local traxx = require "traxx"
require "utils"
require "string"
require "math"

function start_blasting(track)
    local blast = table.shallow_copy(traxx[track])
    blast.channel = "blast"
    ctx.udata.blast = blast
    ctx.udata.last_beat = ctx.udata.time + 60 / blast.bpm
    audio_play(ctx.udata.blast)
end

function game_tick()
    if ctx.initialization_needed then
        ctx.udata = {
            time = 0,
            beat = 0
        }
        start_blasting("mod22")
    end

    local state = ctx.udata

    draw_rectangle {
        rect = { w = 960, h = 540 },
        color = { r = 125, a = 255 }
    }

    state.time = state.time + ctx.frame_duration
    if state.time - state.last_beat > 60 / state.blast.bpm then
        state.last_beat = state.last_beat + 60 / state.blast.bpm
        state.beat = state.beat + 1
        -- draw_rectangle {
        --     rect = { w = 64, h = 64 },
        --     color = { r = 255, a = 255 }
        -- }
    end

    local wobble = sinease(12, state.time - state.beat * (60 / state.blast.bpm) , (60 / state.blast.bpm) / 1.5, 0)

    for i = 0,10 do
        draw_sprite {
            texture = "art/creatures/meathead/" .. string.format("dance-%s.png", pingpong(state.beat, 3)),
            rect = { w = 64, h = 64 + wobble, x = 300 + i * 32, y = 300 - wobble }
        }
    end
end