-- Lesson 13:  A Game Folder.  The finished script, exactly as the lesson ends.
dofile("Singe/Framework.singe")

local SHIP_SPEED  = 3
local SHOT_SPEED  = 6
local ROCK_COUNT  = 6
local STAR_COUNT  = 40
local START_LIVES = 3
local HIT_SCORE   = 10
local SHIP_PAD_X  = 6
local SHIP_PAD_Y  = 5
local ROCK_PAD    = 4
local SHOW_BOXES  = false

local TITLE   = "title"
local PLAYING = "playing"
local DYING   = "dying"
local OVER    = "over"

local shipSprite = spriteLoad(DIR .. "art/spaceship.png")
local rockSprite = spriteLoad(DIR .. "art/asteroid.png")
local shotSprite = spriteLoad(DIR .. "art/bullet.png")
local starSprite = spriteLoad(DIR .. "art/star.png")

local shootClip = soundLoad(DIR .. "art/shoot.wav")
local boomClip  = soundLoad(DIR .. "art/boom.wav")
local clickClip = soundLoad("Singe/click.wav")
local theme     = musicLoad("Singe/menuIntro.flac")

local screenWidth  = overlayGetWidth()
local screenHeight = overlayGetHeight()
local shipWidth    = spriteGetWidth(shipSprite)
local shipHeight   = spriteGetHeight(shipSprite)
local rockWidth    = spriteGetWidth(rockSprite)
local rockHeight   = spriteGetHeight(rockSprite)
local shotWidth    = spriteGetWidth(shotSprite)
local shotHeight   = spriteGetHeight(shotSprite)

local shipX        = (screenWidth - shipWidth) / 2
local shipY        = screenHeight - shipHeight - 4
local goLeft       = false
local goRight      = false
local rocks        = {}
local shots        = {}
local stars        = {}
local score        = 0
local lives        = START_LIVES
local best         = saveGet("highScore", 0)
local state        = TITLE
local deathChannel = -1


function drawBox(x, y, width, height)
    overlayBox(x, y, x + width - 1, y + height - 1)
end


function drawBoxes()
    colorForeground(0, 255, 0)
    drawBox(shipBox())
    for _, rock in ipairs(rocks) do
        drawBox(rockBox(rock))
    end
end


function drawHud()
    overlayPrint(1, 1, "SCORE " .. score)
    overlayPrint(25, 1, "BEST " .. best)
    overlayPrint(50, 1, "LIVES " .. lives)
    if state == OVER then
        overlayPrint(25, 8, "GAME OVER")
        overlayPrint(17, 10, "PRESS 1 TO PLAY AGAIN")
    end
end


function drawRocks()
    for _, rock in ipairs(rocks) do
        spriteDraw(rockSprite, rock.x, rock.y)
    end
end


function drawShots()
    for _, shot in ipairs(shots) do
        spriteDraw(shotSprite, shot.x, shot.y)
    end
end


function drawStars()
    for _, star in ipairs(stars) do
        spriteDraw(starSprite, star.x, star.y)
    end
end


function drawTitle()
    overlayPrint(25, 6, "R O C K S")
    overlayPrint(25, 9, "BEST " .. best)
    overlayPrint(22, 12, "PRESS 1 TO PLAY")
end


function endGame()
    deathChannel = -1
    state        = OVER
    musicStop(theme, 1500)
    if score > best then
        best = score
        saveSet("highScore", best)
        saveFlush()
    end
end


function newRock(rock)
    rock.x     = math.random(0, screenWidth - rockWidth)
    rock.y     = -rockHeight - math.random(0, 160)
    rock.speed = math.random(8, 20) / 10
end


function onInputPressed(what)
    if what == SWITCH_LEFT then
        goLeft = true
    elseif what == SWITCH_RIGHT then
        goRight = true
    elseif what == SWITCH_BUTTON1 and state == PLAYING then
        shots[#shots + 1] = { x = shipX + shipWidth / 2 - shotWidth / 2, y = shipY }
        soundPlay(shootClip, 0, 35)
    elseif what == SWITCH_START1 and (state == TITLE or state == OVER) then
        soundPlay(clickClip)
        startGame()
    end
end


function onInputReleased(what)
    if what == SWITCH_LEFT then
        goLeft = false
    elseif what == SWITCH_RIGHT then
        goRight = false
    end
end


function onOverlayUpdate()
    overlayClear()
    updateStars()
    if state == PLAYING then
        updateShip()
        updateShots()
        updateRocks()
    end
    drawStars()
    drawRocks()
    drawShots()
    spriteDraw(shipSprite, shipX, shipY)
    if SHOW_BOXES then
        drawBoxes()
    end
    if state == TITLE then
        drawTitle()
    else
        drawHud()
    end
    return OVERLAY_UPDATED
end


function onShutdown()
    spriteUnload(shipSprite)
    spriteUnload(rockSprite)
    spriteUnload(shotSprite)
    spriteUnload(starSprite)
    soundUnload(shootClip)
    soundUnload(boomClip)
    soundUnload(clickClip)
    musicUnload(theme)
end


function onSoundCompleted(channel)
    if channel == deathChannel then
        endGame()
    end
end


function rockBox(rock)
    return rock.x + ROCK_PAD, rock.y + ROCK_PAD, rockWidth - ROCK_PAD * 2, rockHeight - ROCK_PAD * 2
end


function shipBox()
    return shipX + SHIP_PAD_X, shipY + SHIP_PAD_Y, shipWidth - SHIP_PAD_X * 2, shipHeight - SHIP_PAD_Y * 2
end


function shipHitsRock(rock)
    local sx, sy, sw, sh = shipBox()
    local rx, ry, rw, rh = rockBox(rock)

    return collideRects(sx, sy, sw, sh, rx, ry, rw, rh)
end


function shotHitsRock(shot, rock)
    local rx, ry, rw, rh = rockBox(rock)

    return collidePointRect(shot.x + shotWidth / 2, shot.y, rx, ry, rw, rh)
end


function startGame()
    shipX        = (screenWidth - shipWidth) / 2
    score        = 0
    lives        = START_LIVES
    state        = PLAYING
    deathChannel = -1
    shots        = {}
    for i = 1, ROCK_COUNT do
        rocks[i] = {}
        newRock(rocks[i])
    end
    musicSetVolume(50)
    musicPlay(theme, -1)
end


function updateRocks()
    for _, rock in ipairs(rocks) do
        rock.y = rock.y + rock.speed
        if rock.y > screenHeight then
            newRock(rock)
        end
        if shipHitsRock(rock) then
            local channel = soundPlay(boomClip)

            newRock(rock)
            lives = lives - 1
            if lives <= 0 then
                state        = DYING
                deathChannel = channel
                if channel < 0 then
                    endGame()
                end
            end
        end
    end
end


function updateShip()
    if goLeft then
        shipX = shipX - SHIP_SPEED
    end
    if goRight then
        shipX = shipX + SHIP_SPEED
    end
    if shipX < 0 then
        shipX = 0
    end
    if shipX > screenWidth - shipWidth then
        shipX = screenWidth - shipWidth
    end
end


function updateShots()
    for i = #shots, 1, -1 do
        local shot = shots[i]
        local gone = false

        shot.y = shot.y - SHOT_SPEED
        if shot.y + shotHeight < 0 then
            gone = true
        end
        for _, rock in ipairs(rocks) do
            if not gone and shotHitsRock(shot, rock) then
                newRock(rock)
                score = score + HIT_SCORE
                gone  = true
                soundPlay(boomClip, 0, 45)
            end
        end
        if gone then
            table.remove(shots, i)
        end
    end
end


function updateStars()
    for _, star in ipairs(stars) do
        star.y = star.y + star.speed
        if star.y > screenHeight then
            star.y = 0
            star.x = math.random(0, screenWidth - 1)
        end
    end
end


for i = 1, STAR_COUNT do
    stars[i] = { x = math.random(0, screenWidth - 1), y = math.random(0, screenHeight - 1), speed = math.random(1, 3) / 4 }
end