From c430340c9d222d560d2d095010a0ac32fa34c1ac Mon Sep 17 00:00:00 2001
From: Martin Michelsen <fuzziqersoftware+g@gmail.com>
Date: Fri, 8 Sep 2023 23:12:35 -0700
Subject: [PATCH] hide Ep3 maps that don't have enough player slots for the
 game

---
 src/Episode3/DataIndexes.cc | 38 ++++++++++++++++++++++++++++---------
 src/Episode3/DataIndexes.hh |  9 +++------
 src/Episode3/Server.cc      |  2 +-
 3 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/src/Episode3/DataIndexes.cc b/src/Episode3/DataIndexes.cc
index c1bd5db6..f9c8423e 100644
--- a/src/Episode3/DataIndexes.cc
+++ b/src/Episode3/DataIndexes.cc
@@ -2026,12 +2026,31 @@ const string& MapIndex::MapEntry::compressed(bool is_trial) const {
   }
 }
 
-const string& MapIndex::get_compressed_list() const {
-  if (this->compressed_map_list.empty()) {
+const string& MapIndex::get_compressed_list(size_t num_players) const {
+  if (num_players == 0) {
+    throw runtime_error("cannot generate map list for no players");
+  }
+  if (num_players > 4) {
+    throw logic_error("player count is too high in map list generation");
+  }
+  string& compressed_map_list = this->compressed_map_lists.at(num_players - 1);
+  if (compressed_map_list.empty()) {
     StringWriter entries_w;
     StringWriter strings_w;
 
+    size_t num_maps = 0;
     for (const auto& map_it : this->maps) {
+      size_t map_num_players = 0;
+      for (size_t z = 0; z < 4; z++) {
+        uint8_t player_type = map_it.second->map.entry_states[z].player_type;
+        if (player_type == 0x00 || player_type == 0x01 || player_type == 0xFF) {
+          map_num_players++;
+        }
+      }
+      if (map_num_players < num_players) {
+        continue;
+      }
+
       MapList::Entry e;
       const auto& map = map_it.second->map;
       e.map_x = map.map_x;
@@ -2059,10 +2078,11 @@ const string& MapIndex::get_compressed_list() const {
       e.unknown_a1 = map_it.second->is_quest ? 0x00 : 0xFF;
 
       entries_w.put(e);
+      num_maps++;
     }
 
     MapList header;
-    header.num_maps = this->maps.size();
+    header.num_maps = num_maps;
     header.unknown_a1 = 0;
     header.strings_offset = entries_w.size();
     header.total_size = sizeof(MapList) + entries_w.size() + strings_w.size();
@@ -2075,15 +2095,15 @@ const string& MapIndex::get_compressed_list() const {
     StringWriter compressed_w;
     compressed_w.put_u32b(prs.input_size());
     compressed_w.write(prs.close());
-    this->compressed_map_list = std::move(compressed_w.str());
-    if (this->compressed_map_list.size() > 0x7BEC) {
-      throw runtime_error("Episode 3 compressed map list is too large");
+    compressed_map_list = std::move(compressed_w.str());
+    if (compressed_map_list.size() > 0x7BEC) {
+      throw runtime_error(string_printf("compressed map list for %zu players is too large (0x%zX bytes)", num_players, compressed_map_list.size()));
     }
     size_t decompressed_size = sizeof(header) + entries_w.size() + strings_w.size();
-    static_game_data_log.info("Generated Episode 3 compressed map list (0x%zX -> 0x%zX bytes)",
-        decompressed_size, this->compressed_map_list.size());
+    static_game_data_log.info("Generated Episode 3 compressed map list for %zu player(s) (%zu maps; 0x%zX -> 0x%zX bytes)",
+        num_players, num_maps, decompressed_size, compressed_map_list.size());
   }
-  return this->compressed_map_list;
+  return compressed_map_list;
 }
 
 shared_ptr<const MapIndex::MapEntry> MapIndex::definition_for_number(uint32_t id) const {
diff --git a/src/Episode3/DataIndexes.hh b/src/Episode3/DataIndexes.hh
index 733cd15a..8ea8d87d 100644
--- a/src/Episode3/DataIndexes.hh
+++ b/src/Episode3/DataIndexes.hh
@@ -1145,17 +1145,14 @@ public:
     mutable std::string compressed_trial_data;
   };
 
-  const std::string& get_compressed_list() const;
+  const std::string& get_compressed_list(size_t num_players) const;
   std::shared_ptr<const MapEntry> definition_for_number(uint32_t id) const;
   std::shared_ptr<const MapEntry> definition_for_name(const std::string& name) const;
   std::set<uint32_t> all_numbers() const;
 
 private:
-  // The compressed map list is generated on demand from the maps map below.
-  // It's marked mutable because the logical consistency of the MapIndex object
-  // is not violated from the caller's perspective even if we don't generate the
-  // compressed map list at load time.
-  mutable std::string compressed_map_list;
+  // The compressed map lists are generated on demand from the maps map below
+  mutable std::array<std::string, 4> compressed_map_lists;
   std::map<uint32_t, std::shared_ptr<MapEntry>> maps;
   std::unordered_map<std::string, std::shared_ptr<MapEntry>> maps_by_name;
 };
diff --git a/src/Episode3/Server.cc b/src/Episode3/Server.cc
index dd61438b..1d4ebcf9 100644
--- a/src/Episode3/Server.cc
+++ b/src/Episode3/Server.cc
@@ -2168,7 +2168,7 @@ void Server::handle_6xB3x40_map_list_request(const string& data) {
     throw runtime_error("lobby is deleted");
   }
 
-  const auto& list_data = this->base()->map_index->get_compressed_list();
+  const auto& list_data = this->base()->map_index->get_compressed_list(l->count_clients());
 
   StringWriter w;
   uint32_t subcommand_size = (list_data.size() + sizeof(G_MapList_GC_Ep3_6xB6x40) + 3) & (~3);