-- File:     codersea/seaplants.lua
-- Purpose:  CoderSea sea-plant support module
-- Credits:  See "codersea.md"
-- Licenses: See "LICENSE"
-- Revision: 200329

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

ocutil.log ("codersea: seaplants.lua")

local reg_alias = ocutil.safe_register_alias
local reg_node  = ocutil.safe_register_node

local codersea_waving = 1
if    codersea_disable_waving then
      codersea_waving = 0
end

local seaplant_groups = { seaplants=1, snappy=3, wrapwater=1 }

-- -------------------------------------------------------------------

-- Sea-dirt that will host no plants or animals
--
minetest.register_node ("codersea:dirt" , {
    description = "Dirt"                  ,
    drop        = "default:dirt"          ,
    sounds      = sounds_dirt             ,
    tiles       = { "default_dirt.png" }  ,

    groups      = {
        crumbly=3, seasoil=1, soil=1,
        not_in_creative_inventory=1
    } ,
})

-- -------------------------------------------------------------------

-- Sea-sand that will host no plants or animals
--
minetest.register_node ("codersea:sand" , {
    description = "Sand"                  ,
    drop        = "default:sand"          ,
    sounds      = sounds_sand             ,
    tiles       = { "default_sand.png" }  ,

    groups      = {
        crumbly=3, falling_node=1, sand=1, seasand=1,
        not_in_creative_inventory=1
    } ,
})

-- -------------------------------------------------------------------

local img_kelpgreen = "seaplants_kelpgreen.png"

minetest.register_node ("codersea:kelpgreen" , {
    climbable         = true                   ,
    description       = "Green Kelp"           ,
    drawtype          = "plantlike"            ,
    drowning          = codersea_drowning      ,
    groups            = seaplant_groups        ,
    is_ground_content = true                   ,
    inventory_image   = img_kelpgreen          ,
    light_source      = codersea_light         ,
    on_use            = minetest.item_eat (1)  ,
    paramtype         = "light"                ,
    sounds            = sounds_leaves          ,
    tiles             = { img_kelpgreen }      ,
    walkable          = false                  ,
    wield_image       = img_kelpgreen          ,

    selection_box = {
        type  = "fixed" ,
        fixed = { -0.3, -0.5, -0.3, 0.3, 0.3, 0.3 }
    },

--  This should probably match the setting for "default:water"
    post_effect_color = { a = 103, r =  30, g =  60, b =  90 } ,

})

-- -------------------------------------------------------------------

local img_kelpgreenmiddle = "seaplants_kelpgreenmiddle.png"

minetest.register_node ("codersea:kelpgreenmiddle" , {
    climbable         = true                     ,
    description       = "Green Kelp middle"      ,
    drawtype          = "plantlike"              ,
    drop              = "codersea:kelpgreen"     ,
    drowning          = codersea_drowning        ,
    groups            = seaplant_groups          ,
    inventory_image   = img_kelpgreenmiddle      ,
    is_ground_content = true                     ,
    light_source      = codersea_light           ,
    paramtype         = "light"                  ,
    sounds            = sounds_leaves            ,
    tiles             = { img_kelpgreenmiddle }  ,
    walkable          = false                    ,
    wield_image       = img_kelpgreenmiddle      ,

    selection_box = {
        type  = "fixed" ,
        fixed = { -0.3, -0.5, -0.3, 0.3, 0.5, 0.3 }
    },

--  This should probably match the setting for "default:water"
    post_effect_color = { a = 103, r =  30, g =  60, b =  90 } ,

})

-- -------------------------------------------------------------------

local img_kelpbrown = "seaplants_kelpbrown.png"

minetest.register_node ("codersea:kelpbrown" , {
    climbable         = true                   ,
    description       = "Brown Kelp"           ,
    drawtype          = "plantlike"            ,
    drowning          = codersea_drowning      ,
    groups            = seaplant_groups        ,
    inventory_image   = img_kelpbrown          ,
    is_ground_content = true                   ,
    light_source      = codersea_light         ,
    on_use            = minetest.item_eat (1)  ,
    paramtype         = "light"                ,
    sounds            = sounds_leaves          ,
    tiles             = { img_kelpbrown }      ,
    walkable          = false                  ,
    wield_image       = img_kelpbrown          ,

    selection_box = {
        type  = "fixed" ,
        fixed = { -0.3, -0.5, -0.3, 0.3, 0.3, 0.3 }
    },

--  This should probably match the setting for "default:water"
    post_effect_color = { a = 103, r =  30, g =  60, b =  90 } ,
})

-- -------------------------------------------------------------------

local img_kelpbrownmiddle = "seaplants_kelpbrownmiddle.png"

minetest.register_node ("codersea:kelpbrownmiddle" , {
    climbable         = true                     ,
    description       = "Brown Kelp middle"      ,
    drawtype          = "plantlike"              ,
    drop              = "codersea:kelpbrown"     ,
    drowning          = codersea_drowning        ,
    groups            = seaplant_groups          ,
    inventory_image   = img_kelpbrownmiddle      ,
    is_ground_content = true                     ,
    light_source      = codersea_light           ,
    paramtype         = "light"                  ,
    sounds            = sounds_leaves            ,
    tiles             = { img_kelpbrownmiddle }  ,
    walkable          = false                    ,
    wield_image       = img_kelpbrownmiddle      ,

    selection_box = {
        type  = "fixed" ,
        fixed = { -0.3, -0.5, -0.3, 0.3, 0.5, 0.3 }
    },

--  This should probably match the setting for "default:water"
    post_effect_color = { a = 103, r =  30, g =  60, b =  90 } ,

})

-- -------------------------------------------------------------------

local img_seagrassgreen = "seaplants_seagrassgreen.png"

minetest.register_node ("codersea:seagrassgreen" , {
    climbable         = true                   ,
    description       = "Green Seagrass"       ,
    drawtype          = "plantlike"            ,
    drowning          = codersea_drowning      ,
    groups            = seaplant_groups        ,
    inventory_image   = img_seagrassgreen      ,
    is_ground_content = true                   ,
    light_source      = codersea_light         ,
    on_use            = minetest.item_eat (1)  ,
    paramtype         = "light"                ,
    sounds            = sounds_leaves          ,
    tiles             = { img_seagrassgreen }  ,
    walkable          = false                  ,
    waving            = codersea_waving        ,
    wield_image       = img_seagrassgreen      ,

    selection_box = {
        type  = "fixed" ,
        fixed = { -0.3, -0.5, -0.3, 0.3, 0.3, 0.3 }
    },

--  This should probably match the setting for "default:water"
    post_effect_color = { a = 103, r =  30, g =  60, b =  90 } ,
})

-- -------------------------------------------------------------------

local img_seagrassred = "seaplants_seagrassred.png"

minetest.register_node ("codersea:seagrassred" , {
    climbable         = true                   ,
    description       = "Red Seagrass"         ,
    drawtype          = "plantlike"            ,
    drowning          = codersea_drowning      ,
    groups            = seaplant_groups        ,
    inventory_image   = img_seagrassred        ,
    is_ground_content = true                   ,
    light_source      = codersea_light         ,
    on_use            = minetest.item_eat (1)  ,
    paramtype         = "light"                ,
    sounds            = sounds_leaves          ,
    tiles             = { img_seagrassred }    ,
    walkable          = false                  ,
    waving            = codersea_waving        ,
    wield_image       = img_seagrassred        ,

    selection_box = {
        type  = "fixed" ,
        fixed = { -0.3, -0.5, -0.3, 0.3, 0.3, 0.3 }
    },

--  This should probably match the setting for "default:water"
    post_effect_color = { a = 103, r =  30, g =  60, b =  90 } ,
})

-- -------------------------------------------------------------------
-- Sea-dirt that will host plants.

minetest.register_node ("codersea:dirtgrow", {
    description = "Sea-dirt that will host plants" ,
    drop        = "default:dirt"                   ,
    sounds      = sounds_dirt                      ,
    tiles       = { "default_dirt.png" }           ,

    groups      = {
        crumbly=3, seasoil=1, soil=1,
        not_in_creative_inventory=1
    } ,

    is_ground_content = true ,
})

-- -------------------------------------------------------------------
-- Sea-sand that will host plants.

minetest.register_node ("codersea:sandgrow", {
    description = "Sea-sand that will host plants" ,
    drop        = "default:sand"                   ,
    sounds      = sounds_sand                      ,
    tiles       = { "default_sand.png" }           ,

    groups = {
        crumbly=3, falling_node=1, sand=1, seasand=1,
        not_in_creative_inventory=1
    } ,

    is_ground_content = true ,
})

-- -------------------------------------------------------------------

local img_seaweed = "ethereal_seaweed.png"

minetest.register_node ("codersea:ethereal_seaweed" , {
    climbable         = true                   ,
    description       = "Ethereal Seaweed"     ,
    drawtype          = "plantlike"            ,
    drowning          = codersea_drowning      ,
    groups            = seaplant_groups        ,
    inventory_image   = img_seaweed            ,
    is_ground_content = true                   ,
    light_source      = codersea_light         ,
    on_use            = minetest.item_eat (1)  ,
    paramtype         = "light"                ,
    sounds            = sounds_leaves          ,
    tiles             = { img_seaweed }        ,
    walkable          = false                  ,
    wield_image       = img_seaweed            ,

    selection_box = {
        type = "fixed",
        fixed = {-0.3, -0.5, -0.3, 0.3, 0.5, 0.3}
    },

--  This should probably match the setting for "default:water"
    post_effect_color = { a = 103, r =  30, g =  60, b =  90 } ,

    after_dig_node = function (pos, node, metadata, digger)
        default.dig_up (pos, node, digger)
    end ,
})

-- -------------------------------------------------------------------

local function register_coral (num, color)
    local basename    = "ethereal_coral" .. num
    local description = "Ethereal " ..  color .. " Coral"
    local imgfile     = basename .. ".png"

    minetest.register_node ("codersea:" .. basename, {
        climbable         = true               ,
        description       = description        ,
        drawtype          = "plantlike"        ,
        drowning          = codersea_drowning  ,
        groups            = seaplant_groups    ,
        inventory_image   = imgfile            ,
        is_ground_content = true               ,
        light_source      = codersea_light     ,
        paramtype         = "light"            ,
        sounds            = sounds_leaves      ,
        tiles             = { imgfile }        ,
        walkable          = false              ,
        wield_image       = imgfile            ,

        selection_box = {
            type = "fixed",
            fixed = {-6 / 16, -0.5, -6 / 16, 6 / 16, 1 / 4, 6 / 16} ,
        } ,
    })

    minetest.log ("action", "[codersea] Registered " .. basename)
end

-- -------------------------------------------------------------------

register_coral (2, "Blue"   )
register_coral (3, "Orange" )
register_coral (4, "Pink"   )
register_coral (5, "Green"  )

-- -------------------------------------------------------------------

-- CRAFT ITEMS

minetest.register_craftitem ("codersea:seasaladmix", {
    description = "Sea salad mix" ,
    inventory_image = "seaplants_seasaladmix.png" ,
    on_use = minetest.item_eat (6) ,
})

-- -------------------------------------------------------------------

-- CRAFTING

minetest.register_craft ({
    type   = "shapeless" ,
    output = "codersea:seasaladmix" ,
    recipe = {
        "codersea:kelpgreen"     ,
        "codersea:kelpbrown"     ,
        "codersea:seagrassgreen" ,
        "codersea:seagrassred"   ,
    } ,
})

-- -------------------------------------------------------------------

local bodenames = {}

local seastone_related = {
    "seabrick", "seacobble", "seagravel", "seastone"
}

if codersea_reset then
    for  _,color in pairs (seaglass_colors) do
        if color:len() > 0 then color = "_" .. color end
        local basenode = "codersea:seaglass" .. color
        table.insert (bodenames, basenode)
        table.insert (bodenames, basenode .. "_off")
    end
end

if codersea_reset or
   codersea_disable_seastone then
    for  _,color in pairs (seastone_colors) do
        if color:len() > 0 then color = "_" .. color end
        for dairy,mtype in pairs (seastone_related) do
            table.insert (bodenames, "codersea:" .. mtype .. color)
        end
    end
end

if codersea_reset or
   codersea_disable_shine or
   codersea_disable_stairs then
    for  _,color in pairs (seaglass_colors) do
        if color:len() > 0 then color = "_" .. color end
        for moo,mtype in pairs ({ "slab", "stair" }) do
            for milk,mstate in pairs ({ "", "_off" }) do
                table.insert (bodenames,
                   "codersea:shine_" ..
                    mtype            ..
                    "_seaglass"      .. color .. mstate)
            end
        end
    end
end

if codersea_reset or
   codersea_disable_stairs then
    for _,mform in pairs (seastone_related) do
        for dairy,color in pairs (seastone_colors) do
            if color:len() > 0 then color = "_" .. color end
            for moo,mtype in pairs ({ "slab", "stair" }) do
                table.insert (bodenames,
                   "stairs:" .. mtype ..
                    "_"      .. mform .. color)
            end
        end
    end
end

-- -------------------------------------------------------------------

minetest.register_lbm ({
    name      = "codersea:reset_materials" ,
    nodenames = bodenames        ,

    action    = function (pos, node)
        local uppos  = CloneTable (pos)
        uppos.x = uppos.x - 1
        local upname = minetest.get_node (uppos).name
        local newname

        if upname:gsub ("water" , "") ~= upname or
           upname:gsub ("sand"  , "") ~= upname or
           upname:gsub ("dirt"  , "") ~= upname or
           upname:gsub ("air"   , "") ~= upname then
            newname = upname
        else
            newname = "default:sand"
        end
        minetest.add_node (pos, { name = newname })
    end ,
})

if false then
minetest.register_abm ({
    catch_up  = false            ,
    chance    = 1                ,
    interval  = 3                ,
    neighbors = { "group:soil" } ,
    nodenames = bodenames        ,

    action    = function (pos, node)
        minetest.add_node (pos, { name = "default:dirt" })
    end ,
})

-- -------------------------------------------------------------------

minetest.register_abm ({
    catch_up  = false            ,
    chance    = 1                ,
    interval  = 3                ,
    neighbors = { "group:sand" } ,
    nodenames = bodenames        ,

    action    = function (pos, node)
        minetest.add_node (pos, { name = "default:sand" })
    end ,
})
end

-- -------------------------------------------------------------------

if codersea_reset then
minetest.register_abm ({
    catch_up  = false                                ,
    chance    = 1                                    ,
    interval  = 5                                    ,
    neighbors = {}                                   ,
    nodenames = { "group:seasand", "group:seasoil" } ,

    action = function (pos, node)
        local newnode
        if StartsWith (node.name, "codersea:dirt") then
            newnode = "default:dirt"
        else
            newnode = "default:sand"
        end
        minetest.add_node (pos, { name = newnode })

        if EndsWith (node.name, "algae") then
            local uppos = { x = pos.x, y = pos.y+1, z = pos.z }
            local tnob  =
                minetest.get_objects_inside_radius (uppos, 1)
            local nnob  = table.getn (tnob)

            if (nnob > 0) then
                for foo,obj in ipairs (tnob) do
                    ent = obj:get_luaentity()
                    if ent ~= nil and ent.name ~= nil then
                        if StartsWith (ent.name, "codersea") then
                            obj:remove()
                        end
                    end
                end
            end
        end
    end
})

-- -------------------------------------------------------------------

minetest.register_abm ({
    catch_up  = false ,
    chance    = 1     ,
    interval  = 3     ,
    neighbors = {}    ,

    nodenames = {
        "codersea:water_flowing" ,
        "codersea:water_source"  ,
        "group:seaplants"        ,
    },

    action = function (pos, node)
        local newnode
        if  node.name == "codersea:water_source" then
            newnode = "default:water_source"
        else
            newnode = "default:water_flowing"
        end
        minetest.add_node (pos, { name = newnode })
    end
})
end

-- -------------------------------------------------------------------

if not codersea_reset then
minetest.register_abm ({
    catch_up  = false                     ,
    chance    = codersea_chance_cvtsoil   ,
    interval  = codersea_interval_cvtsoil ,
    neighbors = {
        "default:water_flowing"  ,
        "default:water_source"   ,
        "codersea:water_flowing" ,
        "codersea:water_source"  ,
    } ,
    nodenames = { "default:dirt", "default:sand" } ,

    action = function (pos, node)
        local uppos = { x = pos.x, y = pos.y, z = pos.z }
        local newnode
        local ptable

        if node.name == "default:dirt" then
            newnode = "codersea:dirt"
        else
            newnode = "codersea:sand"
        end

        for ii = 1,4 do
            uppos.y = uppos.y + 1
            if not is_water (uppos) then
                minetest.add_node (pos, { name = newnode })
                return
            end
        end

        local do_it = 0
        local lpos1
        local lpos2
        local nw1
        local nw2

        local notsolid = {
            "group:seaplants", "group:wrapwater", "group:water"
        }

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

-- Let's look at a 7x7 area, centered on the prospective plant-growing
-- node, but one node up from the node in question:
--
--  .......
--  .......
--  .......
--  ...X...
--  .......
--  .......
--  .......
--
-- The total area is 49 nodes. The node above the prospective node has
-- already been confirmed to be water.  If all 49 nodes are either wa-
-- ter or existing seaplants, it may be possible  to start a new plant
-- here without triggering thermocline effects.

        lpos1 = { x = pos.x-3, y = pos.y+1, z = pos.z-3 }
        lpos2 = { x = pos.x+3, y = pos.y+1, z = pos.z+3 }
        nw1   = #minetest.find_nodes_in_area (lpos1, lpos2, notsolid)

--      minetest.log ("action", "sgrow: case 1 " .. nw1)
        if nw1 == 49 then do_it = 1 end

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

-- This scenario may also work ("S" = solid object):
--
--    ....S
--    ....S
--    ...XS
--    ....S
--    ....S

        lpos1 = { x = pos.x-3, y = pos.y+1, z = pos.z-2 }
        lpos2 = { x = pos.x+0, y = pos.y+1, z = pos.z+2 }
        nw1   = #minetest.find_nodes_in_area (lpos1, lpos2, notsolid)

        lpos1 = { x = pos.x+1, y = pos.y+1, z = pos.z-2 }
        lpos2 = { x = pos.x+1, y = pos.y+1, z = pos.z+2 }
        nw2   = #minetest.find_nodes_in_area (lpos1, lpos2, notsolid)

--      minetest.log ("action", "sgrow: case2 " .. nw1.. " " .. nw2)
        if nw1 == 20 and nw2 == 0 then do_it = 2 end

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

-- This scenario may also work ("S" = solid object):
--
--    S....
--    S....
--    SX...
--    S....
--    S....

        lpos1 = { x = pos.x+0, y = pos.y+1, z = pos.z-2 }
        lpos2 = { x = pos.x+3, y = pos.y+1, z = pos.z+2 }
        nw1   = #minetest.find_nodes_in_area (lpos1, lpos2, notsolid)

        lpos1 = { x = pos.x-1, y = pos.y+1, z = pos.z-2 }
        lpos2 = { x = pos.x-1, y = pos.y+1, z = pos.z+2 }
        nw2   = #minetest.find_nodes_in_area (lpos1, lpos2, notsolid)

--      minetest.log ("action", "sgrow: case 3 " .. nw1.. " " .. nw2)
        if nw1 == 20 and nw2 == 0 then do_it = 3 end

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

-- This scenario may also work ("S" = solid object):
--
--    SSSSS
--    ..X..
--    .....
--    .....
--    .....

        lpos1 = { x = pos.x-2, y = pos.y+1, z = pos.z-3 }
        lpos2 = { x = pos.x+2, y = pos.y+1, z = pos.z+0 }
        nw1   = #minetest.find_nodes_in_area (lpos1, lpos2, notsolid)

        lpos1 = { x = pos.x-2, y = pos.y+1, z = pos.z-1 }
        lpos2 = { x = pos.x+2, y = pos.y+1, z = pos.z-1 }
        nw2   = #minetest.find_nodes_in_area (lpos1, lpos2, notsolid)

--      minetest.log ("action", "sgrow: case 4 " .. nw1.. " " .. nw2)
        if nw1 == 20 and nw2 == 0 then do_it = 4 end

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

-- This scenario may also work ("S" = solid object):
--
--    .....
--    .....
--    .....
--    ..X..
--    SSSSS

        lpos1 = { x = pos.x-2, y = pos.y+1, z = pos.z+0 }
        lpos2 = { x = pos.x+2, y = pos.y+1, z = pos.z+3 }
        nw1   = #minetest.find_nodes_in_area (lpos1, lpos2, notsolid)

        lpos1 = { x = pos.x-2, y = pos.y+1, z = pos.z-1 }
        lpos2 = { x = pos.x+2, y = pos.y+1, z = pos.z-1 }
        nw2   = #minetest.find_nodes_in_area (lpos1, lpos2, notsolid)

--      minetest.log ("action", "sgrow: case 5 " .. nw1.. " " .. nw2)
        if nw1 == 20 and nw2 == 0 then do_it = 5 end

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

--      minetest.log ("action", "sgrow: do_it=" .. do_it)

        if do_it == 0 then
--          minetest.log ("action", "sgrow: skipping")
            minetest.add_node (pos, { name = newnode })
            return
        end

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

                                -- Possible plant?
        if math.random (1, 1000) >
            codersea_decipercent_plant then
                                -- No; possible algae?
            if math.random (1, 1000) <=
                codersea_decipercent_algae then
                                -- Yes
                if node.name == "default:dirt" then
                    newnode = "codersea:dirtalgae"
                else
                    newnode = "codersea:sandalgae"
                end
            else
                                -- Possible seastone?
                if math.random (1, 1000) <=
                    codersea_decipercent_stone then
                                -- Yes
                    ptable  = seastone_list
                    newnode = ptable [math.random (#ptable)]
                else
                                -- Possible seaglass?
                    if math.random (1, 1000) <=
                        codersea_decipercent_glass then
                                -- Yes
                        ptable  = seaglass_list
                        newnode = ptable [math.random (#ptable)]
                    end
                end
            end

            minetest.add_node (pos, { name = newnode })
            return
        end

        if (node.name == "default:dirt") then
            newnode = "codersea:dirtgrow"
        else
            if (node.name == "default:sand") then
                newnode = "codersea:sandgrow"
            end
        end

        minetest.add_node (pos, { name = newnode })
    end ,
})

-- -------------------------------------------------------------------

minetest.register_abm ({
    catch_up  = false                   ,
    chance    = codersea_abm02_chance   ,
    interval  = codersea_abm02_interval ,

    nodenames = {
        "codersea:dirtgrow" ,
        "codersea:sandgrow" ,
    } ,

    action    = function (pos, node)
        local uppos = { x = pos.x, y = pos.y, z = pos.z }

        uppos.y = uppos.y + 1
        if not is_water (uppos) then return end

        pos.y = pos.y + 1       -- Position where new node will go
        local newnode           -- New node

                                -- Grow kelp (or seaweed) ?
        if math.random (1, 2) == 1 then
                                -- Yes
            if not has_ethereal and math.random (1, 7) == 1 then
                                -- Grow seaweed
                newnode = "codersea:ethereal_seaweed"
            else                -- Grow one of two  types of kelp
                local color = "brown"
                if math.random (1, 2) == 1 then color = "green" end
                newnode = "codersea:kelp" .. color
            end
        else                    -- No  - Grow seagrass (or coral)
            if not has_ethereal and math.random (1, 2) == 1 then
                                -- Grow one of four types of coral
                local num = math.random (2, 5)
                newnode = "codersea:ethereal_coral" .. num
            else                -- Grow one of two  types of seagrass
                local color = "green"
                if math.random (1, 2) == 1 then color = "red" end
                newnode = "codersea:seagrass" .. color
            end
        end
                                -- Store the selected type of node
        minetest.add_node (pos, { name = newnode })
    end ,
})

-- -------------------------------------------------------------------

minetest.register_abm ({
    catch_up  = false                   ,
    chance    = codersea_abm03_chance   ,
    interval  = codersea_abm03_interval ,

    nodenames = {
        "codersea:ethereal_seaweed" ,
        "codersea:kelpbrown"        ,
        "codersea:kelpgreen"        ,
    } ,

    action = function (pos, node)
        local name   = node.name
        local uppos  = { x = pos.x, y = pos.y, z = pos.z }

        local nn = 3
        if name == "codersea:ethereal_seaweed" then nn = 5 end

        for ii = 1,nn do
            uppos.y = uppos.y + 1
            if not is_water (uppos) then return end
        end

        if name == "codersea:ethereal_seaweed" then
            pos.y = pos.y + 1
            minetest.add_node (pos,
                { name = "codersea:ethereal_seaweed" })
            return
        end

        if name == "codersea:kelpbrown" then
            minetest.add_node (pos,
                { name = "codersea:kelpbrownmiddle"  })
            pos.y = pos.y + 1
            minetest.add_node (pos,
                { name = "codersea:kelpbrown"        })
            return
        end

        if name == "codersea:kelpgreen" then
            minetest.add_node (pos,
                { name = "codersea:kelpgreenmiddle"  })
            pos.y = pos.y + 1
            minetest.add_node (pos,
                { name = "codersea:kelpgreen"        })
            return
        end
    end ,
})

-- -------------------------------------------------------------------

-- This section adds a set of ABMs that allows  some  sea-plants  that
-- have damaged middle sections to grow back.

local function register_abm_growback (growname, topnames)
    for _,v in pairs (topnames) do topnames [v] = true end

    minetest.register_abm ({
        catch_up  = false                      ,
        chance    = codersea_chance_growback   ,
        interval  = codersea_interval_growback ,
        nodenames = { growname }               ,

       action = function (pos, node)
           local uppos = { x = pos.x, y = pos.y, z = pos.z }
           local upname
           uppos.y = uppos.y + 1
           if not is_water (uppos) then return end
           uppos.y = uppos.y + 1
           if is_water (uppos) then
               uppos.y = uppos.y + 1
               if is_water (uppos) then uppos.y = uppos.y + 1 end
           end
           upname = minetest.get_node (uppos).name
           if not topnames [upname] then return end
           pos.y = pos.y + 1
           minetest.add_node (pos, { name = growname })
        end
    })
end

register_abm_growback ( "codersea:kelpbrownmiddle" ,
                      { "codersea:kelpbrownmiddle" ,
                        "codersea:kelpbrown"       , })
register_abm_growback ( "codersea:kelpgreenmiddle" ,
                      { "codersea:kelpgreenmiddle" ,
                        "codersea:kelpgreen"       , })
register_abm_growback ( "codersea:seagrassgreen"   ,
                      { "codersea:seagrassgreen"   , })
register_abm_growback ( "codersea:seagrassred"     ,
                      { "codersea:seagrassred"     , })
register_abm_growback ( "codersea:seaweed"         ,
                      { "codersea:seaweed"         , })


reg_alias ("seaplants:seagrassgreen" , "codersea:seagrassgreen" )
reg_alias ("seaplants:seagrassred"   , "codersea:seagrassred"   )

-- -------------------------------------------------------------------

end