package core

import (
	"git.urbach.dev/cli/q/src/asm"
	"git.urbach.dev/cli/q/src/errors"
	"git.urbach.dev/cli/q/src/expression"
	"git.urbach.dev/cli/q/src/types"
)

// CompileNew compiles a `new` function call which allocates a struct.
func (f *Function) CompileNew(root *expression.Expression) (types.Type, error) {
	var (
		parameters = root.Children[1:]
		nameNode   = parameters[0]
		pkg        = f.Package
		name       string
	)

	if nameNode.IsLeaf() {
		name = nameNode.Token.Text(f.File.Bytes)
	} else {
		pkg = nameNode.Children[0].Token.Text(f.File.Bytes)
		name = nameNode.Children[1].Token.Text(f.File.Bytes)
	}

	if pkg != f.File.Package {
		if f.File.Imports == nil {
			return nil, errors.New(&errors.UnknownPackage{Name: pkg}, f.File, nameNode.Token.Position)
		}

		imp, exists := f.File.Imports[pkg]

		if !exists {
			return nil, errors.New(&errors.UnknownPackage{Name: pkg}, f.File, nameNode.Token.Position)
		}

		imp.Used = true
	}

	typ, exists := f.All.Structs[pkg+"."+name]

	if !exists {
		return nil, errors.New(&errors.UnknownType{Name: name}, f.File, nameNode.Token.Position)
	}

	f.SaveRegister(f.CPU.Input[0])
	f.RegisterNumber(asm.MOVE, f.CPU.Input[0], typ.Size())
	f.CallSafe(f.All.Functions["mem.alloc"], f.CPU.Input[:1])
	return &types.Pointer{To: typ}, nil
}