import { Share, ScrollView, View } from "react-native";
import { useTranslation } from "react-i18next";
import { Badge } from "@/components/ui/Badge";
import { Button } from "@/components/ui/Button";
import { Card, InfoRow, Section } from "@/components/ui/Card";
import { AppHeader } from "@/components/ui/Header";
import { Screen } from "@/components/ui/Screen";
import { Text } from "@/components/ui/Text";
import { DEMO_VOUCHER } from "@/lib/commerce";
import { useAuthStore } from "@/lib/stores/authStore";
import { useCartStore } from "@/lib/stores/cartStore";
import { colors, gutter } from "@/lib/theme";
import { router } from "expo-router";
import { routes } from "@/lib/routes";
import { Alert } from "react-native";

const tiers = [
  { id: "bronze", min: 0, perks: "1 pt per 10 ETB · Birthday surprise" },
  { id: "silver", min: 300, perks: "1.25x points · Free delivery over 800 ETB" },
  { id: "gold", min: 1000, perks: "1.5x points · Priority pharmacist consult" },
] as const;

export default function LoyaltyScreen() {
  const { t } = useTranslation();
  const user = useAuthStore((s) => s.user);
  const ledger = useAuthStore((s) => s.ledger);
  const redeemPoints = useAuthStore((s) => s.redeemPoints);
  const setVoucher = useCartStore((s) => s.setVoucher);

  const points = user?.points ?? 0;
  const next = tiers.find((tier) => points < tier.min) ?? null;
  const progress = next
    ? Math.min(1, points / next.min)
    : 1;

  return (
    <Screen>
      <AppHeader title={t("common.loyalty")} subtitle="Earn points on every paid order" />
      <ScrollView contentContainerStyle={{ paddingHorizontal: gutter, paddingBottom: 40, gap: 14 }}>
        <Card tone="brand" elevated={false}>
          <View style={{ flexDirection: "row", justifyContent: "space-between" }}>
            <View>
              <Text variant="caption" color={colors.muted}>
                Available points
              </Text>
              <Text variant="display" style={{ marginTop: 4 }}>
                {points}
              </Text>
            </View>
            <Badge label={(user?.tier ?? "bronze").toUpperCase()} solid />
          </View>
          <View
            style={{
              marginTop: 16,
              height: 8,
              borderRadius: 4,
              backgroundColor: "rgba(16,20,16,0.12)",
              overflow: "hidden",
            }}
          >
            <View
              style={{
                width: `${Math.round(progress * 100)}%`,
                height: "100%",
                backgroundColor: colors.ink,
              }}
            />
          </View>
          <Text variant="caption" color={colors.muted} style={{ marginTop: 8 }}>
            {next
              ? `${next.min - points} pts to ${next.id}`
              : "You've reached Gold — enjoy premium perks"}
          </Text>
        </Card>

        <Section title="How tiers work">
          <Card elevated={false}>
            {tiers.map((tier, i) => (
              <InfoRow
                key={tier.id}
                label={`${tier.id} · ${tier.min}+ pts`}
                value={tier.perks}
                last={i === tiers.length - 1}
              />
            ))}
          </Card>
        </Section>

        <Card elevated={false}>
          <Text variant="h3">Redeem rewards</Text>
          <Text variant="bodySm" color={colors.muted} style={{ marginTop: 6 }}>
            Redeem 100 points for a {DEMO_VOUCHER} voucher (10% off your next order).
          </Text>
          {user?.activeVoucher ? (
            <Badge
              label={`Active voucher: ${user.activeVoucher}`}
              tone="brand"
              style={{ marginTop: 12 }}
            />
          ) : null}
          <Button
            title="Redeem 100 pts"
            style={{ marginTop: 14 }}
            disabled={!user || user.isGuest || points < 100}
            onPress={() => {
              const ok = redeemPoints(100);
              if (!ok) {
                Alert.alert("Not enough points", "You need at least 100 points.");
                return;
              }
              setVoucher(DEMO_VOUCHER);
              Alert.alert(
                "Voucher unlocked",
                `${DEMO_VOUCHER} is ready in your cart / checkout.`,
                [
                  { text: "Go to cart", onPress: () => router.push(routes.cart) },
                  { text: "OK" },
                ]
              );
            }}
          />
        </Card>

        <Card elevated={false}>
          <Text variant="h3">{t("common.referral")}</Text>
          <Text variant="priceLg" style={{ marginTop: 8 }}>
            {user?.referralCode ?? "GISHEN-GUEST"}
          </Text>
          <Text variant="bodySm" color={colors.muted} style={{ marginTop: 6 }}>
            Friends get 50 welcome points. You get 100 when they place their first order.
          </Text>
          <Button
            title="Share code"
            variant="outline"
            icon="share-outline"
            style={{ marginTop: 14 }}
            onPress={() =>
              Share.share({
                message: `Join Gishen Pharmacy with my code ${user?.referralCode ?? ""}. Healthcare delivered to your doorstep.`,
              })
            }
          />
        </Card>

        <Section title="Points history">
          <Card elevated={false}>
            {ledger.length === 0 ? (
              <Text variant="bodySm" color={colors.muted}>
                Points from orders will appear here.
              </Text>
            ) : (
              ledger.map((entry, i) => (
                <InfoRow
                  key={entry.id}
                  label={`${entry.label} · ${new Date(entry.at).toLocaleDateString()}`}
                  value={`${entry.delta > 0 ? "+" : ""}${entry.delta}`}
                  valueColor={entry.delta >= 0 ? colors.brandText : colors.danger}
                  last={i === ledger.length - 1}
                />
              ))
            )}
          </Card>
        </Section>
      </ScrollView>
    </Screen>
  );
}