weather = {}

-- Special (unnatural) weather types must be listed last
local weathers  = {
    "snow", "rain", "storm", "none", "locusts", "pennies"
}

-- NormalWeatherTypes = Number of normal weather types
-- TotalWeatherTypes  = Total  number of weather types

local NormalWeatherTypes = 4
local TotalWeatherTypes  = 6

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

local function numsetzero (name)
    return (tonumber (minetest.setting_get (name))) or 0
end

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

local              snow_particles_count  =
      numsetzero ("snow_particles_count" )

if snow_particles_count <   2 then
   snow_particles_count =   2 end
if snow_particles_count >  25 then
   snow_particles_count =  25 end

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

local              snow_particles_range  =
      numsetzero ("snow_particles_range" )

if snow_particles_range <   5 then
   snow_particles_range =   5 end
if snow_particles_range >  50 then
   snow_particles_range =  50 end

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

local                            winter_wonderland     =
      minetest.setting_getbool ("winter_wonderland"    )

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

local apply_weather = function (player, pos, weather_type)

    if weather_type == nil then return end
    if weather_type == "locust"  then
       weather_type =  "locusts"
    end
    if weather_type == "penny"   then
       weather_type =  "pennies"
    end
    if weather_type == "normal"  or
       weather_type == "regular" then
       weather_type = "none"
    end

    local pos = player:getpos()
    if pos.y > 1000 then return end
    if pos.y <  -10 then return end
    local tod = minetest.get_timeofday() * 24000

    if weather_type == "snow"    or
       weather_type == "locusts" or
       weather_type == "pennies" then
        if tod >= 6000 and tod <= 19000 then
            codersky.set_sky (player,
                { r=178, g=193, b=208 }, "plain", nil, false)
        else
            codersky.set_sky (player, nil, "regular", nil, false)
        end

        local weather_particles_range = 10
        local weather_particles_count = 15

        if weather_type == "snow" then
            if snow_particles_count ~= nil then
                weather_particles_count = snow_particles_count
            end
            if snow_particles_range ~= nil then
                weather_particles_range = snow_particles_range
            end
        end

        for ii = 1, weather_particles_count do
            local texture
            if     weather_type == "locusts" then
                texture = "weather_locusts.png"
            elseif weather_type == "pennies" then
                texture = "weather_pennies_" ..
                    math.random (1,2) .. ".png"
            else
                texture = "weather_snow_"    ..
                    math.random (1,2) .. ".png"
            end

            minetest.add_particle ({
                pos = {
                    x=pos.x+math.random (-weather_particles_range  ,
                                          weather_particles_range) ,
                    y=pos.y+math.random (12, 17) ,
                    z=pos.z+math.random (-weather_particles_range  ,
                                          weather_particles_range) ,
                } ,
                velocity = {
                    x=math.random (-5,  5) / 10 ,
                    y=math.random (-4, -6)      ,
                    z=math.random (-5,  5) / 10 ,
                } ,
                acceleration = {
                    x=math.random (-1,   1) /10 ,
                    y=math.random (-5, -10) /10 ,
                    z=math.random (-1,   1) /10 ,
                } ,

                expirationtime = 3,
                size = math.random (3, 5),
                collisiondetection = true,
                collision_removal = true,
                vertical = false,
                texture = texture ,
                glow = 0
            })
        end

    elseif weather_type == "rain" then
        if tod >= 6000 and tod <= 19000 then
            codersky.set_sky (player,
                { r=148, g=148, b=148 }, "plain", nil, false)
        else
            codersky.set_sky (player, nil, "regular", nil, false)
        end

        for ii = 1, 15 do
            minetest.add_particle ({
                pos = { x=pos.x+math.random(-10,10),
                        y=pos.y+math.random(12,17),
                        z=pos.z+math.random(-10,10)},
                velocity = {x=0, y=math.random(-15,-20), z=0},
                acceleration = {x=0, y=-1, z=0},
                expirationtime = 2,
                size = math.random(3,5),
                collisiondetection = true,
                collision_removal = true,
                vertical = true,
                texture = "weather_rain_"..math.random(1,2)..".png",
                glow = 0
            })
        end

    elseif weather_type == "storm" then
        if tod >= 6000 and tod <= 19000 then
            codersky.set_sky (player,
                { r=101, g=101, b=101 }, "plain", nil, false)
        else
            codersky.set_sky (player, nil, "regular", nil, false)
        end

        for ii = 1, 30 do
            minetest.add_particle ({
                pos = {x=pos.x+math.random(-10,10),
                       y=pos.y+math.random(12,17),
                       z=pos.z+math.random(-10,10)},
                velocity = {x=0, y=math.random(-25,-30), z=0},
                acceleration = {x=0, y=-1, z=0},
                expirationtime = 2,
                size = math.random(3,5),
                collisiondetection = true,
                collision_removal = true,
                vertical = true,
                texture = "weather_rain_3.png",
                glow = 0
            })

            if minetest.get_modpath ("lightning") and
                math.random (1,2000) == 1 then
                lightning.strike()
            end
        end

    elseif weather_type == "none" then
        codersky.set_sky (player, nil, "regular", nil, false)
    end
end

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

local function setweather (param)
    local ii
    for ii = 1, TotalWeatherTypes do
        if weathers [ii] == param then
            weather.current = ii
            weather.weather = param
        end
    end
end

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

minetest.register_globalstep (function (dtime)

    if math.random (1, 4) ~= 4 then return end

    if winter_wonderland then
        if weather.weather ~= "snow" then setweather ("snow") end
    elseif math.random (1, 5000) == 1 then
            local num = math.random (1, NormalWeatherTypes)
            weather.current = num
            weather.weather = weathers [num]
    end

    for _, player in ipairs (minetest.get_connected_players()) do
        local pos = player:getpos()

        -- Should weather occur at current position?
        local display_weather = true
        if pos.y <=  -20 or pos.y >= 1000 then
              display_weather = false
        end

        -- apply weather effect
        if display_weather then
            apply_weather (player, pos, weather.weather)
        else
            apply_weather (player, pos, "none")
        end
    end
end)

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

minetest.register_privilege ("weather", {
    description = "Allows control of weather" ,
    give_to_singleplayer = false
})

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

local table_setweather = {
    params      = "<weather_type>" ,
    description = "Sets weather to the given type",
    privs = { weather = true } ,

    func = function (name, param)
        if param == "normal" then param = "none" end
        setweather (param)
    end ,
}

minetest.register_chatcommand ("setweather" , table_setweather)
minetest.register_chatcommand ("weather"    , table_setweather)

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

minetest.register_chatcommand ("rain", {
    params      = nil                     ,
    description = "Sets weather to rain"  ,
    privs       = { weather = true }      ,

    func        = function (name, param)
        setweather ("rain")
    end ,
})

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

minetest.register_chatcommand ("snow", {
    params      = nil                     ,
    description = "Sets weather to snow"  ,
    privs       = { weather = true }      ,

    func        = function (name, param)
        setweather ("snow")
    end ,
})

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

minetest.register_chatcommand ("storm", {
    params      = nil                     ,
    description = "Sets weather to storm" ,
    privs       = { weather = true }      ,

    func        = function (name, param)
        setweather ("storm")
    end ,
})

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

minetest.register_chatcommand ("regular", {
    params      = nil                      ,
    description = "Sets weather to normal" ,
    privs       = { weather = true }       ,

    func        = function (name, param)
        setweather ("none")
    end ,
})

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

local table_locusts = {
    params      = nil                    ,
    description = "Plague of Locusts"    ,
    privs       = { weather = true }     ,

    func        = function (name, param)
        setweather ("locusts")
    end ,
}

minetest.register_chatcommand ("locust"  , table_locusts)
minetest.register_chatcommand ("locusts" , table_locusts)

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

local table_pennies = {
    params      = nil                    ,
    description = "Pennies from Heaven"  ,
    privs       = { weather = true }     ,

    func        = function (name, param)
        setweather ("pennies")
    end ,
}

minetest.register_chatcommand ("pennies" , table_pennies)
minetest.register_chatcommand ("penny"   , table_pennies)