import { createClient, SupabaseClient } from '@supabase/supabase-js';

const supabaseUrl = process.env.SUPABASE_URL || '';
const supabaseAnonKey = process.env.SUPABASE_ANON_KEY || '';

let _client: SupabaseClient | null = null;

const getClient = (): SupabaseClient => {
  if (!_client) {
    if (!supabaseUrl || !supabaseAnonKey) {
      throw new Error('Supabase credentials not configured. Add SUPABASE_URL and SUPABASE_ANON_KEY to environment variables.');
    }
    _client = createClient(supabaseUrl, supabaseAnonKey);
  }
  return _client;
};

export interface VendorDailyRow {
  id?: number;
  date: string;
  market: string;
  asin: string;
  product_title: string | null;
  tags: string | null;
  bsr_top_rank: number | null;
  bsr_top_category: string | null;
  bsr_detail_rank: number | null;
  bsr_detail_category: string | null;
  avg_rating: number | null;
  num_reviews: number | null;
  buybox_owner: string | null;
  buybox_price: number | null;
  amazon_has_buybox: boolean | null;
  glance_views: number | null;
}

export interface VendorFilters {
  markets?: string[];
  tags?: string[];
  asins?: string[];
  dateFrom?: string;
  dateTo?: string;
}

export const fetchVendorData = async (filters: VendorFilters): Promise<VendorDailyRow[]> => {
  const allRows: VendorDailyRow[] = [];
  let offset = 0;
  const pageSize = 1000;
  let hasMore = true;

  while (hasMore) {
    let query = getClient()
      .from('vendor_daily_data')
      .select('*')
      .order('date', { ascending: true })
      .range(offset, offset + pageSize - 1);

    if (filters.markets?.length) {
      query = query.in('market', filters.markets);
    }
    if (filters.tags?.length) {
      query = query.in('tags', filters.tags);
    }
    if (filters.asins?.length) {
      query = query.in('asin', filters.asins);
    }
    if (filters.dateFrom) {
      query = query.gte('date', filters.dateFrom);
    }
    if (filters.dateTo) {
      query = query.lte('date', filters.dateTo);
    }

    const { data, error } = await query;
    if (error) throw error;
    if (data) {
      allRows.push(...data);
      hasMore = data.length === pageSize;
      offset += pageSize;
    } else {
      hasMore = false;
    }
  }

  return allRows;
};

export const fetchVendorFilterOptions = async (): Promise<{
  markets: string[];
  tags: string[];
  dateRange: { min: string; max: string } | null;
}> => {
  const client = getClient();

  const { data: marketData } = await client
    .from('vendor_daily_data')
    .select('market');

  const { data: tagData } = await client
    .from('vendor_daily_data')
    .select('tags');

  const { data: dateMin } = await client
    .from('vendor_daily_data')
    .select('date')
    .order('date', { ascending: true })
    .limit(1);

  const { data: dateMax } = await client
    .from('vendor_daily_data')
    .select('date')
    .order('date', { ascending: false })
    .limit(1);

  const markets = [...new Set((marketData || []).map(r => r.market))].sort();
  const tags = [...new Set((tagData || []).map(r => r.tags).filter(Boolean))].sort();

  return {
    markets,
    tags,
    dateRange: dateMin?.[0] && dateMax?.[0]
      ? { min: dateMin[0].date, max: dateMax[0].date }
      : null,
  };
};