"use client"

import { useEffect, useState } from "react"
import { Card, CardContent } from "@/components/ui/card"
import { RefreshCw, TrendingUp, MapPin, Star } from "lucide-react"
import { useActiveUser } from "@/hooks/useActiveUser"

const MOCK_COLLEGES: Record<string, Array<{ rank: number; name: string; branch: string; match: number; location: string; type: string; starred?: boolean }>> = {
  Reach: [
    { rank: 1, name: "IIT Bombay", branch: "Computer Science", match: 48, location: "Mumbai", type: "IIT", starred: true },
    { rank: 2, name: "IIT Delhi", branch: "Electrical Engineering", match: 52, location: "Delhi", type: "IIT" },
    { rank: 3, name: "IIT Madras", branch: "Mech. Engineering", match: 55, location: "Chennai", type: "IIT" },
    { rank: 4, name: "IIT Roorkee", branch: "Computer Science", match: 60, location: "Roorkee", type: "IIT", starred: true },
    { rank: 5, name: "IIT Kharagpur", branch: "Aerospace Engg.", match: 63, location: "Kharagpur", type: "IIT" },
  ],
  Target: [
    { rank: 1, name: "NIT Trichy", branch: "Computer Science", match: 85, location: "Trichy", type: "NIT", starred: true },
    { rank: 2, name: "NIT Surathkal", branch: "Information Tech.", match: 78, location: "Surathkal", type: "NIT" },
    { rank: 3, name: "NIT Warangal", branch: "Electronics & Comm.", match: 74, location: "Warangal", type: "NIT" },
    { rank: 4, name: "BITS Pilani", branch: "Computer Science", match: 70, location: "Pilani", type: "BITS", starred: true },
    { rank: 5, name: "NIT Calicut", branch: "Computer Science", match: 68, location: "Calicut", type: "NIT" },
  ],
  Safety: [
    { rank: 1, name: "IIIT Hyderabad", branch: "Computer Science", match: 94, location: "Hyderabad", type: "IIIT", starred: true },
    { rank: 2, name: "IIIT Allahabad", branch: "Information Tech.", match: 91, location: "Allahabad", type: "IIIT" },
    { rank: 3, name: "DTU Delhi", branch: "Software Engineering", match: 89, location: "Delhi", type: "State" },
    { rank: 4, name: "NSIT Delhi", branch: "Computer Engineering", match: 87, location: "Delhi", type: "State" },
    { rank: 5, name: "NIT Jamshedpur", branch: "Mech. Engineering", match: 84, location: "Jamshedpur", type: "NIT" },
  ],
}

const MATCH_COLOR = (match: number) => {
  if (match >= 80) return "text-green-500 bg-green-500/10"
  if (match >= 60) return "text-amber-500 bg-amber-500/10"
  return "text-red-400 bg-red-400/10"
}

export function CollegePredictorCard() {
  const [loading, setLoading] = useState(true)
  const [activeTab, setActiveTab] = useState("Target")
  const { userId, loading: userLoading } = useActiveUser()

  useEffect(() => {
    if (userLoading || !userId) return
    async function fetchData() {
      try {
        const res = await fetch(`/api/ai-coach/readiness/${userId}`)
        if (!res.ok) throw new Error("fallback")
      } catch {
        // Use mock data — no-op
      } finally {
        setLoading(false)
      }
    }
    fetchData()
  }, [userId, userLoading])

  if (loading) {
    return (
      <Card className="border-border shadow-sm h-full flex items-center justify-center min-h-[150px]">
        <RefreshCw className="animate-spin text-muted-foreground" />
      </Card>
    )
  }

  const colleges = MOCK_COLLEGES[activeTab] || []

  const TAB_COLORS: Record<string, string> = {
    Reach: "bg-purple-500/10 border-purple-500/20 text-purple-400",
    Target: "bg-[#00F0FF]/10 border-[#00F0FF]/20 text-[#00F0FF]",
    Safety: "bg-green-500/10 border-green-500/20 text-green-400",
  }

  const INACTIVE = "bg-white/5 border-transparent text-muted-foreground hover:bg-white/10"

  return (
    <Card className="border-border bg-card shadow-[0_4px_24px_rgba(0,0,0,0.3)] overflow-hidden group hover:border-[#00F0FF]/30 transition-colors">
      <CardContent className="p-5 flex flex-col gap-4">
        {/* Tabs */}
        <div className="flex gap-1.5">
          {["Reach", "Target", "Safety"].map((tab) => (
            <button
              key={tab}
              onClick={() => setActiveTab(tab)}
              className={`flex-1 py-2 text-xs font-bold rounded-lg border transition-all ${activeTab === tab ? TAB_COLORS[tab] : INACTIVE}`}
            >
              {tab}
            </button>
          ))}
        </div>

        {/* Tab description */}
        <div className="text-xs text-muted-foreground font-medium px-0.5">
          {activeTab === "Reach" && "Colleges where your current score gives you a ~50–65% admission probability. Requires improvement."}
          {activeTab === "Target" && "Colleges within strong reach. Your current trajectory suggests 68–90% match probability."}
          {activeTab === "Safety" && "Colleges highly likely with your current score. Aim to convert all safety options."}
        </div>

        {/* College List */}
        <div className="flex flex-col gap-2">
          {colleges.map((col) => (
            <div key={col.name} className="flex items-center gap-3 p-3 rounded-xl bg-white/5 border border-border hover:bg-white/10 transition-colors group/item">
              <div className={`w-8 h-8 rounded-full flex items-center justify-center text-xs font-black shrink-0 ${activeTab === "Reach" ? "bg-purple-500/10 text-purple-400" : activeTab === "Target" ? "bg-[#00F0FF]/10 text-[#00F0FF]" : "bg-green-500/10 text-green-400"}`}>
                #{col.rank}
              </div>
              <div className="flex-1 min-w-0">
                <div className="flex items-center gap-1.5">
                  <span className="text-sm font-black text-primary truncate">{col.name}</span>
                  {col.starred && <Star size={11} className="text-yellow-400 fill-yellow-400 shrink-0" />}
                </div>
                <div className="flex items-center gap-2 text-xs text-muted-foreground font-semibold">
                  <span>{col.branch}</span>
                  <span className="opacity-40">·</span>
                  <span className="flex items-center gap-0.5">
                    <MapPin size={10} />{col.location}
                  </span>
                  <span className="opacity-40">·</span>
                  <span className="opacity-60">{col.type}</span>
                </div>
              </div>
              <div className={`text-xs font-black px-2.5 py-1 rounded-md shrink-0 ${MATCH_COLOR(col.match)}`}>
                {col.match}%
              </div>
            </div>
          ))}
        </div>

        {/* Bottom Tip */}
        <div className="mt-1 p-3 bg-yellow-500/10 border border-yellow-500/20 rounded-xl text-xs text-yellow-500 font-bold flex items-center gap-2">
          <TrendingUp size={14} className="shrink-0" />
          {activeTab === "Reach" && "Score +20 marks in Maths to convert IIT Roorkee from Reach to Target!"}
          {activeTab === "Target" && "Just 15 more marks in Maths can upgrade you from NIT Trichy to IIT Roorkee!"}
          {activeTab === "Safety" && "You're on track for all safety colleges. Focus your energy on converting Target colleges."}
        </div>
      </CardContent>
    </Card>
  )
}