"use client"

import { useState, useEffect } from "react"
import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card"
import { Avatar, AvatarFallback } from "@/components/ui/avatar"
import { Badge } from "@/components/ui/badge"
import { Trophy, Flame, Medal, Crown } from "lucide-react"
import { getApiUrl } from "@/lib/api-config"
import { motion } from "framer-motion"

interface LeaderboardEntry {
    rank: number
    username: string
    xp: number
    level: number
    level_name: string
    streak: number
}

const getRankIcon = (rank: number) => {
    switch (rank) {
        case 1:
            return <Crown className="h-5 w-5 text-yellow-500" />
        case 2:
            return <Medal className="h-5 w-5 text-slate-400" />
        case 3:
            return <Medal className="h-5 w-5 text-amber-600" />
        default:
            return <span className="text-muted-foreground font-mono">#{rank}</span>
    }
}

const getRankBg = (rank: number) => {
    switch (rank) {
        case 1:
            return "bg-gradient-to-r from-yellow-500/20 to-amber-500/10 border-yellow-500/30"
        case 2:
            return "bg-gradient-to-r from-slate-400/20 to-slate-500/10 border-slate-400/30"
        case 3:
            return "bg-gradient-to-r from-amber-600/20 to-amber-700/10 border-amber-600/30"
        default:
            return "bg-muted/30"
    }
}

export function XPLeaderboard() {
    const [leaderboard, setLeaderboard] = useState<LeaderboardEntry[]>([])
    const [loading, setLoading] = useState(true)

    useEffect(() => {
        fetchLeaderboard()
    }, [])

    const fetchLeaderboard = async () => {
        try {
            const res = await fetch(`${getApiUrl()}/gamification/leaderboard?limit=10`)
            if (res.ok) {
                const data = await res.json()
                setLeaderboard(data)
            }
        } catch (err) {
            console.error("Failed to fetch leaderboard", err)
        } finally {
            setLoading(false)
        }
    }

    if (loading) {
        return <div className="text-muted-foreground">Loading leaderboard...</div>
    }

    if (leaderboard.length === 0) {
        return (
            <Card>
                <CardHeader>
                    <CardTitle className="flex items-center gap-2">
                        <Trophy className="h-5 w-5 text-yellow-500" />
                        XP Leaderboard
                    </CardTitle>
                </CardHeader>
                <CardContent>
                    <p className="text-muted-foreground text-center py-4">
                        No rankings yet. Be the first!
                    </p>
                </CardContent>
            </Card>
        )
    }

    return (
        <Card>
            <CardHeader className="bg-gradient-to-r from-yellow-500/10 via-primary/5 to-transparent">
                <CardTitle className="flex items-center gap-2">
                    <Trophy className="h-5 w-5 text-yellow-500" />
                    XP Leaderboard
                </CardTitle>
            </CardHeader>
            <CardContent className="pt-4">
                <div className="space-y-2">
                    {leaderboard.map((entry, index) => (
                        <motion.div
                            key={entry.username}
                            initial={{ opacity: 0, x: -10 }}
                            animate={{ opacity: 1, x: 0 }}
                            transition={{ delay: index * 0.05 }}
                            className={`flex items-center gap-3 p-3 rounded-lg border ${getRankBg(entry.rank)}`}
                        >
                            <div className="w-8 flex justify-center">
                                {getRankIcon(entry.rank)}
                            </div>

                            <Avatar className="h-8 w-8">
                                <AvatarFallback className="bg-primary/10 text-primary">
                                    {entry.username.slice(0, 2).toUpperCase()}
                                </AvatarFallback>
                            </Avatar>

                            <div className="flex-1 min-w-0">
                                <div className="flex items-center gap-2">
                                    <span className="font-medium truncate">{entry.username}</span>
                                    <Badge variant="outline" className="text-xs">
                                        Lv.{entry.level}
                                    </Badge>
                                </div>
                                <p className="text-xs text-muted-foreground">
                                    {entry.level_name}
                                </p>
                            </div>

                            <div className="text-right">
                                <div className="font-bold font-mono text-primary">
                                    {entry.xp.toLocaleString()}
                                </div>
                                <div className="text-xs text-muted-foreground">XP</div>
                            </div>

                            {entry.streak > 0 && (
                                <div className="flex items-center gap-1 text-orange-500">
                                    <Flame className="h-4 w-4" />
                                    <span className="text-sm font-medium">{entry.streak}</span>
                                </div>
                            )}
                        </motion.div>
                    ))}
                </div>
            </CardContent>
        </Card>
    )
}