rspawn = {}
rspawn.playerspawns = {}

local mpath = minetest.get_modpath("rspawn")

local function notnil_or(d, v)
    if v == nil then
        return d
    else
        return v
    end
end

-- Water level, plus one to ensure we are above the sea.
local water_level = tonumber(minetest.settings:get("water_level", "1") )+1
local radial_step = 16

-- Setting with no namespace for interoperability
local static_spawnpoint = minetest.setting_get_pos("static_spawnpoint") or {x=0, y=0, z=0}

-- Setting from beds mod
rspawn.bedspawn = minetest.setting_getbool("enable_bed_respawn", true) -- from beds mod

-- Detect server mode, of sorts
rspawn.adminname = minetest.settings:get("name", "singleplayer")

-- rSpawn specific settings
rspawn.debug_on = minetest.settings:get_bool("rspawn.debug")
rspawn.spawnanywhere = notnil_or(true, minetest.settings:get_bool("rspawn.spawn_anywhere") )
rspawn.kick_on_fail = notnil_or(false, minetest.settings:get_bool("rspawn.kick_on_fail"))
rspawn.max_pregen_spawns = tonumber(minetest.settings:get("rspawn.max_pregen") or 5)
rspawn.search_radius = tonumber(minetest.settings:get("rspawn.search_radius") or 32)
rspawn.gen_frequency = tonumber(minetest.settings:get("rspawn.gen_frequency") or 30)
    
dofile(mpath.."/src/data.lua")
dofile(mpath.."/src/commands.lua")
dofile(mpath.."/src/forceload.lua")
dofile(mpath.."/src/debugging.lua")




rspawn:spawnload()

local function daylight_above(min_daylight, pos)
    local level = minetest.get_node_light(pos, 0.5)
    return min_daylight <= level
end

function rspawn:get_positions_for(pos, radius)
    local breadth = radius
    local altitude = radius*2

    local pos1 = {x=pos.x-breadth, y=pos.y, z=pos.z-breadth}
    local pos2 = {x=pos.x+breadth, y=pos.y+altitude, z=pos.z+breadth}

    return pos1,pos2
end

function rspawn:newspawn(pos, radius)
    -- Given a seed position and a radius, find an exact spawn location
    --   that is walkable and with 2 air nodes above it

    rspawn:debug("Trying somewhere around "..minetest.pos_to_string(pos))

    local pos1,pos2 = rspawn:get_positions_for(pos, radius)

    rspawn:debug("Searching "..minetest.pos_to_string(pos1).." to "..minetest.pos_to_string(pos2))

    local airnodes = minetest.find_nodes_in_area(pos1, pos2, {"air"})
    local validnodes = {}

    rspawn:debug("Found "..tostring(#airnodes).." air nodes within "..tostring(radius))
    for _,anode in pairs(airnodes) do
        local under = minetest.get_node( {x=anode.x, y=anode.y-1, z=anode.z} ).name
        local over = minetest.get_node( {x=anode.x, y=anode.y+1, z=anode.z} ).name
        under = minetest.registered_nodes[under]
        over = minetest.registered_nodes[over]

        if under.walkable
         and not over.walkable
         and not minetest.is_protected(anode, rspawn.adminname)
         and daylight_above(7, anode) then
            validnodes[#validnodes+1] = anode
        end
    end

    if #validnodes > 0 then
        rspawn:debug("Valid spawn points found with radius "..tostring(radius))
        return validnodes[math.random(1,#validnodes)]
    else
        rspawn:debug("No valid air nodes")
    end
end

function rspawn:genpos()
    -- Generate a random position, and derive a new spawn position
    local pos = static_spawnpoint

    if rspawn.spawnanywhere then
        pos = {
            x = math.random(-30000,30000),
            --y = math.random(water_level, water_level+20),
            y = water_level, -- always at waterlevel
            z = math.random(-30000,30000),
        }
    end

    return pos
end

local function confirm_new_spawn(name, newpos)
    local spos = minetest.pos_to_string(newpos)

    rspawn.debug("Saving spawn for "..name, spos)
    rspawn.playerspawns[name] = newpos
    rspawn:spawnsave()

    minetest.chat_send_player(name, "New spawn set at "..spos)

    minetest.get_player_by_name(name):setpos(rspawn.playerspawns[name])
end

function rspawn:set_newplayer_spawn(player)
    local playername = player:get_player_name()

    if not rspawn.playerspawns[playername] then
        local newpos = rspawn:get_next_spawn()

        if newpos then
            confirm_new_spawn(playername, newpos)

        else
            if rspawn.adminname ~= "singleplayer" or playername ~= rspawn.adminname then
                minetest.chat_send_player(playername, "Please wait until a spawn point is available ...")
                minetest.after(15, function()
                    rspawn:set_newplayer_spawn(player)
                end)
            elseif rspawn.kick_on_fail then
                minetest.kick_player(playername, "No personalized spawn points available - please try again later.")

            else
                minetest.chat_send_player(playername, "Could not get custom spawn! Retrying in "..rspawn.gen_frequency.." seconds")

                minetest.after(gen_frequency, function()
                    rspawn:set_newplayer_spawn(player)
                end)
            end
        end
    end
end

function rspawn:renew_player_spawn(playername)
    local player = minetest.get_player_by_name(playername)

    local newpos = rspawn:get_next_spawn()

    if newpos then
        confirm_new_spawn(playername, newpos)

    else
        minetest.chat_send_player(playername, "Could not get custom spawn!")
    end
end

minetest.register_on_joinplayer(function(player)
    rspawn:set_newplayer_spawn(player)
end)

minetest.register_on_respawnplayer(function(player)
    local name = player:get_player_name()
    if rspawn.bedspawn == true then
        local pos = beds.spawn[name]
        if pos then
            player:setpos(pos)
            return true
        end
    end

    -- And if no bed, nor bed spwawning not active:
    player:setpos(rspawn.playerspawns[name])
    return true
end)

dofile(mpath.."/src/pregeneration.lua")