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 process_player(state)
    input_action { name = "up", control = "W" }
    input_action { name = "left", control = "A" }
    input_action { name = "down", control = "S" }
    input_action { name = "right", control = "D" }

    local right = vec3_norm(vec3_cross(state.player.camera_direction, { x=0, y=1, z=0 }))
    local up = { x = right.z, y = right.y, z = -right.x }

    local direction = { x = 0, y = 0 , z = 0 }

    if input_action_pressed { name = "up" } then
        direction = vec3_add(direction, up)
    end
    if input_action_pressed { name = "down" } then
        direction = vec3_sub(direction, up)
    end
    if input_action_pressed { name = "right" } then
        direction = vec3_add(direction, right)
    end
    if input_action_pressed { name = "left" } then
        direction = vec3_sub(direction, right)
    end

    if vec3_length(direction) > 0 then
        direction = vec3_norm(direction)
    end

    state.player.position = vec3_add(state.player.position, vec3_scale(direction, state.player.speed / (60 / state.blast.bpm)))
end

function game_tick()
    if ctx.initialization_needed then
        ctx.udata = {
            time = 0,
            beat = 0,
            player = {
                position = { x=3, y=0, z=0 },
                speed = 0.06, -- tiles per beat
                camera_direction = { x=-math.sin(math.pi / 4), y=-1, z=math.cos(math.pi / 4) },
            }
        }
        start_blasting("mod171")
    end

    local state = ctx.udata

    process_player(state)

    draw_camera {
        position = state.player.position,
        direction = state.player.camera_direction,
        -- direction = { x=-math.sin(ctx.frame_number / 100), y=-1, z=math.cos(ctx.frame_number / 100) },
        up = { x=0, y=1, z=0 },
        fov = 0,
        zoom = 0.15 + math.sin(ctx.frame_number / 100) / 20,
    }

    -- 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 = -10,10 do
        draw_quad {
            texture = "art/creatures/meathead/" .. string.format("dance-%s.png", pingpong(state.beat, 3)),
            texture_region = { w = 32, h = 32 },
            v0 = { x = 0, y = (64 + wobble) / 64, z = 0 + i/2 },
            v1 = { x = 0, y = 0, z = 0 + i/2 },
            v2 = { x = 0, y = 0, z = 0 + i/2 + 1 },
            v3 = { x = 0, y = (64 + wobble) / 64, z = 0 + i/2 + 1 },
        }

        draw_billboard {
            texture = "art/creatures/meathead/" .. string.format("dance-%s.png", pingpong(state.beat, 3)),
            position = { x = i, y = wobble / 64, z = 0 },
            size = { x = 1, y = (64 + wobble) / 64 },
        }
    end
end