screwdriver = screwdriver or {}
local ceil, abs, random = math.ceil, math.abs, math.random
local reg_tools = minetest.registered_tools

-- Cost in Mese crystal(s) for enchanting.
local mese_cost = 1

-- Force of the enchantments.
local enchanting = {
    uses     = 1.2,  -- Durability
    times    = 0.1,  -- Efficiency
    damages  = 1,    -- Sharpness
}

local function cap(S) return
    S:gsub("^%l", string.upper)
end

local function to_percent(orig_value, final_value)
    return abs(ceil(((final_value - orig_value) / orig_value) * 100))
end

function enchanting:get_tooltip(enchant, orig_caps, fleshy)
    local bonus = {durable = 0, efficiency = 0, damages = 0}

    if orig_caps then
        bonus.durable = to_percent(orig_caps.uses, orig_caps.uses * enchanting.uses)
        local sum_caps_times = 0
        for i=1, #orig_caps.times do
            sum_caps_times = sum_caps_times + orig_caps.times[i]
        end
        local average_caps_time = sum_caps_times / #orig_caps.times
        bonus.efficiency = to_percent(average_caps_time, average_caps_time -
                          enchanting.times)
    end

    if fleshy then
        bonus.damages = to_percent(fleshy, fleshy + enchanting.damages)
    end

    local specs = { -- not finished, to complete
        durable = {"#00baff", " (+" .. bonus.durable .. "%)"},
        fast    = {"#74ff49", " (+" .. bonus.efficiency .. "%)"},
        sharp   = {"#ffff00", " (+" .. bonus.damages .. "%)"},
    }

    return minetest.colorize and minetest.colorize(specs[enchant][1],
            "\n" .. cap(enchant) .. specs[enchant][2]) or
            "\n" .. cap(enchant) .. specs[enchant][2]
end

local enchant_buttons = {
    "image_button[3.9,0.85;4,0.92;bg_btn.png;fast;Efficiency]" ..
    "image_button[3.9,1.77;4,1.12;bg_btn.png;durable;Durability]",
    "image_button[3.9,2.9;4,0.92;bg_btn.png;sharp;Sharpness]",
}

function enchanting.formspec(pos, num)
    local meta = minetest.get_meta(pos)
    local formspec = [[ size[9,9;]
            bgcolor[#080808BB;true]
            background[0,0;9,9;ench_ui.png]
            list[context;tool;0.9,2.9;1,1;]
            list[context;mese;2,2.9;1,1;]
            list[current_player;main;0.5,4.5;8,4;]
            listring[current_player;main]
            listring[context;tool]
            listring[current_player;main]
            listring[context;mese]
            image[2,2.9;1,1;mese_layout.png]
            tooltip[sharp;Your weapon inflicts more damages]
            tooltip[durable;Your tool last longer]
            tooltip[fast;Your tool digs faster] ]] ..
            default.gui_slots .. default.get_hotbar_bg(0.5,4.5)

    formspec = formspec .. (enchant_buttons[num] or "")
    meta:set_string("formspec", formspec)
end

function enchanting.on_put(pos, listname, _, stack)
    if listname == "tool" then
        local stackname = stack:get_name()
        local tool_groups = {
            "axe, pick, shovel",
            "sword",
        }

        for idx, tools in ipairs(tool_groups) do
            if tools:find(stackname:match(":(%w+)")) then
                enchanting.formspec(pos, idx)
            end
        end
    end
end

function enchanting.fields(pos, _, fields, sender)
    if not next(fields) or fields.quit then return end
    local inv = minetest.get_meta(pos):get_inventory()
    local tool = inv:get_stack("tool", 1)
    local mese = inv:get_stack("mese", 1)
    local orig_wear = tool:get_wear()
    local mod, name = tool:get_name():match("(.*):(.*)")
    local enchanted_tool = (mod or "") .. ":enchanted_" .. (name or "") .. "_" .. next(fields)

    if mese:get_count() >= mese_cost and reg_tools[enchanted_tool] then
        minetest.sound_play("xdecor_enchanting", {
            to_player = sender:get_player_name(),
            gain = 0.8
        })

        tool:replace(enchanted_tool)
        tool:add_wear(orig_wear)
        mese:take_item(mese_cost)
        inv:set_stack("mese", 1, mese)
        inv:set_stack("tool", 1, tool)
    end
end

function enchanting.dig(pos)
    local inv = minetest.get_meta(pos):get_inventory()
    return inv:is_empty("tool") and inv:is_empty("mese")
end

local function allowed(tool)
    if not tool then return end

    for item in pairs(reg_tools) do
        if item:find("enchanted_" .. tool) then
            return true
        end
    end
end

function enchanting.put(_, listname, _, stack)
    local stackname = stack:get_name()
    if listname == "mese" and stackname == "default:mese_crystal" then
        return stack:get_count()
    elseif listname == "tool" and allowed(stackname:match("[^:]+$")) then
        return 1
    end

    return 0
end

function enchanting.on_take(pos, listname)
    if listname == "tool" then
        enchanting.formspec(pos)
    end
end

function enchanting.construct(pos)
    local meta = minetest.get_meta(pos)
    meta:set_string("infotext", "Enchantment Table")
    enchanting.formspec(pos)

    local inv = meta:get_inventory()
    inv:set_size("tool", 1)
    inv:set_size("mese", 1)

    minetest.add_entity({x = pos.x, y = pos.y + 0.85, z = pos.z}, "xdecor:book_open")
    local timer = minetest.get_node_timer(pos)
    timer:start(0.5)
end

function enchanting.destruct(pos)
    for _, obj in pairs(minetest.get_objects_inside_radius(pos, 0.9)) do
        if obj and obj:get_luaentity() and
                obj:get_luaentity().name == "xdecor:book_open" then
            obj:remove()
            break
        end
    end
end

function enchanting.timer(pos)
    local num = #minetest.get_objects_inside_radius(pos, 0.9)
    if num == 0 then
        minetest.add_entity({x = pos.x, y = pos.y + 0.85, z = pos.z}, "xdecor:book_open")
    end

    local minp = {x = pos.x - 2, y = pos.y,     z = pos.z - 2}
    local maxp = {x = pos.x + 2, y = pos.y + 1, z = pos.z + 2}

    local bookshelves = minetest.find_nodes_in_area(minp, maxp, "default:bookshelf")
    if #bookshelves == 0 then
        return true
    end

    local bookshelf_pos = bookshelves[random(1, #bookshelves)]
    local x = pos.x - bookshelf_pos.x
    local y = bookshelf_pos.y - pos.y
    local z = pos.z - bookshelf_pos.z

    if tostring(x .. z):find(2) then
        minetest.add_particle({
            pos = bookshelf_pos,
            velocity = {x = x, y = 2 - y, z = z},
            acceleration = {x = 0, y = -2.2, z = 0},
            expirationtime = 1,
            size = 1.5,
            glow = 5,
            texture = "xdecor_glyph" .. random(1,18) .. ".png"
        })
    end

    return true
end

xdecor.register("enchantment_table", {
    description = "Enchantment Table",
    tiles = {
        "xdecor_enchantment_top.png",  "xdecor_enchantment_bottom.png",
        "xdecor_enchantment_side.png", "xdecor_enchantment_side.png",
        "xdecor_enchantment_side.png", "xdecor_enchantment_side.png"
    },
    groups = {cracky = 1, level = 1},
    light_source = 6,
    sounds = default.node_sound_stone_defaults(),
    on_rotate = screwdriver.rotate_simple,
    can_dig = enchanting.dig,
    on_timer = enchanting.timer,
    on_construct = enchanting.construct,
    on_destruct = enchanting.destruct,
    on_receive_fields = enchanting.fields,
    on_metadata_inventory_put = enchanting.on_put,
    on_metadata_inventory_take = enchanting.on_take,
    allow_metadata_inventory_put = enchanting.put,
    allow_metadata_inventory_move = function()
        return 0
    end,
})

minetest.register_entity("xdecor:book_open", {
    visual = "sprite",
    visual_size = {x=0.75, y=0.75},
    collisionbox = {0},
    physical = false,
    textures = {"xdecor_book_open.png"},
    on_activate = function(self)
        local pos = self.object:getpos()
        local pos_under = {x = pos.x, y = pos.y - 1, z = pos.z}

        if minetest.get_node(pos_under).name ~= "xdecor:enchantment_table" then
            self.object:remove()
        end
    end
})

function enchanting:register_tools(mod, def)
    for tool in pairs(def.tools) do
    for material in def.materials:gmatch("[%w_]+") do
    for enchant in def.tools[tool].enchants:gmatch("[%w_]+") do
        local original_tool = reg_tools[mod .. ":" .. tool .. "_" .. material]
        if not original_tool then break end
        local original_toolcaps = original_tool.tool_capabilities

        if original_toolcaps then
            local original_damage_groups = original_toolcaps.damage_groups
            local original_groupcaps = original_toolcaps.groupcaps
            local groupcaps = table.copy(original_groupcaps)
            local fleshy = original_damage_groups.fleshy
            local full_punch_interval = original_toolcaps.full_punch_interval
            local max_drop_level = original_toolcaps.max_drop_level
            local group = next(original_groupcaps)

            if enchant == "durable" then
                groupcaps[group].uses = ceil(original_groupcaps[group].uses *
                                 enchanting.uses)
            elseif enchant == "fast" then
                for i, time in pairs(original_groupcaps[group].times) do
                    groupcaps[group].times[i] = time - enchanting.times
                end
            elseif enchant == "sharp" then
                fleshy = fleshy + enchanting.damages
            end

            minetest.register_tool(":" .. mod .. ":enchanted_" .. tool .. "_" .. material .. "_" .. enchant, {
                description = "Enchanted " .. cap(material) .. " " .. cap(tool) ..
                    self:get_tooltip(enchant, original_groupcaps[group], fleshy),
                inventory_image = original_tool.inventory_image .. "^[colorize:violet:50",
                wield_image = original_tool.wield_image,
                groups = {not_in_creative_inventory = 1},
                tool_capabilities = {
                    groupcaps = groupcaps, damage_groups = {fleshy = fleshy},
                    full_punch_interval = full_punch_interval,
                    max_drop_level = max_drop_level
                }
            })
        end
    end
    end
    end
end

enchanting:register_tools("default", {
    materials = "steel, bronze, mese, diamond",
    tools = {
        axe    = {enchants = "durable, fast"},
        pick   = {enchants = "durable, fast"},
        shovel = {enchants = "durable, fast"},
        sword  = {enchants = "sharp"}
    }
})

-- Recipes

minetest.register_craft({
    output = "xdecor:enchantment_table",
    recipe = {
        {"", "default:book", ""},
        {"default:diamond", "default:obsidian", "default:diamond"},
        {"default:obsidian", "default:obsidian", "default:obsidian"}
    }
})