local reg_alias = ocutil.safe_register_alias

-- ===================================================================

-- These two need to be handled using aliases. Reason: They may be us-
-- ed by mapgen schems that haven't been updated yet to replace them.

reg_alias ("default:acacia_tree" , "default:acacia_trunk" )
reg_alias ("default:aspen_tree"  , "default:aspen_trunk"  )

-- ===================================================================

local cvtmap = {}

cvtmap ["default:chest_open"              ] =
        "default:chest"

cvtmap [ "default:junglewood_cube"        ] =
        "default:jungle_wood_cube"

cvtmap [ "default:junglewood_doublepanel" ] =
        "default:jungle_wood_doublepanel"

cvtmap [ "default:junglewood_halfstair"   ] =
        "default:jungle_wood_halfstair"

cvtmap [ "default:junglewood_micropanel"  ] =
        "default:jungle_wood_micropanel"

cvtmap [ "default:junglewood_microslab"   ] =
        "default:jungle_wood_microslab"

cvtmap [ "default:junglewood_panel"       ] =
        "default:jungle_wood_panel"

cvtmap [ "default:junglewood_thinstair"   ] =
        "default:jungle_wood_thinstair"

cvtmap ["stairs:stair_jungletree"         ] =
        "stairs:stair_jungle_wood"

cvtmap ["stairs:slab_aspen_tree"          ] =
        "stairs:slab_aspen_wood"

cvtmap ["stairs:stair_aspen_tree"         ] =
        "stairs:stair_aspen_wood"

cvtmap ["moretrees:slab_poplar_planks"    ] =
        "stairs:slab_poplar_wood"

cvtmap ["moretrees:stair_poplar_planks"   ] =
        "stairs:stair_poplar_wood"

cvtmap ["default:tree_outerstair"         ] =
        "stairs:stair_outer_wood"

cvtmap ["default:bookshelf_alt"           ] =
        "default:bookshelf"

cvtmap ["default:obsidian_glass_alt"      ] =
        "default:obsidian_glass"

cvtmap ["moontest:vacuum"                 ] =
         "default:vacuum"

-- ===================================================================

cvtmap ["default:junglewood_outerstair"   ] =
        "stairs:stair_outer_junglewood"

cvtmap ["stairs:slab_pine_tree"           ] =
        "stairs:slab_pine_wood"

cvtmap ["stairs:stair_pine_tree"          ] =
        "stairs:stair_pine_wood"

cvtmap ["default:pine_tree_outerstair"    ] =
        "default:pine_wood_outerstair"

cvtmap ["default:pine_tree_thinstair"     ] =
        "default:pine_wood_thinstair"

-- ===================================================================

local moretrees_base = {
    "beech"  , "birch"  , "cedar"   , "date_palm" , "fir"    ,
    "oak"    , "palm"   , "poplar"  , "sequoia"   , "spruce" ,
    "willow" ,
}

local moretrees_part = {
    "leaves" , "planks" , "sapling" , "trunk"     ,
}

for _, base in pairs (moretrees_base) do
    for _, part in pairs (moretrees_part) do
        local str = base .. "_" .. part
        cvtmap ["moretrees:" .. str ] = "default:" .. str
    end
end

-- ===================================================================

cvtmap ["moretrees:apple_tree_leaves"     ] =
          "default:leaves"
cvtmap ["moretrees:apple_tree_planks"     ] =
          "default:wood"
cvtmap ["moretrees:apple_tree_sapling"    ] =
          "default:sapling"
cvtmap ["moretrees:apple_tree_trunk"      ] =
          "default:tree"

-- ===================================================================

cvtmap ["default:apple_mark"                  ] =
          "air"

cvtmap ["moretrees:acorn"                     ] =
          "air"

cvtmap ["moretrees:cedar_cone"                ] =
          "default:cedar_leaves"

cvtmap ["moretrees:coconut"                   ] =
          "air"

cvtmap ["moretrees:fir_cone"                  ] =
          "air"

cvtmap ["moretrees:fir_leaves_bright"         ] =
          "default:fir_leaves"

cvtmap ["moretrees:jungletree_leaves_red"     ] =
          "default:jungle_leaves"

cvtmap ["moretrees:jungletree_leaves_yellow"  ] =
          "default:jungle_leaves"

cvtmap ["moretrees:jungletree_trunk"          ] =
          "default:jungle_trunk"

cvtmap ["moretrees:pine_cone"                 ] =
          "air"

cvtmap ["moretrees:rubber_tree_leaves"        ] =
          "default:rubber_leaves"

cvtmap ["moretrees:rubber_tree_sapling"       ] =
          "default:rubber_sapling"

cvtmap ["moretrees:rubber_tree_trunk"         ] =
          "default:rubber_trunk"

cvtmap ["moretrees:spruce_cone"               ] =
          "air"

cvtmap ["memorandum:letter_empty"             ] =
          "air"

cvtmap ["memorandum:letter_written"           ] =
          "air"

cvtmap ["memorandum:message"                  ] =
          "air"

-- ===================================================================

local function register_cvtmap (old_node)

    if     ocutil.node_exists  (old_node) then
        ocutil.add_item_groups (old_node,
            { cvtmap=1, not_in_creative_inventory=1 })
    elseif ocutil.thing_exists (old_node) then
        return
    else
        minetest.register_node (":" .. old_node, {
            groups = { cvtmap=1, not_in_creative_inventory=1 } ,
        })
    end
end

-- ===================================================================

for old_node, _ in pairs (cvtmap) do
    register_cvtmap (old_node)
end

-- ===================================================================

-- fforce: May be nil, false, 0, true, or 1. If "old_node" is a regis-
-- tered node, and "fforce" isn't true or 1, conversion is skipped.

default.convert_base = function (old_node, new_node, fforce)
    local rtn = "convert_base"
    if ocutil.str_empty (old_node) then ocutil.panic (rtn .. " 1") end
    if ocutil.str_empty (new_node) then ocutil.panic (rtn .. " 2") end

    if cvtmap [old_node] ~= nil then
        return
    end
    if cvtmap [new_node] ~= nil then
        new_node = cvtmap [new_node]
    end
    if cvtmap [new_node] ~= nil then
        new_node = cvtmap [new_node]
    end
    if cvtmap [new_node] ~= nil then
        ocutil.panic (rtn .. " 4: " .. old_node .. " " .. new_node)
    end

    if ocutil.node_missing    (new_node) then return end
    if fforce ~= true and fforce ~= 1 then
        if ocutil.node_exists (old_node) then return end
    end

    cvtmap [old_node] = new_node
    register_cvtmap (old_node)
end

-- ===================================================================

default.convert_node = function (old_node, new_node)
    return default.convert_base (old_node, new_node, false)
end

-- ===================================================================

default.convert_force = function (old_node, new_node)
    return default.convert_base (old_node, new_node, true)
end

-- ===================================================================

minetest.register_lbm ({

    -- For LBM version:
    name  = ":default:cvtmap" ,
    label = ":default:cvtmap" ,
    run_at_every_load = true  ,

    -- For ABM version:
    catch_up = false ,
    chance   = 1     ,
    interval = 3     ,

    nodenames = { "group:cvtmap" } ,

    action = function (pos, node)
        local newname =  cvtmap [node.name]
        if    newname ~= nil and
            ocutil.node_exists (newname) then
            local param2 = node.param2

            minetest.swap_node (pos, {
                name   = newname ,
                param2 = param2  ,
            })
        end
    end
})

-- ===================================================================
-- End of file.