---LuaPlayerBuiltEntityEventFilters
---Events.set_event_filter(defines.events.on_built_entity, {{filter = "name", name = "fast-inserter"}})
local Event = require 'utils.event' --- @dep utils.event

--Credit to Cooldude2606 for using his lua magic to make this function.
local directions = {
    ['W'] = -0.875,
    ['NW'] = -0.625,
    ['N'] = -0.375,
    ['NE'] = -0.125,
    ['E'] = 0.125,
    ['SE'] = 0.375,
    ['S'] = 0.625,
    ['SW'] = 0.875
}

local function Angle(entity)
    local angle = math.atan2(entity.position.y, entity.position.x)/math.pi
    for direction, requiredAngle in pairs(directions) do
        if angle < requiredAngle then
            return direction
        end
    end
    return 'W'
end

local custom_string = ' *'
local custom_string_len = #custom_string

local function station_name_changer(event)
    local entity = event.created_entity
    local name = entity.name
    if name ==  "entity-ghost" then
        if entity.ghost_name ~= "train-stop" then return end
        local backername = entity.backer_name
        if backername ~= '' then
            entity.backer_name = backername..custom_string
        end

    elseif name == "train-stop" then --only do the event if its a train stop
        local backername = entity.backer_name
        if backername:sub(-custom_string_len) == custom_string then
            entity.backer_name = backername:sub(1, -custom_string_len-1)
            return
        end

        local boundingBox = entity.bounding_box
        -- expanded box for recourse search:
        local bounding2 = { {boundingBox.left_top.x -100 ,boundingBox.left_top.y -100}  , {boundingBox.right_bottom.x +100, boundingBox.right_bottom.y +100 } }
        -- gets all resources in bounding_box2:
        local recourses = game.surfaces[1].find_entities_filtered{area = bounding2, type = "resource"}

        if #recourses > 0 then -- save cpu time if their are no recourses in bounding_box2
            local closest_distance
            local px, py = boundingBox.left_top.x, boundingBox.left_top.y
            local recourse_closed

            --Check which recourse is closest
            for i, item in ipairs(recourses) do
                local dx, dy = px - item.bounding_box.left_top.x, py - item.bounding_box.left_top.y
                local distance = (dx*dx)+(dy*dy)
                if not closest_distance  or distance < closest_distance then
                    recourse_closed = item
                    closest_distance = distance
                end

            end

            local item_name = recourse_closed.name
            if item_name then -- prevent errors if something went wrong
                local item_name2 = item_name:gsub("^%l", string.upper):gsub('-', ' ') -- removing the - and making first letter capital

                local Item_ore_fluid = "item"
                if item_name == "crude-oil" then
                    Item_ore_fluid = "fluid"
                end
                --Final string:
                entity.backer_name = string.format("[L] [img=%s.%s] %s %s (%s)", Item_ore_fluid, item_name, item_name2, entity.backer_name, Angle( entity ))
            end
        end
    end
end

-- Add handler to robot and player build entities
Event.add(defines.events.on_built_entity, station_name_changer)
Event.add(defines.events.on_robot_built_entity, station_name_changer)