package core

import (
	"fmt"
	"strconv"

	"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()
		variable := f.Variable(name)

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

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

	case token.Number:
		value := t.Text()
		n, err := strconv.Atoi(value)

		if err != nil {
			return err
		}

		f.RegisterNumber(asm.MOVE, register, n)
		return nil

	case token.String:
		f.count.data++
		label := fmt.Sprintf("%s_data_%d", f.Name, f.count.data)
		value := t.Bytes[1 : len(t.Bytes)-1]
		f.Assembler.SetData(label, value)
		f.RegisterLabel(asm.MOVE, register, label)
		return nil

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