package diffsync

import "sync"

type Version uint64

type void struct{}

type Document struct {
	content    []byte
	patcher    Patcher
	differ     Differ
	peers      map[*Peer]void
	peersMutex sync.RWMutex
}

func (d *Document) NewPeer() *Peer {
	d.peersMutex.Lock()
	defer d.peersMutex.Unlock()

	p := &Peer{
		document:   d,
		shadow:     NewShadow(Copy(d.content)),
		editsStack: make(EditsStack, 0),
	}

	d.peers[p] = void{}

	return p
}

func (d *Document) RemovePeer(p *Peer) {
	d.peersMutex.Lock()
	defer d.peersMutex.Unlock()

	delete(d.peers, p)
	p.document = nil
}

func (d *Document) Content() []byte {
	return d.content
}

func NewDocument(content []byte, funcs ...OptionFunc) *Document {
	opt := MergeOption(
		DefaultOption(),
		funcs...,
	)

	return &Document{
		content: content,
		patcher: opt.Patcher,
		differ:  opt.Differ,
		peers:   make(map[*Peer]void),
	}
}