local internal_bucket  = {}

local wear_levels      = {}
wear_levels[1]         = 65535
wear_levels[2]         = 57337
wear_levels[3]         = 49146
wear_levels[4]         = 40955
wear_levels[5]         = 32764
wear_levels[6]         = 24573
wear_levels[7]         = 16382
wear_levels[8]         = 8191
wear_levels[9]         = 0

local base_mcl_buckets = core.get_modpath("mcl_buckets")
local base_default     = core.get_modpath("default")

local function check_protection(pos, name, text)
    if core.is_protected(pos, name) then
        core.log("action", (name ~= "" and name or "A mod")
            .. " tried to " .. text
            .. " at protected position "
            .. core.pos_to_string(pos)
            .. " with a bucket")
        core.record_protection_violation(pos, name)
        return true
    end
    return false
end

function internal_bucket.get_wear(liquid_level)
    return wear_levels[liquid_level + 1]
end

function internal_bucket.get_liquid_level(wear)
    for i = 1, 9 do
        if wear_levels[i] == wear then
            return i - 1
        end
    end
end

local function set_bucket_item_liquid_level(item, liquid_level)
    local meta = item:get_meta()

    meta:set_string("description",
        ItemStack(item:get_name()):get_description() .. " " .. liquid_level .. "/8")

    item:set_wear(internal_bucket.get_wear(liquid_level))
end

local function mcl_get_pointed_thing(usr)
    local start = usr:get_pos()
    start.y = start.y + usr:get_properties().eye_height
    local look_dir = usr:get_look_dir()
    local _end = vector.add(start, vector.multiply(look_dir, 5))

    local ray = core.raycast(start, _end, false, true)
    for pointed_thing in ray do
        local name = core.get_node(pointed_thing.under).name
        local def = core.registered_nodes[name]
        if not def or def.drawtype ~= "flowingliquid" then
            return pointed_thing
        end
    end
end

local function get_bucket_name_empty()
    if base_default then
        return "bucket:bucket_empty"
    elseif base_mcl_buckets then
        return "mcl_buckets:bucket_empty"
    end
    return nil
end

local function get_bucket_name_filled(source_name)
    if base_default then
        return bucket.liquids[source_name].itemname
    elseif base_mcl_buckets then
        return mcl_buckets.liquids[source_name].bucketname
    end
    return nil
end

local function get_liquid_name(bucket_name)
    if base_default then
        for source, b in pairs(bucket.liquids) do
            if b.itemname and b.itemname == bucket_name then
                return b.source
            end
        end
    elseif base_mcl_buckets then
        return mcl_buckets.buckets[bucket_name].source_place
    end
    return nil
end

local function bucket_on_use(on_use_fallback, itemstack, user, pointed_thing)
    if pointed_thing.type == "object" then
        pointed_thing.ref:punch(user, 1.0, { full_punch_interval = 1.0 }, nil)
        return user:get_wielded_item()
    elseif pointed_thing.type ~= "node" then
        return
    end

    local liquid = liquid_physics.get_liquid_at(pointed_thing.under)

    if liquid == nil then
        return on_use_fallback(itemstack, user, pointed_thing)
    end

    local node = core.get_node(pointed_thing.under)

    if check_protection(pointed_thing.under,
            user:get_player_name(),
            "take " .. node.name) then
        return
    end

    local liquid_source = liquid_physics.get_liquid_node_names(liquid.liquid_id)[8]
    local bucket_name = get_bucket_name_filled(liquid_source)

    if bucket_name == nil then
        return on_use_fallback(itemstack, user, pointed_thing)
    end

    -- Filled Bucket
    local bucket_item = ItemStack(bucket_name)
    set_bucket_item_liquid_level(bucket_item, liquid.liquid_level)

    local return_item = bucket_item

    local item_count = user:get_wielded_item():get_count()

    if item_count > 1 then
        local inv = user:get_inventory()
        if inv:room_for_item("main", { name = bucket_name }) then
            inv:add_item("main", bucket_item)
        else
            local pos = user:getpos()
            pos.y = math.floor(pos.y + 0.5)
            core.add_item(pos, bucket_item)
        end

        -- set to return empty buckets minus 1
        return_item = ItemStack(get_bucket_name_empty() .. tostring(item_count - 1))
    end

    liquid_physics.set_liquid_at(pointed_thing.under, 0, 0)

    return return_item
end

local function bucket_on_place(on_place_fallback, bucket_liquid_id, source_name, itemstack, user, pointed_thing)
    -- Must be pointing to node
    if pointed_thing.type ~= "node" then
        return
    end

    local node = core.get_node(pointed_thing.under)
    local node_def = core.registered_nodes[node.name]

    if not node_def then
        return itemstack
    end

    -- Call on_rightclick if the pointed node defines it
    if node_def.on_rightclick and
        not (user and user:is_player() and
            user:get_player_control().sneak) then
        return node_def.on_rightclick(
            pointed_thing.under,
            node, user,
            itemstack)
    end

    -- Where to place the liquid at
    local place_at_pos

    if node_def.buildable_to then
        place_at_pos = pointed_thing.under
    else
        place_at_pos = pointed_thing.above

        node = core.get_node(place_at_pos)

        local node_above_def = core.registered_nodes[node.name]

        if not node_above_def or not node_above_def.buildable_to then
            return itemstack
        end
    end

    if check_protection(place_at_pos, user
            and user:get_player_name()
            or "", "place " .. source_name) then
        return
    end

    local liquid_level = internal_bucket.get_liquid_level(itemstack:get_wear())
    local liquid = liquid_physics.get_liquid_at(place_at_pos)

    if liquid == nil then
        if liquid_physics.set_liquid_at(place_at_pos, bucket_liquid_id, liquid_level) then
            return ItemStack(get_bucket_name_empty())
        end
        return itemstack
    end

    if liquid.liquid_id == bucket_liquid_id then
        local give_amount = math.min(8 - liquid.liquid_level, liquid_level)
        if liquid_physics.set_liquid_at(place_at_pos, bucket_liquid_id, liquid.liquid_level + give_amount) then
            if give_amount == liquid_level then
                return ItemStack(get_bucket_name_empty())
            end
            set_bucket_item_liquid_level(itemstack, liquid_level - give_amount)
            return itemstack
        end
        return itemstack
    end
end

function internal_bucket.register_empty_bucket(bucket_name)
    local bucket_tool = core.registered_items[bucket_name]

    if base_default then
        local on_use_fallback = bucket_tool.on_use
        local on_use_wrapper = function(itemstack, user, pointed_thing)
            return bucket_on_use(on_use_fallback, itemstack, user, pointed_thing)
        end
        core.override_item(bucket_name, { on_use = on_use_wrapper }, nil)
    elseif base_mcl_buckets then
        local on_use_fallback = bucket_tool.on_place
        local on_use_wrapper = function(itemstack, user, pointed_thing)
            local use_select_box = core.settings:get_bool("mcl_buckets_use_select_box", false)
            if use_select_box == false then
                -- TODO: Understand why this is nil
                if user.get_pos == nil then
                    return itemstack
                end
                pointed_thing = mcl_get_pointed_thing(user)
            end
            return bucket_on_use(on_use_fallback, itemstack, user, pointed_thing)
        end
        core.override_item(bucket_name, { on_place = on_use_wrapper }, nil)
    end
end

function internal_bucket.register_filled_bucket(name)
    local bucket_tool = core.registered_items[name]

    local source_name = get_liquid_name(name)
    if source_name == nil then
        error("Liquid Physics: Could not register bucket. Liquid for bucket " .. name .. " was not found")
    end
    local bucket_liquid_id = liquid_physics.get_liquid_id(source_name)
    if bucket_liquid_id == nil then
        error("Liquid Physics: Could not register bucket. Liquid " ..
            source_name .. " was not registered with liquid physics.")
    end

    if base_default then
        local on_place_fallback = bucket_tool.on_place
        local on_place_wrapper = function(itemstack, user, pointed_thing)
            return bucket_on_place(on_place_fallback, bucket_liquid_id, source_name, itemstack, user, pointed_thing)
        end
        core.override_item(name, {
            on_place = on_place_wrapper
        }, nil)
    elseif base_mcl_buckets then
        local on_place_fallback = bucket_tool.on_place
        local on_place_wrapper = function(itemstack, user, pointed_thing)
            return bucket_on_place(on_place_fallback, bucket_liquid_id, source_name, itemstack, user, pointed_thing)
        end
        core.override_item(name, {
            on_place = on_place_wrapper
        }, nil)
    end
end

return internal_bucket