--- Makes trees which are marked for decon "decay" quickly to allow faster building
-- @addon Tree-Decon

local Event = require 'utils.event' --- @dep utils.event
local Global = require 'utils.global' --- @dep utils.global
local Roles = require 'expcore.roles' --- @dep expcore.roles
local Gui = require 'expcore.gui' --- @dep expcore.gui
local PlayerData = require 'expcore.player_data' --- @dep expcore.player_data

-- Global queue used to store trees that need to be removed, also cache for player roles
local cache = {}
local tree_queue = { _head=0 }
Global.register({tree_queue, cache}, function(tbl)
    tree_queue = tbl[1]
    cache = tbl[2]
end)

local function get_permission(player_index)
    if cache[player_index] == nil then
        local player = game.players[player_index]
        if Roles.player_allowed(player, 'fast-tree-decon') then cache[player_index] = 'fast'
        elseif Roles.player_allowed(player, 'standard-decon') then cache[player_index] = 'standard'
        else cache[player_index] = player.force end
    end

    return cache[player_index]
end

-- Left menu button to toggle between fast decon and normal decon marking
local HasEnabledDecon = PlayerData.Settings:combine('HasEnabledDecon')
HasEnabledDecon:set_default(false)

Gui.toolbar_button("entity/tree-01", {'tree-decon.main-tooltip'}, function (player)
	return Roles.player_allowed(player, "fast-tree-decon")
end)
:on_click(function(player, element)
	local status = HasEnabledDecon:get(player)
	HasEnabledDecon:set(player, not status)
	Gui.toolbar_button_style(element, not status)
	player.print(status and {'tree-decon.toggle-msg', {'tree-decon.disabled'}} or {'tree-decon.toggle-msg', {'tree-decon.enabled'}})
end)


-- Add trees to queue when marked, only allows simple entities and for players with role permission
Event.add(defines.events.on_marked_for_deconstruction, function(event)
    -- Check which type of decon a player is allowed
    local index = event.player_index
    if not index then return end

    -- Check what should happen to this entity
    local entity = event.entity
    if not entity or not entity.valid then return end

    -- Not allowed to decon this entity
    local last_user = entity.last_user
    local allow = get_permission(index)
    if last_user and allow ~= 'standard' and allow ~= 'fast' then
        entity.cancel_deconstruction(allow)
        return
    end

    -- Allowed to decon this entity, but not fast
    if allow ~= 'fast' then return end

    local player = game.get_player(index)
    if not HasEnabledDecon:get(player) then return end

    -- Allowed fast decon on this entity, just trees
    local head = tree_queue._head + 1
    if not last_user and entity.type ~= 'cliff' then
        tree_queue[head] = entity
        tree_queue._head = head
    end

end)

-- Remove trees at random till the queue is empty
Event.add(defines.events.on_tick, function()
    local head = tree_queue._head
    if head == 0 then return end

    local max_remove = math.floor(head/100)+1
    local remove_count = math.random(0, max_remove)
    while remove_count > 0 and head > 0 do
        local remove_index = math.random(1, head)
        local entity = tree_queue[remove_index]
        tree_queue[remove_index] = tree_queue[head]
        head = head - 1
        if entity and entity.valid then
            remove_count = remove_count - 1
            entity.destroy()
        end
    end
    tree_queue._head = head
end)

-- Clear the cache
Event.on_nth_tick(300, function()
    for key, _ in pairs(cache) do
        cache[key] = nil
    end
end)

-- Clear trees when hit with a car
Event.add(defines.events.on_entity_damaged, function(event)
	if not (event.damage_type.name == 'impact' and event.force) then
		return
	end

	if not (event.entity.type == 'tree' or event.entity.type == 'simple-entity') then
		return
	end

	if (not event.cause) or (event.cause.type ~= 'car')then
		return
	end

    local driver = event.cause.get_driver()
    if not driver then return end

    local allow = get_permission(driver.player.index)
    if allow == "fast" and HasEnabledDecon:get(driver.player) then
	    event.entity.destroy()
    else
        event.entity.order_deconstruction(event.force, driver.player)
    end
end)
