import React, { useMemo } from 'react';
import { Calendar, UserPlus, UserMinus, Shield, Flag, AlertTriangle } from 'lucide-react';
import { useLeagueRaces } from "@/hooks/league/useLeagueRaces";
import { ActivityFeedItem } from '@/ui/ActivityFeedItem';
import { Icon } from '@/ui/Icon';
import { Text } from '@/ui/Text';
import { Stack } from '@/ui/Stack';
import { processLeagueActivities } from '@/lib/services/league/LeagueActivityService';

export type LeagueActivity =
  | { type: 'race_completed'; raceId: string; raceName: string; timestamp: Date }
  | { type: 'race_scheduled'; raceId: string; raceName: string; timestamp: Date }
  | { type: 'penalty_applied'; penaltyId: string; driverName: string; reason: string; points: number; timestamp: Date }
  | { type: 'member_joined'; driverId: string; driverName: string; timestamp: Date }
  | { type: 'member_left'; driverId: string; driverName: string; timestamp: Date }
  | { type: 'role_changed'; driverId: string; driverName: string; oldRole: string; newRole: string; timestamp: Date };

interface LeagueActivityFeedProps {
  leagueId: string;
  limit?: number;
}

function timeAgo(timestamp: Date): string {
  const diffMs = Date.now() - timestamp.getTime();
  const diffMinutes = Math.floor(diffMs / 60000);
  if (diffMinutes < 1) return 'Just now';
  if (diffMinutes < 60) return `${diffMinutes} min ago`;
  const diffHours = Math.floor(diffMinutes / 60);
  if (diffHours < 24) return `${diffHours}h ago`;
  const diffDays = Math.floor(diffHours / 24);
  if (diffDays === 1) return 'Yesterday';
  if (diffDays < 7) return `${diffDays}d ago`;
  return timestamp.toLocaleDateString('en-US', { month: 'short', day: 'numeric' });
}

export function LeagueActivityFeed({ leagueId, limit = 10 }: LeagueActivityFeedProps) {
  const { data: raceList = [], isLoading } = useLeagueRaces(leagueId);

  const activities = useMemo(() => {
    if (isLoading || raceList.length === 0) return [];
    return processLeagueActivities(raceList, limit);
  }, [raceList, isLoading, limit]);

  if (isLoading) {
    return (
      <Text color="text-gray-400" textAlign="center" block py={8}>
        Loading activities...
      </Text>
    );
  }

  if (activities.length === 0) {
    return (
      <Text color="text-gray-400" textAlign="center" block py={8}>
        No recent activity
      </Text>
    );
  }

  return (
    <Stack gap={0}>
      {activities.map((activity, index) => (
        <ActivityItem key={`${activity.type}-${index}`} activity={activity} />
      ))}
    </Stack>
  );
}

function ActivityItem({ activity }: { activity: LeagueActivity }) {
  const getIcon = () => {
    switch (activity.type) {
      case 'race_completed':
        return <Icon icon={Flag} size={4} color="var(--performance-green)" />;
      case 'race_scheduled':
        return <Icon icon={Calendar} size={4} color="var(--primary-blue)" />;
      case 'penalty_applied':
        return <Icon icon={AlertTriangle} size={4} color="var(--warning-amber)" />;
      case 'member_joined':
        return <Icon icon={UserPlus} size={4} color="var(--performance-green)" />;
      case 'member_left':
        return <Icon icon={UserMinus} size={4} color="var(--text-gray-400)" />;
      case 'role_changed':
        return <Icon icon={Shield} size={4} color="var(--primary-blue)" />;
    }
  };

  const getContent = () => {
    switch (activity.type) {
      case 'race_completed':
        return (
          <>
            <Text weight="medium" color="text-white">Race Completed</Text>
            <Text color="text-gray-400"> · {activity.raceName}</Text>
          </>
        );
      case 'race_scheduled':
        return (
          <>
            <Text weight="medium" color="text-white">Race Scheduled</Text>
            <Text color="text-gray-400"> · {activity.raceName}</Text>
          </>
        );
      case 'penalty_applied':
        return (
          <>
            <Text weight="medium" color="text-white">{activity.driverName}</Text>
            <Text color="text-gray-400"> received a </Text>
            <Text color="text-warning-amber">{activity.points}-point penalty</Text>
            <Text color="text-gray-400"> · {activity.reason}</Text>
          </>
        );
      case 'member_joined':
        return (
          <>
            <Text weight="medium" color="text-white">{activity.driverName}</Text>
            <Text color="text-gray-400"> joined the league</Text>
          </>
        );
      case 'member_left':
        return (
          <>
            <Text weight="medium" color="text-white">{activity.driverName}</Text>
            <Text color="text-gray-400"> left the league</Text>
          </>
        );
      case 'role_changed':
        return (
          <>
            <Text weight="medium" color="text-white">{activity.driverName}</Text>
            <Text color="text-gray-400"> promoted to </Text>
            <Text color="text-primary-blue">{activity.newRole}</Text>
          </>
        );
    }
  };

  return (
    <ActivityFeedItem
      icon={getIcon()}
      content={getContent()}
      timestamp={timeAgo(activity.timestamp)}
    />
  );
}