"""
AI Control Service — Phase 24 C (2026-04-03 ogt)

Telegram /ai 指令動態控制 AI Router 狀態
- Redis 狀態優先於 env var
- OPENCLAW_TG_USER_WHITELIST 白名單保護

Redis Keys:
  ai:control:use_router          "true"/"false" (TTL: 30天)
  ai:control:primary_provider    legacy compatibility; only "ollama"/"ollama_gcp_a"
  ai:control:disabled:<provider> "1" disabled / Gemini "0" enabled
                                  (Gemini 無 TTL；其他 provider 30 天)

Usage:
  /ai status       — 顯示所有 Provider 狀態 + 當前路由模式
  /ai primary <p>  — legacy compatibility; production always starts at GCP-A
  /ai enable <p>   — 啟用特定 Provider
  /ai disable <p>  — 停用特定 Provider
  /ai cost         — 顯示費用統計
  /ai router on    — 啟用 AIRouter (覆蓋 env var)
  /ai router off   — 停用 AIRouter (回滾到舊 fallback chain)
"""

import structlog

logger = structlog.get_logger(__name__)

# Redis Key 常數
_AI_ROUTER_KEY = "ai:control:use_router"
_PRIMARY_PROVIDER_KEY = "ai:control:primary_provider"
_DISABLED_KEY_PREFIX = "ai:control:disabled:"

# Free-provider/router compatibility controls retain the historical 30-day
# expiry. Gemini's explicit paid-provider state is intentionally persistent.
_CONTROL_KEY_TTL = 30 * 24 * 3600  # 30 days

VALID_PROVIDERS = {
    "ollama",
    "ollama_gcp_a",
    "ollama_gcp_b",
    "ollama_local",
    "gemini",
}
VALID_PRIMARY_PROVIDERS = {"ollama", "ollama_gcp_a"}
SHADOW_METADATA_ONLY_PROVIDERS = {
    "claude",
    "nvidia",
    "nemotron",
    "openclaw",
    "openclaw_nemo",
    "ollama_tool",
}


async def _get_redis():
    from src.core.redis_client import get_redis
    return get_redis()


async def get_ai_router_enabled() -> bool | None:
    """
    從 Redis 取得 AIRouter 啟用狀態。
    回傳 None 表示未設定，使用 env var (USE_AI_ROUTER)。
    """
    try:
        r = await _get_redis()
        val = await r.get(_AI_ROUTER_KEY)
        if val is None:
            return None
        return val.decode() == "true" if isinstance(val, bytes) else val == "true"
    except Exception as e:
        logger.warning("ai_control_redis_read_failed", key=_AI_ROUTER_KEY, error=str(e))
        return None


async def set_ai_router_enabled(enabled: bool) -> bool:
    """設定 AIRouter 啟用狀態到 Redis"""
    try:
        r = await _get_redis()
        await r.set(_AI_ROUTER_KEY, "true" if enabled else "false", ex=_CONTROL_KEY_TTL)
        logger.info("ai_control_router_set", enabled=enabled)
        return True
    except Exception as e:
        logger.error("ai_control_router_set_failed", error=str(e))
        return False


async def get_primary_provider() -> str | None:
    """從 Redis 取得主要 Provider，None 表示使用 Router 智慧路由"""
    try:
        r = await _get_redis()
        val = await r.get(_PRIMARY_PROVIDER_KEY)
        if val is None:
            return None
        return val.decode() if isinstance(val, bytes) else val
    except Exception:
        return None


async def set_primary_provider(provider: str) -> bool:
    """Retain only the fixed GCP-A-compatible legacy override."""
    if provider not in VALID_PRIMARY_PROVIDERS:
        return False
    try:
        r = await _get_redis()
        await r.set(_PRIMARY_PROVIDER_KEY, provider, ex=_CONTROL_KEY_TTL)
        logger.info("ai_control_primary_set", provider=provider)
        return True
    except Exception as e:
        logger.error("ai_control_primary_set_failed", error=str(e))
        return False


async def clear_primary_provider() -> bool:
    """清除主要 Provider 設定（回歸智慧路由）"""
    try:
        r = await _get_redis()
        await r.delete(_PRIMARY_PROVIDER_KEY)
        return True
    except Exception:
        return False


async def is_provider_disabled(provider: str) -> bool:
    """檢查 Provider 是否被停用"""
    try:
        r = await _get_redis()
        val = await r.get(f"{_DISABLED_KEY_PREFIX}{provider}")
        # The paid final fallback has no implicit enable state.  A missing
        # durable control key is disabled until an operator explicitly enables
        # it; free Ollama lanes retain their historical missing-key=enabled
        # behaviour.
        if provider == "gemini":
            return val is None or (
                val.decode() if isinstance(val, bytes) else str(val)
            ) != "0"
        return val is not None
    except Exception:
        # Paid-provider disable truth is fail-closed. Callers can catch this to
        # publish an unavailable readback, but must never re-add Gemini.
        if provider == "gemini":
            raise
        return False


async def set_provider_disabled(provider: str, disabled: bool) -> bool:
    """設定 Provider 啟用/停用"""
    if provider not in VALID_PROVIDERS:
        return False
    try:
        r = await _get_redis()
        key = f"{_DISABLED_KEY_PREFIX}{provider}"
        if disabled:
            if provider == "gemini":
                # Paid-provider disable truth must not silently expire.
                await r.set(key, "1")
            else:
                await r.set(key, "1", ex=_CONTROL_KEY_TTL)
        else:
            if provider == "gemini":
                # Explicitly persist the enabled state.  Deleting the key would
                # fail closed to disabled on the next read.
                await r.set(key, "0")
            else:
                await r.delete(key)
        logger.info("ai_control_provider_set", provider=provider, disabled=disabled)
        return True
    except Exception as e:
        logger.error("ai_control_provider_set_failed", error=str(e))
        return False


async def get_status_summary() -> str:
    """
    取得 AI 控制狀態摘要 (Telegram 格式 HTML)
    """
    from src.core.config import get_settings
    settings = get_settings()

    # AIRouter 狀態
    redis_router = await get_ai_router_enabled()
    if redis_router is not None:
        router_status = "✅ ON (Redis 覆蓋)" if redis_router else "❌ OFF (Redis 覆蓋)"
    else:
        router_status = "✅ ON (env)" if settings.USE_AI_ROUTER else "❌ OFF (env)"

    # Primary Provider
    primary = await get_primary_provider()
    primary_str = f"🎯 {primary}" if primary else "🤖 智慧路由 (AIRouter 決定)"

    # Provider 狀態
    provider_lines = []
    for p in ["ollama_gcp_a", "ollama_gcp_b", "ollama_local", "gemini"]:
        try:
            disabled = await is_provider_disabled(p)
        except Exception:
            disabled = True
        icon = "❌" if disabled else "✅"
        provider_lines.append(f"  {icon} {p}")
    provider_lines.extend(
        f"  ⚪ {provider} (shadow metadata only)"
        for provider in sorted(SHADOW_METADATA_ONLY_PROVIDERS)
    )

    # 費用統計
    cost_lines = []
    try:
        r = await _get_redis()
        for p in ["gemini"]:
            val = await r.get(f"ai_rate:total_cost:{p}")
            if val:
                cost = float(val)
                if cost > 0:
                    cost_lines.append(f"  💰 {p}: ${cost:.4f}")
    except Exception:
        cost_lines.append("  (費用統計不可用)")

    providers_str = "\n".join(provider_lines)
    costs_str = "\n".join(cost_lines) if cost_lines else "  (尚無費用記錄)"

    return (
        f"<b>🤖 AI Router 控制面板</b>\n\n"
        f"<b>路由模式</b>: {router_status}\n"
        f"<b>主要 Provider</b>: {primary_str}\n\n"
        f"<b>Provider 狀態</b>:\n{providers_str}\n\n"
        f"<b>費用統計</b>:\n{costs_str}\n\n"
        f"<code>/ai primary &lt;provider&gt;</code> 切換\n"
        f"<code>/ai router on/off</code> 開關 AIRouter\n"
        f"<code>/ai enable/disable &lt;provider&gt;</code> 控制 Provider"
    )


async def handle_ai_command(text: str) -> str:
    """
    處理 /ai 指令，回傳 Telegram HTML 回應。

    Args:
        text: 完整訊息文字 (e.g., "/ai status", "/ai primary gemini")

    Returns:
        HTML 格式回應字串
    """
    parts = text.strip().split()
    if len(parts) < 2:
        return await get_status_summary()

    sub = parts[1].lower()

    if sub == "status":
        return await get_status_summary()

    elif sub == "router":
        if len(parts) < 3:
            return "用法: <code>/ai router on</code> 或 <code>/ai router off</code>"
        action = parts[2].lower()
        if action in ("on", "true", "enable"):
            ok = await set_ai_router_enabled(True)
            return "✅ AIRouter 已啟用 (Redis 覆蓋)" if ok else "❌ 寫入 Redis 失敗"
        elif action in ("off", "false", "disable"):
            ok = await set_ai_router_enabled(False)
            return "⚠️ AIRouter 已停用，回滾舊 fallback chain (Redis 覆蓋)" if ok else "❌ 寫入 Redis 失敗"
        else:
            return f"❌ 未知動作: {action}，請用 on/off"

    elif sub == "primary":
        if len(parts) < 3:
            current = await get_primary_provider()
            if current:
                return f"當前主要 Provider: <b>{current}</b>\n用法: <code>/ai primary &lt;provider&gt;</code> 或 <code>/ai primary auto</code>"
            return "當前: 🤖 智慧路由\n用法: <code>/ai primary &lt;provider&gt;</code>"
        provider = parts[2].lower()
        if provider == "auto":
            ok = await clear_primary_provider()
            return "✅ 已清除主要 Provider，恢復智慧路由" if ok else "❌ 操作失敗"
        if provider not in VALID_PRIMARY_PROVIDERS:
            return (
                f"❌ Provider 不可改寫 production 起點: {provider}\n"
                "production 固定從 ollama_gcp_a 開始"
            )
        ok = await set_primary_provider(provider)
        return f"✅ 主要 Provider 已設為 <b>{provider}</b>" if ok else "❌ 寫入 Redis 失敗"

    elif sub == "enable":
        if len(parts) < 3:
            return "用法: <code>/ai enable &lt;provider&gt;</code>"
        provider = parts[2].lower()
        if provider not in VALID_PROVIDERS:
            return f"❌ 未知 Provider: {provider}"
        ok = await set_provider_disabled(provider, False)
        return f"✅ {provider} 已啟用" if ok else "❌ 操作失敗"

    elif sub == "disable":
        if len(parts) < 3:
            return "用法: <code>/ai disable &lt;provider&gt;</code>"
        provider = parts[2].lower()
        if provider not in VALID_PROVIDERS:
            return f"❌ 未知 Provider: {provider}"
        ok = await set_provider_disabled(provider, True)
        return f"⚠️ {provider} 已停用" if ok else "❌ 操作失敗"

    elif sub == "cost":
        lines = ["<b>💰 AI 費用統計</b>\n"]
        try:
            r = await _get_redis()
            total = 0.0
            for p in ["gemini"]:
                val = await r.get(f"ai_rate:total_cost:{p}")
                if val:
                    cost = float(val)
                    total += cost
                    if cost > 0:
                        lines.append(f"  {p}: ${cost:.4f}")
            if total > 0:
                lines.append(f"\n  <b>總計: ${total:.4f}</b>")
            else:
                lines.append("  (尚無費用記錄)")
        except Exception as e:
            lines.append(f"  ⚠️ 費用查詢失敗: {e}")
        return "\n".join(lines)

    elif sub == "help":
        return (
            "<b>/ai 指令說明</b>\n\n"
            "<code>/ai status</code> — 顯示所有狀態\n"
            "<code>/ai router on/off</code> — 開關 AIRouter\n"
            "<code>/ai primary &lt;p&gt;</code> — 設主要 Provider\n"
            "<code>/ai primary auto</code> — 恢復智慧路由\n"
            "<code>/ai enable &lt;p&gt;</code> — 啟用 Provider\n"
            "<code>/ai disable &lt;p&gt;</code> — 停用 Provider\n"
            "<code>/ai cost</code> — 費用統計\n\n"
            f"可控 Provider: {', '.join(sorted(VALID_PROVIDERS))}\n"
            "Legacy providers 僅保留 shadow metadata，不可執行"
        )

    else:
        return f"❌ 未知子指令: {sub}\n輸入 <code>/ai help</code> 查看說明"