From 9c0f7a79dca06775f03a05f8fb5565b2f6cafdc3 Mon Sep 17 00:00:00 2001
From: Guillaume ARM <trapcodien@gmail.com>
Date: Fri, 15 Jul 2022 10:25:29 +0200
Subject: [PATCH] chore: init base

---
 apis/net.lua        | 139 ++++++++++++++++++++++++++++++++++++++++++++
 ping-server.lua     |  30 ++++++++++
 ping.lua            |  33 +++++++++++
 router.lua          |  71 ++++++++++++++++++++++
 startup/servers.lua |  41 +++++++++++++
 5 files changed, 314 insertions(+)
 create mode 100644 apis/net.lua
 create mode 100644 ping-server.lua
 create mode 100644 ping.lua
 create mode 100644 router.lua
 create mode 100644 startup/servers.lua

diff --git a/apis/net.lua b/apis/net.lua
new file mode 100644
index 0000000..f70d01f
--- /dev/null
+++ b/apis/net.lua
@@ -0,0 +1,139 @@
+-- Network API v1.0.1
+
+local DEFAULT_TIMEOUT_WAIT_MESSAGE = 0.5;  -- in seconds
+local DEFAULT_ROUTING_CHANNEL = 10;
+
+-- Utilitaire pour savoir si un payload nous est destiné.
+-- le parametre 'payload' est une table avec les champs suivants:
+--   - sourceId: l'id de la machine qui a envoyé le message
+--   - destId: l'id du destinataire, si l'id est nil le message est routé a tout le monde
+--   - routerId: l'id du routeur qui s'est occupé de transmettre le message
+--   - message: le contenu du message (qui sera le plus souvent une table)
+-- return un boolean
+local function isPayloadOk(payload)
+  if type(payload) ~= "table" then
+    return false;
+  end
+
+  if not payload.routerId or not payload.sourceId then
+    return false;
+  end
+
+  if payload.sourceId == os.getComputerID() then
+    return false;
+  end
+
+  if payload.destId == nil then
+    return true;
+  end
+
+  if type(payload.destId) == 'number' and payload.destId == os.getComputerID() then
+    return true;
+  end
+
+  if type(payload.destId) == 'string' and payload.destId == os.getComputerLabel() then
+    return true;
+  end
+
+  return false;
+end
+
+-- Une simple fonction pour chercher une valeur dans une table
+local function find(predicate, values)
+  for k, v in ipairs(values) do
+    if predicate(v, k) then
+      return v;
+    end
+  end
+
+  return nil;
+end
+
+-- Fonction utilitaire pour pouvoir pull plusieurs events (modem_message et timer par exemple)
+local function pullMultipleEvents(...)
+  local eventNames = table.pack(...);
+
+  while true do
+    local payload = table.pack(os.pullEvent());
+    local eventName = payload[1]
+
+    -- TODO index events
+    if find(function(e) return e == eventName end, eventNames) then
+      return table.unpack(payload);
+    end
+  end
+end
+
+-- -- Example: implementation simple de ping
+--
+--
+-- local createNet = require('apis/net');
+-- net = createNet();
+--
+-- -- envoyer un message sur le canal 9
+-- net.send(9, 'ping');
+--
+-- -- recevoir et afficher un message sur le canal 9
+-- local message = net.waitMessage(9);
+-- if message == 'pong' then
+--   print('pong recu');
+-- end
+--
+local function createNetwork(modem, routingChannel, timeoutInSec)
+  modem = modem or peripheral.find("modem") or error("modem not found");
+  routingChannel = routingChannel or DEFAULT_ROUTING_CHANNEL;
+  timeoutInSec = timeoutInSec or DEFAULT_TIMEOUT_WAIT_MESSAGE;
+
+  -- net.send function
+  local function send(channel, message, destId)
+    local payload = {
+      sourceId = os.getComputerID(),
+      sourceLabel = os.getComputerLabel(),
+      routerId = nil,
+      destId = destId,
+      message = message
+    }
+
+    modem.transmit(routingChannel, channel, payload);
+  end
+
+  -- net.waitMessage function
+  local function waitMessage(channelToListen)
+    local receivedPayload;
+
+    modem.open(channelToListen);
+
+    local timerId = os.startTimer(timeoutInSec);
+    local timedOut = false;
+
+    repeat
+      local messageType, timerIdOrSide, channel, _, payload = pullMultipleEvents("modem_message", "timer");
+      local channelOk, payloadOk;
+
+      if messageType == "modem_message" then
+        receivedPayload = payload;
+        channelOk = channel == channelToListen;
+        payloadOk = isPayloadOk(payload);
+      elseif messageType == 'timer' and timerIdOrSide == timerId then
+        timedOut = true;
+      end
+    until channelOk and payloadOk or timedOut
+
+    if timedOut then
+      return nil;
+    end
+
+    if receivedPayload then
+      return receivedPayload.message, receivedPayload;
+    end
+
+    return nil;
+  end
+
+  return {
+    send = send,
+    waitMessage = waitMessage
+  }
+end
+
+return createNetwork;
diff --git a/ping-server.lua b/ping-server.lua
new file mode 100644
index 0000000..c0aa4d1
--- /dev/null
+++ b/ping-server.lua
@@ -0,0 +1,30 @@
+-- ping-server v1.0.0
+
+-- -- Example: implementation simple de ping-server
+local PING_CHANNEL = 9;
+local MODEM_DETECTION_TIME = 3;  -- in seconds
+
+local createNet = require('apis/net');
+
+local modem = peripheral.find('modem');
+
+if not modem then
+  print("Warning: modem not found!");
+end
+
+-- on attend le modem
+while not modem do
+  modem = peripheral.find('modem');
+  os.sleep(MODEM_DETECTION_TIME);
+end
+
+local net = createNet(modem);
+
+while true do
+  local message, payload = net.waitMessage(PING_CHANNEL);
+
+  if message == 'ping' then
+    -- le troisième parametre de la fonction `net.send` est pour router un message a une machine specifique
+    net.send(PING_CHANNEL, 'pong', payload.sourceId);
+  end
+end
diff --git a/ping.lua b/ping.lua
new file mode 100644
index 0000000..1b4f7b6
--- /dev/null
+++ b/ping.lua
@@ -0,0 +1,33 @@
+-- ping v1.2.0
+local PING_CHANNEL = 9;
+
+local createNet = require('apis/net');
+local net = createNet();
+
+local args = table.pack(...);
+local targetComputerId = tonumber(args[1]) or args[1];
+
+
+local sourceId = os.getComputerID()
+local sourceLabel = os.getComputerLabel();
+
+-- gérer les pongs locales
+if targetComputerId == nil or targetComputerId == sourceId or targetComputerId == sourceLabel then
+  print("=> local pong from " .. tostring(sourceId)
+    .. (sourceLabel and " (label=" .. tostring(sourceLabel) .. ")" or ""));
+end
+
+-- envoyer un message sur le canal 9 à la machine cible
+net.send(PING_CHANNEL, "ping", targetComputerId);
+
+-- recevoir et afficher un message sur le canal 9
+while true do
+  local message, payload = net.waitMessage(PING_CHANNEL);
+
+  if message == "pong" then
+    print("=> pong from " .. tostring(payload.sourceId)
+      .. (payload.sourceLabel and " (label=" .. tostring(payload.sourceLabel) .. ")" or ""));
+  elseif message == nil then
+    break
+  end
+end
diff --git a/router.lua b/router.lua
new file mode 100644
index 0000000..5c509a1
--- /dev/null
+++ b/router.lua
@@ -0,0 +1,71 @@
+-- router v1.1.0
+
+local ROUTER_CHANNEL = 10;
+local VERBOSE = true;
+
+local modem = peripheral.find("modem") or error("modem not found");
+modem.open(ROUTER_CHANNEL);
+
+local routerId = os.getComputerID();
+
+local function isPingForServer(payload)
+  if payload.message ~= 'ping' then
+    return false;
+  end
+
+  if payload.destId == routerId or payload.destId == os.getComputerLabel() then
+    return true;
+  end
+
+  if payload.destId == nil then
+    return true;
+  end
+
+  return false;
+end
+
+while true do
+  local channel, replyChannel, payload, pingForServer;
+
+  repeat
+    _, _, channel, replyChannel, payload = os.pullEvent("modem_message");
+    pingForServer = isPingForServer(payload)
+
+    local channelOk = channel == ROUTER_CHANNEL;
+    local payloadOk = type(payload) == 'table' and not payload.routerId or pingForServer;
+    local loopFinished = channelOk and payloadOk;
+  until loopFinished
+
+
+  if payload and not payload.routerId then
+    if pingForServer then
+      local responseRouterPayload = {
+        sourceId = os.getComputerID(),
+        sourceLabel = os.getComputerLabel(),
+        routerId = routerId,
+        destId = payload.sourceId,
+        message = 'pong'
+      }
+      modem.transmit(replyChannel, replyChannel, responseRouterPayload)
+    end
+    if not pingForServer or payload.destId == nil then
+      payload.routerId = routerId;
+      modem.transmit(replyChannel, replyChannel, payload);
+    end
+  end
+
+  if VERBOSE then
+    if payload.destId then
+      if pingForServer then
+        print('ping for server received!');
+      else
+        print("Routed message from " .. tostring(payload.sourceId)
+          .. " to " .. tostring(payload.destId)
+          .. " using channel " .. tostring(replyChannel));
+      end
+    else
+      print("Broadcasted message from " .. tostring(payload.sourceId)
+        .. " using channel " .. tostring(replyChannel));
+    end
+  end
+end
diff --git a/startup/servers.lua b/startup/servers.lua
new file mode 100644
index 0000000..ed62ab9
--- /dev/null
+++ b/startup/servers.lua
@@ -0,0 +1,41 @@
+-- Server Launcher v1.0.0
+
+local SERVERS = {
+  "ping-server",
+};
+
+local function shellFn()
+  os.sleep(0.1);
+  shell.run("shell");
+end
+
+local function getServerFns(serverList)
+  local servers = {};
+
+  for k, v in ipairs(serverList) do
+    local serverName = serverList[k];
+
+    servers[k] = function()
+      if serverName then
+        shell.run(serverName);
+      end
+    end
+  end
+
+  return servers;
+end
+
+local servers = getServerFns(SERVERS);
+
+print("\nStarting servers...");
+
+for _, v in ipairs(SERVERS) do
+  print("\t\t" .. v)
+end
+
+parallel.waitForAny(shellFn, table.unpack(servers));
+
+print("Servers stopped, reboot the machine...");
+
+os.sleep(1);
+os.reboot();