"""
财务数据缓存管理器
用于管理 2024 FY Financial Metrics 和 Latest 3 Years Financial Metrics 的数据加载和缓存
"""

from datetime import datetime
from typing import Callable, Dict, Any
import threading
import time


class DataTask:
    """数据加载任务"""
    def __init__(self, company: str, data_type: str, loader_func: Callable):
        self.company = company
        self.data_type = data_type
        self.loader_func = loader_func
        self.status = "pending"  # pending, running, completed, error
        self.result = None
        self.error = None
        self.start_time = None
        self.end_time = None
        self.thread = None
        
    def run(self):
        """执行数据加载"""
        self.status = "running"
        self.start_time = datetime.now()
        
        try:
            self.result = self.loader_func()
            self.status = "completed"
        except Exception as e:
            self.status = "error"
            self.error = str(e)
            import traceback
            self.error_trace = traceback.format_exc()
        finally:
            self.end_time = datetime.now()
    
    def get_age_seconds(self):
        """获取任务年龄(秒)"""
        if self.end_time:
            return (datetime.now() - self.end_time).total_seconds()
        elif self.start_time:
            return (datetime.now() - self.start_time).total_seconds()
        return 0


class FinancialDataCacheManager:
    """财务数据缓存管理器"""
    
    def __init__(self, cache_ttl_seconds=1800, max_cache_size=100):
        self.cache_ttl = cache_ttl_seconds
        self.max_cache_size = max_cache_size
        self.tasks: Dict[tuple, DataTask] = {}
        self.lock = threading.Lock()
        self.stats = {
            "cache_hits": 0,
            "cache_misses": 0,
            "background_completions": 0,
            "total_requests": 0
        }
    
    def get_or_load_data(self, company: str, data_type: str, loader_func: Callable) -> Any:
        """获取或加载财务数据 (同步版本,返回最终结果)"""
        with self.lock:
            self.stats["total_requests"] += 1
            key = (company, data_type)
            
            # 清理过期缓存
            self._cleanup_expired_cache()
            
            task = self.tasks.get(key)
            
            # 场景1: 缓存已存在且已完成
            if task:
                if task.status == "completed":
                    if task.get_age_seconds() < self.cache_ttl:
                        self.stats["cache_hits"] += 1
                        print(f"✅ [Data Cache HIT] {company} - {data_type} (age: {task.get_age_seconds():.1f}s)")
                        return task.result
                    else:
                        print(f"⏰ [Data Cache EXPIRED] {company} - {data_type}")
                        del self.tasks[key]
                        task = None
                
                # 场景2: 后台任务正在运行
                elif task.status == "running":
                    self.stats["cache_hits"] += 1
                    print(f"🔄 [Data Cache WAIT] {company} - {data_type} (running for {task.get_age_seconds():.1f}s)")
                    
                    # 等待后台任务完成
                    max_wait = 30
                    waited = 0
                    while task.status == "running" and waited < max_wait:
                        time.sleep(0.5)
                        waited += 0.5
                    
                    if task.status == "completed":
                        self.stats["background_completions"] += 1
                        print(f"✅ [Data Background COMPLETED] {company} - {data_type}")
                        return task.result
                    elif task.status == "error":
                        print(f"❌ [Data Background ERROR] {company} - {data_type}: {task.error}")
                        raise Exception(f"Data loading failed: {task.error}")
                
                # 场景3: 之前失败了,重试
                elif task.status == "error":
                    print(f"🔄 [Data Retry after ERROR] {company} - {data_type}")
                    del self.tasks[key]
                    task = None
            
            # 场景4: 缓存不存在,启动新任务
            if not task:
                self.stats["cache_misses"] += 1
                print(f"🆕 [Data Cache MISS] {company} - {data_type} - Starting background loading")
                
                task = DataTask(company, data_type, loader_func)
                self.tasks[key] = task
                task.thread = threading.Thread(target=task.run, daemon=True)
                task.thread.start()
                
                # 等待任务完成
                max_wait = 30
                waited = 0
                while task.status == "running" and waited < max_wait:
                    time.sleep(0.5)
                    waited += 0.5
                
                if task.status == "completed":
                    print(f"✅ [Data NEW COMPLETED] {company} - {data_type}")
                    return task.result
                elif task.status == "error":
                    print(f"❌ [Data NEW ERROR] {company} - {data_type}: {task.error}")
                    raise Exception(f"Data loading failed: {task.error}")
                else:
                    print(f"⏱️ [Data TIMEOUT] {company} - {data_type}")
                    raise Exception(f"Data loading timeout after {max_wait}s")
    
    def _cleanup_expired_cache(self):
        """清理过期缓存"""
        keys_to_remove = []
        for key, task in self.tasks.items():
            if task.status == "completed" and task.get_age_seconds() > self.cache_ttl:
                keys_to_remove.append(key)
        
        for key in keys_to_remove:
            company, data_type = key
            print(f"🗑️ [Data Cache CLEANUP] {company} - {data_type}")
            del self.tasks[key]
        
        # 限制缓存大小
        if len(self.tasks) > self.max_cache_size:
            completed_tasks = [(k, v) for k, v in self.tasks.items() if v.status == "completed"]
            completed_tasks.sort(key=lambda x: x[1].end_time or datetime.min)
            to_remove = len(self.tasks) - self.max_cache_size
            for i in range(to_remove):
                key, task = completed_tasks[i]
                company, data_type = key
                print(f"🗑️ [Data Cache SIZE LIMIT] {company} - {data_type}")
                del self.tasks[key]
    
    def get_stats(self):
        """获取缓存统计"""
        with self.lock:
            total = self.stats["total_requests"]
            hits = self.stats["cache_hits"]
            misses = self.stats["cache_misses"]
            hit_rate = (hits / total * 100) if total > 0 else 0
            
            return {
                **self.stats,
                "hit_rate": f"{hit_rate:.1f}%",
                "active_tasks": len([t for t in self.tasks.values() if t.status == "running"]),
                "cached_data": len([t for t in self.tasks.values() if t.status == "completed"])
            }