Add an aos_send

It's basically the opposite of aos_dump.

Change-Id: I12fc53f8afbc3eef3ad4293d37b1a575e7a8d596
diff --git a/aos/aos_cli_utils.cc b/aos/aos_cli_utils.cc
new file mode 100644
index 0000000..e36c3d2
--- /dev/null
+++ b/aos/aos_cli_utils.cc
@@ -0,0 +1,162 @@
+#include "aos/aos_cli_utils.h"
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <iostream>
+
+DEFINE_string(config, "./config.json", "File path of aos configuration");
+
+DEFINE_bool(
+    _bash_autocomplete, false,
+    "Internal use: Outputs channel list for use with autocomplete script.");
+DEFINE_string(_bash_autocomplete_word, "",
+              "Internal use: Current word being autocompleted");
+
+DEFINE_bool(all, false,
+            "If true, print out the channels for all nodes, not just the "
+            "channels which are visible on this node.");
+
+namespace aos {
+namespace {
+
+bool EndsWith(std::string_view str, std::string_view ending) {
+  const std::size_t offset = str.size() - ending.size();
+  return str.size() >= ending.size() &&
+         std::equal(str.begin() + offset, str.end(), ending.begin(),
+                    ending.end());
+}
+
+}  // namespace
+
+bool CliUtilInfo::Initialize(
+    int *argc, char ***argv,
+    std::function<bool(const aos::Channel *)> channel_filter) {
+  // Don't generate failure output if the config doesn't exist while attempting
+  // to autocomplete.
+  if (struct stat file_stat;
+      FLAGS__bash_autocomplete &&
+      (!(EndsWith(FLAGS_config, ".json") || EndsWith(FLAGS_config, ".bfbs")) ||
+       stat(FLAGS_config.c_str(), &file_stat) != 0 ||
+       (file_stat.st_mode & S_IFMT) != S_IFREG)) {
+    std::cout << "COMPREPLY=()";
+    return true;
+  }
+
+  std::string channel_name;
+  std::string message_type;
+  if (*argc > 1) {
+    channel_name = (*argv)[1];
+    ShiftArgs(argc, argv);
+  }
+  if (*argc > 1) {
+    message_type = (*argv)[1];
+    ShiftArgs(argc, argv);
+  }
+
+  config.emplace(aos::configuration::ReadConfig(FLAGS_config));
+  event_loop.emplace(&config->message());
+  event_loop->SkipTimingReport();
+  event_loop->SkipAosLog();
+
+  if (FLAGS__bash_autocomplete) {
+    Autocomplete(channel_name, message_type, channel_filter);
+    return true;
+  }
+
+  const flatbuffers::Vector<flatbuffers::Offset<aos::Channel>> *const channels =
+      event_loop->configuration()->channels();
+  if (channel_name.empty() && message_type.empty()) {
+    std::cout << "Channels:\n";
+    for (const aos::Channel *channel : *channels) {
+      if (FLAGS_all || channel_filter(channel)) {
+        std::cout << channel->name()->c_str() << ' ' << channel->type()->c_str()
+                  << '\n';
+      }
+    }
+    return true;
+  }
+
+  bool found_exact = false;
+  for (const aos::Channel *channel : *channels) {
+    if (!FLAGS_all && !channel_filter(channel)) {
+      continue;
+    }
+    if (channel->name()->c_str() != channel_name) {
+      continue;
+    }
+    if (channel->type()->string_view() == message_type) {
+      if (!found_exact) {
+        found_channels.clear();
+        found_exact = true;
+      }
+    } else if (!found_exact && channel->type()->string_view().find(
+                                   message_type) != std::string_view::npos) {
+    } else {
+      continue;
+    }
+    found_channels.push_back(channel);
+  }
+
+  if (found_channels.empty()) {
+    LOG(FATAL) << "Could not find any channels with the given name and type.";
+  } else if (found_channels.size() > 1 && !message_type.empty()) {
+    LOG(FATAL) << "Multiple channels found with same type";
+  }
+
+  return false;
+}
+
+void CliUtilInfo::Autocomplete(
+    std::string_view channel_name, std::string_view message_type,
+    std::function<bool(const aos::Channel *)> channel_filter) {
+  const aos::Configuration *const config_msg = event_loop->configuration();
+  const bool unique_match =
+      std::count_if(config_msg->channels()->begin(),
+                    config_msg->channels()->end(),
+                    [channel_name, message_type](const aos::Channel *channel) {
+                      return channel->name()->string_view() == channel_name &&
+                             channel->type()->string_view() == message_type;
+                    }) == 1;
+
+  const bool editing_message =
+      !channel_name.empty() && FLAGS__bash_autocomplete_word == message_type;
+  const bool editing_channel =
+      !editing_message && FLAGS__bash_autocomplete_word == channel_name;
+
+  std::cout << "COMPREPLY=(";
+
+  // If we have a unique match, don't provide any suggestions. Otherwise, check
+  // that were're editing one of the two positional arguments.
+  if (!unique_match && (editing_message || editing_channel)) {
+    for (const aos::Channel *channel : *config_msg->channels()) {
+      if (FLAGS_all || channel_filter(channel)) {
+        // Suggest only message types if the message type argument is being
+        // entered.
+        if (editing_message) {
+          // Then, filter for only channel names that match exactly and types
+          // that begin with message_type.
+          if (channel->name()->string_view() == channel_name &&
+              channel->type()->string_view().find(message_type) == 0) {
+            std::cout << '\'' << channel->type()->c_str() << "' ";
+          }
+        } else if (channel->name()->string_view().find(channel_name) == 0) {
+          // If the message type empty, then return full autocomplete.
+          // Otherwise, since the message type is poulated yet not being edited,
+          // the user must be editing the channel name alone, in which case only
+          // suggest channel names, not pairs.
+          if (message_type.empty()) {
+            std::cout << '\'' << channel->name()->c_str() << ' '
+                      << channel->type()->c_str() << "' ";
+          } else {
+            std::cout << '\'' << channel->name()->c_str() << "' ";
+          }
+        }
+      }
+    }
+  }
+  std::cout << ')';
+}
+
+}  // namespace aos