# Standalone MicroPython Screensaver: Alien Invaders
# Inspired by alien-wave shooter classic. Exposes run(text="", frames=None).

import time
import math
import random

try:
    import board_config
    display = getattr(board_config, 'display_instance', None)
except Exception:
    board_config = None
    display = None

def sleep_ms(ms):
    try:
        time.sleep_ms(ms)
    except AttributeError:
        time.sleep(ms / 1000.0)

def check_touch(d, bc):
    """Robust check for screen touch to stop the screensaver."""
    if bc is not None:
        touch_inst = getattr(bc, 'touch_instance', None)
        if touch_inst is not None:
            if hasattr(touch_inst, 'is_touched'):
                try:
                    if touch_inst.is_touched():
                        return True
                except Exception:
                    pass
            for meth in ('get_touch', 'read_touch'):
                if hasattr(touch_inst, meth):
                    try:
                        res = getattr(touch_inst, meth)()
                        if res is not None and res is not False and res != 0:
                            return True
                    except Exception:
                        pass
        touch_val = getattr(bc, 'touch', None)
        if touch_val is not None:
            if callable(touch_val):
                try:
                    res = touch_val()
                    if res is not None and res is not False and res != 0:
                        return True
                except Exception:
                    pass
            else:
                if hasattr(touch_val, 'is_touched'):
                    try:
                        if touch_val.is_touched():
                            return True
                    except Exception:
                        pass
                for meth in ('get_touch', 'read_touch'):
                    if hasattr(touch_val, meth):
                        try:
                            res = getattr(touch_val, meth)()
                            if res is not None and res is not False and res != 0:
                                return True
                        except Exception:
                            pass
    if d is not None:
        for meth in ('get_touch', 'touch'):
            if hasattr(d, meth):
                try:
                    res = getattr(d, meth)()
                    if res is not None and res is not False and res != 0:
                        return True
                except Exception:
                    pass
    return False

def draw_invader(d, ix, iy, frame_state):
    # Alternating animation frames for crawling legs
    d.fill_rect(ix - 7, iy - 4, 14, 3, 1)
    d.fill_rect(ix - 5, iy - 1, 10, 3, 1)
    if frame_state:
        # Legs out
        d.fill_rect(ix - 7, iy + 2, 2, 3, 1)
        d.fill_rect(ix + 5, iy + 2, 2, 3, 1)
    else:
        # Legs in
        d.fill_rect(ix - 4, iy + 2, 2, 3, 1)
        d.fill_rect(ix + 2, iy + 2, 2, 3, 1)
    # Eyes
    d.fill_rect(ix - 3, iy - 3, 2, 2, 0)
    d.fill_rect(ix + 1, iy - 3, 2, 2, 0)

def draw_ship(d, sx, sy):
    d.fill_rect(sx - 9, sy - 4, 18, 5, 1)
    d.fill_rect(sx - 3, sy - 8, 6, 4, 1)
    d.fill_rect(sx - 1, sy - 12, 2, 4, 1)

def run(text="", frames=None):
    if not display:
        print("board_config.display_instance is not available. Skipping screensaver.")
        return

    width = getattr(display, 'width', 400)
    height = getattr(display, 'height', 300)
    
    # Game parameters
    invader_w, invader_h = 14, 9
    col_spacing = 28
    row_spacing = 18
    
    grid_cols = 6
    grid_rows = 3
    
    # Initialize game objects
    invaders = [] # entries: [col, row, alive_bool]
    def reset_invaders():
        invaders.clear()
        for r in range(grid_rows):
            for c in range(grid_cols):
                invaders.append([c, r, True])
                
    reset_invaders()
    
    inv_grid_x = (width - (grid_cols * col_spacing)) // 2
    inv_grid_y = 40
    inv_speed = 1.5
    inv_dir = 1
    
    ship_x = width // 2
    ship_y = height - 15
    ship_speed = 2.0
    
    bullets = [] # player bullets: [x, y]
    bombs = []   # alien bombs: [x, y]
    explosions = [] # particle list: [x, y, vx, vy, life]
    
    score = 0
    frame = 0
    cooldown = 0
    death_timer = 0
    
    try:
        while True:
            if frames is not None and frames > 0 and frame >= frames:
                break
                
            if check_touch(display, board_config):
                print("Screensaver stopped by screen touch.")
                break
                
            # If player was hit, run a death screen-shake / reset sequence
            if death_timer > 0:
                death_timer -= 1
                display.clear(0)
                # Simple screen shake by offsetting lines slightly
                shake = random.randint(-4, 4)
                display.text("SYSTEM ERROR", width // 2 - 48 + shake, height // 2 - 4 + shake, 1)
                display.show()
                if death_timer == 0:
                    reset_invaders()
                    bullets.clear()
                    bombs.clear()
                    explosions.clear()
                    inv_grid_x = (width - (grid_cols * col_spacing)) // 2
                    inv_grid_y = 40
                    ship_x = width // 2
                frame += 1
                sleep_ms(30)
                continue
                
            # AI: Move player ship toward closest invader horizontally
            alive_invaders = [inv for inv in invaders if inv[2]]
            if not alive_invaders:
                score += 500
                reset_invaders()
                inv_grid_y = 40
                bullets.clear()
                bombs.clear()
                continue
                
            # Find the lowest/closest invader to follow
            target_inv = None
            max_r = -1
            for inv in alive_invaders:
                if inv[1] > max_r:
                    max_r = inv[1]
                    target_inv = inv
                    
            if target_inv:
                inv_col, inv_row = target_inv[0], target_inv[1]
                t_x = inv_grid_x + inv_col * col_spacing + col_spacing // 2
                if ship_x < t_x:
                    ship_x = min(width - 15, ship_x + ship_speed)
                elif ship_x > t_x:
                    ship_x = max(15, ship_x - ship_speed)
                    
            # Auto shooting
            if cooldown > 0:
                cooldown -= 1
            elif random.random() < 0.15:
                bullets.append([ship_x, ship_y - 12])
                cooldown = 12
                
            # Invader movements
            # Calculate grid bounds based on active invaders
            left_col = min(inv[0] for inv in alive_invaders)
            right_col = max(inv[0] for inv in alive_invaders)
            
            grid_left = inv_grid_x + left_col * col_spacing
            grid_right = inv_grid_x + right_col * col_spacing + col_spacing
            
            # Check boundary collision
            if inv_dir == 1 and grid_right >= width - 15:
                inv_dir = -1
                inv_grid_y += row_spacing
            elif inv_dir == -1 and grid_left <= 15:
                inv_dir = 1
                inv_grid_y += row_spacing
            else:
                inv_grid_x += inv_dir * inv_speed
                
            # Invader shooting (bombs)
            if random.random() < 0.03:
                shooter = random.choice(alive_invaders)
                bx = inv_grid_x + shooter[0] * col_spacing + col_spacing // 2
                by = inv_grid_y + shooter[1] * row_spacing + row_spacing
                bombs.append([bx, by])
                
            # Update bullets (going up)
            next_bullets = []
            for b in bullets:
                b[1] -= 4
                hit = False
                # Collision check with invaders
                for inv in invaders:
                    if inv[2]:
                        ix = inv_grid_x + inv[0] * col_spacing + col_spacing // 2
                        iy = inv_grid_y + inv[1] * row_spacing + row_spacing // 2
                        if abs(b[0] - ix) < inv_col * 0 + 8 and abs(b[1] - iy) < 6:
                            inv[2] = False
                            hit = True
                            score += 30
                            # Spawn explosion particles
                            for _ in range(8):
                                explosions.append([ix, iy, random.uniform(-2, 2), random.uniform(-2, 2), 10])
                            break
                if not hit and b[1] > 28:
                    next_bullets.append(b)
            bullets = next_bullets
            
            # Update bombs (going down)
            next_bombs = []
            for b in bombs:
                b[1] += 3
                # Collision check with player ship
                if abs(b[0] - ship_x) < 10 and abs(b[1] - ship_y) < 6:
                    death_timer = 50 # Start system error state
                    # Large explosion
                    for _ in range(20):
                        explosions.append([ship_x, ship_y, random.uniform(-4, 4), random.uniform(-4, 4), 20])
                    break
                elif b[1] < height:
                    next_bombs.append(b)
            bombs = next_bombs
            
            # Update explosions
            next_explosions = []
            for p in explosions:
                p[0] += p[2]
                p[1] += p[3]
                p[4] -= 1
                if p[4] > 0:
                    next_explosions.append(p)
            explosions = next_explosions
            
            # Check game over by invaders reaching bottom
            max_y = max(inv_grid_y + inv[1] * row_spacing for inv in alive_invaders)
            if max_y >= ship_y - 8:
                death_timer = 50
                for _ in range(20):
                    explosions.append([ship_x, ship_y, random.uniform(-4, 4), random.uniform(-4, 4), 20])
                continue
                
            # Render game objects
            display.clear(0)
            
            # Draw header
            display.text(text if text else "INVADER DRIFT", 10, 10, 1)
            display.text(f"SCORE: {score:05d}", width - 120, 10, 1)
            display.line(0, 26, width, 26, 1)
            
            # Draw invaders
            inv_anim_state = (frame // 10) % 2 == 0
            for inv in invaders:
                if inv[2]:
                    ix = inv_grid_x + inv[0] * col_spacing + col_spacing // 2
                    iy = inv_grid_y + inv[1] * row_spacing + row_spacing // 2
                    draw_invader(display, ix, iy, inv_anim_state)
                    
            # Draw player ship
            draw_ship(display, ship_x, ship_y)
            
            # Draw player bullets
            for b in bullets:
                display.fill_rect(b[0] - 1, b[1] - 3, 2, 6, 1)
                
            # Draw alien bombs
            for b in bombs:
                display.line(b[0], b[1] - 3, b[0], b[1] + 3, 1)
                display.line(b[0] - 1, b[1], b[0] + 1, b[1], 1)
                
            # Draw explosion particles
            for p in explosions:
                display.fill_rect(int(p[0]), int(p[1]), 2, 2, 1)
                
            display.show()
            frame += 1
            sleep_ms(30)
            
    except KeyboardInterrupt:
        print("Screensaver stopped by user interrupt.")

if __name__ in ('__main__', '__name__'):
    run()