-- File:     codersea/fixwater.lua
-- Purpose:  CoderSea water fixup module
-- Credits:  See "codersea.md"
-- Licenses: See "LICENSE"

-- ===================================================================
--                                notes
-- ===================================================================

-- If "plantlike" nodes are drawn under water, by default, they appear
-- inside transparent boxes.  "sea" used code  referred to as  "noair-
-- blocks" to fix this.  "codersea" uses similar but simpler code,  in
-- this file, for the same purpose.

-- "codersea's" code produces  better results and,  additionally, sup-
-- ports Ethereal seaplants.

-- "codersea's" approach requires a special PNG file named:  codersea_
-- water.png

-- The PNG file in question is  simply a  16x16 blank PNG file  with a
-- transparent background.

-- ===================================================================
--                            initial setup
-- ===================================================================

local codersea_drowning =
    minetest.setting_getbool ("codersea_drowning")

-- ===================================================================
--                       handle external plants
-- ===================================================================

local external_plants = {
    "ethereal:coral2"            ,
    "ethereal:coral3"            ,
    "ethereal:coral4"            ,
    "ethereal:coral5"            ,
    "ethereal:seaweed"           ,
}

local function setplant (name)
    local table1 = minetest.registered_nodes [name]
    if table1 == nil then return end

    local table2 = {}
    for i,v in pairs (table1) do table2 [i] = v end
    if table2.groups == nil then table2.groups = { xyzzy=1 } end
    table2.groups.seaplants = 1
    table2.groups.wrapwater = 1
    minetest.register_node (":" .. name, table2)
end

for _,node_name in ipairs (external_plants) do
    setplant (node_name)
end

-- ===================================================================
--                   disable flowing-water animation
-- ===================================================================

-- This is "debug" code.

local debug_flowing_water = false

if    debug_flowing_water then
    local wname   = "default:water_flowing"
    local wtable1 = minetest.registered_nodes [wname]
    local wtable2 = {}
    for i,v in pairs (wtable1) do wtable2 [i] = v end
    wtable2.special_tiles = nil
    minetest.register_node (":" .. wname, wtable2)
end

-- ===================================================================
--                                nodes
-- ===================================================================

local inventory_water = "default_water.png"

minetest.register_node ("codersea:water_flowing", {
    description     = "Flowing Water" ,
    inventory_image = inventory_water ,
    drawtype        = "flowingliquid" ,
    tiles           = { "codersea_water.png" } ,
    alpha           = 1 ,
    paramtype       = "light" ,
    paramtype2      = "flowingliquid" ,
    walkable        = false ,
    pointable       = false ,
    diggable        = false ,
    buildable_to    = true ,
    drop            = "" ,
    drowning        = codersea_drowning ,
    liquidtype      = "flowing" ,

    liquid_alternative_flowing = "codersea:water_flowing" ,
    liquid_alternative_source  = "codersea:water_source"  ,
    liquid_viscosity = 1,
    freezemelt = "default:snow" ,

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

    groups = {
        water=3, liquid=3, puts_out_fire=1,
        not_in_creative_inventory=1, freezes=1, melt_around=1
    } ,
})

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

minetest.register_node ("codersea:water_source" , {
    alpha            = 1                       ,
    buildable_to     = true                      ,
    description      = "Codersea Water Source"   ,
    diggable         = false                     ,
    drawtype         = "liquid"                  ,
    drop             = ""                        ,
    drowning         = codersea_drowning         ,
    freezemelt       = "default:ice"             ,
    inventory_image  = inventory_water           ,
    liquid_viscosity = 1                         ,
    liquidtype       = "source"                  ,
    paramtype        = "light"                   ,
    pointable        = false                     ,
    tiles            = { "codersea_water.png" }  ,
    walkable         = false                     ,

    liquid_alternative_flowing = "codersea:water_flowing" ,
    liquid_alternative_source  = "codersea:water_source"  ,

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

    groups = {
        water=3, liquid=3, puts_out_fire=1, freezes=1,
        not_in_creative_inventory=1
    } ,
})

-- ===================================================================
--                                ABMs
-- ===================================================================

-- This section defines the ABMs used by this module.

-- -------------------------------------------------------------------
-- Wrap seaplants in layers of coderwater to fix visual glitches.

minetest.register_abm ({
    catch_up  = false ,
    chance    = 1 ,
    interval  = 4 ,
    neighbors = { "group:wrapwater" } ,
    nodenames = { "default:water_source", "default:water_flowing" } ,

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

        local uppos  = { x = pos.x, y = pos.y+1, z = pos.z }
        local upname = minetest.get_node (uppos).name
        if upname ~= "air" then
            minetest.add_node (pos, { name = newnode })
        end
    end ,
})

-- -------------------------------------------------------------------
-- Periodically revert unneeded "codersea" water nodes.

-- This  ABM affects wide areas,  so the interval used should be rela-
-- tively large.

minetest.register_abm ({
    catch_up  = false ,
    chance    =  1    ,
    interval  = 30    ,
    nodenames = { "codersea:water_source",
                  "codersea:water_flowing" } ,

    action = function (pos, node)
        local pos0 = { x=pos.x-1, y=pos.y-1, z=pos.z-1 }
        local pos1 = { x=pos.x+1, y=pos.y+1, z=pos.z+1 }

        if #minetest.find_nodes_in_area (pos0, pos1,
            "group:wrapwater") < 1 then
            local newnode =   "default:water_source"
            if node.name  == "codersea:water_flowing" then
                newnode   =   "default:water_flowing"
            end
            minetest.add_node (pos, { name = newnode })
        end
    end ,
})

-- -------------------------------------------------------------------
-- "Debug" code.

local debug_thermoclines = false

if    debug_thermoclines then
minetest.register_abm ({
    catch_up  = false                        ,
    chance    = 1                            ,
    interval  = 2                            ,
    neighbors = { "codersea:water_source" ,
                  "codersea:water_flowing" } ,
    nodenames = { "default:water_flowing"  } ,

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