-- players trample paths, tiles change as players walk around

local Event = require 'utils.event'
local math_random = math.random

local blacklisted_tiles = {
    ['concrete'] = true,
    ['deepwater'] = true,
    ['deepwater-green'] = true,
    ['dirt-1'] = true,
    ['hazard-concrete-left'] = true,
    ['hazard-concrete-right'] = true,
    ['lab-dark-1'] = true,
    ['lab-dark-2'] = true,
    ['lab-white'] = true,
    ['out-of-map'] = true,
    ['refined-concrete'] = true,
    ['refined-hazard-concrete-left'] = true,
    ['refined-hazard-concrete-right'] = true,
    ['stone-path'] = true,
    ['tutorial-grid'] = true,
    ['water'] = true,
    ['water-green'] = true
}

local replacement_tiles = {
    ['dirt-7'] = 'dirt-6',
    ['dirt-6'] = 'dirt-5',
    ['dirt-5'] = 'dirt-4',
    ['dirt-4'] = 'dirt-3',
    ['dirt-3'] = 'dirt-2',
    ['dirt-2'] = 'dirt-1'
}

local function on_player_changed_position(event)
    if math_random(1, 2) ~= 1 then
        return
    end
    local player = game.players[event.player_index]
    if not player.character then
        return
    end
    if player.character.driving then
        return
    end

    local tile = player.surface.get_tile(player.position)
    if not tile then
        return
    end
    if not tile.valid then
        return
    end

    if blacklisted_tiles[tile.name] then
        return
    end

    local new_tile = 'dirt-7'
    if replacement_tiles[tile.name] then
        new_tile = replacement_tiles[tile.name]
    end

    player.surface.set_tiles({{name = new_tile, position = tile.position}}, true)
end

Event.add(defines.events.on_player_changed_position, on_player_changed_position)