# --- routers/config.py ---
import re
import json
import os
import database
from fastapi import APIRouter, HTTPException
from pydantic import BaseModel
from typing import List
from netmiko import ConnectHandler
# 🌟 移除了舊的 load_settings, save_settings，改用專屬的雙軌機制
from shared import CMTS_DEVICE, cmts_config_lock, parse_cli_to_tree, deep_split_tree, USE_DB
from collections import defaultdict

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):
    # 使用非同步鎖，確保同一時間只有一個寫入任務執行
    async with cmts_config_lock:
        try:
            device = CMTS_DEVICE.copy()
            device.update({'host': req.host, 'username': req.username, 'password': req.password})
            
            # 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('!')]
            
            net_connect = ConnectHandler(**device)
            # 1. 手動進入設定模式
            net_connect.send_command_timing("config")
            
            # 2. 批次送出設定指令
            output = net_connect.send_config_set(
                commands, 
                read_timeout=60, 
                cmd_verify=False,
                enter_config_mode=False, 
                exit_config_mode=False
            )
            
            # 3. 手動退出設定模式
            net_connect.send_command_timing("exit")
            net_connect.disconnect()

            # 檢查設備回傳的文字中是否包含拒絕或錯誤的關鍵字
            lower_output = output.lower()
            if "aborted" in lower_output or "error" in lower_output or "invalid" in lower_output:
                return {
                    "status": "error", 
                    "message": "CMTS 拒絕了設定 (Commit Aborted)", 
                    "detail": output
                }
            
            return {"status": "success", "data": output}
        except Exception as e:
            raise HTTPException(status_code=500, detail=f"CMTS Config Error: {str(e)}")
        
@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"""
    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))
        net_connect.disconnect()
        
        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)}


@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"""
    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))
        net_connect.disconnect()
        
        base_tree = parse_cli_to_tree(raw_output)
        perfect_tree = 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)}
    

@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"""
    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))
            
        net_connect.disconnect()
        
        clean_output = re.sub(r"^(?:Building configuration\.\.\.|Current configuration.*?)\n+", "", raw_output, flags=re.IGNORECASE | re.MULTILINE)
        clean_output = clean_output.lstrip()

        base_tree = parse_cli_to_tree(clean_output)
        perfect_tree = 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)}
    
# ==========================================
# 🌟 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"}