import "CoreLibs/graphics"
import "CoreLibs/ui"

local function clamp(value, min, max)
    return math.max(math.min(value, max), min)
end

local function clamp_angle(value)
    if value < 0 then value = value + 360 end
    if value > 360 then value = value - 360 end
    return value
end

local function make_projectile(position)
    local projectile = { position=table.deepcopy(position), speed=3 }

    projectile.draw = function(self, id)
        local current_width = playdate.graphics.getLineWidth()
        playdate.graphics.setLineWidth(2)
        local angle_rad = math.rad(self.position.theta)
        local dx, dy = self.speed * math.cos(angle_rad), self.speed * math.sin(angle_rad)
        local new_x, new_y = self.position.x + dx, self.position.y + dy
        playdate.graphics.drawLine(self.position.x,self.position.y,  new_x,new_y)
        playdate.graphics.setLineWidth(current_width)
        self.position.x, self.position.y = new_x, new_y
    end

    return projectile
end

local function make_player(x, y, width, height, screen)
    local crankPosition = playdate.getCrankPosition()
    local player = { position={ x=x, y=y, theta=crankPosition}, width=width, height=height, screen=screen, projectiles={} }

    player.draw = function(self)
        local w, h, transform = self.width / 2, self.height / 2, playdate.geometry.affineTransform.new()
        local polygon = playdate.geometry.polygon.new(-w,-0.5*h,  -w,0.5*h,  w,0, -w,-0.5*h)
        transform:translate(self.position.x, self.position.y)
        transform:rotate(self.position.theta, self.position.x, self.position.y)
        local transformedPolygon = transform:transformedPolygon(polygon)
        playdate.graphics.drawPolygon(transformedPolygon)

        for i, projectile in ipairs(self.projectiles) do
            projectile:draw(i)
        end
    end

    player.translate = function(self, offset_theta, amount)
        local w, h, theta = self.width / 2, self.height / 2, self.position.theta
        local angle_rad = math.rad(clamp_angle(theta + offset_theta))
        local new_x = self.position.x + (amount * math.cos(angle_rad))
        local new_y = self.position.y + (amount * math.sin(angle_rad))
        self.position.x = clamp(new_x, w, self.screen.width - w)
        self.position.y = clamp(new_y, h, self.screen.height - h)
    end

    player.rotate = function(self, degrees)
        self.position.theta = clamp_angle(self.position.theta + degrees)
    end

    player.handle_crank = function(self)
        local change, _acceleratedChange = playdate.getCrankChange()
        self:rotate(change)
    end

    player.shoot_projectile = function(self)
        local projectile = make_projectile(self.position)
        table.insert(self.projectiles, projectile)
    end

    return player
end

local screen = { width=400, height=240 }
local player = make_player(screen.width / 2, screen.height / 2, 20, 30, screen)

function playdate.update()
    playdate.graphics.clear()
    if playdate.isCrankDocked() then playdate.ui.crankIndicator:draw() end

    if playdate.buttonIsPressed(playdate.kButtonUp) then player:translate(0, 10) end
    if playdate.buttonIsPressed(playdate.kButtonDown) then player:translate(180, 10) end

    if playdate.buttonIsPressed(playdate.kButtonLeft) then player:translate(270, 1) end
    if playdate.buttonIsPressed(playdate.kButtonRight) then player:translate(90, 1) end

    if playdate.buttonJustPressed(playdate.kButtonA) then player:shoot_projectile() end

    player:handle_crank()
    player:draw()
end