package core

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

// TokenToRegister moves a token into a register.
// It only works with identifiers, numbers and strings.
func (f *Function) TokenToRegister(t token.Token, register cpu.Register) error {
	switch t.Kind {
	case token.Identifier:
		name := t.Text(f.File.Bytes)
		variable := f.VariableByName(name)

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

		f.UseVariable(variable)
		f.SaveRegister(register)
		f.RegisterRegister(asm.MOVE, register, variable.Register)
		return nil

	case token.Number, token.Rune:
		number, err := f.Number(t)

		if err != nil {
			return err
		}

		f.SaveRegister(register)
		f.RegisterNumber(asm.MOVE, register, number)
		return nil

	case token.String:
		data := t.Bytes(f.File.Bytes)
		data = String(data)
		label := f.AddBytes(data)
		f.SaveRegister(register)
		f.RegisterLabel(asm.MOVE, register, label)
		return nil

	default:
		return errors.New(errors.InvalidExpression, f.File, t.Position)
	}
}