import { useLocalSearchParams } from "expo-router";
import { useMemo, useState } from "react";
import { FlatList, useWindowDimensions, View } from "react-native";
import { useTranslation } from "react-i18next";
import { Chip, ChipRow } from "@/components/ui/Chip";
import { EmptyState } from "@/components/ui/EmptyState";
import { AppHeader } from "@/components/ui/Header";
import { ProductCard, GRID_CARD_GAP } from "@/components/ui/ProductCard";
import { Screen } from "@/components/ui/Screen";
import { SearchField } from "@/components/ui/SearchField";
import { products } from "@/lib/data/products";
import { categories } from "@/lib/routes";
import { gutter } from "@/lib/theme";

export default function ShopScreen() {
  const { t } = useTranslation();
  const params = useLocalSearchParams<{ q?: string; category?: string }>();
  const [q, setQ] = useState(params.q ?? "");
  const [category, setCategory] = useState(params.category ?? "");
  const { width } = useWindowDimensions();
  const cardWidth = (width - gutter * 2 - GRID_CARD_GAP) / 2;

  const data = useMemo(() => {
    return products.filter((p) => {
      const catOk = !category || p.category === category;
      const qOk =
        !q ||
        p.name.toLowerCase().includes(q.toLowerCase()) ||
        p.brand.toLowerCase().includes(q.toLowerCase()) ||
        p.description.toLowerCase().includes(q.toLowerCase());
      return catOk && qOk;
    });
  }, [q, category]);

  return (
    <Screen>
      <AppHeader
        large
        back
        title="Explore products"
        subtitle="Trusted medicines, vitamins and care essentials"
      />
      <View style={{ paddingHorizontal: gutter, marginBottom: 12 }}>
        <SearchField
          value={q}
          onChangeText={setQ}
          onClear={() => setQ("")}
          placeholder={t("common.search")}
        />
      </View>
      <ChipRow gutters={gutter}>
        <Chip
          label="All"
          selected={!category}
          onPress={() => setCategory("")}
        />
        {categories.map((c) => (
          <Chip
            key={c.id}
            label={t(c.labelKey)}
            selected={category === c.id}
            onPress={() => setCategory(c.id)}
            icon={c.icon}
          />
        ))}
      </ChipRow>
      <FlatList
        data={data}
        numColumns={2}
        keyExtractor={(i) => i.id}
        showsVerticalScrollIndicator={false}
        contentContainerStyle={{
          paddingHorizontal: gutter,
          paddingTop: 16,
          paddingBottom: 40,
          gap: GRID_CARD_GAP,
        }}
        columnWrapperStyle={{ gap: GRID_CARD_GAP }}
        ListEmptyComponent={
          <EmptyState
            icon="search-outline"
            title="No matches"
            body="Try another medicine name, brand or category."
            compact
          />
        }
        renderItem={({ item }) => <ProductCard product={item} width={cardWidth} />}
      />
    </Screen>
  );
}