local Sounds = {}
local sources = {}
local SAMPLE_RATE = 44100

local function makeSoundData(duration, generator)
    local samples = math.floor(SAMPLE_RATE * duration)
    local sd = love.sound.newSoundData(samples, SAMPLE_RATE, 16, 1)
    for i = 0, samples - 1 do
        local t = i / SAMPLE_RATE
        local p = i / samples
        sd:setSample(i, math.max(-1, math.min(1, generator(t, p))))
    end
    return sd
end

local function makeSource(sd)
    return love.audio.newSource(sd, "static")
end

local function genThrust(t, p)
    local noise = (math.random() * 2 - 1) * 0.25
    local low = math.sin(2 * math.pi * 45 * t) * 0.2
    local rumble = math.sin(2 * math.pi * 25 * t) * 0.15
    return (noise + low + rumble) * 0.4
end

local function genLandGood(t, p)
    local freq
    if p < 0.33 then freq = 500
    elseif p < 0.66 then freq = 700
    else freq = 900 end
    local env = 0.7
    if p > 0.9 then env = (1-p)/0.1 * 0.7 end
    return math.sin(2 * math.pi * freq * t) * env * 0.35
end

local function genLandHard(t, p)
    local env = (1 - p) ^ 2
    return math.sin(2 * math.pi * 250 * t) * env * 0.3
end

local function genCrash(t, p)
    local env = (1 - p) ^ 1.2
    local sine = math.sin(2 * math.pi * (60 + 30*(1-p)) * t) * 0.5
    local noise = (math.random() * 2 - 1) * 0.5
    return (sine + noise) * env * 0.5
end

local function genFuelWarn(t, p)
    local freq = 800
    local env = 0.6
    if p > 0.5 then env = 0 end
    return math.sin(2 * math.pi * freq * t) * env * 0.3
end

local function genAbort(t, p)
    local freq = 600 - p * 300
    local env = (1 - p) ^ 1.5
    local noise = (math.random() * 2 - 1) * 0.3
    return (math.sin(2 * math.pi * freq * t) * 0.4 + noise) * env * 0.4
end

function Sounds.init()
    sources = {}
    local defs = {
        thrust    = {0.25, genThrust},
        land_good = {0.4,  genLandGood},
        land_hard = {0.3,  genLandHard},
        crash     = {0.6,  genCrash},
        fuel_warn = {0.15, genFuelWarn},
        abort     = {0.3,  genAbort},
    }
    for name, def in pairs(defs) do
        sources[name] = makeSource(makeSoundData(def[1], def[2]))
    end
end

function Sounds.play(name)
    local src = sources[name]
    if not src then return end
    src:clone():play()
end

return Sounds