import { useEffect, useState } from "react";
import { View, Text, ScrollView } from "react-native";
import { useTranslation } from "react-i18next";
import { getWeeklyStats, getTotalStats, getPersonalBests } from "@db/operations";
import { formatDistance } from "@utils/formatDistance";
import { formatTime } from "@utils/formatTime";

type WeeklyStats = {
  count: number;
  totalDistance: number;
  totalDuration: number;
  avgCalories: number;
};

type TotalStats = {
  totalWorkouts: number;
  totalDistance: number;
  totalDuration: number;
};

type PersonalBest = {
  distance: number;
  bestTime: number;
  bestSwolf: number | null;
};

export function StatsScreen() {
  const { t } = useTranslation("history");
  const { t: tc } = useTranslation("common");
  const [weekly, setWeekly] = useState<WeeklyStats | null>(null);
  const [total, setTotal] = useState<TotalStats | null>(null);
  const [bests, setBests] = useState<PersonalBest[]>([]);

  useEffect(() => {
    loadStats();
  }, []);

  const loadStats = async () => {
    const [w, t, b] = await Promise.all([
      getWeeklyStats(),
      getTotalStats(),
      getPersonalBests(),
    ]);
    setWeekly(w as WeeklyStats);
    setTotal(t as TotalStats);
    setBests(b as PersonalBest[]);
  };

  return (
    <ScrollView className="flex-1 bg-white p-4">
      <Text className="text-2xl font-bold text-slate-900 mb-6">{t("statistics")}</Text>

      <Text className="text-xs font-semibold text-slate-500 uppercase tracking-wide mb-2">
        {t("thisWeek")}
      </Text>
      <View className="bg-sky-50 rounded-2xl p-4 mb-6">
        {weekly ? (
          <View className="flex-row justify-between">
            <View className="items-center flex-1">
              <Text className="text-2xl font-bold text-sky-600">{weekly.count}</Text>
              <Text className="text-xs text-slate-500">{tc("workouts")}</Text>
            </View>
            <View className="items-center flex-1">
              <Text className="text-2xl font-bold text-sky-600">
                {formatDistance(weekly.totalDistance)}
              </Text>
              <Text className="text-xs text-slate-500">{tc("distance")}</Text>
            </View>
            <View className="items-center flex-1">
              <Text className="text-2xl font-bold text-sky-600">
                {formatTime(weekly.totalDuration)}
              </Text>
              <Text className="text-xs text-slate-500">{tc("duration")}</Text>
            </View>
          </View>
        ) : (
          <Text className="text-slate-400 text-center py-4">{t("noDataYet")}</Text>
        )}
      </View>

      <Text className="text-xs font-semibold text-slate-500 uppercase tracking-wide mb-2">
        {t("allTime")}
      </Text>
      <View className="bg-slate-50 rounded-2xl p-4 mb-6">
        {total ? (
          <View className="flex-row justify-between">
            <View className="items-center flex-1">
              <Text className="text-2xl font-bold text-slate-700">{total.totalWorkouts}</Text>
              <Text className="text-xs text-slate-500">{tc("workouts")}</Text>
            </View>
            <View className="items-center flex-1">
              <Text className="text-2xl font-bold text-slate-700">
                {formatDistance(total.totalDistance)}
              </Text>
              <Text className="text-xs text-slate-500">{tc("distance")}</Text>
            </View>
            <View className="items-center flex-1">
              <Text className="text-2xl font-bold text-slate-700">
                {formatTime(total.totalDuration)}
              </Text>
              <Text className="text-xs text-slate-500">{tc("duration")}</Text>
            </View>
          </View>
        ) : (
          <Text className="text-slate-400 text-center py-4">{t("noDataYet")}</Text>
        )}
      </View>

      {bests.length > 0 && (
        <>
          <Text className="text-xs font-semibold text-slate-500 uppercase tracking-wide mb-2">
            {t("personalBests")}
          </Text>
          {bests.map((best) => (
            <View
              key={best.distance}
              className="bg-green-50 rounded-2xl p-4 mb-2 flex-row justify-between items-center"
            >
              <Text className="text-green-700 font-medium">{tc("meter", { count: best.distance })}</Text>
              <View className="items-end">
                <Text className="text-green-800 font-bold">{formatTime(best.bestTime)}</Text>
                {best.bestSwolf && (
                  <Text className="text-green-600 text-xs">{t("swolf", { value: best.bestSwolf })}</Text>
                )}
              </View>
            </View>
          ))}
        </>
      )}
    </ScrollView>
  );
}