[dragonfireclient.git] / builtin / game / chat.lua

-- Minetest: builtin/game/chat.lua

local S = core.get_translator("__builtin")

-- Helper function that implements search and replace without pattern matching
-- Returns the string and a boolean indicating whether or not the string was modified
local function safe_gsub(s, replace, with)
        local i1, i2 = s:find(replace, 1, true)
        if not i1 then
                return s, false
        end

        return s:sub(1, i1 - 1) .. with .. s:sub(i2 + 1), true
end

--
-- Chat message formatter
--

-- Implemented in Lua to allow redefinition
function core.format_chat_message(name, message)
        local error_str = "Invalid chat message format - missing %s"
        local str = core.settings:get("chat_message_format")
        local replaced

        -- Name
        str, replaced = safe_gsub(str, "@name", name)
        if not replaced then
                error(error_str:format("@name"), 2)
        end

        -- Timestamp
        str = safe_gsub(str, "@timestamp", os.date("%H:%M:%S", os.time()))

        -- Insert the message into the string only after finishing all other processing
        str, replaced = safe_gsub(str, "@message", message)
        if not replaced then
                error(error_str:format("@message"), 2)
        end

        return str
end

--
-- Chat command handler
--

core.chatcommands = core.registered_chatcommands -- BACKWARDS COMPATIBILITY

local msg_time_threshold =
        tonumber(core.settings:get("chatcommand_msg_time_threshold")) or 0.1
core.register_on_chat_message(function(name, message)
        if message:sub(1,1) ~= "/" then
                return
        end

        local cmd, param = string.match(message, "^/([^ ]+) *(.*)")
        if not cmd then
                core.chat_send_player(name, "-!- "..S("Empty command."))
                return true
        end

        param = param or ""

        -- Run core.registered_on_chatcommands callbacks.
        if core.run_callbacks(core.registered_on_chatcommands, 5, name, cmd, param) then
                return true
        end

        local cmd_def = core.registered_chatcommands[cmd]
        if not cmd_def then
                core.chat_send_player(name, "-!- "..S("Invalid command: @1", cmd))
                return true
        end
        local has_privs, missing_privs = core.check_player_privs(name, cmd_def.privs)
        if has_privs then
                core.set_last_run_mod(cmd_def.mod_origin)
                local t_before = core.get_us_time()
                local success, result = cmd_def.func(name, param)
                local delay = (core.get_us_time() - t_before) / 1000000
                if success == false and result == nil then
                        core.chat_send_player(name, "-!- "..S("Invalid command usage."))
                        local help_def = core.registered_chatcommands["help"]
                        if help_def then
                                local _, helpmsg = help_def.func(name, cmd)
                                if helpmsg then
                                        core.chat_send_player(name, helpmsg)
                                end
                        end
                else
                        if delay > msg_time_threshold then
                                -- Show how much time it took to execute the command
                                if result then
                                        result = result .. core.colorize("#f3d2ff", S(" (@1 s)",
                                                string.format("%.5f", delay)))
                                else
                                        result = core.colorize("#f3d2ff", S(
                                                "Command execution took @1 s",
                                                string.format("%.5f", delay)))
                                end
                        end
                        if result then
                                core.chat_send_player(name, result)
                        end
                end
        else
                core.chat_send_player(name,
                                S("You don't have permission to run this command "
                                .. "(missing privileges: @1).",
                                table.concat(missing_privs, ", ")))
        end
        return true  -- Handled chat message
end)

if core.settings:get_bool("profiler.load") then
        -- Run after register_chatcommand and its register_on_chat_message
        -- Before any chatcommands that should be profiled
        profiler.init_chatcommand()
end

-- Parses a "range" string in the format of "here (number)" or
-- "(x1, y1, z1) (x2, y2, z2)", returning two position vectors
local function parse_range_str(player_name, str)
        local p1, p2
        local args = str:split(" ")

        if args[1] == "here" then
                p1, p2 = core.get_player_radius_area(player_name, tonumber(args[2]))
                if p1 == nil then
                        return false, S("Unable to get position of player @1.", player_name)
                end
        else
                p1, p2 = core.string_to_area(str)
                if p1 == nil then
                        return false, S("Incorrect area format. "
                                .. "Expected: (x1,y1,z1) (x2,y2,z2)")
                end
        end

        return p1, p2
end

--
-- Chat commands
--
core.register_chatcommand("me", {
        params = S("<action>"),
        description = S("Show chat action (e.g., '/me orders a pizza' "
                .. "displays '<player name> orders a pizza')"),
        privs = {shout=true},
        func = function(name, param)
                core.chat_send_all("* " .. name .. " " .. param)
                return true
        end,
})

core.register_chatcommand("admin", {
        description = S("Show the name of the server owner"),
        func = function(name)
                local admin = core.settings:get("name")
                if admin then
                        return true, S("The administrator of this server is @1.", admin)
                else
                        return false, S("There's no administrator named "
                                .. "in the config file.")
                end
        end,
})

local function privileges_of(name, privs)
        if not privs then
                privs = core.get_player_privs(name)
        end
        local privstr = core.privs_to_string(privs, ", ")
        if privstr == "" then
                return S("@1 does not have any privileges.", name)
        else
                return S("Privileges of @1: @2", name, privstr)
        end
end

core.register_chatcommand("privs", {
        params = S("[<name>]"),
        description = S("Show privileges of yourself or another player"),
        func = function(caller, param)
                param = param:trim()
                local name = (param ~= "" and param or caller)
                if not core.player_exists(name) then
                        return false, S("Player @1 does not exist.", name)
                end
                return true, privileges_of(name)
        end,
})

core.register_chatcommand("haspriv", {
        params = S("<privilege>"),
        description = S("Return list of all online players with privilege"),
        privs = {basic_privs = true},
        func = function(caller, param)
                param = param:trim()
                if param == "" then
                        return false, S("Invalid parameters (see /help haspriv).")
                end
                if not core.registered_privileges[param] then
                        return false, S("Unknown privilege!")
                end
                local privs = core.string_to_privs(param)
                local players_with_priv = {}
                for _, player in pairs(core.get_connected_players()) do
                        local player_name = player:get_player_name()
                        if core.check_player_privs(player_name, privs) then
                                table.insert(players_with_priv, player_name)
                        end
                end
                if #players_with_priv == 0 then
                        return true, S("No online player has the \"@1\" privilege.",
                                        param)
                else
                        return true, S("Players online with the \"@1\" privilege: @2",
                                        param,
                                        table.concat(players_with_priv, ", "))
                end
        end
})

local function handle_grant_command(caller, grantname, grantprivstr)
        local caller_privs = core.get_player_privs(caller)
        if not (caller_privs.privs or caller_privs.basic_privs) then
                return false, S("Your privileges are insufficient.")
        end

        if not core.get_auth_handler().get_auth(grantname) then
                return false, S("Player @1 does not exist.", grantname)
        end
        local grantprivs = core.string_to_privs(grantprivstr)
        if grantprivstr == "all" then
                grantprivs = core.registered_privileges
        end
        local privs = core.get_player_privs(grantname)
        local privs_unknown = ""
        local basic_privs =
                core.string_to_privs(core.settings:get("basic_privs") or "interact,shout")
        for priv, _ in pairs(grantprivs) do
                if not basic_privs[priv] and not caller_privs.privs then
                        return false, S("Your privileges are insufficient. "..
                                        "'@1' only allows you to grant: @2",
                                        "basic_privs",
                                        core.privs_to_string(basic_privs, ', '))
                end
                if not core.registered_privileges[priv] then
                        privs_unknown = privs_unknown .. S("Unknown privilege: @1", priv) .. "\n"
                end
                privs[priv] = true
        end
        if privs_unknown ~= "" then
                return false, privs_unknown
        end
        core.set_player_privs(grantname, privs)
        for priv, _ in pairs(grantprivs) do
                -- call the on_grant callbacks
                core.run_priv_callbacks(grantname, priv, caller, "grant")
        end
        core.log("action", caller..' granted ('..core.privs_to_string(grantprivs, ', ')..') privileges to '..grantname)
        if grantname ~= caller then
                core.chat_send_player(grantname,
                                S("@1 granted you privileges: @2", caller,
                                core.privs_to_string(grantprivs, ', ')))
        end
        return true, privileges_of(grantname)
end

core.register_chatcommand("grant", {
        params = S("<name> (<privilege> [, <privilege2> [<...>]] | all)"),
        description = S("Give privileges to player"),
        func = function(name, param)
                local grantname, grantprivstr = string.match(param, "([^ ]+) (.+)")
                if not grantname or not grantprivstr then
                        return false, S("Invalid parameters (see /help grant).")
                end
                return handle_grant_command(name, grantname, grantprivstr)
        end,
})

core.register_chatcommand("grantme", {
        params = S("<privilege> [, <privilege2> [<...>]] | all"),
        description = S("Grant privileges to yourself"),
        func = function(name, param)
                if param == "" then
                        return false, S("Invalid parameters (see /help grantme).")
                end
                return handle_grant_command(name, name, param)
        end,
})

local function handle_revoke_command(caller, revokename, revokeprivstr)
        local caller_privs = core.get_player_privs(caller)
        if not (caller_privs.privs or caller_privs.basic_privs) then
                return false, S("Your privileges are insufficient.")
        end

        if not core.get_auth_handler().get_auth(revokename) then
                return false, S("Player @1 does not exist.", revokename)
        end

        local privs = core.get_player_privs(revokename)

        local revokeprivs = core.string_to_privs(revokeprivstr)
        local is_singleplayer = core.is_singleplayer()
        local is_admin = not is_singleplayer
                        and revokename == core.settings:get("name")
                        and revokename ~= ""
        if revokeprivstr == "all" then
                revokeprivs = table.copy(privs)
        end

        local privs_unknown = ""
        local basic_privs =
                core.string_to_privs(core.settings:get("basic_privs") or "interact,shout")
        local irrevokable = {}
        local has_irrevokable_priv = false
        for priv, _ in pairs(revokeprivs) do
                if not basic_privs[priv] and not caller_privs.privs then
                        return false, S("Your privileges are insufficient. "..
                                        "'@1' only allows you to revoke: @2",
                                        "basic_privs",
                                        core.privs_to_string(basic_privs, ', '))
                end
                local def = core.registered_privileges[priv]
                if not def then
                        -- Old/removed privileges might still be granted to certain players
                        if not privs[priv] then
                                privs_unknown = privs_unknown .. S("Unknown privilege: @1", priv) .. "\n"
                        end
                elseif is_singleplayer and def.give_to_singleplayer then
                        irrevokable[priv] = true
                elseif is_admin and def.give_to_admin then
                        irrevokable[priv] = true
                end
        end
        for priv, _ in pairs(irrevokable) do
                revokeprivs[priv] = nil
                has_irrevokable_priv = true
        end
        if privs_unknown ~= "" then
                return false, privs_unknown
        end
        if has_irrevokable_priv then
                if is_singleplayer then
                        core.chat_send_player(caller,
                                        S("Note: Cannot revoke in singleplayer: @1",
                                        core.privs_to_string(irrevokable, ', ')))
                elseif is_admin then
                        core.chat_send_player(caller,
                                        S("Note: Cannot revoke from admin: @1",
                                        core.privs_to_string(irrevokable, ', ')))
                end
        end

        local revokecount = 0
        for priv, _ in pairs(revokeprivs) do
                privs[priv] = nil
                revokecount = revokecount + 1
        end

        if revokecount == 0 then
                return false, S("No privileges were revoked.")
        end

        core.set_player_privs(revokename, privs)
        for priv, _ in pairs(revokeprivs) do
                -- call the on_revoke callbacks
                core.run_priv_callbacks(revokename, priv, caller, "revoke")
        end
        local new_privs = core.get_player_privs(revokename)

        core.log("action", caller..' revoked ('
                        ..core.privs_to_string(revokeprivs, ', ')
                        ..') privileges from '..revokename)
        if revokename ~= caller then
                core.chat_send_player(revokename,
                        S("@1 revoked privileges from you: @2", caller,
                        core.privs_to_string(revokeprivs, ', ')))
        end
        return true, privileges_of(revokename, new_privs)
end

core.register_chatcommand("revoke", {
        params = S("<name> (<privilege> [, <privilege2> [<...>]] | all)"),
        description = S("Remove privileges from player"),
        privs = {},
        func = function(name, param)
                local revokename, revokeprivstr = string.match(param, "([^ ]+) (.+)")
                if not revokename or not revokeprivstr then
                        return false, S("Invalid parameters (see /help revoke).")
                end
                return handle_revoke_command(name, revokename, revokeprivstr)
        end,
})

core.register_chatcommand("revokeme", {
        params = S("<privilege> [, <privilege2> [<...>]] | all"),
        description = S("Revoke privileges from yourself"),
        privs = {},
        func = function(name, param)
                if param == "" then
                        return false, S("Invalid parameters (see /help revokeme).")
                end
                return handle_revoke_command(name, name, param)
        end,
})

core.register_chatcommand("setpassword", {
        params = S("<name> <password>"),
        description = S("Set player's password"),
        privs = {password=true},
        func = function(name, param)
                local toname, raw_password = string.match(param, "^([^ ]+) +(.+)$")
                if not toname then
                        toname = param:match("^([^ ]+) *$")
                        raw_password = nil
                end

                if not toname then
                        return false, S("Name field required.")
                end

                local msg_chat, msg_log, msg_ret
                if not raw_password then
                        core.set_player_password(toname, "")
                        msg_chat = S("Your password was cleared by @1.", name)
                        msg_log = name .. " clears password of " .. toname .. "."
                        msg_ret = S("Password of player \"@1\" cleared.", toname)
                else
                        core.set_player_password(toname,
                                        core.get_password_hash(toname,
                                                        raw_password))
                        msg_chat = S("Your password was set by @1.", name)
                        msg_log = name .. " sets password of " .. toname .. "."
                        msg_ret = S("Password of player \"@1\" set.", toname)
                end

                if toname ~= name then
                        core.chat_send_player(toname, msg_chat)
                end

                core.log("action", msg_log)

                return true, msg_ret
        end,
})

core.register_chatcommand("clearpassword", {
        params = S("<name>"),
        description = S("Set empty password for a player"),
        privs = {password=true},
        func = function(name, param)
                local toname = param
                if toname == "" then
                        return false, S("Name field required.")
                end
                core.set_player_password(toname, '')

                core.log("action", name .. " clears password of " .. toname .. ".")

                return true, S("Password of player \"@1\" cleared.", toname)
        end,
})

core.register_chatcommand("auth_reload", {
        params = "",
        description = S("Reload authentication data"),
        privs = {server=true},
        func = function(name, param)
                local done = core.auth_reload()
                return done, (done and S("Done.") or S("Failed."))
        end,
})

core.register_chatcommand("remove_player", {
        params = S("<name>"),
        description = S("Remove a player's data"),
        privs = {server=true},
        func = function(name, param)
                local toname = param
                if toname == "" then
                        return false, S("Name field required.")
                end

                local rc = core.remove_player(toname)

                if rc == 0 then
                        core.log("action", name .. " removed player data of " .. toname .. ".")
                        return true, S("Player \"@1\" removed.", toname)
                elseif rc == 1 then
                        return true, S("No such player \"@1\" to remove.", toname)
                elseif rc == 2 then
                        return true, S("Player \"@1\" is connected, cannot remove.", toname)
                end

                return false, S("Unhandled remove_player return code @1.", tostring(rc))
        end,
})


-- pos may be a non-integer position
local function find_free_position_near(pos)
        local tries = {
                vector.new( 1, 0,  0),
                vector.new(-1, 0,  0),
                vector.new( 0, 0,  1),
                vector.new( 0, 0, -1),
        }
        for _, d in ipairs(tries) do
                local p = vector.add(pos, d)
                local n = core.get_node_or_nil(p)
                if n then
                        local def = core.registered_nodes[n.name]
                        if def and not def.walkable then
                                return p
                        end
                end
        end
        return pos
end

-- Teleports player <name> to <p> if possible
local function teleport_to_pos(name, p)
        local lm = 31007 -- equals MAX_MAP_GENERATION_LIMIT in C++
        if p.x < -lm or p.x > lm or p.y < -lm or p.y > lm
                        or p.z < -lm or p.z > lm then
                return false, S("Cannot teleport out of map bounds!")
        end
        local teleportee = core.get_player_by_name(name)
        if not teleportee then
                return false, S("Cannot get player with name @1.", name)
        end
        if teleportee:get_attach() then
                return false, S("Cannot teleport, @1 " ..
                        "is attached to an object!", name)
        end
        teleportee:set_pos(p)
        return true, S("Teleporting @1 to @2.", name, core.pos_to_string(p, 1))
end

-- Teleports player <name> next to player <target_name> if possible
local function teleport_to_player(name, target_name)
        if name == target_name then
                return false, S("One does not teleport to oneself.")
        end
        local teleportee = core.get_player_by_name(name)
        if not teleportee then
                return false, S("Cannot get teleportee with name @1.", name)
        end
        if teleportee:get_attach() then
                return false, S("Cannot teleport, @1 " ..
                        "is attached to an object!", name)
        end
        local target = core.get_player_by_name(target_name)
        if not target then
                return false, S("Cannot get target player with name @1.", target_name)
        end
        local p = find_free_position_near(target:get_pos())
        teleportee:set_pos(p)
        return true, S("Teleporting @1 to @2 at @3.", name, target_name,
                core.pos_to_string(p, 1))
end

core.register_chatcommand("teleport", {
        params = S("<X>,<Y>,<Z> | <to_name> | <name> <X>,<Y>,<Z> | <name> <to_name>"),
        description = S("Teleport to position or player"),
        privs = {teleport=true},
        func = function(name, param)
                local p = {}
                p.x, p.y, p.z = param:match("^([%d.-]+)[, ] *([%d.-]+)[, ] *([%d.-]+)$")
                p = vector.apply(p, tonumber)
                if p.x and p.y and p.z then
                        return teleport_to_pos(name, p)
                end

                local target_name = param:match("^([^ ]+)$")
                if target_name then
                        return teleport_to_player(name, target_name)
                end

                local has_bring_priv = core.check_player_privs(name, {bring=true})
                local missing_bring_msg = S("You don't have permission to teleport " ..
                        "other players (missing privilege: @1).", "bring")

                local teleportee_name
                teleportee_name, p.x, p.y, p.z = param:match(
                                "^([^ ]+) +([%d.-]+)[, ] *([%d.-]+)[, ] *([%d.-]+)$")
                p = vector.apply(p, tonumber)
                if teleportee_name and p.x and p.y and p.z then
                        if not has_bring_priv then
                                return false, missing_bring_msg
                        end
                        return teleport_to_pos(teleportee_name, p)
                end

                teleportee_name, target_name = string.match(param, "^([^ ]+) +([^ ]+)$")
                if teleportee_name and target_name then
                        if not has_bring_priv then
                                return false, missing_bring_msg
                        end
                        return teleport_to_player(teleportee_name, target_name)
                end

                return false
        end,
})

core.register_chatcommand("set", {
        params = S("([-n] <name> <value>) | <name>"),
        description = S("Set or read server configuration setting"),
        privs = {server=true},
        func = function(name, param)
                local arg, setname, setvalue = string.match(param, "(-[n]) ([^ ]+) (.+)")
                if arg and arg == "-n" and setname and setvalue then
                        core.settings:set(setname, setvalue)
                        return true, setname .. " = " .. setvalue
                end

                setname, setvalue = string.match(param, "([^ ]+) (.+)")
                if setname and setvalue then
                        if setname:sub(1, 7) == "secure." then
                                return false, S("Failed. Cannot modify secure settings. "
                                        .. "Edit the settings file manually.")
                        end
                        if not core.settings:get(setname) then
                                return false, S("Failed. Use '/set -n <name> <value>' "
                                        .. "to create a new setting.")
                        end
                        core.settings:set(setname, setvalue)
                        return true, S("@1 = @2", setname, setvalue)
                end

                setname = string.match(param, "([^ ]+)")
                if setname then
                        setvalue = core.settings:get(setname)
                        if not setvalue then
                                setvalue = S("<not set>")
                        end
                        return true, S("@1 = @2", setname, setvalue)
                end

                return false, S("Invalid parameters (see /help set).")
        end,
})

local function emergeblocks_callback(pos, action, num_calls_remaining, ctx)
        if ctx.total_blocks == 0 then
                ctx.total_blocks   = num_calls_remaining + 1
                ctx.current_blocks = 0
        end
        ctx.current_blocks = ctx.current_blocks + 1

        if ctx.current_blocks == ctx.total_blocks then
                core.chat_send_player(ctx.requestor_name,
                        S("Finished emerging @1 blocks in @2ms.",
                                ctx.total_blocks,
                                string.format("%.2f", (os.clock() - ctx.start_time) * 1000)))
        end
end

local function emergeblocks_progress_update(ctx)
        if ctx.current_blocks ~= ctx.total_blocks then
                core.chat_send_player(ctx.requestor_name,
                        S("emergeblocks update: @1/@2 blocks emerged (@3%)",
                        ctx.current_blocks, ctx.total_blocks,
                        string.format("%.1f", (ctx.current_blocks / ctx.total_blocks) * 100)))

                core.after(2, emergeblocks_progress_update, ctx)
        end
end

core.register_chatcommand("emergeblocks", {
        params = S("(here [<radius>]) | (<pos1> <pos2>)"),
        description = S("Load (or, if nonexistent, generate) map blocks contained in "
                .. "area pos1 to pos2 (<pos1> and <pos2> must be in parentheses)"),
        privs = {server=true},
        func = function(name, param)
                local p1, p2 = parse_range_str(name, param)
                if p1 == false then
                        return false, p2
                end

                local context = {
                        current_blocks = 0,
                        total_blocks   = 0,
                        start_time     = os.clock(),
                        requestor_name = name
                }

                core.emerge_area(p1, p2, emergeblocks_callback, context)
                core.after(2, emergeblocks_progress_update, context)

                return true, S("Started emerge of area ranging from @1 to @2.",
                        core.pos_to_string(p1, 1), core.pos_to_string(p2, 1))
        end,
})

core.register_chatcommand("deleteblocks", {
        params = S("(here [<radius>]) | (<pos1> <pos2>)"),
        description = S("Delete map blocks contained in area pos1 to pos2 "
                .. "(<pos1> and <pos2> must be in parentheses)"),
        privs = {server=true},
        func = function(name, param)
                local p1, p2 = parse_range_str(name, param)
                if p1 == false then
                        return false, p2
                end

                if core.delete_area(p1, p2) then
                        return true, S("Successfully cleared area "
                                .. "ranging from @1 to @2.",
                                core.pos_to_string(p1, 1), core.pos_to_string(p2, 1))
                else
                        return false, S("Failed to clear one or more "
                                .. "blocks in area.")
                end
        end,
})

core.register_chatcommand("fixlight", {
        params = S("(here [<radius>]) | (<pos1> <pos2>)"),
        description = S("Resets lighting in the area between pos1 and pos2 "
                .. "(<pos1> and <pos2> must be in parentheses)"),
        privs = {server = true},
        func = function(name, param)
                local p1, p2 = parse_range_str(name, param)
                if p1 == false then
                        return false, p2
                end

                if core.fix_light(p1, p2) then
                        return true, S("Successfully reset light in the area "
                                .. "ranging from @1 to @2.",
                                core.pos_to_string(p1, 1), core.pos_to_string(p2, 1))
                else
                        return false, S("Failed to load one or more blocks in area.")
                end
        end,
})

core.register_chatcommand("mods", {
        params = "",
        description = S("List mods installed on the server"),
        privs = {},
        func = function(name, param)
                local mods = core.get_modnames()
                if #mods == 0 then
                        return true, S("No mods installed.")
                else
                        return true, table.concat(core.get_modnames(), ", ")
                end
        end,
})

local function handle_give_command(cmd, giver, receiver, stackstring)
        core.log("action", giver .. " invoked " .. cmd
                        .. ', stackstring="' .. stackstring .. '"')
        local itemstack = ItemStack(stackstring)
        if itemstack:is_empty() then
                return false, S("Cannot give an empty item.")
        elseif (not itemstack:is_known()) or (itemstack:get_name() == "unknown") then
                return false, S("Cannot give an unknown item.")
        -- Forbid giving 'ignore' due to unwanted side effects
        elseif itemstack:get_name() == "ignore" then
                return false, S("Giving 'ignore' is not allowed.")
        end
        local receiverref = core.get_player_by_name(receiver)
        if receiverref == nil then
                return false, S("@1 is not a known player.", receiver)
        end
        local leftover = receiverref:get_inventory():add_item("main", itemstack)
        local partiality
        if leftover:is_empty() then
                partiality = nil
        elseif leftover:get_count() == itemstack:get_count() then
                partiality = false
        else
                partiality = true
        end
        -- The actual item stack string may be different from what the "giver"
        -- entered (e.g. big numbers are always interpreted as 2^16-1).
        stackstring = itemstack:to_string()
        local msg
        if partiality == true then
                msg = S("@1 partially added to inventory.", stackstring)
        elseif partiality == false then
                msg = S("@1 could not be added to inventory.", stackstring)
        else
                msg = S("@1 added to inventory.", stackstring)
        end
        if giver == receiver then
                return true, msg
        else
                core.chat_send_player(receiver, msg)
                local msg_other
                if partiality == true then
                        msg_other = S("@1 partially added to inventory of @2.",
                                        stackstring, receiver)
                elseif partiality == false then
                        msg_other = S("@1 could not be added to inventory of @2.",
                                        stackstring, receiver)
                else
                        msg_other = S("@1 added to inventory of @2.",
                                        stackstring, receiver)
                end
                return true, msg_other
        end
end

core.register_chatcommand("give", {
        params = S("<name> <ItemString> [<count> [<wear>]]"),
        description = S("Give item to player"),
        privs = {give=true},
        func = function(name, param)
                local toname, itemstring = string.match(param, "^([^ ]+) +(.+)$")
                if not toname or not itemstring then
                        return false, S("Name and ItemString required.")
                end
                return handle_give_command("/give", name, toname, itemstring)
        end,
})

core.register_chatcommand("giveme", {
        params = S("<ItemString> [<count> [<wear>]]"),
        description = S("Give item to yourself"),
        privs = {give=true},
        func = function(name, param)
                local itemstring = string.match(param, "(.+)$")
                if not itemstring then
                        return false, S("ItemString required.")
                end
                return handle_give_command("/giveme", name, name, itemstring)
        end,
})

core.register_chatcommand("spawnentity", {
        params = S("<EntityName> [<X>,<Y>,<Z>]"),
        description = S("Spawn entity at given (or your) position"),
        privs = {give=true, interact=true},
        func = function(name, param)
                local entityname, p = string.match(param, "^([^ ]+) *(.*)$")
                if not entityname then
                        return false, S("EntityName required.")
                end
                core.log("action", ("%s invokes /spawnentity, entityname=%q")
                                :format(name, entityname))
                local player = core.get_player_by_name(name)
                if player == nil then
                        core.log("error", "Unable to spawn entity, player is nil")
                        return false, S("Unable to spawn entity, player is nil.")
                end
                if not core.registered_entities[entityname] then
                        return false, S("Cannot spawn an unknown entity.")
                end
                if p == "" then
                        p = player:get_pos()
                else
                        p = core.string_to_pos(p)
                        if p == nil then
                                return false, S("Invalid parameters (@1).", param)
                        end
                end
                p.y = p.y + 1
                local obj = core.add_entity(p, entityname)
                if obj then
                        return true, S("@1 spawned.", entityname)
                else
                        return true, S("@1 failed to spawn.", entityname)
                end
        end,
})

core.register_chatcommand("pulverize", {
        params = "",
        description = S("Destroy item in hand"),
        func = function(name, param)
                local player = core.get_player_by_name(name)
                if not player then
                        core.log("error", "Unable to pulverize, no player.")
                        return false, S("Unable to pulverize, no player.")
                end
                local wielded_item = player:get_wielded_item()
                if wielded_item:is_empty() then
                        return false, S("Unable to pulverize, no item in hand.")
                end
                core.log("action", name .. " pulverized \"" ..
                        wielded_item:get_name() .. " " .. wielded_item:get_count() .. "\"")
                player:set_wielded_item(nil)
                return true, S("An item was pulverized.")
        end,
})

-- Key = player name
core.rollback_punch_callbacks = {}

core.register_on_punchnode(function(pos, node, puncher)
        local name = puncher and puncher:get_player_name()
        if name and core.rollback_punch_callbacks[name] then
                core.rollback_punch_callbacks[name](pos, node, puncher)
                core.rollback_punch_callbacks[name] = nil
        end
end)

core.register_chatcommand("rollback_check", {
        params = S("[<range>] [<seconds>] [<limit>]"),
        description = S("Check who last touched a node or a node near it "
                .. "within the time specified by <seconds>. "
                .. "Default: range = 0, seconds = 86400 = 24h, limit = 5. "
                .. "Set <seconds> to inf for no time limit"),
        privs = {rollback=true},
        func = function(name, param)
                if not core.settings:get_bool("enable_rollback_recording") then
                        return false, S("Rollback functions are disabled.")
                end
                local range, seconds, limit =
                        param:match("(%d+) *(%d*) *(%d*)")
                range = tonumber(range) or 0
                seconds = tonumber(seconds) or 86400
                limit = tonumber(limit) or 5
                if limit > 100 then
                        return false, S("That limit is too high!")
                end

                core.rollback_punch_callbacks[name] = function(pos, node, puncher)
                        local name = puncher:get_player_name()
                        core.chat_send_player(name, S("Checking @1 ...", core.pos_to_string(pos)))
                        local actions = core.rollback_get_node_actions(pos, range, seconds, limit)
                        if not actions then
                                core.chat_send_player(name, S("Rollback functions are disabled."))
                                return
                        end
                        local num_actions = #actions
                        if num_actions == 0 then
                                core.chat_send_player(name,
                                                S("Nobody has touched the specified "
                                                .. "location in @1 seconds.",
                                                seconds))
                                return
                        end
                        local time = os.time()
                        for i = num_actions, 1, -1 do
                                local action = actions[i]
                                core.chat_send_player(name,
                                        S("@1 @2 @3 -> @4 @5 seconds ago.",
                                                        core.pos_to_string(action.pos),
                                                        action.actor,
                                                        action.oldnode.name,
                                                        action.newnode.name,
                                                        time - action.time))
                        end
                end

                return true, S("Punch a node (range=@1, seconds=@2, limit=@3).",
                                range, seconds, limit)
        end,
})

core.register_chatcommand("rollback", {
        params = S("(<name> [<seconds>]) | (:<actor> [<seconds>])"),
        description = S("Revert actions of a player. "
                .. "Default for <seconds> is 60. "
                .. "Set <seconds> to inf for no time limit"),
        privs = {rollback=true},
        func = function(name, param)
                if not core.settings:get_bool("enable_rollback_recording") then
                        return false, S("Rollback functions are disabled.")
                end
                local target_name, seconds = string.match(param, ":([^ ]+) *(%d*)")
                local rev_msg
                if not target_name then
                        local player_name
                        player_name, seconds = string.match(param, "([^ ]+) *(%d*)")
                        if not player_name then
                                return false, S("Invalid parameters. "
                                        .. "See /help rollback and "
                                        .. "/help rollback_check.")
                        end
                        seconds = tonumber(seconds) or 60
                        target_name = "player:"..player_name
                        rev_msg = S("Reverting actions of player '@1' since @2 seconds.",
                                player_name, seconds)
                else
                        seconds = tonumber(seconds) or 60
                        rev_msg = S("Reverting actions of @1 since @2 seconds.",
                                target_name, seconds)
                end
                core.chat_send_player(name, rev_msg)
                local success, log = core.rollback_revert_actions_by(
                                target_name, seconds)
                local response = ""
                if #log > 100 then
                        response = S("(log is too long to show)").."\n"
                else
                        for _, line in pairs(log) do
                                response = response .. line .. "\n"
                        end
                end
                if success then
                        response = response .. S("Reverting actions succeeded.")
                else
                        response = response .. S("Reverting actions FAILED.")
                end
                return success, response
        end,
})

core.register_chatcommand("status", {
        description = S("Show server status"),
        func = function(name, param)
                local status = core.get_server_status(name, false)
                if status and status ~= "" then
                        return true, status
                end
                return false, S("This command was disabled by a mod or game.")
        end,
})

core.register_chatcommand("time", {
        params = S("[<0..23>:<0..59> | <0..24000>]"),
        description = S("Show or set time of day"),
        privs = {},
        func = function(name, param)
                if param == "" then
                        local current_time = math.floor(core.get_timeofday() * 1440)
                        local minutes = current_time % 60
                        local hour = (current_time - minutes) / 60
                        return true, S("Current time is @1:@2.",
                                        string.format("%d", hour),
                                        string.format("%02d", minutes))
                end
                local player_privs = core.get_player_privs(name)
                if not player_privs.settime then
                        return false, S("You don't have permission to run "
                                .. "this command (missing privilege: @1).", "settime")
                end
                local hour, minute = param:match("^(%d+):(%d+)$")
                if not hour then
                        local new_time = tonumber(param) or -1
                        if new_time ~= new_time or new_time < 0 or new_time > 24000 then
                                return false, S("Invalid time (must be between 0 and 24000).")
                        end
                        core.set_timeofday(new_time / 24000)
                        core.log("action", name .. " sets time to " .. new_time)
                        return true, S("Time of day changed.")
                end
                hour = tonumber(hour)
                minute = tonumber(minute)
                if hour < 0 or hour > 23 then
                        return false, S("Invalid hour (must be between 0 and 23 inclusive).")
                elseif minute < 0 or minute > 59 then
                        return false, S("Invalid minute (must be between 0 and 59 inclusive).")
                end
                core.set_timeofday((hour * 60 + minute) / 1440)
                core.log("action", ("%s sets time to %d:%02d"):format(name, hour, minute))
                return true, S("Time of day changed.")
        end,
})

core.register_chatcommand("days", {
        description = S("Show day count since world creation"),
        func = function(name, param)
                return true, S("Current day is @1.", core.get_day_count())
        end
})

local function parse_shutdown_param(param)
        local delay, reconnect, message
        local one, two, three
        one, two, three = param:match("^(%S+) +(%-r) +(.*)")
        if one and two and three then
                -- 3 arguments: delay, reconnect and message
                return one, two, three
        end
        -- 2 arguments
        one, two = param:match("^(%S+) +(.*)")
        if one and two then
                if tonumber(one) then
                        delay = one
                        if two == "-r" then
                                reconnect = two
                        else
                                message = two
                        end
                elseif one == "-r" then
                        reconnect, message = one, two
                end
                return delay, reconnect, message
        end
        -- 1 argument
        one = param:match("(.*)")
        if tonumber(one) then
                delay = one
        elseif one == "-r" then
                reconnect = one
        else
                message = one
        end
        return delay, reconnect, message
end

core.register_chatcommand("shutdown", {
        params = S("[<delay_in_seconds> | -1] [-r] [<message>]"),
        description = S("Shutdown server (-1 cancels a delayed shutdown, -r allows players to reconnect)"),
        privs = {server=true},
        func = function(name, param)
                local delay, reconnect, message = parse_shutdown_param(param)
                local bool_reconnect = reconnect == "-r"
                if not message then
                        message = ""
                end
                delay = tonumber(delay) or 0

                if delay == 0 then
                        core.log("action", name .. " shuts down server")
                        core.chat_send_all("*** "..S("Server shutting down (operator request)."))
                end
                core.request_shutdown(message:trim(), bool_reconnect, delay)
                return true
        end,
})

core.register_chatcommand("ban", {
        params = S("[<name>]"),
        description = S("Ban the IP of a player or show the ban list"),
        privs = {ban=true},
        func = function(name, param)
                if param == "" then
                        local ban_list = core.get_ban_list()
                        if ban_list == "" then
                                return true, S("The ban list is empty.")
                        else
                                return true, S("Ban list: @1", ban_list)
                        end
                end
                if not core.get_player_by_name(param) then
                        return false, S("Player is not online.")
                end
                if not core.ban_player(param) then
                        return false, S("Failed to ban player.")
                end
                local desc = core.get_ban_description(param)
                core.log("action", name .. " bans " .. desc .. ".")
                return true, S("Banned @1.", desc)
        end,
})

core.register_chatcommand("unban", {
        params = S("<name> | <IP_address>"),
        description = S("Remove IP ban belonging to a player/IP"),
        privs = {ban=true},
        func = function(name, param)
                if not core.unban_player_or_ip(param) then
                        return false, S("Failed to unban player/IP.")
                end
                core.log("action", name .. " unbans " .. param)
                return true, S("Unbanned @1.", param)
        end,
})

core.register_chatcommand("kick", {
        params = S("<name> [<reason>]"),
        description = S("Kick a player"),
        privs = {kick=true},
        func = function(name, param)
                local tokick, reason = param:match("([^ ]+) (.+)")
                tokick = tokick or param
                if not core.kick_player(tokick, reason) then
                        return false, S("Failed to kick player @1.", tokick)
                end
                local log_reason = ""
                if reason then
                        log_reason = " with reason \"" .. reason .. "\""
                end
                core.log("action", name .. " kicks " .. tokick .. log_reason)
                return true, S("Kicked @1.", tokick)
        end,
})

core.register_chatcommand("clearobjects", {
        params = S("[full | quick]"),
        description = S("Clear all objects in world"),
        privs = {server=true},
        func = function(name, param)
                local options = {}
                if param == "" or param == "quick" then
                        options.mode = "quick"
                elseif param == "full" then
                        options.mode = "full"
                else
                        return false, S("Invalid usage, see /help clearobjects.")
                end

                core.log("action", name .. " clears objects ("
                                .. options.mode .. " mode).")
                if options.mode == "full" then
                        core.chat_send_all(S("Clearing all objects. This may take a long time. "
                                .. "You may experience a timeout. (by @1)", name))
                end
                core.clear_objects(options)
                core.log("action", "Object clearing done.")
                core.chat_send_all("*** "..S("Cleared all objects."))
                return true
        end,
})

core.register_chatcommand("msg", {
        params = S("<name> <message>"),
        description = S("Send a direct message to a player"),
        privs = {shout=true},
        func = function(name, param)
                local sendto, message = param:match("^(%S+)%s(.+)$")
                if not sendto then
                        return false, S("Invalid usage, see /help msg.")
                end
                if not core.get_player_by_name(sendto) then
                        return false, S("The player @1 is not online.", sendto)
                end
                core.log("action", "DM from " .. name .. " to " .. sendto
                                .. ": " .. message)
                core.chat_send_player(sendto, S("DM from @1: @2", name, message))
                return true, S("Message sent.")
        end,
})

core.register_chatcommand("last-login", {
        params = S("[<name>]"),
        description = S("Get the last login time of a player or yourself"),
        func = function(name, param)
                if param == "" then
                        param = name
                end
                local pauth = core.get_auth_handler().get_auth(param)
                if pauth and pauth.last_login and pauth.last_login ~= -1 then
                        -- Time in UTC, ISO 8601 format
                        return true, S("@1's last login time was @2.",
                                param,
                                os.date("!%Y-%m-%dT%H:%M:%SZ", pauth.last_login))
                end
                return false, S("@1's last login time is unknown.", param)
        end,
})

core.register_chatcommand("clearinv", {
        params = S("[<name>]"),
        description = S("Clear the inventory of yourself or another player"),
        func = function(name, param)
                local player
                if param and param ~= "" and param ~= name then
                        if not core.check_player_privs(name, {server=true}) then
                                return false, S("You don't have permission to "
                                        .. "clear another player's inventory "
                                        .. "(missing privilege: @1).", "server")
                        end
                        player = core.get_player_by_name(param)
                        core.chat_send_player(param, S("@1 cleared your inventory.", name))
                else
                        player = core.get_player_by_name(name)
                end

                if player then
                        player:get_inventory():set_list("main", {})
                        player:get_inventory():set_list("craft", {})
                        player:get_inventory():set_list("craftpreview", {})
                        core.log("action", name.." clears "..player:get_player_name().."'s inventory")
                        return true, S("Cleared @1's inventory.", player:get_player_name())
                else
                        return false, S("Player must be online to clear inventory!")
                end
        end,
})

local function handle_kill_command(killer, victim)
        if core.settings:get_bool("enable_damage") == false then
                return false, S("Players can't be killed, damage has been disabled.")
        end
        local victimref = core.get_player_by_name(victim)
        if victimref == nil then
                return false, S("Player @1 is not online.", victim)
        elseif victimref:get_hp() <= 0 then
                if killer == victim then
                        return false, S("You are already dead.")
                else
                        return false, S("@1 is already dead.", victim)
                end
        end
        if killer ~= victim then
                core.log("action", string.format("%s killed %s", killer, victim))
        end
        -- Kill victim
        victimref:set_hp(0)
        return true, S("@1 has been killed.", victim)
end

core.register_chatcommand("kill", {
        params = S("[<name>]"),
        description = S("Kill player or yourself"),
        privs = {server=true},
        func = function(name, param)
                return handle_kill_command(name, param == "" and name or param)
        end,
})