# --- routers/config.py ---
import re
import json
import os
import database
import asyncio
import asyncssh
from fastapi import APIRouter, HTTPException
from pydantic import BaseModel
from typing import List
from netmiko import ConnectHandler
# 🌟 [Priority 1 修復] 引入 cmts_config_locks
from shared import CMTS_DEVICE, cmts_config_locks, parse_cli_to_tree, deep_split_tree, USE_DB
from collections import defaultdict
from fastapi.responses import StreamingResponse
from logger import get_all_log_levels, set_log_level

router = APIRouter()

# ==========================================
# 🌟 雙軌過濾器檔案讀寫輔助函數 (加入高可用性 Fallback)
# ==========================================
def get_filter_file_path(config_type: str) -> str:
    # 確保檔名安全，只允許 'running' 或 'full'
    safe_type = "full" if config_type == "full" else "running"
    return f"filters_{safe_type}.json"

async def load_tree_filters(config_type: str) -> list:
    if USE_DB:
        try:
            db_filters = await database.get_tree_filters(config_type)
            if db_filters is not None:
                return db_filters
            else:
                print("⚠️ [Fallback] 資料庫無法取得過濾器，自動切換至 JSON 快取讀取...")
        except Exception as e:
            print(f"⚠️ [Fallback] 資料庫讀取過濾器發生例外: {e}，自動切換至 JSON 快取讀取...")

    file_path = get_filter_file_path(config_type)
    if os.path.exists(file_path):
        try:
            with open(file_path, 'r', encoding='utf-8') as f:
                data = json.load(f)
                return data.get("hidden_keys", [])
        except Exception as e:
            print(f"讀取過濾器檔案失敗: {e}")
            return []
    return []

async def save_tree_filters(config_type: str, hidden_keys: list):
    db_success = False
    if USE_DB:
        try:
            if await database.upsert_tree_filters(config_type, hidden_keys):
                db_success = True
            else:
                print("⚠️ [Fallback] 資料庫儲存過濾器失敗，自動切換至 JSON 快取寫入...")
        except Exception as e:
            print(f"⚠️ [Fallback] 資料庫寫入過濾器發生例外: {e}，自動切換至 JSON 快取寫入...")

    if not db_success:
        file_path = get_filter_file_path(config_type)
        try:
            with open(file_path, 'w', encoding='utf-8') as f:
                json.dump({"hidden_keys": hidden_keys}, f, ensure_ascii=False, indent=4)
        except Exception as e:
            print(f"儲存過濾器檔案失敗: {e}")

# ==========================================

class ConfigRequest(BaseModel):
    script: str
    host: str
    username: str
    password: str

# 定義前端傳來的 Diff 資料結構
class DiffItem(BaseModel):
    path: str       # 例如: "cable.ds-rf-port.1:9/0.down-channel.0.frequency"
    old_val: str
    new_val: str

class GenerateCliRequest(BaseModel):
    diffs: List[DiffItem]
    interfaces_with_admin_state: List[str] = []  

@router.post("/cmts-config")
async def execute_cmts_config(req: ConfigRequest):
    # 過濾掉空行與註解 (! 開頭的行)
    commands = [cmd.strip() for cmd in req.script.splitlines() if cmd.strip() and not cmd.strip().startswith('!')]

    async def config_streamer():
        # 🌟 [Priority 1 修復] 使用依 IP 隔離的鎖
        host_lock = cmts_config_locks[req.host]
        async with host_lock:
            try:
                yield json.dumps({"status": "progress", "message": f"🔌 準備連線至設備 {req.host}..."}) + "\n"
                
                # 使用 asyncssh 建立非同步連線
                async with asyncssh.connect(
                    req.host, 
                    username=req.username, 
                    password=req.password, 
                    known_hosts=None
                ) as conn:
                    async with conn.create_process() as process:
                        
                        # 🌟 建立安全的非同步讀取函數 (讀到安靜為止，避免卡死)
                        async def read_until_quiet(timeout=0.5, prompt_pattern: str = None):
                            out_data = ""
                            while True:
                                try:
                                    # 利用 wait_for 設定超時，時間內沒資料就當作設備吐完了
                                    chunk = await asyncio.wait_for(process.stdout.read(4096), timeout=timeout)
                                    if not chunk:
                                        break
                                    out_data += str(chunk)
                                    # 🌟 精準 Prompt 偵測
                                    if prompt_pattern and re.search(prompt_pattern, out_data):
                                        break
                                except asyncio.TimeoutError:
                                    break
                            return out_data

                        # 1. 進入設定模式
                        process.stdin.write("config\n")
                        await process.stdin.drain()
                        await read_until_quiet(0.5, prompt_pattern=r"\(config\)#") # 清空歡迎訊息
                        
                        # 2. 逐行送出指令並回報進度
                        for cmd in commands:
                            yield json.dumps({"status": "progress", "message": f"▶️ 執行: {cmd}"}) + "\n"
                            process.stdin.write(cmd + "\n")
                            await process.stdin.drain()
                            
                            # ⏱️ 智慧等待：如果是 commit 指令，給予 5 秒讓設備存檔；其他指令等 0.5 秒
                            wait_time = 5.0 if cmd.strip() == "commit" else 0.5
                            output = await read_until_quiet(wait_time, prompt_pattern=r"\(config.*\)#")
                            
                            # 🛡️ 防呆撤銷機制：偵測到錯誤立刻 abort
                            lower_output = output.lower()
                            if "% invalid" in lower_output or "% incomplete" in lower_output or "error" in lower_output or "aborted" in lower_output:
                                yield json.dumps({
                                    "status": "error", 
                                    "message": f"❌ 設備拒絕指令: {cmd}", 
                                    "output": output.strip()
                                }) + "\n"
                                
                                process.stdin.write("abort\n")
                                await process.stdin.drain()
                                return # 發生錯誤，提早結束串流
                        
                        # 3. 退出設定模式
                        process.stdin.write("exit\n")
                        await process.stdin.drain()
                        final_output = await read_until_quiet(1.0, prompt_pattern=r"(?:#|>)")
                        
                        yield json.dumps({
                            "status": "success", 
                            "message": "✅ 所有配置已成功寫入並 Commit！",
                            "output": final_output.strip()
                        }) + "\n"

            except Exception as e:
                yield json.dumps({"status": "error", "message": f"SSH 執行發生例外錯誤: {str(e)}"}) + "\n"

    # 回傳 NDJSON 串流格式
    return StreamingResponse(config_streamer(), media_type="application/x-ndjson")
        
@router.post("/cmts-generate-cli")
async def generate_cli(req: GenerateCliRequest):
    """
    將前端的 JSON Diff 轉譯為 Harmonic 單行 CLI 腳本
    並自動處理 admin-state 的安全生命週期 (先 down 後 up)
    """
    interface_groups = defaultdict(list)
    interface_admin_states = {}

    for diff in req.diffs:
        parts = diff.path.split('::')
        
        param_name = parts[-1]
        interface_path = " ".join(parts[:-1]) 
        
        # 全域清除路徑中間可能夾帶的虛擬資料夾索引
        interface_path = re.sub(r"\s*\[\d+\]", "", interface_path)
        
        if param_name == "admin-state":
            interface_admin_states[interface_path] = diff.new_val
        else:
            interface_groups[interface_path].append((param_name, diff.old_val, diff.new_val))

    cli_lines = []
    cli_lines.append("! --- Auto-Generated Configuration Script ---")

    for interface, changes in interface_groups.items():
        cli_lines.append(f"! Configuring: {interface}")
        
        supports_admin_state = interface in req.interfaces_with_admin_state
        
        if supports_admin_state:
            cli_lines.append(f"{interface} admin-state down")
        
        for param, old_val, new_val in changes:
            if re.match(r"^\[\d+\]$", param):
                if new_val == "":
                    if old_val: 
                        cli_lines.append(f"no {interface} {old_val}")
                else:
                    if old_val and old_val != new_val:
                        cli_lines.append(f"no {interface} {old_val}")
                    cli_lines.append(f"{interface} {new_val}")
            else:
                if new_val == "":
                    cli_lines.append(f"no {interface} {param}")
                else:
                    cli_lines.append(f"{interface} {param} {new_val}")
        
        if supports_admin_state:
            final_state = interface_admin_states.get(interface, "up")
            cli_lines.append(f"{interface} admin-state {final_state}")
            
        cli_lines.append("commit") 
        cli_lines.append("!") 

    for interface, state in interface_admin_states.items():
        if interface not in interface_groups:
            cli_lines.append(f"! Configuring state only: {interface}")
            cli_lines.append(f"{interface} admin-state {state}")
            cli_lines.append("commit") 
            cli_lines.append("!")

    final_script = "\n".join(cli_lines)
    return {"status": "success", "data": final_script}

# ==========================================
# DS RF Port 動態樹狀查詢 API
# ==========================================

@router.get("/cmts-ds-rf-port-list")
async def get_ds_rf_port_list(host: str, username: str, password: str = ""):
    """獲取設備上所有的 DS RF Port 清單"""
    net_connect = None
    try:
        device = CMTS_DEVICE.copy()
        device.update({'host': host, 'username': username, 'password': password})
        
        net_connect = ConnectHandler(**device)
        command = 'show running-config | include "cable ds-rf-port"'
        raw_output = str(net_connect.send_command(command, read_timeout=60))
        
        pattern = r"cable ds-rf-port\s+([0-9:/]+)"
        ports = re.findall(pattern, raw_output)
        unique_ports = sorted(list(set(ports)))
        
        return {
            "status": "success", 
            "data": unique_ports,
            "raw_output": raw_output  
        }
    except Exception as e:
        return {"status": "error", "message": str(e)}
    finally:
        if net_connect:
            net_connect.disconnect()


@router.get("/cmts-ds-rf-port-config")
async def get_ds_rf_port_config(target: str, host: str, username: str, password: str = ""):
    """獲取特定 DS RF Port 的配置，並轉換為樹狀 JSON"""
    net_connect = None
    try:
        device = CMTS_DEVICE.copy()
        device.update({'host': host, 'username': username, 'password': password})
        
        net_connect = ConnectHandler(**device)
        command = f"show running-config interface cable ds-rf-port {target} | nomore"
        raw_output = str(net_connect.send_command(command, read_timeout=60))
        
        # 🌟 [Priority 1 修復] 將 CPU-Bound 任務移至 ThreadPool
        base_tree = await asyncio.to_thread(parse_cli_to_tree, raw_output)
        perfect_tree = await asyncio.to_thread(deep_split_tree, base_tree)
        
        return {
            "status": "success", 
            "data": perfect_tree,         
            "raw_cli": raw_output.strip() 
        }
    except Exception as e:
        return {"status": "error", "message": str(e)}
    finally:
        if net_connect:
            net_connect.disconnect()
    

@router.get("/cmts-full-config")
async def get_full_config(host: str, username: str, password: str = "", skip_filter: bool = False, config_type: str = "running"):
    """獲取整台 CMTS 的完整配置，並轉換為大型樹狀 JSON"""
    net_connect = None
    try:
        device = CMTS_DEVICE.copy()
        device.update({'host': host, 'username': username, 'password': password})
        
        net_connect = ConnectHandler(**device)
        
        if config_type == "full":
            net_connect.send_command_timing("config") 
            command = "show full-configuration | nomore"
            raw_output = str(net_connect.send_command(command, read_timeout=180))
            net_connect.send_command_timing("exit")   
        else:
            command = "show running-config | nomore"
            raw_output = str(net_connect.send_command(command, read_timeout=180))
            
        clean_output = re.sub(r"^(?:Building configuration\.\.\.|Current configuration.*?)\n+", "", raw_output, flags=re.IGNORECASE | re.MULTILINE)
        clean_output = clean_output.lstrip()

        # 🌟 [Priority 1 修復] 將 CPU-Bound 任務移至 ThreadPool
        base_tree = await asyncio.to_thread(parse_cli_to_tree, clean_output)
        perfect_tree = await asyncio.to_thread(deep_split_tree, base_tree)

        # ==========================================
        # 🌟 深度過濾攔截器：改用雙軌過濾器讀取邏輯
        # ==========================================
        if not skip_filter:
            hidden_keys = await load_tree_filters(config_type)
            
            for path in hidden_keys:
                keys = path.split('::')
                current = perfect_tree
                # 走到倒數第二層
                for k in keys[:-1]:
                    if isinstance(current, dict) and k in current:
                        current = current[k]
                    else:
                        current = None
                        break
                # 刪除最後一層的目標節點
                if isinstance(current, dict) and keys[-1] in current:
                    current.pop(keys[-1], None)
        # ==========================================
        
        return {"status": "success", "data": perfect_tree}
    except Exception as e:
        return {"status": "error", "message": str(e)}
    finally:
        if net_connect:
            net_connect.disconnect()

@router.get("/cmts-full-config/stream")
async def get_full_config_stream(host: str, username: str, password: str = "", skip_filter: bool = False, config_type: str = "running"):
    """獲取整台 CMTS 的完整配置 (串流進度回報版)"""
    
    async def config_streamer():
        net_connect = None
        try:
            # 1. 廣播：正在連線
            yield json.dumps({"status": "progress", "message": f"🔌 正在建立 SSH 連線至 {host}..."}) + "\n"
            await asyncio.sleep(0.1) # 讓前端有時間渲染
            
            device = CMTS_DEVICE.copy()
            device.update({'host': host, 'username': username, 'password': password})
            
            # 使用 asyncio.to_thread 將阻塞的 netmiko 連線放到背景執行，避免卡住其他非同步任務
            net_connect = await asyncio.to_thread(ConnectHandler, **device)
            
            # 2. 廣播：正在下載
            yield json.dumps({"status": "progress", "message": f"📥 正在下載 {config_type} 配置檔 (可能需要 30~60 秒)..."}) + "\n"
            
            if config_type == "full":
                await asyncio.to_thread(net_connect.send_command_timing, "config") 
                command = "show full-configuration | nomore"
                raw_output = await asyncio.to_thread(net_connect.send_command, command, read_timeout=180)
                await asyncio.to_thread(net_connect.send_command_timing, "exit")   
            else:
                command = "show running-config | nomore"
                raw_output = await asyncio.to_thread(net_connect.send_command, command, read_timeout=180)
                
            # 3. 廣播：正在解析
            yield json.dumps({"status": "progress", "message": "🧩 正在解析配置並建構樹狀圖結構..."}) + "\n"
            await asyncio.sleep(0.1)
            
            clean_output = re.sub(r"^(?:Building configuration\.\.\.|Current configuration.*?)\n+", "", raw_output, flags=re.IGNORECASE | re.MULTILINE)
            clean_output = clean_output.lstrip()

            # 🌟 [Priority 1 修復] 將 CPU-Bound 任務移至 ThreadPool
            base_tree = await asyncio.to_thread(parse_cli_to_tree, clean_output)
            perfect_tree = await asyncio.to_thread(deep_split_tree, base_tree)

            # ==========================================
            # 🌟 深度過濾攔截器 (維持原樣)
            # ==========================================
            if not skip_filter:
                yield json.dumps({"status": "progress", "message": "🔍 正在套用系統過濾器規則..."}) + "\n"
                await asyncio.sleep(0.1)
                
                hidden_keys = await load_tree_filters(config_type)
                
                for path in hidden_keys:
                    keys = path.split('::')
                    current = perfect_tree
                    for k in keys[:-1]:
                        if isinstance(current, dict) and k in current:
                            current = current[k]
                        else:
                            current = None
                            break
                    if isinstance(current, dict) and keys[-1] in current:
                        current.pop(keys[-1], None)
            # ==========================================
            
            # 4. 廣播：完成並傳送最終資料
            yield json.dumps({"status": "success", "data": perfect_tree}) + "\n"
            
        except Exception as e:
            yield json.dumps({"status": "error", "message": f"載入失敗: {str(e)}"}) + "\n"
        finally:
            # 🌟 [Priority 1 修復] 確保背景連線被正確釋放
            if net_connect:
                await asyncio.to_thread(net_connect.disconnect)

    # 回傳 NDJSON 串流格式
    return StreamingResponse(config_streamer(), media_type="application/x-ndjson")
    
# ==========================================
# 🌟 系統設定 API (System Settings)
# ==========================================
class SettingsRequest(BaseModel):
    hidden_keys: list[str]
    config_type: str = "running" # 🌟 加入 config_type 參數

@router.get("/settings/tree-filters")
async def get_tree_filters(config_type: str = "running"):
    """獲取目前的樹狀圖隱藏名單"""
    # 🌟 根據 config_type 讀取對應的 JSON
    hidden_keys = await load_tree_filters(config_type)
    return {"status": "success", "data": hidden_keys}

@router.post("/settings/tree-filters")
async def update_tree_filters(req: SettingsRequest):
    """更新樹狀圖隱藏名單並存檔"""
    # 🌟 根據 config_type 寫入對應的 JSON
    await save_tree_filters(req.config_type, req.hidden_keys)
    return {"status": "success", "message": f"系統設定 ({req.config_type}) 已更新"}

# ==========================================
# 🌟 伺服器日誌管控 API (Server Log Management)
# ==========================================
class LogLevelRequest(BaseModel):
    module: str
    level: str

@router.get("/settings/logs")
async def api_get_log_levels():
    """獲取目前所有模組的日誌等級"""
    return {"status": "success", "data": get_all_log_levels()}

@router.post("/settings/logs")
async def api_set_log_level(req: LogLevelRequest):
    """動態修改特定模組的日誌等級"""
    success = set_log_level(req.module, req.level)
    if success:
        return {"status": "success", "message": f"已將 {req.module} 的日誌等級設為 {req.level}"}
    raise HTTPException(status_code=400, detail="未知的模組名稱")