mtimer/system/on_receive_fields.lua

local m = mtimer
local d = mtimer.dialog


-- When formspec data is sent to the server check for the formname and run the
-- specific action for the given form. See Individual descriptions. The code
-- for this is very simple because most of the logic is handled in the
-- timer functions and not in the formspec code.
minetest.register_on_player_receive_fields(function(player, formname, fields)
    if not player:is_player() then return end
    local meta = player:get_meta()
    local name = player:get_player_name()


    -- Select what formspec to show basing on main menu button
    if formname == 'mtimer:main_menu' then
        if fields.set_visibility then d.set_visibility(name) end
        if fields.set_position then d.set_position(name) end
        if fields.set_color then d.set_color(name) end
        if fields.timezone_offset then d.timezone_offset(name) end
        if fields.ingame_time_format then d.ingame_time_format(name) end
        if fields.real_world_time_format then d.real_world_time_format(name) end
        if fields.host_time_format then d.host_time_format(name) end
        if fields.session_start_time_format then
            d.session_start_time_format(name)
        end
        if fields.session_duration_format then
            d.session_duration_format(name)
        end
        if fields.hud_element_scale then d.hud_element_scale(name) end
        if fields.hud_element_offset then d.hud_element_offset(name) end
        if fields.timer_format then d.timer_format(name) end
        if fields.custom_timer then d.custom_timer(name) end
    end


    -- Set timer visibility
    if formname == 'mtimer:set_visibility' then
        local attr = m.meta.visible
        if fields.set_visible then meta:set_string(attr.key, 'true') end
        if fields.set_invisible then meta:set_string(attr.key, 'false') end
        if fields.default then meta:set_string(attr.key, attr.default) end
        if not fields.quit then d.set_visibility(name) end
    end


    -- Set timer position
    if formname == 'mtimer:set_position' then
        local attr = m.meta.position
        for p,_ in pairs(fields) do
            if p == 'default' then
                meta:set_string(attr.key, attr.default)
            elseif p:gsub('_.*', '') == 'pos' then
                local new_pos = p:gsub('pos_', '')
                if new_pos ~= 'xx' then meta:set_string(attr.key, new_pos) end
            end
        end
        if not fields.quit then d.set_position(name) end
    end


    -- Set timer text color
    if formname == 'mtimer:set_color' then
        local attr = m.meta.color
        local color = ''

        -- Set fields.color to predefined color if a button was clicked
        if fields.set_color ~= nil then
            fields.color = '#'..fields.set_color
        end

        -- Validate the given color and set it
        if fields.color then
            local valid = fields.color:match('^#'..('[0-9a-fA-F]'):rep(6)..'$')
            local color = valid and fields.color or attr.default
            meta:set_string(attr.key, color)
        end

        if fields.default then meta:set_string(attr.key, attr.default) end
        if not fields.quit then d.set_color(name) end
    end


    -- Configure timezone offset
    if formname == 'mtimer:timezone_offset' then
        local attr = m.meta.timezone_offset
        local value = tonumber(fields.offset) or attr.default

        -- Check if a timezone offset button was clicked
        for p,_ in pairs(fields) do
            if string.sub(p,1,11) == 'new_offset_' then
                value = tonumber((p:gsub('new_offset_', '')))
            end
        end

        -- Validate and set new timezone offset
        if fields.offset then
            if value > 12 then value = 12 end
            if value < -12 then value = -12 end
            meta:set_string(attr.key, value)
        end

        if fields.default then meta:set_string(attr.key, attr.default) end
        if not fields.quit then d.timezone_offset(name) end
    end


    -- Set ingame time format
    if formname == 'mtimer:ingame_time_format' then
        local attr = m.meta.ingame_time_format
        local value = fields.format or attr.default
        meta:set_string(attr.key, value)
        if fields.default then meta:set_string(attr.key, attr.default) end
        if not fields.quit then d.ingame_time_format(name)end
    end


    -- Set real-time format
    if formname == 'mtimer:real_world_time_format' then
        local attr = m.meta.real_time_format
        local value = fields.format or attr.default
        meta:set_string(attr.key, value)
        if fields.default then meta:set_string(attr.key, attr.default) end
        if not fields.quit then d.real_world_time_format(name) end
    end


    -- Set host time format
    if formname == 'mtimer:host_time_format' then
        local attr = m.meta.host_time_format
        local value = fields.format or attr.default
        meta:set_string(attr.key, value)
        if fields.default then meta:set_string(attr.key, attr.default) end
        if not fields.quit then d.host_time_format(name) end
    end


    -- Set session start time format
    if formname == 'mtimer:session_start_time_format' then
        local attr = m.meta.session_start_time_format
        local value = fields.format or attr.default
        meta:set_string(attr.key, value)
        if fields.default then meta:set_string(attr.key, attr.default) end
        if not fields.quit then d.session_start_time_format(name)  end
    end


    -- Set session duration format
    if formname == 'mtimer:session_duration_format' then
        local attr = m.meta.session_duration_format
        local value = fields.format or attr.default
        meta:set_string(attr.key, value)
        if fields.default then meta:set_string(attr.key, attr.default) end
        if not fields.quit then d.session_duration_format(name) end
    end


    -- Set scale of the timer HUD element
    if formname == 'mtimer:hud_element_scale' then
        local attr = m.meta.hud_element_scale
        local value = tonumber(attr.default)
        local nv_data = minetest.explode_scrollbar_event(fields.new_value)

        -- Set new value if value was changed
        if nv_data.type == 'CHG' then
            value = nv_data.value
            if value < 1 then value = 1 end
            if value > 10 then value = 10 end
            meta:set_string(attr.key, value)
        end

        -- DEVELOPERS: Ideally this formspec would fully reset (like when
        --             closed and re-opened) to reflect the scale position when
        --             clicking the “Default” button. But for whatever reason
        --             this does not work. The scollbar position is simply
        --             not set accordingly no matter what I tried.
        --
        --             A pesky pseudosolution is to accept what it is and just
        --             inform the player about this fact.
        --
        --             Trust me, I tried for roughly 1-2 hours before giving
        --             up, without having either the formspec not reset when
        --             clicking the default button or not being able to drag
        --             the scollbar because the formspec gets re-sent.
        --
        --             I even tried to manually closing the formspec and
        --             re-opening it via `minetest.after` to prevent race
        --             conditions. This worked with a delay of 0.1 seconds
        --             every now and then and with smaller delays the whole
        --             screen looked like it “flashed” because, well, the
        --             formspec was closed and then re-opened after the delay.
        --
        --             But I absolutely hate the solution so I just accepted
        --             how it works. If everyone ever reading this and knows
        --             a proper solution to re-sent the formspec and have it
        --             using the actual value instead of keeping the previous
        --             value I’d be glad hearing from you :)
        --
        --             Have awonderful day!
        --
        --             Kind regards,
        --             Dirk
        if fields.default then
            -- This works as expected
            meta:set_string(attr.key, attr.default)
            -- it should reset the scrollbar position here when clicking the
            -- default button but it doesn’t …
            d.hud_element_scale(name)
        end
    end


    -- Set offset (used as border/padding) of the timer HUD element
    if formname == 'mtimer:hud_element_offset' then
        local attr = m.meta.hud_element_offset
        local default = minetest.deserialize(attr.default)
        local x_offset = tonumber(fields.x_offset) or default.x
        local y_offset = tonumber(fields.y_offset) or default.y

        if fields.x_add_1 then x_offset = x_offset + 1 end
        if fields.y_add_1 then y_offset = y_offset + 1 end
        if fields.x_substract_1 then x_offset = x_offset - 1 end
        if fields.y_substract_1 then y_offset = y_offset - 1 end

        meta:set_string(attr.key, minetest.serialize({
            x = x_offset,
            y = y_offset
        }))

        if fields.default then meta:set_string(attr.key, attr.default) end
        if not fields.quit then d.hud_element_offset(name) end
    end


    -- Set timer text
    if formname == 'mtimer:timer_format' then
        local attr = m.meta.timer_format
        local value = fields.format or attr.default
        meta:set_string(attr.key, value)
        if fields.default then meta:set_string(attr.key, attr.default) end
        if not fields.quit then d.timer_format(name) end
    end


    -- Custom timer setting and configuration
    if formname == 'mtimer:custom_timer' then
        local attr = m.meta.custom_timer_settings
        local ctv = minetest.deserialize(meta:get_string(attr.key))
        local entered = fields.key_enter_field or ''

        -- Set mode
        if fields.mode_countdown ~= nil then ctv.timer_mode='countdown' end
        if fields.mode_timer ~= nil then ctv.timer_mode='timer' end
        if fields.mode_continuous ~= nil then ctv.timer_mode='continuous' end

        -- Validate direct input
        local days = tonumber(fields.v_days) or 0
        local hours = tonumber(fields.v_hours) or 0
        local minutes = tonumber(fields.v_minutes) or 0
        local seconds = tonumber(fields.v_seconds) or 0

         -- Set values from plus/minus input
        if fields.c_days_p then days = days + 1 end
        if fields.c_hours_p then hours = hours + 1 end
        if fields.c_minutes_p then minutes = minutes + 1 end
        if fields.c_seconds_p then seconds = seconds + 1 end
        if fields.c_days_m then days = days - 1 end
        if fields.c_hours_m then hours = hours - 1 end
        if fields.c_minutes_m then minutes = minutes - 1 end
        if fields.c_seconds_m then seconds = seconds - 1 end

        -- Validate values
        if seconds >= 60 then  seconds = 0   minutes = minutes + 1  end
        if minutes >= 60 then  minutes = 0   hours = hours + 1      end
        if hours >= 24   then  hours = 0     days = days + 1        end
        if seconds < 0   then  seconds = 59  minutes = minutes - 1  end
        if minutes < 0   then  minutes = 59  hours = hours - 1      end
        if hours < 0     then  hours = 23    days = days - 1        end
        if days < 0      then  days = 0                             end

        -- set relevant values
        ctv.format = {
            running = fields.v_format_running,
            stopped = fields.v_format_stopped,
            finished = fields.v_format_finished
        }
        ctv.values = {
            days = days,
            hours = hours,
            minutes = minutes,
            seconds = seconds
        }

        -- Set default values if requested and instantly return to prevent the
        -- rest of the configuration to be executed. At this point only
        -- resetting all values is desired.
        if fields.default then
            meta:set_string(attr.key, attr.default)
            d.custom_timer(name)
            m.update_timer(name)
            return
        end

        -- Set values if not quitting
        if not fields.quit then
            meta:set_string(attr.key, minetest.serialize(ctv))
        end

        -- Control timer if one of the control buttons was pressed. This is run
        -- after the values safing in order to use the new values instead of
        -- the values that were stored before.
        local ct_update = false
        if fields.ct_start then ct_update = { action = 'start' } end
        if fields.ct_stop then ct_update = { action = 'stop' } end
        if fields.ct_restart then ct_update = { action = 'restart' } end
        if ct_update~=false then mtimer.update_custom_timer(name,ct_update) end

        -- Show the timer formspec if not quitting
        if not fields.quit then d.custom_timer(name) end
    end


    -- Back to menu from all formspecs and conditionally update timer
    if fields.main_menu then d.main_menu(name) end
    if formname ~= 'mtimer:main_menu' then m.update_timer(name) end


    -- Reset everything
    if fields.reset_everything then
        for _,def in pairs(m.meta) do
            meta:set_string(def.key, def.default)
        end
    end


end)