import React, { useState } from "react";
import {
  View,
  TextInput,
  ActivityIndicator,
  KeyboardAvoidingView,
  Platform,
  Pressable,
  useColorScheme,
} from "react-native";
import { useSirouRouter } from "@sirou/react-native";
import { AppRoutes } from "@/lib/routes";
import { Text } from "@/components/ui/text";
import { Button } from "@/components/ui/button";
import { ScreenWrapper } from "@/components/ScreenWrapper";
import { StandardHeader } from "@/components/StandardHeader";
import { useAuthStore } from "@/lib/auth-store";
import { api } from "@/lib/api";
import { toast } from "@/lib/toast-store";
import { getPlaceholderColor } from "@/lib/colors";
import { Search, ChevronDown } from "@/lib/icons";
import { PickerModal, SelectOption } from "@/components/PickerModal";

const providers = [
  { label: "Telebirr", value: "telebirr", needsAccount: false },
  { label: "Dashen", value: "dashen", needsAccount: false },
  { label: "CBE", value: "cbe", needsAccount: true },
  { label: "Abyssinia", value: "abyssinia", needsAccount: true },
  { label: "Other", value: "other", needsAccount: false },
];

function getSuffix(provider: string, accountNumber: string): string {
  const clean = accountNumber.replace(/\s+/g, "");
  switch (provider) {
    case "cbe":
      return clean.slice(-8);
    case "abyssinia":
      return clean.slice(-5);
    default:
      return "";
  }
}

export default function VerifyPaymentScreen() {
  const nav = useSirouRouter<AppRoutes>();
  const user = useAuthStore((s) => s.user);
  const colorScheme = useColorScheme();
  const isDark = colorScheme === "dark";
  const [reference, setReference] = useState("");
  const [accountNumber, setAccountNumber] = useState("");
  const [provider, setProvider] = useState("telebirr");
  const [loading, setLoading] = useState(false);
  const [showProvider, setShowProvider] = useState(false);

  const selectedProvider = providers.find((p) => p.value === provider);
  const needsAccount = selectedProvider?.needsAccount ?? false;

  const handleVerify = async () => {
    const trimmed = reference.trim();
    if (!trimmed) {
      toast.error("Required", "Please enter the transaction reference number");
      return;
    }

    if (needsAccount && !accountNumber.trim()) {
      toast.error("Required", "Please enter the account number");
      return;
    }

    setLoading(true);
    try {
      const response = await api.scan.verifyPaymentReference({
        body: {
          reference: trimmed,
          phoneNumber: user?.phone || "",
          suffix: getSuffix(provider, accountNumber),
        },
      });

      if (!response.success) {
        toast.error(
          "Verification Failed",
          response.message || "Could not verify payment",
        );
        return;
      }

      const refVerification = response.verifierApi?.referenceVerification;
      if (!refVerification) {
        toast.error(
          "No Data",
          response.message || "No verification data returned",
        );
        return;
      }

      if (refVerification.ok && refVerification.data?.data) {
        nav.go("verify-payment-result", {
          data: JSON.stringify(refVerification.data.data),
        });
        setReference("");
        setAccountNumber("");
      } else {
        const msg =
          refVerification.skippedReason ||
          refVerification.data?.error ||
          "No data available";
        toast.warning("Verification Skipped", msg);
      }
    } catch (err: any) {
      toast.error(
        "Verification Failed",
        err.message || "Could not verify payment reference",
      );
    } finally {
      setLoading(false);
    }
  };

  return (
    <ScreenWrapper className="bg-background">
      <KeyboardAvoidingView
        behavior={Platform.OS === "ios" ? "padding" : "height"}
        className="flex-1"
      >
        <StandardHeader title="Verify Payment" showBack />

        <View className="flex-1 px-[16px] pt-8">
          <View className="items-center mb-8">
            <Text
              variant="h3"
              className="text-foreground font-sans-bold text-center"
            >
              Verify Payment Reference
            </Text>
            <Text variant="muted" className="mt-2 text-center">
              Enter the transaction / FT number to verify the payment
            </Text>
          </View>

          <View className="gap-5">
            <View className="gap-2">
              <Text variant="small" className="font-sans-semibold ml-1">
                Provider
              </Text>
              <Pressable
                onPress={() => setShowProvider(true)}
                className="flex-row items-center rounded-[6px] px-4 border border-border h-10 bg-card"
              >
                <Text className="flex-1 text-foreground text-sm font-sans-medium capitalize">
                  {provider}
                </Text>
                <ChevronDown
                  size={16}
                  color={isDark ? "#94a3b8" : "#64748b"}
                  strokeWidth={2.5}
                />
              </Pressable>
            </View>

            <View className="gap-2">
              <Text variant="small" className="font-sans-semibold ml-1">
                Transaction Reference
              </Text>
              <View className="flex-row items-center rounded-[6px] px-4 border border-border h-10">
                <Search size={18} color={isDark ? "#94a3b8" : "#64748b"} />
                <TextInput
                  className="flex-1 ml-3 text-foreground py-0 text-sm"
                  placeholder="e.g. DECSETAA017743744407991639"
                  placeholderTextColor={getPlaceholderColor(isDark)}
                  value={reference}
                  onChangeText={setReference}
                  autoCapitalize="characters"
                  autoCorrect={false}
                />
              </View>
            </View>

            {needsAccount && (
              <View className="gap-2">
                <Text variant="small" className="font-sans-semibold ml-1">
                  Account Number
                </Text>
                <View className="flex-row items-center rounded-[6px] px-4 border border-border h-10">
                  <TextInput
                    className="flex-1 text-foreground py-0 text-sm"
                    placeholder={
                      provider === "cbe"
                        ? "Last 8 digits of account"
                        : "Last 5 digits of account"
                    }
                    placeholderTextColor={getPlaceholderColor(isDark)}
                    value={accountNumber}
                    onChangeText={setAccountNumber}
                    keyboardType="numeric"
                    maxLength={provider === "cbe" ? 8 : 5}
                  />
                </View>
              </View>
            )}
          </View>

          <Button
            className="h-12 bg-primary rounded-[10px] shadow-lg shadow-primary/30 mt-8"
            onPress={handleVerify}
            disabled={loading}
          >
            {loading ? (
              <ActivityIndicator color="white" />
            ) : (
              <Text className="text-white font-sans-bold text-base">
                Verify Payment
              </Text>
            )}
          </Button>

          {/* {needsAccount && accountNumber.length > 0 && (
            <View className="mt-4 items-center">
              <Text variant="muted" className="text-xs">
                Suffix:{" "}
                <Text className="text-primary font-sans-bold">
                  {getSuffix(provider, accountNumber)}
                </Text>
              </Text>
            </View>
          )} */}
        </View>
      </KeyboardAvoidingView>

      <PickerModal
        visible={showProvider}
        onClose={() => setShowProvider(false)}
        title="Select Provider"
      >
        {providers.map((p) => (
          <SelectOption
            key={p.value}
            label={p.label}
            value={p.value}
            selected={provider === p.value}
            onSelect={(v) => {
              setProvider(v);
              setAccountNumber("");
              setShowProvider(false);
            }}
          />
        ))}
      </PickerModal>
    </ScreenWrapper>
  );
}