from fastapi import APIRouter, Depends, HTTPException, Body, Request
from pydantic import BaseModel
import logging

from app.core.auth import verify_api_key
from app.services.chat.api.llm_router import llm_router, circuit_registry
import app.services.chat.api.llm_router as router_module
from app.core.redis_client import redis_client
from app.core.config import settings, BASE_DIR
from app.services.chat.api.model_registry import model_registry
import os
import re
import time

logger = logging.getLogger(__name__)

router = APIRouter(
    prefix="/admin",
    tags=["admin"],
    dependencies=[Depends(verify_api_key)]
)

class BulkheadUpdate(BaseModel):
    limit: int

class CircuitTune(BaseModel):
    failure_threshold: int
    recovery_timeout: int

class ModelBanReq(BaseModel):
    model_name: str

class KillSwitchReq(BaseModel):
    active: bool

class EnvUpdateReq(BaseModel):
    provider: str
    models_string: str

class BudgetUpdateReq(BaseModel):
    daily_token_budget: int


# ─── Permanent Configuration (.env) ───────────────────────────────────────────

def _update_env_file(key: str, new_value: str):
    """Safely updates a key inside the physical .env file. Fails gracefully if Read-Only."""
    env_path = BASE_DIR / ".env"
    
    try:
        if not env_path.exists():
            # Fallback creation if it doesn't exist
            with open(env_path, "w", encoding="utf-8") as f:
                f.write(f"{key}={new_value}\n")
            return

        with open(env_path, "r", encoding="utf-8") as f:
            lines = f.readlines()

        updated = False
        with open(env_path, "w", encoding="utf-8") as f:
            for line in lines:
                if line.startswith(f"{key}="):
                    f.write(f"{key}={new_value}\n")
                    updated = True
                else:
                    f.write(line)
            if not updated:
                # Key wasn't found, append it
                if lines and not lines[-1].endswith("\n"):
                    f.write("\n")
                f.write(f"{key}={new_value}\n")
    except IOError as e:
        logger.warning(f"File system is restricted (e.g. Hugging Face Space). Could not save {key} to disk. Falling back to hot RAM reload only. Error: {e}")
        pass

@router.get("/env")
async def get_env_models():
    """Retrieve current permanent models defined in the core system."""
    return {
        "groq": settings.LLM_MODELS_GROQ,
        "gemini": settings.LLM_MODELS_GEMINI,
        "openai": settings.LLM_MODELS_OPENAI,
        "openrouter": settings.LLM_MODELS_OPENROUTER,
    }

@router.post("/env")
async def update_env_models(payload: EnvUpdateReq):
    """Securely writes default fallback models to physical .env file and hot-reloads."""
    provider = payload.provider.strip().lower()
    mapping = {
        "groq": "LLM_MODELS_GROQ",
        "gemini": "LLM_MODELS_GEMINI",
        "openai": "LLM_MODELS_OPENAI",
        "openrouter": "LLM_MODELS_OPENROUTER",
    }
    
    if provider not in mapping:
        raise HTTPException(status_code=400, detail="Invalid provider ID")
    
    key = mapping[provider]
    
    # Write to physical file securely
    _update_env_file(key, payload.models_string)
    
    # Write to local settings memory so it's instantly available everywhere
    setattr(settings, key, payload.models_string)
    
    # Reload model_registry defaults instantly to trigger Hot-Reload
    model_registry._load_defaults()
    
    return {"status": "success", "msg": f"Updated {key} to {payload.models_string} safely."}

@router.post("/provider/{name}/disable")
async def disable_provider(name: str):
    """Manually force a provider offline unconditionally."""
    state = llm_router.provider_states.get(name)
    if not state:
        raise HTTPException(status_code=404, detail="Provider not found")
    state.is_permanently_disabled = True
    logger.critical(f"Admin action: Provider {name} FORCE DISABLED.")
    return {"status": "success", "provider": name, "disabled": True}

@router.post("/provider/{name}/enable")
async def enable_provider(name: str):
    """Restore a manually disabled provider."""
    state = llm_router.provider_states.get(name)
    if not state:
        raise HTTPException(status_code=404, detail="Provider not found")
    state.is_permanently_disabled = False
    state.disable_until = 0.0
    logger.warning(f"Admin action: Provider {name} ENABLED.")
    return {"status": "success", "provider": name, "disabled": False}

@router.post("/provider/{name}/bulkhead")
async def update_bulkhead(name: str, payload: BulkheadUpdate):
    """Dynamically resize concurrency limit to throttle/boost a provider."""
    ok = llm_router.set_bulkhead_limit(name, payload.limit)
    if not ok:
        raise HTTPException(status_code=404, detail="Provider not found")
    return {"status": "success", "provider": name, "new_limit": payload.limit}


# ─── Circuit Controls ─────────────────────────────────────────────────────────

@router.post("/circuit/{name}/trip")
async def trip_circuit(name: str):
    """Force circuit OPEN (throws it into cooldown natively)."""
    cb = circuit_registry.get(name)
    if not cb:
        raise HTTPException(status_code=404, detail="Circuit not found")
    cb.record_failure(recovery_override=86400) # Open for 24h (admin tripped)
    logger.critical(f"Admin action: Circuit for {name} TRIPPED.")
    return {"status": "success", "provider": name, "circuit_state": cb.state.value}

@router.post("/circuit/{name}/reset")
async def reset_circuit(name: str):
    """Force circuit CLOSED (instant heal)."""
    cb = circuit_registry.get(name)
    if not cb:
        raise HTTPException(status_code=404, detail="Circuit not found")
    cb.record_success()
    state = llm_router.provider_states.get(name)
    if state:
        state.consecutive_failures = 0
        state.cooldown_until = 0.0
    logger.warning(f"Admin action: Circuit for {name} RESET to CLOSED.")
    return {"status": "success", "provider": name, "circuit_state": cb.state.value}


@router.post("/circuit/{name}/tune")
async def tune_circuit(name: str, payload: CircuitTune):
    """Dynamically adjust failure threshold and base recovery timeout."""
    cb = circuit_registry.get(name)
    if not cb:
        raise HTTPException(status_code=404, detail="Circuit not found")
    cb.failure_threshold = max(1, payload.failure_threshold)
    cb._recovery_base = max(1, payload.recovery_timeout)
    cb.recovery_timeout = cb._recovery_base
    logger.warning(f"Admin action: Circuit {name} tuned (thr={cb.failure_threshold}, timeout={cb._recovery_base})")
    return {"status": "success", "provider": name, "tuned": payload.dict()}


# ─── Model & Global Controls ──────────────────────────────────────────────────

@router.post("/model/ban")
async def ban_model(payload: ModelBanReq):
    """Add a model string to the global banlist."""
    router_module.banned_models.add(payload.model_name)
    logger.critical(f"Admin action: Model {payload.model_name} GLOBALLY BANNED.")
    return {"status": "success", "banned_models": list(router_module.banned_models)}

@router.post("/model/unban")
async def unban_model(payload: ModelBanReq):
    """Remove a model string from the global banlist."""
    router_module.banned_models.discard(payload.model_name)
    logger.warning(f"Admin action: Model {payload.model_name} unbanned.")
    return {"status": "success", "banned_models": list(router_module.banned_models)}

@router.post("/system/killswitch")
async def toggle_killswitch(payload: KillSwitchReq, request: Request):
    """Global emergency stop. All LLM calls return 503 instantly."""
    router_module.KILL_SWITCH_ACTIVE = payload.active
    ip = request.headers.get("X-Forwarded-For", getattr(request.client, "host", "unknown"))
    if payload.active:
        logger.critical("🚨 ADMIN ACTION: GLOBAL KILL SWITCH ACTIVATED. System halted.")
    else:
        logger.warning("🟢 ADMIN ACTION: GLOBAL KILL SWITCH DEACTIVATED. System restored.")
    # Fire Telegram alert (non-blocking)
    try:
        import asyncio
        from app.core.alerts import telegram_alerter
        asyncio.create_task(telegram_alerter.send_kill_switch_alert(payload.active, by_ip=ip))
    except Exception:
        pass
    return {"status": "success", "kill_switch_active": payload.active}

@router.post("/system/flush-cache")
async def flush_cache():
    """Nuke all Redis keys (cache & telemetry). Extreme warning."""
    if redis_client.is_connected and redis_client.redis:
        try:
            await redis_client.redis.flushdb()
            logger.critical("Admin action: Redis FLUSHDB executed.")
            return {"status": "success", "msg": "Redis flushed"}
        except Exception as e:
            raise HTTPException(status_code=500, detail=str(e))
    raise HTTPException(status_code=503, detail="Redis offline")

@router.get("/config-state")
async def get_config_state():
    """Retrieve current dynamic config state for Dashboard UI sync."""
    return {
        "kill_switch_active": router_module.KILL_SWITCH_ACTIVE,
        "banned_models": list(router_module.banned_models),
    }


# ─── Intelligence & Observability Endpoints ────────────────────────────────────────────

@router.get("/alert-feed")
async def get_alert_feed():
    """Returns last 20 alerts in reverse chronological order for Dashboard alert feed."""
    from app.core.alerts import get_alert_history
    return {"alerts": get_alert_history()[:20]}


@router.post("/test-alert")
async def send_test_alert(request: Request):
    """Sends a test Telegram alert to verify webhook configuration is working."""
    from app.core.alerts import telegram_alerter
    ok = await telegram_alerter.send_test_ping()
    if ok:
        return {"status": "delivered", "msg": "Test alert sent to Telegram successfully!"}
    else:
        return {
            "status": "not_delivered",
            "msg": "Telegram not configured or delivery failed. Check TELEGRAM_BOT_TOKEN and TELEGRAM_CHAT_ID.",
        }


@router.get("/budget")
async def get_budget():
    """Returns current daily token usage and budget configuration."""
    from app.core.cost_tracker import cost_tracker
    stats = await cost_tracker.get_daily_stats()
    return stats


@router.post("/budget")
async def update_budget(payload: BudgetUpdateReq):
    """Hot-updates the daily token budget limit (takes effect immediately)."""
    if payload.daily_token_budget < 1000:
        raise HTTPException(status_code=400, detail="Budget must be at least 1000 tokens")
    settings.DAILY_TOKEN_BUDGET = payload.daily_token_budget
    _update_env_file("DAILY_TOKEN_BUDGET", str(payload.daily_token_budget))
    logger.warning(f"Admin action: Daily token budget updated to {payload.daily_token_budget:,}")
    return {"status": "success", "daily_token_budget": payload.daily_token_budget}


@router.get("/routing-log")
async def get_routing_log():
    """Returns last 50 LLM routing decisions for Dashboard Intelligence Panel."""
    from app.core.redis_client import redis_client
    if redis_client.is_connected and redis_client.redis:
        try:
            raw = await redis_client.redis.lrange("awn:routing:log", 0, 49)
            import json
            entries = []
            for item in raw:
                try:
                    entries.append(json.loads(item))
                except Exception:
                    pass
            return {"decisions": entries}
        except Exception:
            pass
    return {"decisions": []}