package asmc

import (
	"fmt"

	"git.urbach.dev/cli/q/src/arm"
	"git.urbach.dev/cli/q/src/asm"
)

func (c *compiler) compileARM(x asm.Instruction) {
	switch x.Mnemonic {
	case asm.CALL:
		switch data := x.Data.(type) {
		case *asm.Label:
			position := len(c.code)
			c.code = arm.Call(c.code, 0)

			pointer := &pointer{
				Position: Address(position),
				OpSize:   0,
				Size:     4,
			}

			pointer.Resolve = func() Address {
				destination, exists := c.codeLabels[data.Name]

				if !exists {
					panic(fmt.Sprintf("unknown jump label %s", data.Name))
				}

				distance := (destination - pointer.Position) / 4
				return arm.EncodeCall(distance)
			}

			c.codePointers = append(c.codePointers, pointer)
		}

	case asm.LABEL:
		c.codeLabels[x.Data.(*asm.Label).Name] = Address(len(c.code))

	case asm.MOVE:
		switch operands := x.Data.(type) {
		case *asm.RegisterNumber:
			c.code = arm.MoveRegisterNumber(c.code, operands.Register, operands.Number)
		}

	case asm.RETURN:
		c.code = arm.Return(c.code)

	case asm.SYSCALL:
		c.code = arm.Syscall(c.code)

	default:
		c.code = arm.Nop(c.code)
	}
}