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#!/usr/bin/env python3
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"""
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sand.py — Falling sand simulation
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​
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No metaphor. Just physics. Particles fall, pile up, interact.
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Different materials: sand, water, stone, fire.
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"""
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​
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import random
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import time
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import os
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​
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# Grid size
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WIDTH = 60
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HEIGHT = 24
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​
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# Materials
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EMPTY = ' '
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SAND = '░'
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WATER = '~'
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STONE = '█'
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FIRE = '*'
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STEAM = '.'
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​
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# Colors (ANSI)
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COLORS = {
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    EMPTY: '\033[0m',
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    SAND: '\033[93m',    # Yellow
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    WATER: '\033[94m',   # Blue
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    STONE: '\033[90m',   # Gray
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    FIRE: '\033[91m',    # Red
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    STEAM: '\033[97m',   # White
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}
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RESET = '\033[0m'
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​
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class SandWorld:
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    def __init__(self, width, height):
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        self.width = width
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        self.height = height
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        self.grid = [[EMPTY for _ in range(width)] for _ in range(height)]
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        self.frame = 0
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​
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    def get(self, x, y):
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        if 0 <= x < self.width and 0 <= y < self.height:
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            return self.grid[y][x]
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        return STONE  # Walls are implicit stone
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​
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    def set(self, x, y, material):
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        if 0 <= x < self.width and 0 <= y < self.height:
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            self.grid[y][x] = material
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​
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    def update_sand(self, x, y):
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        """Sand falls down, or slides diagonally if blocked"""
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        below = self.get(x, y + 1)
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​
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        # Fall straight down into empty or water
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        if below == EMPTY:
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            self.set(x, y, EMPTY)
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            self.set(x, y + 1, SAND)
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            return True
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        elif below == WATER:
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            # Swap with water (sand sinks)
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            self.set(x, y, WATER)
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            self.set(x, y + 1, SAND)
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            return True
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​
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        # Try to slide diagonally
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        left_below = self.get(x - 1, y + 1)
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        right_below = self.get(x + 1, y + 1)
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​
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        can_left = left_below in [EMPTY, WATER]
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        can_right = right_below in [EMPTY, WATER]
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​
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        if can_left and can_right:
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            # Choose randomly
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            direction = random.choice([-1, 1])
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        elif can_left:
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            direction = -1
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        elif can_right:
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            direction = 1
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        else:
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            return False
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​
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        target = self.get(x + direction, y + 1)
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        if target == WATER:
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            self.set(x, y, WATER)
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        else:
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            self.set(x, y, EMPTY)
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        self.set(x + direction, y + 1, SAND)
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        return True
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​
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    def update_water(self, x, y):
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        """Water falls down, or spreads sideways"""
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        below = self.get(x, y + 1)
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​
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        # Fall straight down
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        if below == EMPTY:
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            self.set(x, y, EMPTY)
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            self.set(x, y + 1, WATER)
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            return True
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​
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        # Try to spread sideways
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        left = self.get(x - 1, y)
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        right = self.get(x + 1, y)
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​
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        can_left = left == EMPTY
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        can_right = right == EMPTY
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​
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        if can_left and can_right:
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            direction = random.choice([-1, 1])
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        elif can_left:
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            direction = -1
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        elif can_right:
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            direction = 1
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        else:
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            return False
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​
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        self.set(x, y, EMPTY)
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        self.set(x + direction, y, WATER)
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        return True
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​
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    def update_fire(self, x, y):
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        """Fire rises, creates steam when touching water, dies randomly"""
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        # Random chance to die
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        if random.random() < 0.1:
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            self.set(x, y, EMPTY)
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            return True
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​
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        # Check for adjacent water — create steam
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        for dx, dy in [(0, -1), (0, 1), (-1, 0), (1, 0)]:
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            if self.get(x + dx, y + dy) == WATER:
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                self.set(x + dx, y + dy, STEAM)
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​
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        # Rise up
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        above = self.get(x, y - 1)
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        if above == EMPTY:
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            if random.random() < 0.7:  # Usually rises
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                self.set(x, y, EMPTY)
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                self.set(x, y - 1, FIRE)
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                return True
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​
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        # Spread sideways sometimes
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        if random.random() < 0.3:
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            direction = random.choice([-1, 1])
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            if self.get(x + direction, y) == EMPTY:
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                self.set(x, y, EMPTY)
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                self.set(x + direction, y, FIRE)
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                return True
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​
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        return False
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​
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    def update_steam(self, x, y):
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        """Steam rises and dissipates"""
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        if random.random() < 0.15:
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            self.set(x, y, EMPTY)
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            return True
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​
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        above = self.get(x, y - 1)
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        if above == EMPTY:
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            self.set(x, y, EMPTY)
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            self.set(x, y - 1, STEAM)
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            return True
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​
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        # Drift sideways
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        direction = random.choice([-1, 1])
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        if self.get(x + direction, y - 1) == EMPTY:
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            self.set(x, y, EMPTY)
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            self.set(x + direction, y - 1, STEAM)
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            return True
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​
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        return False
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​
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    def update(self):
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        """Update all particles (bottom to top, randomized horizontal)"""
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        self.frame += 1
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​
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        # Process bottom to top so falling works correctly
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        for y in range(self.height - 1, -1, -1):
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            # Randomize horizontal order to prevent bias
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            xs = list(range(self.width))
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            random.shuffle(xs)
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​
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            for x in xs:
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                cell = self.grid[y][x]
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                if cell == SAND:
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                    self.update_sand(x, y)
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                elif cell == WATER:
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                    self.update_water(x, y)
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                elif cell == FIRE:
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                    self.update_fire(x, y)
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                elif cell == STEAM:
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                    self.update_steam(x, y)
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​
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    def spawn_material(self, material, count=1, x=None):
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        """Spawn material at the top"""
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        for _ in range(count):
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            if x is None:
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                spawn_x = random.randint(5, self.width - 6)
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            else:
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                spawn_x = x + random.randint(-2, 2)
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​
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            if self.get(spawn_x, 0) == EMPTY:
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                self.set(spawn_x, 0, material)
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​
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    def add_floor(self):
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        """Add a stone floor"""
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        for x in range(self.width):
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            self.set(x, self.height - 1, STONE)
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​
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    def add_obstacle(self, x, y, width, height):
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        """Add a stone obstacle"""
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        for dy in range(height):
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            for dx in range(width):
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                self.set(x + dx, y + dy, STONE)
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​
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    def render(self):
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        """Render the grid with colors"""
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        lines = []
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        lines.append('┌' + '─' * self.width + '┐')
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​
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        for row in self.grid:
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            line = '│'
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            for cell in row:
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                line += COLORS.get(cell, '') + cell + RESET
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            line += '│'
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            lines.append(line)
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​
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        lines.append('└' + '─' * self.width + '┘')
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        lines.append(f'  Frame: {self.frame}  │  Sand: {COLORS[SAND]}░{RESET}  Water: {COLORS[WATER]}~{RESET}  Fire: {COLORS[FIRE]}*{RESET}  Steam: {COLORS[STEAM]}.{RESET}')
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​
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        return '\n'.join(lines)
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​
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    def count_materials(self):
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        """Count each material type"""
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        counts = {SAND: 0, WATER: 0, STONE: 0, FIRE: 0, STEAM: 0}
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        for row in self.grid:
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            for cell in row:
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                if cell in counts:
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                    counts[cell] += 1
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        return counts
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​
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​
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def main():
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    world = SandWorld(WIDTH, HEIGHT)
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​
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    # Add floor and some obstacles
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    world.add_floor()
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    world.add_obstacle(15, 15, 8, 2)  # Platform left
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    world.add_obstacle(37, 15, 8, 2)  # Platform right
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    world.add_obstacle(26, 10, 8, 2)  # Platform center high
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​
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    # Spawn pattern
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    spawn_cycle = 0
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​
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    print('\033[2J')  # Clear screen
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​
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    for frame in range(200):
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        # Clear and render
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        print('\033[H')  # Move cursor to top
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        print(world.render())
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​
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        # Spawn materials in patterns
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        spawn_cycle = frame % 60
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​
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        if spawn_cycle < 20:
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            # Sand from left
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            world.spawn_material(SAND, 2, x=10)
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        elif spawn_cycle < 40:
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            # Water from right
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            world.spawn_material(WATER, 2, x=50)
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        else:
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            # Fire from center
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            if frame % 3 == 0:
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                world.spawn_material(FIRE, 1, x=30)
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​
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        # Update physics
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        world.update()
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​
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        time.sleep(0.05)
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​
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    # Final stats
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    counts = world.count_materials()
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    print(f"\n  Final state: Sand={counts[SAND]} Water={counts[WATER]} Steam={counts[STEAM]}")
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    print("\n  Just physics. No metaphor needed.\n")
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​
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​
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if __name__ == '__main__':
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    main()
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​