-- Learn to Program with Singe -- Lesson 17: Light Guns

dofile("Singe/Framework.singe")

overlaySetResolution(discGetWidth(), discGetHeight())

local FIRST_FRAME = 20
local LAST_FRAME  = 400
local TARGET_SIZE = 96
local HIT_SCORE   = 100
local FLASH_TIME  = 12

local targets = {
    { first =  40, last = 110, x =  80, y = 110 },
    { first = 120, last = 190, x = 470, y = 140 },
    { first = 200, last = 270, x = 290, y = 250 },
    { first = 280, last = 360, x = 150, y = 300 },
}

local aimX    = overlayGetWidth() / 2
local aimY    = overlayGetHeight() / 2
local score   = 0
local shots   = 0
local hits    = 0
local flash   = 0
local flashX  = 0
local flashY  = 0
local drawAim = singeWantsCrosshairs()


local function drawCrosshair(x, y)
    colorForeground(255, 255, 255, 255)
    overlayCircle(x, y, 10)
    overlayLine(x - 18, y, x - 4, y)
    overlayLine(x + 4, y, x + 18, y)
    overlayLine(x, y - 18, x, y - 4)
    overlayLine(x, y + 4, x, y + 18)
end


local function targetIsUp(target, frame)
    return not target.hit and frame >= target.first and frame <= target.last
end


local function startRound()
    score = 0
    shots = 0
    hits  = 0
    flash = 0
    for _, target in ipairs(targets) do
        target.hit = false
    end
    discSkipToFrame(FIRST_FRAME)
end


function onInputPressed(what, device)
    if what == SWITCH_START1 then
        startRound()
        return
    end

    if what ~= SWITCH_BUTTON3 then
        return
    end

    local x, y = mouseGetPosition(device or 0)
    local frame = discGetFrame()

    shots = shots + 1

    for _, target in ipairs(targets) do
        if targetIsUp(target, frame) and collidePointRect(x, y, target.x, target.y, TARGET_SIZE, TARGET_SIZE) then
            target.hit = true
            hits       = hits + 1
            score      = score + HIT_SCORE
            flash      = FLASH_TIME
            flashX     = x
            flashY     = y
            return
        end
    end
end


function onOverlayUpdate()
    local frame = discGetFrame()

    if frame >= LAST_FRAME then
        startRound()
        frame = FIRST_FRAME
    end

    aimX, aimY = mouseGetPosition(0)

    overlayClear()

    for _, target in ipairs(targets) do
        if targetIsUp(target, frame) then
            colorForeground(255, 200, 0, 255)
            overlayBox(target.x, target.y, target.x + TARGET_SIZE - 1, target.y + TARGET_SIZE - 1)
            overlayCircle(target.x + TARGET_SIZE / 2, target.y + TARGET_SIZE / 2, TARGET_SIZE / 3)
        end
    end

    if flash > 0 then
        colorForeground(255, 255, 255, 255)
        overlayCircle(flashX, flashY, 30 - flash * 2)
        flash = flash - 1
    end

    overlayPrint(2, 1, "SCORE " .. score .. "   HITS " .. hits .. "/" .. shots .. "   FRAME " .. frame)

    if drawAim then
        drawCrosshair(aimX, aimY)
    end

    return OVERLAY_UPDATED
end


startRound()