package vm

import "jinx/pkg/lang/vm/value"

func (vm *VM) execPushInt(x int64) {
	vm.stack.Top().Push(value.NewInt(x))
}

func (vm *VM) execPushFloat(x float64) {
	vm.stack.Top().Push(value.NewFloat(x))
}

func (vm *VM) execPushString(str string) {
	vm.stack.Top().Push(value.NewString(str))
}

func (vm *VM) execPushBool(b bool) {
	vm.stack.Top().Push(value.NewBool(b))
}

func (vm *VM) execPushNull() {
	vm.stack.Top().Push(value.NewNull())
}

func (vm *VM) execPushArray() {
	vm.stack.Top().Push(value.NewArray([]value.Value{}))
}

func (vm *VM) execGetLocal(offset int) {
	top := vm.stack.Top()
	top.Push(top.At(int(offset)))
}

func (vm *VM) execGetArg() {
	vm.stack.Top().Push(vm.stack.Prev().Pop())
}

func (vm *VM) execAdd() {
	top := vm.stack.Top()

	x := top.Pop()
	y := top.Pop()

	var res value.Value

	switch x.Type().Kind {
	case value.IntType:
		xv := x.Data().(int64)
		switch y.Type().Kind {
		case value.IntType:
			res = value.NewInt(xv + y.Data().(int64))
		case value.FloatType:
			res = value.NewFloat(float64(xv) + y.Data().(float64))
		default:
			panic("invalid operand types")
		}
	case value.FloatType:
		xv := x.Data().(float64)
		switch y.Type().Kind {
		case value.IntType:
			res = value.NewFloat(xv + float64(y.Data().(int64)))
		case value.FloatType:
			res = value.NewFloat(xv + y.Data().(float64))
		default:
			panic("invalid operand types")
		}
	case value.StringType:
		switch y.Type().Kind {
		case value.StringType:
			res = value.NewString(x.Data().(string) + y.Data().(string))
		default:
			panic("invalid operand types")
		}
	default:
		panic("invalid operand types")
	}

	top.Push(res)
}

func (vm *VM) execSub() {
	top := vm.stack.Top()

	x := top.Pop()
	y := top.Pop()

	var res value.Value

	switch x.Type().Kind {
	case value.IntType:
		xv := x.Data().(int64)
		switch y.Type().Kind {
		case value.IntType:
			res = value.NewInt(xv - y.Data().(int64))
		case value.FloatType:
			res = value.NewFloat(float64(xv) - y.Data().(float64))
		default:
			panic("invalid operand types")
		}
	case value.FloatType:
		xv := x.Data().(float64)
		switch y.Type().Kind {
		case value.IntType:
			res = value.NewFloat(xv - float64(y.Data().(int64)))
		case value.FloatType:
			res = value.NewFloat(xv - y.Data().(float64))
		default:
			panic("invalid operand types")
		}
	default:
		panic("invalid operand types")
	}

	top.Push(res)
}

func (vm *VM) execIndex() {
	top := vm.stack.Top()

	v := top.Pop()
	i := top.Pop()

	switch v.Type().Kind {
	case value.ArrayType:
		arr := v.Data().([]value.Value)
		idx := i.Data().(int64)
		if idx < 0 || idx >= int64(len(arr)) {
			panic("index out of bounds")
		}

		top.Push(arr[idx])
	default:
		panic("invalid operand types")
	}
}