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echoes-of-the-ash/api/services/stats.py

279 lines
9.7 KiB
Python

"""
Central stat calculation service.
All derived stats are computed here from base attributes + equipment + buffs.
Results are cached in Redis and invalidated on any change.
"""
import json
from typing import Dict, Any, Optional, List
from .. import database as db
from ..items import items_manager as ITEMS_MANAGER
# ─── Game Config (raise per expansion) ───
STAT_CAP = 50 # Max base stat points per attribute
MAX_LEVEL = 60 # Max character level
POINTS_PER_LEVEL = 1 # Stat points granted per level
async def calculate_derived_stats(character_id: int, redis_mgr=None) -> Dict[str, Any]:
"""
Calculate all derived stats for a character.
Checks Redis cache first; if miss, computes from DB and caches result.
Returns dict with all derived stat values.
"""
# 1. Check Redis cache
if redis_mgr and redis_mgr.redis_client:
try:
cached = await redis_mgr.redis_client.get(f"stats:{character_id}")
if cached:
return json.loads(cached)
except Exception:
pass # Graceful degradation — recalculate if Redis fails
# 2. Fetch data from DB
char = await db.get_player_by_id(character_id)
if not char:
return _empty_stats()
raw_equipment = await db.get_all_equipment(character_id)
enriched_equipment = {}
for slot, item_data in raw_equipment.items():
if not item_data or not item_data.get('item_id'):
continue
inv_item = await db.get_inventory_item_by_id(item_data['item_id'])
if not inv_item:
continue
enriched_item = {
'item_id': inv_item['item_id'], # String ID
'inventory_id': item_data['item_id']
}
unique_item_id = inv_item.get('unique_item_id')
if unique_item_id:
unique_item = await db.get_unique_item(unique_item_id)
if unique_item and unique_item.get('unique_stats'):
enriched_item['unique_stats'] = unique_item['unique_stats']
enriched_equipment[slot] = enriched_item
effects = await db.get_player_effects(character_id)
# 3. Fetch owned perks
owned_perks = await db.get_character_perks(character_id)
owned_perk_ids = [row['perk_id'] for row in owned_perks]
# 4. Compute derived stats
stats = _compute_stats(char, enriched_equipment, effects, owned_perk_ids)
# 5. Cache in Redis (5 min TTL)
if redis_mgr and redis_mgr.redis_client:
try:
await redis_mgr.redis_client.setex(
f"stats:{character_id}", 300, json.dumps(stats)
)
except Exception:
pass
return stats
def _compute_stats(char: Dict[str, Any], equipment: Dict[str, Any], effects: List[Dict], perk_ids: List[str] = None) -> Dict[str, Any]:
"""Pure computation of derived stats from base data."""
strength = char.get('strength', 0)
agility = char.get('agility', 0)
endurance = char.get('endurance', 0)
intellect = char.get('intellect', 0)
level = char.get('level', 1)
if perk_ids is None:
perk_ids = []
# ─── Base derived stats from attributes ───
attack_power = 5 + int(strength * 1.5) + level
crit_chance = 0.05 + (agility * 0.005)
crit_damage = 1.5 + (strength * 0.01)
dodge_chance = min(0.25, 0.02 + (agility * 0.005)) # Cap 25%
flee_chance_base = 0.4 + (agility * 0.01)
max_hp = 30 + (endurance * 5) + (level * 3)
max_stamina = 20 + (endurance * 2) + level
status_resistance = endurance * 0.01
block_chance = 0.0
item_effectiveness = 1.0 + (intellect * 0.02)
xp_bonus = 1.0 + (intellect * 0.01)
loot_quality = 1.0 + (intellect * 0.005)
crafting_bonus = intellect * 0.01
carry_weight = 10.0 + (strength * 0.5)
# ─── Equipment bonuses ───
total_armor = 0
weapon_crit = 0.0
weapon_damage_min = 0
weapon_damage_max = 0
has_shield = False
for slot, item_data in equipment.items():
if not item_data or not item_data.get('item_id'):
continue
item_id_str = item_data.get('item_id', '')
item_def = ITEMS_MANAGER.get_item(item_id_str)
if not item_def:
continue
# Merge base stats and unique stats
merged_stats = {}
if item_def.stats:
merged_stats.update(item_def.stats)
if item_data.get('unique_stats'):
merged_stats.update(item_data['unique_stats'])
if merged_stats:
total_armor += merged_stats.get('armor', 0)
weapon_crit += merged_stats.get('crit_chance', 0)
max_hp += merged_stats.get('max_hp', 0)
max_stamina += merged_stats.get('max_stamina', 0)
carry_weight += merged_stats.get('weight_capacity', 0)
if slot == 'weapon':
weapon_damage_min = merged_stats.get('damage_min', 0)
weapon_damage_max = merged_stats.get('damage_max', 0)
if slot == 'offhand':
has_shield = True
# Apply equipment to derived stats
crit_chance += weapon_crit
armor_reduction = total_armor / (total_armor + 50) if total_armor > 0 else 0.0
if has_shield:
block_chance = strength * 0.003
# ─── Buff effects ───
for effect in effects:
effect_name = effect.get('effect_name', '')
value = effect.get('value', 0)
# Future: apply buff modifiers here
# ─── Perk passive bonuses ───
if 'thick_skin' in perk_ids:
max_hp = int(max_hp * 1.10) # +10% max HP
if 'lucky_strike' in perk_ids:
crit_chance += 0.05 # +5% crit chance
if 'quick_learner' in perk_ids:
xp_bonus *= 1.15 # +15% XP
if 'glass_cannon' in perk_ids:
attack_power = int(attack_power * 1.30) # +30% attack
max_hp = int(max_hp * 0.80) # -20% HP
if 'survivor' in perk_ids:
max_hp = int(max_hp * 1.02) # Small HP boost from regen perk
if 'scavenger' in perk_ids:
loot_quality *= 1.10 # +10% loot quality
if 'fleet_footed' in perk_ids:
# Travel stamina reduction tracked for movement system
pass
stats = {
# Core combat
"attack_power": attack_power,
"crit_chance": round(crit_chance, 4),
"crit_damage": round(crit_damage, 2),
"dodge_chance": round(dodge_chance, 4),
"flee_chance_base": round(flee_chance_base, 2),
# Vitals
"max_hp": max_hp,
"max_stamina": max_stamina,
# Defense
"total_armor": total_armor,
"armor_reduction": round(armor_reduction, 4),
"block_chance": round(block_chance, 4),
"status_resistance": round(status_resistance, 4),
# Utility
"item_effectiveness": round(item_effectiveness, 2),
"xp_bonus": round(xp_bonus, 2),
"loot_quality": round(loot_quality, 3),
"crafting_bonus": round(crafting_bonus, 2),
"carry_weight": round(carry_weight, 1),
# Weapon info
"weapon_damage_min": weapon_damage_min,
"weapon_damage_max": weapon_damage_max,
"has_shield": has_shield,
# Perk flags
"has_last_stand": 'last_stand' in perk_ids,
"has_resilient": 'resilient' in perk_ids,
"has_iron_fist": 'iron_fist' in perk_ids,
"has_heavy_hitter": 'heavy_hitter' in perk_ids,
}
return stats
def _empty_stats() -> Dict[str, Any]:
"""Default stats for error cases."""
return {
"attack_power": 5,
"crit_chance": 0.05,
"crit_damage": 1.5,
"dodge_chance": 0.02,
"flee_chance_base": 0.4,
"max_hp": 30,
"max_stamina": 20,
"total_armor": 0,
"armor_reduction": 0.0,
"block_chance": 0.0,
"status_resistance": 0.0,
"item_effectiveness": 1.0,
"xp_bonus": 1.0,
"loot_quality": 1.0,
"crafting_bonus": 0.0,
"carry_weight": 10.0,
"weapon_damage_min": 0,
"weapon_damage_max": 0,
"has_shield": False,
}
async def invalidate_stats_cache(character_id: int, redis_mgr=None):
"""
Delete cached stats for a character. Call this whenever:
- Equipment changes (equip/unequip/break)
- Stat points allocated
- Level up
- Buff applied/expired
"""
if redis_mgr and redis_mgr.redis_client:
try:
await redis_mgr.redis_client.delete(f"stats:{character_id}")
except Exception:
pass
# Sync derived max_hp and max_stamina to the database characters table
try:
derived = await calculate_derived_stats(character_id, redis_mgr)
char = await db.get_player_by_id(character_id)
if char:
new_max_hp = derived.get('max_hp', char['max_hp'])
new_max_stamina = derived.get('max_stamina', char['max_stamina'])
if new_max_hp != char['max_hp'] or new_max_stamina != char['max_stamina']:
new_hp = min(char['hp'], new_max_hp)
new_stamina = min(char['stamina'], new_max_stamina)
await db.update_player(
character_id,
max_hp=new_max_hp,
max_stamina=new_max_stamina,
hp=new_hp,
stamina=new_stamina
)
except Exception as e:
import logging
logging.getLogger(__name__).warning(f"Failed to sync derived stats to DB for {character_id}: {e}")
def get_flee_chance(flee_chance_base: float, enemy_level: int) -> float:
"""Calculate actual flee chance against a specific enemy."""
return max(0.1, min(0.9, flee_chance_base - (enemy_level * 0.02)))