasmModule::new(&arena);
    let start_fn_name = "test";

    module.code.function_count = 2;

    // Function 0
    let func0_offset = module.code.bytes.len() as u32;
    module.code.function_offsets.push(func0_offset);
    module.add_function_signature(Signature {
        param_types: Vec::new_in(&arena),
        ret_type: Some(ValueType::I32),
    });
    module.export.append(Export {
        name: start_fn_name,
        ty: ExportType::Func,
        index: 0,
    });
    [
        1, // 1 group of locals
        1, // 1 local
        ValueType::I32 as u8,
        OpCode::BLOCK as u8, /*  */
        // call from inside a block. callee's implicit return should still work correctly.
        ValueType::VOID as u8,
        OpCode::CALL as u8,
        1, // function 1
        OpCode::SETLOCAL as u8,
        0, // local 0
        OpCode::END as u8,
        OpCode::GETLOCAL as u8,
        0, // local 0
        OpCode::END as u8,
    ]
    .serialize(&mut module.code.bytes);

    // Function 1
    let func1_offset = module.code.bytes.len() as u32;
    module.code.function_offsets.push(func1_offset);
    module.add_function_signature(Signature {
        param_types: Vec::new_in(&arena),
        ret_type: Some(ValueType::I32),
    });
    [
        0, // no locals
        OpCode::I32CONST as u8,
        42, // constant value (<64 so that LEB-128 is just one byte)
        OpCode::END as u8,
    ]
    .serialize(&mut module.code.bytes);

    if false {
        let mut buf = Vec::new_in(&arena);
        module.serialize(&mut buf);
        let filename = "/tmp/roc/call-return.wasm";
        std::fs::write(filename, buf).unwrap();
        println!("Wrote to {}", filename);
    }

    let mut inst = Instance::for_module(&arena, &module, DEFAULT_IMPORTS, true).unwrap();

    let return_val = inst
        .call_export(&module, start_fn_name, [])
        .unwrap()
        .unwrap();

    assert_eq!(return_val, Value::I32(42));
}

#[test]
fn test_call_return_with_args() {
    let arena = Bump::new();
    let mut state = default_state(&arena);
    let mut module = WasmModule::new(&arena);

    // Function 0: calculate 2+2
    let func0_offset = module.code.bytes.len() as u32;
    module.code.function_offsets.push(func0_offset);
    module.add_function_signature(Signature {
        param_types: bumpalo::vec![in &arena;],
        ret_type: Some(ValueType::I32),
    });
    [
        0, // no locals
        OpCode::I32CONST as u8,
        2,
        OpCode::I32CONST as u8,
        2,
        OpCode::CALL as u8,
        1,
        OpCode::END as u8,
    ]
    .serialize(&mut module.code.bytes);
    let func0_first_instruction = func0_offset + 2; // skip function length and locals length

    // Function 1: add two numbers
    let func1_offset = module.code.bytes.len() as u32;
    module.code.function_offsets.push(func1_offset);
    module.add_function_signature(Signature {
        param_types: bumpalo::vec![in &arena; ValueType::I32, ValueType::I32],
        ret_type: Some(ValueType::I32),
    });
    [
        0, // no locals
        OpCode::GETLOCAL as u8,
        0,
        OpCode::GETLOCAL as u8,
        1,
        OpCode::I32ADD as u8,
        OpCode::END as u8,
    ]
    .serialize(&mut module.code.bytes);

    state.program_counter = func0_first_instruction as usize;

    while let Ok(Action::Continue) = state.execute_next_instruction(&module) {}

    assert_eq!(state.value_stack.peek(), Value::I32(4));
}

#[test]
fn test_call_indirect_ok() {
    let result = test_call_indirect_help(0, 0);
    assert_eq!(result, Value::I32(111));
}

#[test]
#[should_panic(expected = "Expected signature")]
fn test_call_indirect_wrong_signature() {
    test_call_indirect_help(0, 1);
}

#[test]
#[should_panic(expected = "element index")]
fn test_call_indirect_index_out_of_bounds() {
    test_call_indirect_help(0, 2);
}

#[test]
#[should_panic(expected = "Table index")]
fn test_call_indirect_unsupported_table() {
    test_call_indirect_help(1, 0);
}

fn test_call_indirect_help(table_index: u32, elem_index: u32) -> Value {
    let arena = Bump::new();
    let mut module = WasmModule::new(&arena);

    let is_debug_mode = true;
    let start_fn_name = "test";

    // function 0: caller
    let signature0 = || Signature {
        param_types: bumpalo::vec![in &arena],
        ret_type: Some(ValueType::I32),
    };
    create_exported_function_no_locals(&mut module, start_fn_name, signature0(), |buf| {
        buf.append_u8(OpCode::I32CONST as u8);
        buf.encode_u32(elem_index);
        buf.append_u8(OpCode::CALLINDIRECT as u8);
        buf.encode_u32(0); // signature index
        buf.encode_u32(table_index);
        buf.append_u8(OpCode::END as u8);
    });

    // function 1: callee, right signature
    create_exported_function_no_locals(&mut module, "callee1", signature0(), |buf| {
        buf.append_u8(OpCode::I32CONST as u8);
        buf.encode_i32(111);
        buf.append_u8(OpCode::END as u8);
    });

    // function 2: callee, wrong signature
    let signature1 = Signature {
        param_types: bumpalo::vec![in &arena],
        ret_type: Some(ValueType::F32),
    };
    create_exported_function_no_locals(&mut module, "callee2", signature1, |buf| {
        buf.append_u8(OpCode::F32CONST as u8);
        buf.encode_f32(2.22);
        buf.append_u8(OpCode::END as u8);
    });

    // Put functions 1 and 2 in the function table
    module.element.segments.push(ElementSegment::new(&arena));
    assert_eq!(module.element.get_or_insert_fn(1), 0);
    assert_eq!(module.element.get_or_insert_fn(2), 1);

    if false {
        let mut outfile_buf = Vec::new_in(&arena);
        module.serialize(&mut outfile_buf);
        std::fs::write(
            format!("/tmp/roc/call_indirect_{}_{}.wasm", table_index, elem_index),
            outfile_buf,
        )
        .unwrap();
    }

    let mut inst = Instance::for_module(&arena, &module, DEFAULT_IMPORTS, is_debug_mode).unwrap();
    inst.call_export(&module, start_fn_name, [])
        .unwrap()
        .unwrap()
}

// #[test]
// fn test_drop() {}

#[test]
fn test_select() {
    test_select_help(Value::F32(1.11), Value::F32(2.22), -100, Value::F32(1.11));
    test_select_help(Value::F64(1.11), Value::F64(2.22), 0, Value::F64(2.22));
}

fn test_select_help(first: Value, second: Value, condition: i32, expected: Value) {
    let arena = Bump::new();
    let mut module = WasmModule::new(&arena);
    let buf = &mut module.code.bytes;

    buf.push(0); // no locals

    const_value(buf, first);
    const_value(buf, second);
    const_value(buf, Value::I32(condition));
    buf.push(OpCode::SELECT as u8);
    buf.push(OpCode::END as u8);

    let mut state = default_state(&arena);
    state
        .call_stack
        .push_frame(
            0,
            0,
            &[],
            &mut state.value_stack,
            &module.code.bytes,
            &mut state.program_counter,
        )
        .unwrap();

    while let Ok(Action::Continue) = state.execute_next_instruction(&module) {}

    assert_eq!(state.value_stack.pop(), expected);
}

#[test]
fn test_set_get_local() {
    let arena = Bump::new();
    let mut state = default_state(&arena);
    let mut module = WasmModule::new(&arena);
    let mut vs = ValueStack::new(&arena);

    let mut buffer = vec![];
    let mut cursor = 0;
    [
        (1u32, ValueType::F32),
        (1u32, ValueType::F64),
        (1u32, ValueType::I32),
        (1u32, ValueType::I64),
    ]
    .serialize(&mut buffer);
    state
        .call_stack
        .push_frame(0x1234, 0, &[], &mut vs, &buffer, &mut cursor)
        .unwrap();

    module.code.bytes.push(OpCode::I32CONST as u8);
    module.code.bytes.encode_i32(12345);
    module.code.bytes.push(OpCode::SETLOCAL as u8);
    module.code.bytes.encode_u32(2);

    module.code.bytes.push(OpCode::GETLOCAL as u8);
    module.code.bytes.encode_u32(2);

    state.execute_next_instruction(&module).unwrap();
    state.execute_next_instruction(&module).unwrap();
    state.execute_next_instruction(&module).unwrap();
    assert_eq!(state.value_stack.depth(), 1);
    assert_eq!(state.value_stack.pop(), Value::I32(12345));
}

#[test]
fn test_tee_get_local() {
    let arena = Bump::new();
    let mut state = default_state(&arena);
    let mut module = WasmModule::new(&arena);
    let mut vs = ValueStack::new(&arena);

    let mut buffer = vec![];
    let mut cursor = 0;
    [
        (1u32, ValueType::F32),
        (1u32, ValueType::F64),
        (1u32, ValueType::I32),
        (1u32, ValueType::I64),
    ]
    .serialize(&mut buffer);
    state
        .call_stack
        .push_frame(0x1234, 0, &[], &mut vs, &buffer, &mut cursor)
        .unwrap();

    module.code.bytes.push(OpCode::I32CONST as u8);
    module.code.bytes.encode_i32(12345);
    module.code.bytes.push(OpCode::TEELOCAL as u8);
    module.code.bytes.encode_u32(2);

    module.code.bytes.push(OpCode::GETLOCAL as u8);
    module.code.bytes.encode_u32(2);

    state.execute_next_instruction(&module).unwrap();
    state.execute_next_instruction(&module).unwrap();
    state.execute_next_instruction(&module).unwrap();
    assert_eq!(state.value_stack.depth(), 2);
    assert_eq!(state.value_stack.pop(), Value::I32(12345));
    assert_eq!(state.value_stack.pop(), Value::I32(12345));
}

#[test]
fn test_global() {
    let arena = Bump::new();
    let mut state = default_state(&arena);
    state
        .globals
        .extend_from_slice(&[Value::F64(1.11), Value::I32(222), Value::F64(3.33)]);
    let mut module = WasmModule::new(&arena);

    module.code.bytes.push(OpCode::GETGLOBAL as u8);
    module.code.bytes.encode_u32(1);
    module.code.bytes.push(OpCode::I32CONST as u8);
    module.code.bytes.encode_i32(555);
    module.code.bytes.push(OpCode::SETGLOBAL as u8);
    module.code.bytes.encode_u32(1);
    module.code.bytes.push(OpCode::GETGLOBAL as u8);
    module.code.bytes.encode_u32(1);

    state.execute_next_instruction(&module).unwrap();
    state.execute_next_instruction(&module).unwrap();
    state.execute_next_instruction(&module).unwrap();
    state.execute_next_instruction(&module).unwrap();
    assert_eq!(state.value_stack.depth(), 2);
    assert_eq!(state.value_stack.pop(), Value::I32(555));
    assert_eq!(state.value_stack.pop(), Value::I32(222));
}

#[test]
fn test_i32const() {
    let arena = Bump::new();
    let mut state = default_state(&arena);
    let mut module = WasmModule::new(&arena);

    module.code.bytes.push(OpCode::I32CONST as u8);
    module.code.bytes.encode_i32(12345);

    state.execute_next_instruction(&module).unwrap();
    assert_eq!(state.value_stack.pop(), Value::I32(12345))
}

#[test]
fn test_i64const() {
    let arena = Bump::new();
    let mut state = default_state(&arena);
    let mut module = WasmModule::new(&arena);

    module.code.bytes.push(OpCode::I64CONST as u8);
    module.code.bytes.encode_i64(1234567890);

    state.execute_next_instruction(&module).unwrap();
    assert_eq!(state.value_stack.pop(), Value::I64(1234567890))
}

#[test]
fn test_f32const() {
    let arena = Bump::new();
    let mut state = default_state(&arena);
    let mut module = WasmModule::new(&arena);

    module.code.bytes.push(OpCode::F32CONST as u8);
    module.code.bytes.encode_f32(123.45);

    state.execute_next_instruction(&module).unwrap();
    assert_eq!(state.value_stack.pop(), Value::F32(123.45))
}

#[test]
fn test_f64const() {
    let arena = Bump::new();
    let mut state = default_state(&arena);
    let mut module = WasmModule::new(&arena);

    module.code.bytes.push(OpCode::F64CONST as u8);
    module.code.bytes.encode_f64(12345.67890);

    state.execute_next_instruction(&module).unwrap();
    assert_eq!(state.value_stack.pop(), Value::F64(12345.67890))
}