///! Basic tests for instructions/constructions, missing in wabt tests

use std::sync::{Arc, Weak};
use builder::module;
use elements::{ExportEntry, Internal, ImportEntry, External, GlobalEntry, GlobalType,
	InitExpr, ValueType, BlockType, Opcodes, Opcode, FunctionType};
use interpreter::Error;
use interpreter::env_native::{env_native_module, UserFunction, UserFunctions, UserFunctionExecutor, UserFunctionDescriptor};
use interpreter::imports::ModuleImports;
use interpreter::memory::MemoryInstance;
use interpreter::module::{ModuleInstanceInterface, CallerContext, ItemIndex, ExecutionParams};
use interpreter::program::ProgramInstance;
use interpreter::validator::{FunctionValidationContext, Validator};
use interpreter::value::RuntimeValue;

#[test]
fn import_function() {
	let module1 = module()
		.with_export(ExportEntry::new("external_func".into(), Internal::Function(0)))
		.function()
			.signature().return_type().i32().build()
			.body().with_opcodes(Opcodes::new(vec![
				Opcode::I32Const(3),
				Opcode::End,
			])).build()
			.build()
		.build();

	let module2 = module()
		.with_import(ImportEntry::new("external_module".into(), "external_func".into(), External::Function(0)))
		.function()
			.signature().return_type().i32().build()
			.body().with_opcodes(Opcodes::new(vec![
				Opcode::Call(0),
				Opcode::I32Const(7),
				Opcode::I32Add,
				Opcode::End,
			])).build()
			.build()
		.build();

	let program = ProgramInstance::new().unwrap();
	let external_module = program.add_module("external_module", module1, None).unwrap();
	let main_module = program.add_module("main", module2, None).unwrap();

	assert_eq!(external_module.execute_index(0, vec![].into()).unwrap().unwrap(), RuntimeValue::I32(3));
	assert_eq!(main_module.execute_index(1, vec![].into()).unwrap().unwrap(), RuntimeValue::I32(10));
}

#[test]
fn wrong_import() {
	let side_module = module()
		.with_export(ExportEntry::new("cool_func".into(), Internal::Function(0)))
		.function()
			.signature().return_type().i32().build()
			.body().with_opcodes(Opcodes::new(vec![
				Opcode::I32Const(3),
				Opcode::End,
			])).build()
			.build()
		.build();

	let module = module()
		.with_import(ImportEntry::new("side_module".into(), "not_cool_func".into(), External::Function(0)))
		.function()
			.signature().return_type().i32().build()
			.body().with_opcodes(Opcodes::new(vec![
				Opcode::Call(0),
				Opcode::I32Const(7),
				Opcode::I32Add,
				Opcode::End,
			])).build()
			.build()
		.build();

	let program = ProgramInstance::new().unwrap();
	let _side_module_instance = program.add_module("side_module", side_module, None).unwrap();
	assert!(program.add_module("main", module, None).is_err());	
}

#[test]
fn global_get_set() {
	let module = module()
		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, true), InitExpr::new(vec![Opcode::I32Const(42)])))
		.with_global(GlobalEntry::new(GlobalType::new(ValueType::I32, false), InitExpr::new(vec![Opcode::I32Const(777)])))
		.function()
			.signature().return_type().i32().build()
			.body().with_opcodes(Opcodes::new(vec![
				Opcode::GetGlobal(0),
				Opcode::I32Const(8),
				Opcode::I32Add,
				Opcode::SetGlobal(0),
				Opcode::GetGlobal(0),
				Opcode::End,
			])).build()
			.build()
		.function()
			.signature().return_type().i32().build()
			.body().with_opcodes(Opcodes::new(vec![
				Opcode::GetGlobal(1),
				Opcode::I32Const(8),
				Opcode::I32Add,
				Opcode::SetGlobal(1),
				Opcode::GetGlobal(1),
				Opcode::End,
			])).build()
			.build()
		.function()
			.signature().return_type().i32().build()
			.body().with_opcodes(Opcodes::new(vec![
				Opcode::I64Const(8),
				Opcode::SetGlobal(0),
				Opcode::GetGlobal(0),
				Opcode::End,
			])).build()
			.build()
		.build();

	let program = ProgramInstance::new().unwrap();
	let module = program.add_module_without_validation("main", module, None).unwrap(); // validation is failing (accessing immutable global)
	assert_eq!(module.execute_index(0, vec![].into()).unwrap().unwrap(), RuntimeValue::I32(50));
	assert_eq!(module.execute_index(1, vec![].into()).unwrap_err(), Error::Variable("trying to update immutable variable".into()));
	assert_eq!(module.execute_index(2, vec![].into()).unwrap_err(), Error::Variable("trying to update variable of type I32 with value of type Some(I64)".into()));
}

const SIGNATURE_I32: &'static [ValueType] = &[ValueType::I32];

const SIGNATURES: &'static [UserFunction] = &[
	UserFunction {
		desc: UserFunctionDescriptor::Static(
			"add",
			SIGNATURE_I32,
		),
		result: Some(ValueType::I32),
	},
	UserFunction {
		desc: UserFunctionDescriptor::Static(
			"sub",
			SIGNATURE_I32,
		),
		result: Some(ValueType::I32),
	},
];

#[test]
fn single_program_different_modules() {
	// user function executor
	struct FunctionExecutor {
		pub memory: Arc<MemoryInstance>,
		pub values: Vec<i32>,
	}

	impl UserFunctionExecutor for FunctionExecutor {
		fn execute(&mut self, name: &str, context: CallerContext) -> Result<Option<RuntimeValue>, Error> {
			match name {
				"add" => {
					let memory_value = self.memory.get(0, 1).unwrap()[0];
					let fn_argument = context.value_stack.pop_as::<u32>().unwrap() as u8;
					let sum = memory_value + fn_argument;
					self.memory.set(0, &vec![sum]).unwrap();
					self.values.push(sum as i32);
					Ok(Some(RuntimeValue::I32(sum as i32)))
				},
				"sub" => {
					let memory_value = self.memory.get(0, 1).unwrap()[0];
					let fn_argument = context.value_stack.pop_as::<u32>().unwrap() as u8;
					let diff = memory_value - fn_argument;
					self.memory.set(0, &vec![diff]).unwrap();
					self.values.push(diff as i32);
					Ok(Some(RuntimeValue::I32(diff as i32)))
				},
				_ => Err(Error::Trap("not implemented".into())),
			}
		}
	}

	// create new program
	let program = ProgramInstance::new().unwrap();
	// => env module is created
	let env_instance = program.module("env").unwrap();
	// => linear memory is created
	let env_memory = env_instance.memory(ItemIndex::Internal(0)).unwrap();

	// create native env module executor
	let mut executor = FunctionExecutor {
		memory: env_memory.clone(),
		values: Vec::new(),
	};
	{
		let functions: UserFunctions = UserFunctions {
			executor: &mut executor,
			functions: ::std::borrow::Cow::from(SIGNATURES),
		};
		let native_env_instance = Arc::new(env_native_module(env_instance, functions).unwrap());
		let params = ExecutionParams::with_external("env".into(), native_env_instance);

		let module = module()
			.with_import(ImportEntry::new("env".into(), "add".into(), External::Function(0)))
			.with_import(ImportEntry::new("env".into(), "sub".into(), External::Function(0)))
			.function()
				.signature().param().i32().return_type().i32().build()
				.body().with_opcodes(Opcodes::new(vec![
					Opcode::GetLocal(0),
					Opcode::Call(0),
					Opcode::End,
				])).build()
				.build()
			.function()
				.signature().param().i32().return_type().i32().build()
				.body().with_opcodes(Opcodes::new(vec![
					Opcode::GetLocal(0),
					Opcode::Call(1),
					Opcode::End,
				])).build()
				.build()
			.build();

		// load module
		let module_instance = program.add_module("main", module, Some(&params.externals)).unwrap();

		{
			assert_eq!(module_instance.execute_index(2, params.clone().add_argument(RuntimeValue::I32(7))).unwrap().unwrap(), RuntimeValue::I32(7));
			assert_eq!(module_instance.execute_index(2, params.clone().add_argument(RuntimeValue::I32(50))).unwrap().unwrap(), RuntimeValue::I32(57));
			assert_eq!(module_instance.execute_index(3, params.clone().add_argument(RuntimeValue::I32(15))).unwrap().unwrap(), RuntimeValue::I32(42));
		}
	}

	assert_eq!(executor.memory.get(0, 1).unwrap()[0], 42);
	assert_eq!(executor.values, vec![7, 57, 42]);
}

#[test]
fn if_else_with_return_type_validation() {
	let module = module().build();
	let imports = ModuleImports::new(Weak::default(), None);
	let mut context = FunctionValidationContext::new(&module, &imports, &[], 1024, 1024, &FunctionType::default());

	Validator::validate_function(&mut context, BlockType::NoResult, &[
		Opcode::I32Const(1),
		Opcode::If(BlockType::NoResult, Opcodes::new(vec![
			Opcode::I32Const(1),
			Opcode::If(BlockType::Value(ValueType::I32), Opcodes::new(vec![
				Opcode::I32Const(1),
				Opcode::Else,
				Opcode::I32Const(2),
				Opcode::End,
			])),
			Opcode::Drop,
			Opcode::End,
		])),
		Opcode::End,
	]).unwrap();
}