package core

import (
	"strconv"

	"git.akyoto.dev/cli/q/src/build/cpu"
	"git.akyoto.dev/cli/q/src/build/errors"
	"git.akyoto.dev/cli/q/src/build/token"
)

// ExecuteLeaf performs an operation on a register with the given leaf operand.
func (f *Function) ExecuteLeaf(operation token.Token, register cpu.Register, operand token.Token) error {
	switch operand.Kind {
	case token.Identifier:
		name := operand.Text()
		variable := f.Variable(name)

		if variable == nil {
			return errors.New(&errors.UnknownIdentifier{Name: name}, f.File, operand.Position)
		}

		defer f.useVariable(variable)
		return f.ExecuteRegisterRegister(operation, register, variable.Register)

	case token.Number:
		value := operand.Text()
		number, err := strconv.Atoi(value)

		if err != nil {
			return err
		}

		return f.ExecuteRegisterNumber(operation, register, number)

	case token.String:
		if operation.Text() == "=" {
			return f.TokenToRegister(operand, register)
		}
	}

	return errors.New(errors.NotImplemented, f.File, operation.Position)
}