local leg_immobilize_mul = pvp_revamped.config.leg_immobilize_mul
local player_data = pvp_revamped.player_data
local get_player_data = pvp_revamped.get_player_data
local player_persistent_data = pvp_revamped.player_persistent_data
local remove_text_center = pvp_revamped.remove_text_center
local clear_blockdata = pvp_revamped.clear_blockdata
local clear_shielddata = pvp_revamped.clear_shielddata
local set_immobilize_data = pvp_revamped.set_immobilize_data
local get_player_by_name = minetest.get_player_by_name
local add_item = minetest.add_item
local new = vector.new
local max = math.max
local min = math.min

-- Create an empty data sheet for the player.
minetest.register_on_joinplayer(function(player)
    player_persistent_data[player:get_player_name()] = {
        damage_texture_modifier = player:get_properties().damage_texture_modifier,
        throw_style = player:get_meta():get_int("pvp_revamped.throw_style")
    }
end)

-- Immobilize the player on fall.
minetest.register_on_player_hpchange(function(player, hp_change, reason)
    local data = get_player_data(player:get_player_name())
    local dmg = max(hp_change - player:get_hp(), 1)
    local speed = min(1 / dmg * leg_immobilize_mul, 0.01)

    if reason.type == "fall" then
        data.immobilize = set_immobilize_data(player, speed, hp_change)
    end
end)

-- Drops an item at the given or player's position.
local function drop(player, item, pos)
    -- Check if the param is true or not.
    if not pos then
        -- Get the player's position.
        pos = player:get_pos()
    end

    -- Create the item.
    local obj = add_item(pos, item)

    if obj then
        obj:get_luaentity().collect = true
    end
end

-- Clear up memory if the player leaves.
-- Drop any item the player is about to throw on leave.
-- Remove the shield entity.
minetest.register_on_leaveplayer(function(player)
    local name = player:get_player_name()
    local pdata = player_data[name]

    player_persistent_data[name] = nil

    if not pdata then
        return
    end

    local throw_data = pdata.throw
    
    if throw_data then
        drop(player, throw_data.item)
    end

    local entity = pdata.entity

    if entity then
        entity.object:remove()
    end

    if pdata.block then
        remove_text_center(player, "pvp_revamped:block_pool")
    end

    if pdata.shield then
        remove_text_center(player, "pvp_revamped:shield_pool")
    end

    player_data[name] = nil
end)

-- Drop any item the player is about to throw on death.
-- Remove the shield entity.
minetest.register_on_dieplayer(function(player)
    local name = player:get_player_name()
    local pdata = player_data[name]
    local old_ppd = player_persistent_data[name]

    player_persistent_data[name] = {
        damage_texture_modifier = old_ppd.damage_texture_modifier,
        throw_style = old_ppd.throw_style
    }

    if not pdata then
        return
    end

    local throw_data = pdata.throw
    
    if throw_data then
        drop(player, throw_data.item)
    end

    local entity = pdata.entity

    if entity then
        entity.object:remove()
    end

    local aim = pdata.aim

    if aim then
        -- Drop hand.
        player:set_bone_position(aim.bone, aim.position, new(-180, 0, 0))
    end

    if pdata.immobilize then
        player:set_physics_override({speed = 1, jump = 1})
    end

    if pdata.block then
        remove_text_center(player, "pvp_revamped:block_pool")
    end

    if pdata.shield then
        remove_text_center(player, "pvp_revamped:shield_pool")
    end

    player_data[name] = nil
end)

-- Drop any item the player is about to throw on shutdown.
-- Remove the shield entity.
minetest.register_on_shutdown(function()
    for k, v in pairs(player_data) do
        local throw_data = v.throw

        if throw_data then
            drop(get_player_by_name(k), throw_data.item)
        end
    end
end)

minetest.register_on_player_inventory_action(function(player)
    local name = player:get_player_name()

    if not player_data or not player_data[name] then
        return
    end

    local pdata = player_data[name]
    local data_shield = pdata.shield

    if data_shield and not data_shield.armor_inv and player:get_wielded_item():get_name() ~= data_shield.name then
        player_data[name].shield = nil

        -- Remove un-used hud element.
        remove_text_center(player, "pvp_revamped:shield_pool")
    end

    local data_block = pdata.block

    if data_block and player:get_wielded_item():get_name() ~= data_block.name then
        player_data[name].block = nil

        -- Remove un-used hud element.
        remove_text_center(player, "pvp_revamped:block_pool")
    end
end)

local function break_guard(player, name)
    if not player_data or not player_data[name] then
        return
    end

    local pdata = player_data[name]

    clear_shielddata(pdata.shield, player, name)
    clear_blockdata(pdata.block, player, name)

    player_data[name] = pdata
end

minetest.register_on_placenode(function(pos, newnode, placer)
    if placer then
        local name = placer:get_player_name()
        
        -- Break guard if player placed a node.
        break_guard(placer, name)
    end
end)

minetest.register_on_dignode(function(pos, oldnode, digger)
    if digger then
        local name = digger:get_player_name()
        
        -- Break guard if player dug a node.
        break_guard(digger, name)
    end
end)