4 files changed, 338 insertions, 0 deletions
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 2bbc7d0..d6d5441 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -5,6 +5,7 @@ include_directories(
 add_library(erebos
 	channel
 	identity
+	message
 	network
 	pubkey
 	service
diff --git a/src/identity.cpp b/src/identity.cpp
index 8f606ae..3cba97c 100644
--- a/src/identity.cpp
+++ b/src/identity.cpp
@@ -58,6 +58,13 @@ Stored<PublicKey> Identity::keyMessage() const
 	return p->keyMessage;
 }
 
+bool Identity::sameAs(const Identity & other) const
+{
+	// TODO: proper identity check
+	return p->data[0]->data->keyIdentity ==
+		other.p->data[0]->data->keyIdentity;
+}
+
 optional<Ref> Identity::ref() const
 {
 	if (p->data.size() == 1)
diff --git a/src/message.cpp b/src/message.cpp
new file mode 100644
index 0000000..0fcb587
--- /dev/null
+++ b/src/message.cpp
@@ -0,0 +1,273 @@
+#include "message.h"
+
+#include <erebos/network.h>
+
+using namespace erebos;
+using std::nullopt;
+using std::scoped_lock;
+using std::unique_lock;
+
+static const UUID myUUID("c702076c-4928-4415-8b6b-3e839eafcb0d");
+
+static vector<DirectMessageThread> threadList;
+static mutex threadLock;
+
+DirectMessageThread DirectMessageThread::Priv::getThreadLocked(const Identity & peer)
+{
+	for (const auto & t : threadList)
+		if (t.p->peer.sameAs(peer))
+			return t;
+
+	DirectMessageThread t(new DirectMessageThread::Priv {
+		.peer = peer,
+		.head = {},
+	});
+	threadList.push_back(t);
+	return t;
+}
+
+DirectMessageThread DirectMessageThread::Priv::updateThreadLocked(const Identity & peer, vector<Stored<DirectMessageData>> && head)
+{
+	DirectMessageThread nt(new DirectMessageThread::Priv {
+		.peer = peer,
+		.head = std::move(head),
+	});
+
+	for (auto & t : threadList)
+		if (t.p->peer.sameAs(peer)) {
+			t = nt;
+			return nt;
+		}
+
+	threadList.push_back(nt);
+	return nt;
+}
+
+
+DirectMessage::DirectMessage(Priv * p):
+	p(p)
+{}
+
+optional<DirectMessageData> DirectMessageData::load(const Ref & ref)
+{
+	auto rec = ref->asRecord();
+	if (!rec)
+		return nullopt;
+
+	vector<Stored<DirectMessageData>> prev;
+	for (auto p : rec->items("PREV"))
+		if (const auto & x = p.as<DirectMessageData>())
+			prev.push_back(*x);
+
+	auto fref = rec->item("from").asRef();
+	if (!fref)
+		return nullopt;
+
+	auto from = Identity::load(*fref);
+	if (!from)
+		return nullopt;
+
+	return DirectMessageData {
+		.prev = std::move(prev),
+		.from = *from,
+		.time = *rec->item("time").asDate(),
+		.text = rec->item("text").asText().value(),
+	};
+}
+
+Ref DirectMessageData::store(const Storage & st) const
+{
+	vector<Record::Item> items;
+
+	for (const auto prev : prev)
+		items.emplace_back("PREV", prev.ref());
+	items.emplace_back("from", from.ref().value());
+	items.emplace_back("time", time);
+	items.emplace_back("text", text);
+
+	return st.storeObject(Record(std::move(items)));
+}
+
+
+const Identity & DirectMessage::from() const
+{
+	return p->data->from;
+}
+
+const ZonedTime & DirectMessage::time() const
+{
+	return p->data->time;
+}
+
+const string & DirectMessage::text() const
+{
+	return p->data->text;
+}
+
+
+DirectMessageThread::DirectMessageThread(Priv * p):
+	p(p)
+{}
+
+DirectMessageThread::Iterator::Iterator(Priv * p):
+	p(p)
+{}
+
+DirectMessageThread::Iterator::Iterator(const Iterator & other):
+	Iterator(new Priv(*other.p))
+{}
+
+DirectMessageThread::Iterator::~Iterator() = default;
+
+DirectMessageThread::Iterator & DirectMessageThread::Iterator::operator=(const Iterator & other)
+{
+	p.reset(new Priv(*other.p));
+	return *this;
+}
+
+DirectMessageThread::Iterator & DirectMessageThread::Iterator::operator++()
+{
+	if (p->current)
+		for (const auto & m : p->current->p->data->prev)
+			p->next.push_back(m);
+
+	if (p->next.empty()) {
+		p->current.reset();
+	} else {
+		filterAncestors(p->next);
+		auto ncur = p->next[0];
+
+		for (const auto & m : p->next)
+			if (m->time.time >= ncur->time.time)
+				ncur = m;
+
+		p->current.emplace(DirectMessage(new DirectMessage::Priv {
+			.data = ncur,
+		}));
+
+		p->next.erase(std::remove(p->next.begin(), p->next.end(), p->current->p->data));
+	}
+
+	return *this;
+}
+
+DirectMessage DirectMessageThread::Iterator::operator*() const
+{
+	return *p->current;
+}
+
+bool DirectMessageThread::Iterator::operator==(const Iterator & other) const
+{
+	if (p->current && other.p->current)
+		return p->current->p->data == other.p->current->p->data;
+	return bool(p->current) == bool(other.p->current);
+}
+
+bool DirectMessageThread::Iterator::operator!=(const Iterator & other) const
+{
+	return !(*this == other);
+}
+
+DirectMessageThread::Iterator DirectMessageThread::begin() const
+{
+	return ++Iterator(new Iterator::Priv {
+		.current = {},
+		.next = p->head,
+	});
+}
+
+DirectMessageThread::Iterator DirectMessageThread::end() const
+{
+	return Iterator(new Iterator::Priv {
+		.current = {},
+		.next = {},
+	});
+}
+
+size_t DirectMessageThread::size() const
+{
+	size_t c = 0;
+	for (auto it = begin(); it != end(); ++it)
+		c++;
+	return c;
+}
+
+DirectMessage DirectMessageThread::at(size_t i) const
+{
+	return *std::next(begin(), i);
+}
+
+const Identity & DirectMessageThread::peer() const
+{
+	return p->peer;
+}
+
+
+vector<DirectMessageService::ThreadWatcher> DirectMessageService::Priv::watchers;
+mutex DirectMessageService::Priv::watcherLock;
+
+DirectMessageService::DirectMessageService() = default;
+DirectMessageService::~DirectMessageService() = default;
+
+UUID DirectMessageService::uuid() const
+{
+	return myUUID;
+}
+
+void DirectMessageService::handle(Context & ctx) const
+{
+	auto dm = Stored<DirectMessageData>::load(ctx.ref());
+	if (!dm)
+		return;
+
+	auto pid = ctx.peer().identity();
+	if (!pid)
+		return;
+
+	unique_lock lock(threadLock);
+
+	vector<Stored<DirectMessageData>> head(DirectMessageThread::Priv::getThreadLocked(*pid).p->head);
+	head.push_back(*dm);
+	filterAncestors(head);
+	auto dmt = DirectMessageThread::Priv::updateThreadLocked(*pid, std::move(head));
+
+	lock.unlock();
+
+	for (const auto & w : Priv::watchers)
+		w(dmt, -1, -1);
+}
+
+void DirectMessageService::onUpdate(ThreadWatcher w)
+{
+	scoped_lock l(Priv::watcherLock);
+	Priv::watchers.push_back(w);
+}
+
+DirectMessageThread DirectMessageService::thread(const Identity & peer)
+{
+	scoped_lock lock(threadLock);
+	return DirectMessageThread::Priv::getThreadLocked(peer);
+}
+
+DirectMessage DirectMessageService::send(const Identity & from, const Peer & peer, const string & text)
+{
+	auto pid = peer.identity();
+	if (!pid)
+		throw std::runtime_error("Peer without known identity");
+
+	scoped_lock lock(threadLock);
+
+	auto msg = from.ref()->storage().store(DirectMessageData {
+		.prev = DirectMessageThread::Priv::getThreadLocked(*pid).p->head,
+		.from = from,
+		.time = ZonedTime::now(),
+		.text = text,
+	});
+
+	DirectMessageThread::Priv::updateThreadLocked(*pid, { msg });
+	peer.send(myUUID, msg.ref());
+
+	return DirectMessage(new DirectMessage::Priv {
+		.data = msg,
+	});
+}
diff --git a/src/message.h b/src/message.h
new file mode 100644
index 0000000..48487ba
--- /dev/null
+++ b/src/message.h
@@ -0,0 +1,57 @@
+#pragma once
+
+#include <erebos/identity.h>
+#include <erebos/message.h>
+#include <erebos/storage.h>
+
+#include <mutex>
+#include <vector>
+
+namespace chrono = std::chrono;
+using chrono::system_clock;
+using std::mutex;
+using std::optional;
+using std::string;
+using std::vector;
+
+namespace erebos {
+
+struct DirectMessageData
+{
+	static optional<DirectMessageData> load(const Ref &);
+	Ref store(const Storage &) const;
+
+	vector<Stored<DirectMessageData>> prev;
+	Identity from;
+	ZonedTime time;
+	string text;
+};
+
+struct DirectMessage::Priv
+{
+	Stored<DirectMessageData> data;
+};
+
+struct DirectMessageThread::Priv
+{
+	const Identity peer;
+	const vector<Stored<DirectMessageData>> head;
+
+	static DirectMessageThread getThreadLocked(const Identity & peer);
+	static DirectMessageThread updateThreadLocked(const Identity & peer,
+			vector<Stored<DirectMessageData>> && head);
+};
+
+struct DirectMessageThread::Iterator::Priv
+{
+	optional<DirectMessage> current;
+	vector<Stored<DirectMessageData>> next;
+};
+
+struct DirectMessageService::Priv
+{
+	static vector<ThreadWatcher> watchers;
+	static mutex watcherLock;
+};
+
+}