'use server';

import { createClient } from '@/lib/supabase/server';

interface TrackApiUsageParams {
    userId: string;
    apiType: 'google_search' | 'gemini_ai';
    endpoint?: string;
    success: boolean;
    errorMessage?: string;
}

interface ApiStats {
    totalCalls: number;
    successfulCalls: number;
    failedCalls: number;
    todayCalls: number;
    googleSearchCalls: number;
    geminiAiCalls: number;
}

interface DailyLimitCheck {
    allowed: boolean;
    remaining: number;
    limit: number;
}

const GOOGLE_SEARCH_DAILY_LIMIT = 80;

/**
 * Track an API usage event
 */
export async function trackApiUsage(params: TrackApiUsageParams): Promise<{ success: boolean; error?: string }> {
    try {
        const supabase = await createClient();

        // Security check: Ensure user is only tracking their own usage
        const { data: { user } } = await supabase.auth.getUser();
        if (!user || user.id !== params.userId) {
            console.error('Unauthorized API tracking attempt');
            return { success: false, error: 'Nicht autorisiert' };
        }

        const { error } = await supabase
            .from('api_usage')
            .insert({
                user_id: params.userId,
                api_type: params.apiType,
                endpoint: params.endpoint,
                success: params.success,
                error_message: params.errorMessage,
            });

        if (error) {
            console.error('Failed to track API usage:', error);
            return { success: false, error: error.message };
        }

        return { success: true };
    } catch (err) {
        console.error('Error tracking API usage:', err);
        return { success: false, error: 'Failed to track API usage' };
    }
}

/**
 * Check if daily limit has been reached for a specific API type
 */
export async function checkDailyLimit(apiType: 'google_search' | 'gemini_ai'): Promise<DailyLimitCheck> {
    try {
        const supabase = await createClient();

        // Only enforce limit for Google Search
        if (apiType !== 'google_search') {
            return { allowed: true, remaining: 999999, limit: 999999 };
        }

        // Get today's date in Europe/Berlin timezone
        const today = new Date();
        const berlinDate = new Date(today.toLocaleString('en-US', { timeZone: 'Europe/Berlin' }));
        const startOfDay = new Date(berlinDate);
        startOfDay.setHours(0, 0, 0, 0);
        const endOfDay = new Date(berlinDate);
        endOfDay.setHours(23, 59, 59, 999);

        const { count, error } = await supabase
            .from('api_usage')
            .select('*', { count: 'exact', head: true })
            .eq('api_type', apiType)
            .gte('created_at', startOfDay.toISOString())
            .lte('created_at', endOfDay.toISOString());

        if (error) {
            console.error('Error checking daily limit:', error);
            // Allow on error to avoid blocking users
            return { allowed: true, remaining: GOOGLE_SEARCH_DAILY_LIMIT, limit: GOOGLE_SEARCH_DAILY_LIMIT };
        }

        const currentCount = count || 0;
        const remaining = Math.max(0, GOOGLE_SEARCH_DAILY_LIMIT - currentCount);
        const allowed = currentCount < GOOGLE_SEARCH_DAILY_LIMIT;

        return { allowed, remaining, limit: GOOGLE_SEARCH_DAILY_LIMIT };
    } catch (err) {
        console.error('Error in checkDailyLimit:', err);
        // Allow on error
        return { allowed: true, remaining: GOOGLE_SEARCH_DAILY_LIMIT, limit: GOOGLE_SEARCH_DAILY_LIMIT };
    }
}

/**
 * Get API usage statistics for a specific user
 */
export async function getUserApiStats(userId: string): Promise<ApiStats | null> {
    try {
        const supabase = await createClient();

        const { data, error } = await supabase
            .from('api_usage')
            .select('*')
            .eq('user_id', userId);

        if (error) {
            console.error('Error fetching user API stats:', error);
            return null;
        }

        const today = new Date();
        const berlinDate = new Date(today.toLocaleString('en-US', { timeZone: 'Europe/Berlin' }));
        const startOfDay = new Date(berlinDate);
        startOfDay.setHours(0, 0, 0, 0);

        const todayData = data.filter(item => new Date(item.created_at) >= startOfDay);

        return {
            totalCalls: data.length,
            successfulCalls: data.filter(item => item.success).length,
            failedCalls: data.filter(item => !item.success).length,
            todayCalls: todayData.length,
            googleSearchCalls: data.filter(item => item.api_type === 'google_search').length,
            geminiAiCalls: data.filter(item => item.api_type === 'gemini_ai').length,
        };
    } catch (err) {
        console.error('Error in getUserApiStats:', err);
        return null;
    }
}

/**
 * Get global API usage statistics (admin only)
 */
export async function getGlobalApiStats(): Promise<ApiStats | null> {
    try {
        const supabase = await createClient();

        // Check if user is admin
        const { data: { user } } = await supabase.auth.getUser();
        if (!user) return null;

        const isAdmin = await checkIsAdmin(user.id);
        if (!isAdmin) return null;

        const { data, error } = await supabase
            .from('api_usage')
            .select('*');

        if (error) {
            console.error('Error fetching global API stats:', error);
            return null;
        }

        const today = new Date();
        const berlinDate = new Date(today.toLocaleString('en-US', { timeZone: 'Europe/Berlin' }));
        const startOfDay = new Date(berlinDate);
        startOfDay.setHours(0, 0, 0, 0);

        const todayData = data.filter(item => new Date(item.created_at) >= startOfDay);

        return {
            totalCalls: data.length,
            successfulCalls: data.filter(item => item.success).length,
            failedCalls: data.filter(item => !item.success).length,
            todayCalls: todayData.length,
            googleSearchCalls: data.filter(item => item.api_type === 'google_search').length,
            geminiAiCalls: data.filter(item => item.api_type === 'gemini_ai').length,
        };
    } catch (err) {
        console.error('Error in getGlobalApiStats:', err);
        return null;
    }
}

/**
 * Check if a user is an admin
 */
export async function checkIsAdmin(userId: string): Promise<boolean> {
    try {
        console.log('[checkIsAdmin] Checking admin status for user:', userId);
        const supabase = await createClient();

        const { data, error } = await supabase
            .from('admin_users')
            .select('role')
            .eq('user_id', userId)
            .single();

        console.log('[checkIsAdmin] Query result - data:', data, 'error:', error);

        if (error) {
            console.log('[checkIsAdmin] Error occurred:', error.message);
            return false;
        }

        const isAdmin = !!data;
        console.log('[checkIsAdmin] Final result:', isAdmin);
        return isAdmin;
    } catch (err) {
        console.error('[checkIsAdmin] Exception:', err);
        return false;
    }
}