From 9e95bac75d43534614d168614624fa24048faf48 Mon Sep 17 00:00:00 2001
From: HybridDog <3192173+HybridDog@users.noreply.github.com>
Date: Thu, 26 Sep 2019 21:03:54 +0200
Subject: [PATCH] Automatically enable depends of mods when enabling the mods
 in the world config menu (#3473)

---
 builtin/mainmenu/pkgmgr.lua | 112 ++++++++++++++++++++++++++++++------
 1 file changed, 95 insertions(+), 17 deletions(-)

diff --git a/builtin/mainmenu/pkgmgr.lua b/builtin/mainmenu/pkgmgr.lua
index b9b612963..f87367689 100644
--- a/builtin/mainmenu/pkgmgr.lua
+++ b/builtin/mainmenu/pkgmgr.lua
@@ -285,8 +285,8 @@ function pkgmgr.identify_modname(modpath,filename)
 end
 --------------------------------------------------------------------------------
 function pkgmgr.render_packagelist(render_list)
-	if render_list == nil then
-		if pkgmgr.global_mods == nil then
+	if not render_list then
+		if not pkgmgr.global_mods then
 			pkgmgr.refresh_globals()
 		end
 		render_list = pkgmgr.global_mods
@@ -347,35 +347,113 @@ function pkgmgr.is_modpack_entirely_enabled(data, name)
 	return true
 end
 
----------- toggles or en/disables a mod or modpack -----------------------------
+---------- toggles or en/disables a mod or modpack and its dependencies --------
 function pkgmgr.enable_mod(this, toset)
-	local mod = this.data.list:get_list()[this.data.selected_mod]
+	local list = this.data.list:get_list()
+	local mod = list[this.data.selected_mod]
 
-	-- game mods can't be enabled or disabled
+	-- Game mods can't be enabled or disabled
 	if mod.is_game_content then
 		return
 	end
 
-	-- toggle or en/disable the mod
+	local toggled_mods = {}
+
+	local enabled_mods = {}
 	if not mod.is_modpack then
+		-- Toggle or en/disable the mod
 		if toset == nil then
-			mod.enabled = not mod.enabled
-		else
-			mod.enabled = toset
+			toset = not mod.enabled
 		end
+		if mod.enabled ~= toset then
+			mod.enabled = toset
+			toggled_mods[#toggled_mods+1] = mod.name
+		end
+		if toset then
+			-- Mark this mod for recursive dependency traversal
+			enabled_mods[mod.name] = true
+		end
+	else
+		-- Toggle or en/disable every mod in the modpack,
+		-- interleaved unsupported
+		for i = 1, #list do
+			if list[i].modpack == mod.name then
+				if toset == nil then
+					toset = not list[i].enabled
+				end
+				if list[i].enabled ~= toset then
+					list[i].enabled = toset
+					toggled_mods[#toggled_mods+1] = list[i].name
+				end
+				if toset then
+					enabled_mods[list[i].name] = true
+				end
+			end
+		end
+	end
+	if not toset then
+		-- Mod(s) were disabled, so no dependencies need to be enabled
+		table.sort(toggled_mods)
+		minetest.log("info", "Following mods were disabled: " ..
+			table.concat(toggled_mods, ", "))
 		return
 	end
 
-	-- toggle or en/disable every mod in the modpack, interleaved unsupported
-	local list = this.data.list:get_raw_list()
-	for i = 1, #list do
-		if list[i].modpack == mod.name then
-			if toset == nil then
-				toset = not list[i].enabled
-			end
-			list[i].enabled = toset
+	-- Enable mods' depends after activation
+
+	-- Make a list of mod ids indexed by their names
+	local mod_ids = {}
+	for id, mod in pairs(list) do
+		if mod.type == "mod" and not mod.is_modpack then
+			mod_ids[mod.name] = id
 		end
 	end
+
+	-- to_enable is used as a DFS stack with sp as stack pointer
+	local to_enable = {}
+	local sp = 0
+	for name in pairs(enabled_mods) do
+		local depends = pkgmgr.get_dependencies(list[mod_ids[name]].path)
+		for i = 1, #depends do
+			local dependency_name = depends[i]
+			if not enabled_mods[dependency_name] then
+				sp = sp+1
+				to_enable[sp] = dependency_name
+			end
+		end
+	end
+	-- If sp is 0, every dependency is already activated
+	while sp > 0 do
+		local name = to_enable[sp]
+		sp = sp-1
+
+		if not enabled_mods[name] then
+			enabled_mods[name] = true
+			local mod = list[mod_ids[name]]
+			if not mod then
+				minetest.log("warning", "Mod dependency \"" .. name ..
+					"\" not found!")
+			else
+				if mod.enabled == false then
+					mod.enabled = true
+					toggled_mods[#toggled_mods+1] = mod.name
+				end
+				-- Push the dependencies of the dependency onto the stack
+				local depends = pkgmgr.get_dependencies(mod.path)
+				for i = 1, #depends do
+					if not enabled_mods[name] then
+						sp = sp+1
+						to_enable[sp] = depends[i]
+					end
+				end
+			end
+		end
+	end
+
+	-- Log the list of enabled mods
+	table.sort(toggled_mods)
+	minetest.log("info", "Following mods were enabled: " ..
+		table.concat(toggled_mods, ", "))
 end
 
 --------------------------------------------------------------------------------