package asm

import "git.akyoto.dev/cli/q/src/build/cpu"

// RegisterNumber adds an instruction with a register and a number.
func (a *Assembler) RegisterNumber(mnemonic Mnemonic, reg cpu.Register, number int) {
	a.Instructions = append(a.Instructions, Instruction{
		Mnemonic: mnemonic,
		Data: &RegisterNumber{
			Register: reg,
			Number:   number,
		},
	})
}

// RegisterRegister adds an instruction using two registers.
func (a *Assembler) RegisterRegister(mnemonic Mnemonic, left cpu.Register, right cpu.Register) {
	a.Instructions = append(a.Instructions, Instruction{
		Mnemonic: mnemonic,
		Data: &RegisterRegister{
			Destination: left,
			Source:      right,
		},
	})
}

// Register adds an instruction using a single register.
func (a *Assembler) Register(mnemonic Mnemonic, register cpu.Register) {
	a.Instructions = append(a.Instructions, Instruction{
		Mnemonic: mnemonic,
		Data: &Register{
			Register: register,
		},
	})
}

// Label adds an instruction using a label.
func (a *Assembler) Label(mnemonic Mnemonic, name string) {
	a.Instructions = append(a.Instructions, Instruction{
		Mnemonic: mnemonic,
		Data: &Label{
			Name: name,
		},
	})
}

// Comment adds a comment at the current position.
func (a *Assembler) Comment(text string) {
	a.Instructions = append(a.Instructions, Instruction{
		Mnemonic: COMMENT,
		Data: &Label{
			Name: text,
		},
	})
}

// Call calls a function whose position is identified by a label.
func (a *Assembler) Call(name string) {
	a.Instructions = append(a.Instructions, Instruction{
		Mnemonic: CALL,
		Data: &Label{
			Name: name,
		},
	})
}

// Jump jumps to a position that is identified by a label.
func (a *Assembler) Jump(name string) {
	a.Instructions = append(a.Instructions, Instruction{
		Mnemonic: JUMP,
		Data: &Label{
			Name: name,
		},
	})
}

// Return returns back to the caller.
func (a *Assembler) Return() {
	if len(a.Instructions) > 0 && a.Instructions[len(a.Instructions)-1].Mnemonic == RETURN {
		return
	}

	a.Instructions = append(a.Instructions, Instruction{Mnemonic: RETURN})
}

// Syscall executes a kernel function.
func (a *Assembler) Syscall() {
	a.Instructions = append(a.Instructions, Instruction{Mnemonic: SYSCALL})
}