local Event = require 'utils.event'
local Game = require 'utils.game'
local Global = require 'utils.global'
local Gui = require 'utils.gui'
local Color = require 'resources.color_presets'

local type = type
local tonumber = tonumber
local pairs = pairs
local size = table.size

local Public = {}

local memory = {
    id = 0,
    active_toasts = {},
}

Global.register(memory, function (tbl) memory = tbl end)

---Creates a unique ID for a toast message
local function autoincrement()
    local id = memory.id + 1
    memory.id = id
    return id
end

---Toast to a specific player
---@param p number|string|LuaPlayer player index or object
---@param duration number in seconds
---@param message|nil message displayed, leave empty to have an empty LuaGuiElement
function Public.toast_player(p, duration, message)
    local player

    if type(p) == 'string' then
        player = Game.get_player_by_index(tonumber(p))
    elseif type(p) == 'number' then
        player = Game.get_player_by_index(p)
    else
        player = p
    end

    if not player or not player.valid then
        return nil
    end

    local frame = player.gui.left.add({type = 'frame', direction = 'vertical', style = 'captionless_frame'})
    frame.style.width = 300

    local container = frame.add({type = 'flow', direction = 'horizontal'})
    container.style.horizontally_stretchable = true

    local progressbar = frame.add({type = 'progressbar'})
    local style = progressbar.style
    style.width = 290
    style.height = 3
    style.color = Color.grey
    progressbar.value = 1 -- it starts full

    local id = autoincrement()
    local tick = game.tick
    if not duration then
        duration = 15
    end

    Gui.set_data(frame, {
        is_toast = true,
        toast_id = id,
        progressbar = progressbar,
        start_tick = tick,
        end_tick = tick + duration * 60
    })
    memory.active_toasts[id] = true

    if message ~= nil then
        local label = container.add({type = 'label', caption = message})
        label.style.single_line = false
    end

    return container
end

---Attempts to get a toast based on the element, will traverse through parents to find it.
---@param element LuaGuiElement
local function get_toast(element)
    if not element or not element.valid then
        return nil
    end

    local data = Gui.get_data(element)

    if data and data.is_toast then
        return element, data
    end

    -- no data, have to check the parent
    return get_toast(element.parent)
end

Event.add(defines.events.on_gui_click, function (event)
    local element = get_toast(event.element)
    if not element then
        return
    end

    Gui.destroy(element)
end)

Event.on_nth_tick(2, function (event)
    local active_toasts = memory.active_toasts
    if size(active_toasts) == 0 then
        return
    end

    local tick = event.tick
    local players = game.connected_players

    local finished_toasts = {}

    for _, player in pairs(players) do
        for _, element in pairs(player.gui.left.children) do
            local toast, data = get_toast(element)
            if toast and data then
                local toast_id = data.toast_id
                local end_tick = data.end_tick

                if tick > end_tick then
                    Gui.destroy(element)
                    finished_toasts[toast_id] = true
                else
                    local start_tick = data.start_tick
                    local limit = end_tick - start_tick
                    local current = end_tick - tick
                    data.progressbar.value = current / limit
                end
            end
        end
    end

    for toast_id, _ in pairs(finished_toasts) do
        active_toasts[toast_id] = nil
    end
end)

Event.add(defines.events.on_player_left_game, function (event)
    local active_toasts = memory.active_toasts
    if size(active_toasts) == 0 then
        return
    end

    -- active toasts, do a cleanup so data remains uncorrupted
    for _, element in pairs(Game.get_player_by_index(event.player_index).gui.left.children) do
        local toast = get_toast(element)
        if toast then
            Gui.destroy(element)
        end
    end
end)

return Public