magic.manadb = {}
local huds = {}
local timer = 0

kingdoms.at_mod_load("kingdoms", function()
    kingdoms.db.magic = kingdoms.db.magic or {}
    kingdoms.db.magic.mana = kingdoms.db.magic.mana or {}
    magic.manadb = kingdoms.db.magic.mana
end)

minetest.register_globalstep(function(dtime)
    timer = timer + dtime
    if timer < 0.1 then return end
    timer = 0

    for _, player in pairs(minetest.get_connected_players()) do
        local name = player:get_player_name()
        local p = magic.manadb[name]
        p.mana = math.min(p.max_mana, p.mana + (dtime / magic.config.mana_regen) * (player:get_hp() >= magic.config.mana_fast_regen_threshold and magic.config.mana_fast_regen or 1 ))
        local hud = huds[name]
        if not hud then
            hud = {}
            huds[name] = hud
            hud.id = player:hud_add({
                name = "mana",
                hud_elem_type = "statbar",
                position = {x = 0.5, y = 1},
                size = {x = 24, y = 24},
                text = "magic_essence.png^[colorize:#00A:200",
                number = p.mana,
                alignment = {x = -1, y = -1},
                offset = {x = -266, y = -110 - 24},
                max = 0,
            })
            hud.oldvalue = p.mana
            return
        elseif hud.oldvalue ~= p.mana then
            player:hud_change(hud.id, "number", p.mana)
            hud.oldvalue = p.mana
        end
    end
end)

function magic.require_mana(player, cost, message)
    local p = magic.manadb[player:get_player_name()]
    if not p then return false end
    if p.mana < cost then
        if message then minetest.chat_send_player(player:get_player_name(), "You do not have enough mana.") end
        return false
    end
    p.mana = math.max(0, p.mana - cost)
    return true
end

function magic.require_energy(player, cost, message)
    local p = magic.manadb[player:get_player_name()]
    if not p then return false end
    if magic.require_mana(player, cost) then
        return true
    end
    local newcost = cost - p.mana
    p.mana = 0
    if player:get_hp() <= newcost then
        if message then minetest.chat_send_player(player:get_player_name(), "You do not have enough health.") end
        return false
    end
    player:set_hp(player:get_hp() - newcost)
    return true
end

minetest.register_on_joinplayer(function(player)
    magic.manadb[player:get_player_name()] = magic.manadb[player:get_player_name()] or {
        mana = magic.config.max_mana,
    }
    magic.manadb[player:get_player_name()].max_mana = magic.config.max_mana
end)
minetest.register_on_leaveplayer(function(player)
    huds[player:get_player_name()] = nil
end)