--luacheck: ignore
--[[
Character Experience Gain RPG by MewMew

STRENGTH > character_inventory_slots_bonus , character_mining_speed_modifier

MAGIC >	character_build_distance_bonus, character_item_drop_distance_bonus, character_reach_distance_bonus,
				character_item_pickup_distance_bonus, character_loot_pickup_distance_bonus,

DEXTERITY > character_running_speed_modifier, character_crafting_speed_modifier

VITALITY > character_health_bonus

Modified by Gerkiz *-*
]]
local math_random = math.random
local math_sqrt = math.sqrt
local math_floor = math.floor
local Global = require 'utils.global'
local Tabs = require 'comfy_panel.main'
local P = require 'player_modifiers'
local visuals_delay = 1800
local level_up_floating_text_color = {0, 205, 0}
local xp_floating_text_color = {157, 157, 157}
local experience_levels = {0}
for a = 1, 9999, 1 do
    experience_levels[#experience_levels + 1] = experience_levels[#experience_levels] + a * 8
end
local gain_info_tooltip = 'XP gain from mining, moving, crafting, repairing and combat.'

local rpg_t = {}
local rpg_frame_icons = {
    'entity/small-worm-turret',
    'entity/medium-worm-turret',
    'entity/big-worm-turret',
    'entity/behemoth-worm-turret',
    'entity/small-biter',
    'entity/small-biter',
    'entity/small-spitter',
    'entity/medium-biter',
    'entity/medium-biter',
    'entity/medium-spitter',
    'entity/big-biter',
    'entity/big-biter',
    'entity/big-spitter',
    'entity/behemoth-biter',
    'entity/behemoth-biter',
    'entity/behemoth-spitter'
}

Global.register(
    {rpg_t = rpg_t, rpg_frame_icons = rpg_frame_icons},
    function(tbl)
        rpg_t = tbl.rpg_t
        rpg_frame_icons = tbl.rpg_frame_icons
    end
)

local Public = {}

function Public.get_table()
    return rpg_t
end

local classes = {
    ['engineer'] = 'ENGINEER',
    ['strength'] = 'MINER',
    ['magic'] = 'SORCERER',
    ['dexterity'] = 'ROGUE',
    ['vitality'] = 'TANK'
}

local xp_yield = {
    ['behemoth-biter'] = 16,
    ['behemoth-spitter'] = 16,
    ['behemoth-worm-turret'] = 64,
    ['big-biter'] = 8,
    ['big-spitter'] = 8,
    ['big-worm-turret'] = 48,
    ['biter-spawner'] = 64,
    ['character'] = 16,
    ['gun-turret'] = 8,
    ['laser-turret'] = 16,
    ['medium-biter'] = 4,
    ['medium-spitter'] = 4,
    ['medium-worm-turret'] = 32,
    ['small-biter'] = 1,
    ['small-spitter'] = 1,
    ['small-worm-turret'] = 16,
    ['spitter-spawner'] = 64
}

local enemy_types = {
    ['unit'] = true,
    ['unit-spawner'] = true,
    ['turret'] = true
}

local function level_up_effects(player)
    local position = {x = player.position.x - 0.75, y = player.position.y - 1}
    player.surface.create_entity({name = 'flying-text', position = position, text = '+LVL ', color = level_up_floating_text_color})
    local b = 0.75
    for a = 1, 5, 1 do
        local p = {(position.x + 0.4) + (b * -1 + math_random(0, b * 20) * 0.1), position.y + (b * -1 + math_random(0, b * 20) * 0.1)}
        player.surface.create_entity({name = 'flying-text', position = p, text = '✚', color = {255, math_random(0, 100), 0}})
    end
    player.play_sound {path = 'utility/achievement_unlocked', volume_modifier = 0.40}
end

local function get_melee_modifier(player)
    return (rpg_t[player.index].strength - 10) * 0.10
end

local function get_life_on_hit(player)
    return (rpg_t[player.index].vitality - 10) * 0.4
end

local function get_one_punch_chance(player)
    if rpg_t[player.index].strength < 100 then
        return 0
    end
    local chance = math.round(rpg_t[player.index].strength * 0.01, 1)
    if chance > 100 then
        chance = 100
    end
    return chance
end

local function draw_gui_char_button(player)
    if player.gui.top.rpg then
        return
    end
    local b = player.gui.top.add({type = 'sprite-button', name = 'rpg', caption = 'CHAR'})
    b.style.font_color = {165, 165, 165}
    b.style.font = 'heading-1'
    b.style.minimal_height = 38
    b.style.minimal_width = 60
    b.style.padding = 0
    b.style.margin = 0
end

local function update_char_button(player)
    if not player.gui.top.rpg then
        draw_gui_char_button(player)
    end
    if rpg_t[player.index].points_left > 0 then
        player.gui.top.rpg.style.font_color = {245, 0, 0}
    else
        player.gui.top.rpg.style.font_color = {175, 175, 175}
    end
end

local function update_player_stats(player)
    local strength = rpg_t[player.index].strength - 10
    P.update_single_modifier(player, 'character_inventory_slots_bonus', 'rpg', math.round(strength * 0.2, 3))
    P.update_single_modifier(player, 'character_mining_speed_modifier', 'rpg', math.round(strength * 0.008, 3))

    local magic = rpg_t[player.index].magic - 10
    local v = magic * 0.15
    P.update_single_modifier(player, 'character_build_distance_bonus', 'rpg', math.round(v, 3))
    P.update_single_modifier(player, 'character_item_drop_distance_bonus', 'rpg', math.round(v, 3))
    P.update_single_modifier(player, 'character_reach_distance_bonus', 'rpg', math.round(v, 3))
    P.update_single_modifier(player, 'character_loot_pickup_distance_bonus', 'rpg', math.round(v * 0.5, 3))
    P.update_single_modifier(player, 'character_item_pickup_distance_bonus', 'rpg', math.round(v * 0.25, 3))
    P.update_single_modifier(player, 'character_resource_reach_distance_bonus', 'rpg', math.round(v * 0.15, 3))

    local dexterity = rpg_t[player.index].dexterity - 10
    P.update_single_modifier(player, 'character_running_speed_modifier', 'rpg', math.round(dexterity * 0.002, 3))
    P.update_single_modifier(player, 'character_crafting_speed_modifier', 'rpg', math.round(dexterity * 0.015, 3))
    P.update_single_modifier(player, 'character_health_bonus', 'rpg', math.round((rpg_t[player.index].vitality - 10) * 6, 3))
    P.update_player_modifiers(player)
end

local function get_class(player)
    local average = (rpg_t[player.index].strength + rpg_t[player.index].magic + rpg_t[player.index].dexterity + rpg_t[player.index].vitality) / 4
    local high_attribute = 0
    local high_attribute_name = ''
    for _, attribute in pairs({'strength', 'magic', 'dexterity', 'vitality'}) do
        if rpg_t[player.index][attribute] > high_attribute then
            high_attribute = rpg_t[player.index][attribute]
            high_attribute_name = attribute
        end
    end
    if high_attribute < average + average * 0.25 then
        high_attribute_name = 'engineer'
    end
    return classes[high_attribute_name]
end

local function add_gui_description(element, value, width)
    local e = element.add({type = 'label', caption = value})
    e.style.single_line = false
    e.style.maximal_width = width
    e.style.minimal_width = width
    e.style.maximal_height = 40
    e.style.minimal_height = 38
    e.style.font = 'default-bold'
    e.style.font_color = {175, 175, 200}
    e.style.horizontal_align = 'right'
    e.style.vertical_align = 'center'
    return e
end

local function add_gui_stat(element, value, width)
    local e = element.add({type = 'sprite-button', caption = value})
    e.style.maximal_width = width
    e.style.minimal_width = width
    e.style.maximal_height = 38
    e.style.minimal_height = 38
    e.style.font = 'default-bold'
    e.style.font_color = {222, 222, 222}
    e.style.horizontal_align = 'center'
    e.style.vertical_align = 'center'
    return e
end

local function add_gui_increase_stat(element, name, player, width)
    local sprite = 'virtual-signal/signal-red'
    local symbol = '✚'
    if rpg_t[player.index].points_left <= 0 then
        sprite = 'virtual-signal/signal-black'
    end
    local e = element.add({type = 'sprite-button', name = name, caption = symbol, sprite = sprite})
    e.style.maximal_height = 38
    e.style.minimal_height = 38
    e.style.maximal_width = 38
    e.style.minimal_width = 38
    e.style.font = 'default-large-semibold'
    e.style.font_color = {0, 0, 0}
    e.style.horizontal_align = 'center'
    e.style.vertical_align = 'center'
    e.style.padding = 0
    e.style.margin = 0
    e.tooltip = 'Rightclick to allocate 5 points.'

    return e
end

local function add_separator(element, width)
    local e = element.add({type = 'line'})
    e.style.maximal_width = width
    e.style.minimal_width = width
    e.style.minimal_height = 12
    return e
end

local function draw_gui(player, forced)
    if not forced then
        if rpg_t[player.index].gui_refresh_delay > game.tick then
            return
        end
    end

    Tabs.comfy_panel_clear_left_gui(player)

    if player.gui.left.rpg then
        player.gui.left.rpg.destroy()
    end
    if not player.character then
        return
    end

    local frame = player.gui.left.add({type = 'frame', name = 'rpg', direction = 'vertical'})
    frame.style.maximal_width = 425
    frame.style.minimal_width = 425
    frame.style.margin = 6

    add_separator(frame, 400)

    local t = frame.add({type = 'table', column_count = 2})
    local e = add_gui_stat(t, player.name, 200)
    e.style.font_color = player.chat_color
    e.style.font = 'default-large-bold'
    local e = add_gui_stat(t, get_class(player), 200)
    e.style.font = 'default-large-bold'

    add_separator(frame, 400)

    local t = frame.add({type = 'table', column_count = 4})
    t.style.cell_padding = 1

    add_gui_description(t, 'LEVEL', 80)
    add_gui_stat(t, rpg_t[player.index].level, 80)

    add_gui_description(t, 'EXPERIENCE', 100)
    local e = add_gui_stat(t, math.floor(rpg_t[player.index].xp), 125)
    e.tooltip = gain_info_tooltip

    add_gui_description(t, ' ', 75)
    add_gui_description(t, ' ', 75)

    add_gui_description(t, 'NEXT LEVEL', 100)
    local e = add_gui_stat(t, experience_levels[rpg_t[player.index].level + 1], 125)
    e.tooltip = gain_info_tooltip

    add_separator(frame, 400)

    local t = frame.add({type = 'table', column_count = 2})
    local tt = t.add({type = 'table', column_count = 3})
    tt.style.cell_padding = 1
    local w1 = 85
    local w2 = 63

    local tip = 'Increases inventory slots and mining speed.\nIncreases melee damage.'
    local e = add_gui_description(tt, 'STRENGTH', w1)
    e.tooltip = tip
    local e = add_gui_stat(tt, rpg_t[player.index].strength, w2)
    e.tooltip = tip
    add_gui_increase_stat(tt, 'strength', player)

    local tip = 'Increases reach distance.'
    local e = add_gui_description(tt, 'MAGIC', w1)
    e.tooltip = tip
    local e = add_gui_stat(tt, rpg_t[player.index].magic, w2)
    e.tooltip = tip
    add_gui_increase_stat(tt, 'magic', player)

    local tip = 'Increases running and crafting speed.'
    local e = add_gui_description(tt, 'DEXTERITY', w1)
    e.tooltip = tip
    local e = add_gui_stat(tt, rpg_t[player.index].dexterity, w2)
    e.tooltip = tip
    add_gui_increase_stat(tt, 'dexterity', player)

    local tip = 'Increases health.\nIncreases melee life on-hit.'
    local e = add_gui_description(tt, 'VITALITY', w1)
    e.tooltip = tip
    local e = add_gui_stat(tt, rpg_t[player.index].vitality, w2)
    e.tooltip = tip
    add_gui_increase_stat(tt, 'vitality', player)

    add_gui_description(tt, 'POINTS TO\nDISTRIBUTE', w1)
    local e = add_gui_stat(tt, rpg_t[player.index].points_left, w2)
    e.style.font_color = {200, 0, 0}
    add_gui_description(tt, ' ', w2)

    add_gui_description(tt, ' ', w1)
    add_gui_description(tt, ' ', w2)
    add_gui_description(tt, ' ', w2)

    add_gui_description(tt, 'LIFE', w1)
    add_gui_stat(tt, math.floor(player.character.health), w2)
    add_gui_stat(tt, math.floor(player.character.prototype.max_health + player.character_health_bonus + player.force.character_health_bonus), w2)

    local shield = 0
    local shield_max = 0
    local i = player.character.get_inventory(defines.inventory.character_armor)
    if not i.is_empty() then
        if i[1].grid then
            shield = math.floor(i[1].grid.shield)
            shield_max = math.floor(i[1].grid.max_shield)
        end
    end
    add_gui_description(tt, 'SHIELD', w1)
    add_gui_stat(tt, shield, w2)
    add_gui_stat(tt, shield_max, w2)

    local tt = t.add({type = 'table', column_count = 3})
    tt.style.cell_padding = 1
    local w0 = 2
    local w1 = 80
    local w2 = 80

    add_gui_description(tt, ' ', w0)
    add_gui_description(tt, 'MINING\nSPEED', w1)
    local value = (player.force.manual_mining_speed_modifier + player.character_mining_speed_modifier + 1) * 100 .. '%'
    add_gui_stat(tt, value, w2)

    add_gui_description(tt, ' ', w0)
    add_gui_description(tt, 'SLOT\nBONUS', w1)
    local value = '+ ' .. player.force.character_inventory_slots_bonus + player.character_inventory_slots_bonus
    add_gui_stat(tt, value, w2)

    add_gui_description(tt, ' ', w0)
    add_gui_description(tt, 'MELEE\nDAMAGE', w1)
    local value = 100 * (1 + get_melee_modifier(player)) .. '%'
    local e = add_gui_stat(tt, value, w2)
    e.tooltip = 'Life on-hit: ' .. get_life_on_hit(player) .. '\nOne punch chance: ' .. get_one_punch_chance(player) .. '%'

    local e = add_gui_description(tt, '', w0)
    e.style.maximal_height = 10
    local e = add_gui_description(tt, '', w0)
    e.style.maximal_height = 10
    local e = add_gui_description(tt, '', w0)
    e.style.maximal_height = 10

    local value = '+ ' .. (player.force.character_reach_distance_bonus + player.character_reach_distance_bonus)
    local tooltip = ''
    tooltip = tooltip .. 'Reach distance bonus: ' .. player.character_reach_distance_bonus
    tooltip = tooltip .. '\nBuild distance bonus: ' .. player.character_build_distance_bonus
    tooltip = tooltip .. '\nItem drop distance bonus: ' .. player.character_item_drop_distance_bonus
    tooltip = tooltip .. '\nLoot pickup distance bonus: ' .. player.character_loot_pickup_distance_bonus
    tooltip = tooltip .. '\nItem pickup distance bonus: ' .. player.character_item_pickup_distance_bonus
    tooltip = tooltip .. '\nResource reach distance bonus: ' .. player.character_resource_reach_distance_bonus
    add_gui_description(tt, ' ', w0)
    local e = add_gui_description(tt, 'REACH\nDISTANCE', w1)
    e.tooltip = tooltip
    local e = add_gui_stat(tt, value, w2)
    e.tooltip = tooltip

    local e = add_gui_description(tt, '', w0)
    e.style.maximal_height = 10
    local e = add_gui_description(tt, '', w0)
    e.style.maximal_height = 10
    local e = add_gui_description(tt, '', w0)
    e.style.maximal_height = 10

    add_gui_description(tt, ' ', w0)
    add_gui_description(tt, 'CRAFTING\nSPEED', w1)
    local value = (player.force.manual_crafting_speed_modifier + player.character_crafting_speed_modifier + 1) * 100 .. '%'
    add_gui_stat(tt, value, w2)

    add_gui_description(tt, ' ', w0)
    add_gui_description(tt, 'RUNNING\nSPEED', w1)
    local value = (player.force.character_running_speed_modifier + player.character_running_speed_modifier + 1) * 100 .. '%'
    add_gui_stat(tt, value, w2)

    local e = add_gui_description(tt, '', w0)
    e.style.maximal_height = 10
    local e = add_gui_description(tt, '', w0)
    e.style.maximal_height = 10
    local e = add_gui_description(tt, '', w0)
    e.style.maximal_height = 10

    add_gui_description(tt, ' ', w0)
    add_gui_description(tt, 'HEALTH\nBONUS', w1)
    local value = '+ ' .. (player.force.character_health_bonus + player.character_health_bonus)
    add_gui_stat(tt, value, w2)

    add_separator(frame, 400)
    local t = frame.add({type = 'table', column_count = 14})
    for i = 1, 14, 1 do
        local e = t.add({type = 'sprite', sprite = rpg_frame_icons[i]})
        e.style.maximal_width = 24
        e.style.maximal_height = 24
        e.style.padding = 0
    end
    add_separator(frame, 400)

    rpg_t[player.index].gui_refresh_delay = game.tick + 60
    update_char_button(player)
end

local function draw_level_text(player)
    if not player.character then
        return
    end

    if rpg_t[player.index].text then
        rendering.destroy(rpg_t[player.index].text)
        rpg_t[player.index].text = nil
    end

    local players = {}
    for _, p in pairs(game.players) do
        if p.index ~= player.index then
            players[#players + 1] = p.index
        end
    end
    if #players == 0 then
        return
    end

    rpg_t[player.index].text =
        rendering.draw_text {
        text = 'lvl ' .. rpg_t[player.index].level,
        surface = player.surface,
        target = player.character,
        target_offset = {0, -3.25},
        color = {
            r = player.color.r * 0.6 + 0.25,
            g = player.color.g * 0.6 + 0.25,
            b = player.color.b * 0.6 + 0.25,
            a = 1
        },
        players = players,
        scale = 1.00,
        font = 'default-large-semibold',
        alignment = 'center',
        scale_with_zoom = false
    }
end

local function level_up(player)
    local distribute_points_gain = 0
    for i = rpg_t[player.index].level + 1, #experience_levels, 1 do
        if rpg_t[player.index].xp > experience_levels[i] then
            rpg_t[player.index].level = i
            distribute_points_gain = distribute_points_gain + 5
        else
            break
        end
    end
    if distribute_points_gain == 0 then
        return
    end
    draw_level_text(player)
    rpg_t[player.index].points_left = rpg_t[player.index].points_left + distribute_points_gain
    update_char_button(player)
    table.shuffle_table(rpg_frame_icons)
    if player.gui.left.rpg then
        draw_gui(player, true)
    end
    level_up_effects(player)
end

local function gain_xp(player, amount)
    amount = math.round(amount, 2)
    rpg_t[player.index].xp = rpg_t[player.index].xp + amount
    rpg_t[player.index].xp_since_last_floaty_text = rpg_t[player.index].xp_since_last_floaty_text + amount
    if player.gui.left.rpg then
        draw_gui(player, false)
    end
    if not experience_levels[rpg_t[player.index].level + 1] then
        return
    end
    if rpg_t[player.index].xp >= experience_levels[rpg_t[player.index].level + 1] then
        level_up(player)
        return
    end
    if rpg_t[player.index].last_floaty_text > game.tick then
        return
    end
    player.create_local_flying_text {
        text = '+' .. rpg_t[player.index].xp_since_last_floaty_text .. ' xp',
        position = player.position,
        color = xp_floating_text_color,
        time_to_live = 120,
        speed = 2
    }
    rpg_t[player.index].xp_since_last_floaty_text = 0
    rpg_t[player.index].last_floaty_text = game.tick + visuals_delay
end

function Public.rpg_reset_player(player)
    if player.gui.left.rpg then
        player.gui.left.rpg.destroy()
    end
    if not player.character then
        player.set_controller({type = defines.controllers.god})
        player.create_character()
    end
    rpg_t[player.index] = {
        level = 1,
        xp = 0,
        strength = 10,
        magic = 10,
        dexterity = 10,
        vitality = 10,
        points_left = 0,
        last_floaty_text = visuals_delay,
        xp_since_last_floaty_text = 0,
        rotated_entity_delay = 0,
        gui_refresh_delay = 0,
        last_mined_entity_position = {x = 0, y = 0}
    }
    draw_gui_char_button(player)
    draw_level_text(player)
    update_char_button(player)
    update_player_stats(player)
end

function Public.rpg_reset_all_players()
    for _, p in pairs(game.players) do
        rpg_t[p.index] = nil
    end
    for _, p in pairs(game.connected_players) do
        Public.rpg_reset_player(p)
    end
end

local function on_gui_click(event)
    if not event.element then
        return
    end
    if not event.element.valid then
        return
    end
    local element = event.element

    if element.type ~= 'sprite-button' then
        return
    end

    if element.caption == 'CHAR' then
        if element.name == 'rpg' then
            local player = game.players[event.player_index]
            if player.gui.left.rpg then
                player.gui.left.rpg.destroy()
                return
            end
            draw_gui(player, true)
        end
    end

    if element.caption ~= '✚' then
        return
    end
    if element.sprite ~= 'virtual-signal/signal-red' then
        return
    end

    local index = element.name
    local player = game.players[event.player_index]
    if not rpg_t[player.index][index] then
        return
    end
    if not player.character then
        return
    end

    if event.button == defines.mouse_button_type.right then
        for a = 1, 5, 1 do
            if rpg_t[player.index].points_left <= 0 then
                draw_gui(player, true)
                return
            end
            rpg_t[player.index].points_left = rpg_t[player.index].points_left - 1
            rpg_t[player.index][index] = rpg_t[player.index][index] + 1
            update_player_stats(player)
        end
        draw_gui(player, true)
        return
    end

    if rpg_t[player.index].points_left <= 0 then
        draw_gui(player, true)
        return
    end
    rpg_t[player.index].points_left = rpg_t[player.index].points_left - 1
    rpg_t[player.index][index] = rpg_t[player.index][index] + 1
    update_player_stats(player)
    draw_gui(player, true)
end

local function train_type_cause(cause)
    local players = {}
    if cause.train.passengers then
        for _, player in pairs(cause.train.passengers) do
            players[#players + 1] = player
        end
    end
    return players
end

local get_cause_player = {
    ['character'] = function(cause)
        if not cause.player then
            return
        end
        return {cause.player}
    end,
    ['combat-robot'] = function(cause)
        if not cause.last_user then
            return
        end
        if not game.players[cause.last_user.index] then
            return
        end
        return {game.players[cause.last_user.index]}
    end,
    ['car'] = function(cause)
        local players = {}
        local driver = cause.get_driver()
        if driver then
            if driver.player then
                players[#players + 1] = driver.player
            end
        end
        local passenger = cause.get_passenger()
        if passenger then
            if passenger.player then
                players[#players + 1] = passenger.player
            end
        end
        return players
    end,
    ['locomotive'] = train_type_cause,
    ['cargo-wagon'] = train_type_cause,
    ['artillery-wagon'] = train_type_cause,
    ['fluid-wagon'] = train_type_cause
}

local function on_entity_died(event)
    if not event.entity.valid then
        return
    end

    --Grant XP for hand placed land mines
    if event.entity.last_user then
        if event.entity.type == 'land-mine' then
            if event.cause then
                if event.cause.valid then
                    if event.cause.force.index == event.entity.force.index then
                        return
                    end
                end
            end
            gain_xp(event.entity.last_user, 1)
            return
        end
    end

    if not event.cause then
        return
    end
    if not event.cause.valid then
        return
    end
    if event.cause.force.index == event.entity.force.index then
        return
    end
    if not get_cause_player[event.cause.type] then
        return
    end

    local players = get_cause_player[event.cause.type](event.cause)
    if not players then
        return
    end
    if not players[1] then
        return
    end

    --Grant modified XP for health boosted units
    if global.biter_health_boost then
        if enemy_types[event.entity.type] then
            for _, player in pairs(players) do
                if xp_yield[event.entity.name] then
                    gain_xp(player, xp_yield[event.entity.name] * global.biter_health_boost)
                else
                    gain_xp(player, 0.5 * global.biter_health_boost)
                end
            end
            return
        end
    end

    --Grant normal XP
    for _, player in pairs(players) do
        if xp_yield[event.entity.name] then
            gain_xp(player, xp_yield[event.entity.name])
        else
            gain_xp(player, 0.5)
        end
    end
end

--Melee damage modifier
local function one_punch(character, target, damage)
    local base_vector = {target.position.x - character.position.x, target.position.y - character.position.y}

    local vector = {base_vector[1], base_vector[2]}
    vector[1] = vector[1] * 1000
    vector[2] = vector[2] * 1000

    character.surface.create_entity(
        {name = 'flying-text', position = {character.position.x + base_vector[1] * 0.5, character.position.y + base_vector[2] * 0.5}, text = 'ONE PUNCH', color = {255, 0, 0}}
    )
    character.surface.create_entity({name = 'blood-explosion-huge', position = target.position})
    character.surface.create_entity({name = 'big-artillery-explosion', position = {target.position.x + vector[1] * 0.5, target.position.y + vector[2] * 0.5}})

    if math.abs(vector[1]) > math.abs(vector[2]) then
        local d = math.abs(vector[1])
        if math.abs(vector[1]) > 0 then
            vector[1] = vector[1] / d
        end
        if math.abs(vector[2]) > 0 then
            vector[2] = vector[2] / d
        end
    else
        local d = math.abs(vector[2])
        if math.abs(vector[2]) > 0 then
            vector[2] = vector[2] / d
        end
        if math.abs(vector[1]) > 0 and d > 0 then
            vector[1] = vector[1] / d
        end
    end

    vector[1] = vector[1] * 1.5
    vector[2] = vector[2] * 1.5

    local a = 0.25

    for i = 1, 16, 1 do
        for x = i * -1 * a, i * a, 1 do
            for y = i * -1 * a, i * a, 1 do
                local p = {character.position.x + x + vector[1] * i, character.position.y + y + vector[2] * i}
                character.surface.create_trivial_smoke({name = 'train-smoke', position = p})
                for _, e in pairs(character.surface.find_entities({{p[1] - a, p[2] - a}, {p[1] + a, p[2] + a}})) do
                    if e.valid then
                        if e.health then
                            if e.destructible and e.minable and e.force.index ~= 3 then
                                if e.force.index ~= character.force.index then
                                    e.health = e.health - damage * 0.05
                                    if e.health <= 0 then
                                        e.die(e.force.name, character)
                                    end
                                end
                            end
                        end
                    end
                end
            end
        end
    end
end

local function on_entity_damaged(event)
    if not event.cause then
        return
    end
    if not event.cause.valid then
        return
    end
    if event.cause.force.index == 2 then
        return
    end
    if event.cause.name ~= 'character' then
        return
    end
    if event.damage_type.name ~= 'physical' then
        return
    end
    if not event.entity.valid then
        return
    end
    if
        event.cause.get_inventory(defines.inventory.character_ammo)[event.cause.selected_gun_index].valid_for_read and
            event.cause.get_inventory(defines.inventory.character_guns)[event.cause.selected_gun_index].valid_for_read
     then
        return
    end
    if not event.cause.player then
        return
    end

    --Grant the player life-on-hit.
    event.cause.health = event.cause.health + get_life_on_hit(event.cause.player)

    --Calculate modified damage.
    local damage = event.original_damage_amount + event.original_damage_amount * get_melee_modifier(event.cause.player)
    if event.entity.prototype.resistances then
        if event.entity.prototype.resistances.physical then
            damage = damage - event.entity.prototype.resistances.physical.decrease
            damage = damage - damage * event.entity.prototype.resistances.physical.percent
        end
    end
    damage = math.round(damage, 3)
    if damage < 1 then
        damage = 1
    end

    --Cause a one punch.
    if math_random(0, 999) < get_one_punch_chance(event.cause.player) * 10 then
        one_punch(event.cause, event.entity, damage)
        if event.entity.valid then
            event.entity.die(event.entity.force.name, event.cause)
        end
        return
    end

    --Floating messages and particle effects.
    if math_random(1, 7) == 1 then
        damage = damage * math_random(250, 350) * 0.01
        event.cause.surface.create_entity({name = 'flying-text', position = event.entity.position, text = '‼' .. math.floor(damage), color = {255, 0, 0}})
        event.cause.surface.create_entity({name = 'blood-explosion-huge', position = event.entity.position})
    else
        damage = damage * math_random(100, 125) * 0.01
        event.cause.player.create_local_flying_text({text = math.floor(damage), position = event.entity.position, color = {150, 150, 150}, time_to_live = 90, speed = 2})
    end

    --Handle the custom health pool of the biter health booster, if it is used in the map.
    if global.biter_health_boost then
        local health_pool = global.biter_health_boost_units[event.entity.unit_number]
        if health_pool then
            health_pool[1] = health_pool[1] + event.final_damage_amount
            health_pool[1] = health_pool[1] - damage

            --Set entity health relative to health pool
            event.entity.health = health_pool[1] * health_pool[2]

            if health_pool[1] <= 0 then
                global.biter_health_boost_units[event.entity.unit_number] = nil
                event.entity.die(event.entity.force.name, event.cause)
            end
            return
        end
    end

    --Handle vanilla damage.
    event.entity.health = event.entity.health + event.final_damage_amount
    event.entity.health = event.entity.health - damage
    if event.entity.health <= 0 then
        event.entity.die(event.entity.force.name, event.cause)
    end
end

local function on_player_repaired_entity(event)
    if math_random(1, 4) ~= 1 then
        return
    end
    local player = game.players[event.player_index]
    if not player.character then
        return
    end
    gain_xp(player, 0.40)
end

local function on_player_rotated_entity(event)
    local player = game.players[event.player_index]
    if not player.character then
        return
    end
    if rpg_t[player.index].rotated_entity_delay > game.tick then
        return
    end
    rpg_t[player.index].rotated_entity_delay = game.tick + 20
    gain_xp(player, 0.20)
end

local function on_player_changed_position(event)
    if math_random(1, 64) ~= 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
    gain_xp(player, 1.0)
end

local building_and_mining_blacklist = {
    ['tile-ghost'] = true,
    ['entity-ghost'] = true,
    ['item-entity'] = true
}

local function on_pre_player_mined_item(event)
    local entity = event.entity
    if not entity.valid then
        return
    end
    if building_and_mining_blacklist[entity.type] then
        return
    end
    if entity.force.index ~= 3 then
        return
    end
    local player = game.players[event.player_index]

    if rpg_t[player.index].last_mined_entity_position.x == event.entity.position.x and rpg_t[player.index].last_mined_entity_position.y == event.entity.position.y then
        return
    end
    rpg_t[player.index].last_mined_entity_position.x = entity.position.x
    rpg_t[player.index].last_mined_entity_position.y = entity.position.y

    local distance_multiplier = math_floor(math_sqrt(entity.position.x ^ 2 + entity.position.y ^ 2)) * 0.0005 + 1

    local xp_amount
    if entity.type == 'resource' then
        xp_amount = 0.5 * distance_multiplier
    else
        xp_amount = (1.5 + event.entity.prototype.max_health * 0.0035) * distance_multiplier
    end

    gain_xp(player, xp_amount)
end

local function on_player_crafted_item(event)
    if not event.recipe.energy then
        return
    end
    local player = game.players[event.player_index]
    gain_xp(player, event.recipe.energy * 0.20)
end

local function on_player_respawned(event)
    local player = game.players[event.player_index]
    if not rpg_t[player.index] then
        Public.rpg_reset_player(player)
        return
    end
    update_player_stats(player)
    draw_level_text(player)
end

local function on_player_joined_game(event)
    local player = game.players[event.player_index]
    if not rpg_t[player.index] then
        Public.rpg_reset_player(player)
    end
    for _, p in pairs(game.connected_players) do
        draw_level_text(p)
    end
    draw_gui_char_button(player)
    if not player.character then
        return
    end
    update_player_stats(player)
end

local function on_init(event)
    table.shuffle_table(rpg_frame_icons)
end

local event = require 'utils.event'
event.on_init(on_init)
event.add(defines.events.on_entity_damaged, on_entity_damaged)
event.add(defines.events.on_entity_died, on_entity_died)
event.add(defines.events.on_gui_click, on_gui_click)
event.add(defines.events.on_player_changed_position, on_player_changed_position)
event.add(defines.events.on_player_crafted_item, on_player_crafted_item)
event.add(defines.events.on_player_joined_game, on_player_joined_game)
event.add(defines.events.on_player_repaired_entity, on_player_repaired_entity)
event.add(defines.events.on_player_respawned, on_player_respawned)
event.add(defines.events.on_player_rotated_entity, on_player_rotated_entity)
event.add(defines.events.on_pre_player_mined_item, on_pre_player_mined_item)

return Public
