#!/usr/bin/env python3
"""
ProceduralHash: Seed-based generation.
Seed x Biome x Depth = Content. Deterministic. Infinite worlds. O(1).

No dependencies. Pure Python.
"""
import hashlib
import time
import struct

# === THE LATTICE: generation rules ===
BIOMES = {
    "forest":    {"terrain": ["tree", "bush", "mushroom", "grass", "fallen_log", "rock", "stream"],
                  "creatures": ["deer", "rabbit", "wolf", "bear", "sprite", "goblin"],
                  "loot": ["herb", "mushroom", "stick", "stone", "feather", "leather"],
                  "temp": 70, "moisture": 80},
    "desert":    {"terrain": ["sand_dune", "cactus", "rock", "skull", "oasis", "ruins"],
                  "creatures": ["scorpion", "snake", "vulture", "lizard", "genie"],
                  "loot": ["cactus_fruit", "gem", "ancient_coin", "bone", "glass"],
                  "temp": 110, "moisture": 10},
    "tundra":    {"terrain": ["ice", "snow", "rock", "frozen_tree", "cave", "aurora"],
                  "creatures": ["wolf", "bear", "yeti", "mammoth", "ice_sprite"],
                  "loot": ["frost_crystal", "fur", "ice_shard", "mammoth_tusk"],
                  "temp": -20, "moisture": 30},
    "swamp":     {"terrain": ["mud", "cypress", "willow", "fog", "water", "lily_pad"],
                  "creatures": ["frog", "snake", "alligator", "lizard", "witch"],
                  "loot": ["mushroom", "herb", "bone", "witch_craft", "swamp_gas"],
                  "temp": 85, "moisture": 95},
    "mountain":  {"terrain": ["rock", "cliff", "cave", "peak", "snow_cap", "goat_path"],
                  "creatures": ["goat", "eagle", "bear", "griffin", "dragon"],
                  "loot": ["gem", "ore", "dragon_scale", "ancient_relic", "gold_vein"],
                  "temp": 40, "moisture": 50},
    "ocean":     {"terrain": ["water", "wave", "island", "coral", "shipwreck", "whale_bone"],
                  "creatures": ["fish", "shark", "whale", "dolphin", "kraken"],
                  "loot": ["pearl", "coral", "fish", "shipwreck_chest", "treasure_map"],
                  "temp": 65, "moisture": 100},
    "cave":      {"terrain": ["rock", "stalagmite", "crystal", "underground_pool", "lava"],
                  "creatures": ["bat", "spider", "troll", "dragon", "demon"],
                  "loot": ["ore", "crystal", "gem", "ancient_relic", "demon_heart"],
                  "temp": 55, "moisture": 60},
    "plains":    {"terrain": ["grass", "flower", "rock", "stream", "tree_solo", "windmill"],
                  "creatures": ["deer", "horse", "rabbit", "hawk", "merchant"],
                  "loot": ["herb", "grain", "flower", "leather", "feather"],
                  "temp": 75, "moisture": 50}
}

BIOME_ICONS = {
    "forest": "\033[32m", "desert": "\033[93m", "tundra": "\033[96m", "swamp": "\033[33m",
    "mountain": "\033[90m", "ocean": "\033[94m", "cave": "\033[91m", "plains": "\033[92m"
}

def hash_to_int(seed: int, biome: str, depth: int, category: str, index: int) -> int:
    """O(1) deterministic hash. Returns int."""
    h = hashlib.sha256(f"{seed}:{biome}:{depth}:{category}:{index}".encode()).digest()
    return struct.unpack("<I", h[:4])[0]

def pick_from_list(seed: int, biome: str, depth: int, category: str, index: int) -> str:
    """O(1) pick from category list. Deterministic."""
    items = BIOMES[biome][category]
    return items[hash_to_int(seed, biome, depth, category, index) % len(items)]

def generate_chunk(seed: int, biome: str, depth: int = 0) -> dict:
    """O(1) chunk generation. Deterministic."""
    biome_data = BIOMES[biome]
    return {
        "biome": biome,
        "seed": seed,
        "depth": depth,
        "temp": biome_data["temp"] + (hash_to_int(seed, biome, depth, "temp", 0) % 21 - 10),
        "moisture": biome_data["moisture"] + (hash_to_int(seed, biome, depth, "moist", 0) % 21 - 10),
        "terrain": [pick_from_list(seed, biome, depth, "terrain", i) for i in range(6)],
        "creatures": [pick_from_list(seed, biome, depth, "creatures", i) for i in range(3)],
        "loot": [pick_from_list(seed, biome, depth, "loot", i) for i in range(4)]
    }

# === DEMO ===
def demo():
    print("=" * 50)
    print("  ProceduralHash: Seed-based world generation")
    print("=" * 50)
    print()
    print("  Generating chunks for 8 biomes, 3 depths each...")
    print()

    reset = "\033[0m"
    for biome in BIOMES:
        color = BIOME_ICONS[biome]
        print(f"  {color}[{biome.upper()}]{reset}")
        for depth in range(3):
            start = time.perf_counter_ns()
            chunk = generate_chunk(seed=42, biome=biome, depth=depth)
            elapsed = time.perf_counter_ns() - start
            print(f"    depth {depth}: T:{chunk['temp']:3d}deg F  M:{chunk['moisture']:3d}%  "
                  f"terrain:[{','.join(chunk['terrain'][:3])}...]  "
                  f"creatures:[{','.join(chunk['creatures'])}]  [{elapsed}ns]")
        print()

    print("  Determinism check: same seed = same world")
    print()
    c1 = generate_chunk(seed=42, biome="forest", depth=0)
    c2 = generate_chunk(seed=42, biome="forest", depth=0)
    print(f"    Chunk 1 creatures: {c1['creatures']}")
    print(f"    Chunk 2 creatures: {c2['creatures']}")
    print(f"    Match: {c1 == c2}")

    print()
    print("=" * 50)
    print("  8 biomes, infinite seeds, O(1) per chunk. Deterministic.")
    print("=" * 50)

if __name__ == "__main__":
    demo()