'use client'

import { useEffect, useState, useMemo } from 'react'
import { Header } from '@/components/Header'
import { Footer } from '@/components/Footer'
import { useStore } from '@/lib/store'
import { api } from '@/lib/api'
import {
  TrendingUp,
  TrendingDown,
  Minus,
  ArrowRight,
  BarChart3,
  ChevronUp,
  ChevronDown,
  ChevronsUpDown,
  Lock,
  ChevronRight,
} from 'lucide-react'
import Link from 'next/link'
import clsx from 'clsx'

interface TldData {
  tld: string
  type: string
  description: string
  avg_registration_price: number
  min_registration_price: number
  max_registration_price: number
  registrar_count: number
  trend: string
}

interface TrendingTld {
  tld: string
  reason: string
  price_change: number
  current_price: number
}

interface TldHistoryData {
  history: Array<{
    date: string
    price: number
  }>
}

type SortField = 'tld' | 'avg_registration_price' | 'min_registration_price' | 'registrar_count'
type SortDirection = 'asc' | 'desc'

// Mini sparkline chart component with real data
function MiniChart({ tld, isAuthenticated }: { tld: string, isAuthenticated: boolean }) {
  const [historyData, setHistoryData] = useState<number[]>([])
  const [loading, setLoading] = useState(true)

  useEffect(() => {
    if (isAuthenticated) {
      loadHistory()
    }
  }, [tld, isAuthenticated])

  const loadHistory = async () => {
    try {
      const data = await api.getTldHistory(tld, 365) // Get 1 year of data
      // Sample down to 12 data points (monthly)
      const history = data.history || []
      const sampledData = history
        .filter((_, i) => i % Math.floor(history.length / 12) === 0)
        .slice(0, 12)
        .map(h => h.price)
      
      setHistoryData(sampledData.length > 0 ? sampledData : [])
    } catch (error) {
      console.error('Failed to load history:', error)
      setHistoryData([])
    } finally {
      setLoading(false)
    }
  }

  if (!isAuthenticated || loading || historyData.length === 0) {
    return (
      <div className="flex items-center gap-2 text-ui-sm text-foreground-subtle">
        <Lock className="w-3 h-3" />
        Sign in
      </div>
    )
  }

  const min = Math.min(...historyData)
  const max = Math.max(...historyData)
  const range = max - min || 1

  const points = historyData.map((value, i) => {
    const x = (i / (historyData.length - 1)) * 100
    const y = 100 - ((value - min) / range) * 100
    return `${x},${y}`
  }).join(' ')

  const isIncreasing = historyData[historyData.length - 1] > historyData[0]

  return (
    <svg className="w-24 h-8" viewBox="0 0 100 100" preserveAspectRatio="none">
      <polyline
        points={points}
        fill="none"
        stroke="currentColor"
        strokeWidth="3"
        className={clsx(
          "transition-colors",
          isIncreasing ? "text-[#f97316]/60" : "text-accent/60"
        )}
      />
    </svg>
  )
}

function SortIcon({ field, currentField, direction }: { field: SortField, currentField: SortField, direction: SortDirection }) {
  if (field !== currentField) {
    return <ChevronsUpDown className="w-4 h-4 text-foreground-subtle" />
  }
  return direction === 'asc' 
    ? <ChevronUp className="w-4 h-4 text-accent" />
    : <ChevronDown className="w-4 h-4 text-accent" />
}

function ShimmerBlock({ className }: { className?: string }) {
  return (
    <div className={clsx(
      "relative overflow-hidden rounded bg-background-tertiary",
      className
    )}>
      <div className="absolute inset-0 -translate-x-full animate-[shimmer_2s_infinite] bg-gradient-to-r from-transparent via-foreground/5 to-transparent" />
    </div>
  )
}

export default function TldPricingPage() {
  const { isAuthenticated, checkAuth, isLoading: authLoading } = useStore()
  const [tlds, setTlds] = useState<TldData[]>([])
  const [trending, setTrending] = useState<TrendingTld[]>([])
  const [loading, setLoading] = useState(true)
  const [sortField, setSortField] = useState<SortField>('tld')
  const [sortDirection, setSortDirection] = useState<SortDirection>('asc')

  useEffect(() => {
    checkAuth()
    loadData()
  }, [checkAuth])

  const loadData = async () => {
    try {
      const [overviewData, trendingData] = await Promise.all([
        api.getTldOverview(100),
        api.getTrendingTlds(),
      ])
      setTlds(overviewData?.tlds || [])
      setTrending(trendingData?.trending || [])
    } catch (error) {
      console.error('Failed to load TLD data:', error)
      setTlds([])
      setTrending([])
    } finally {
      setLoading(false)
    }
  }

  const handleSort = (field: SortField) => {
    if (sortField === field) {
      setSortDirection(sortDirection === 'asc' ? 'desc' : 'asc')
    } else {
      setSortField(field)
      setSortDirection('asc')
    }
  }

  const sortedTlds = useMemo(() => {
    const sorted = [...tlds].sort((a, b) => {
      let aVal: number | string = a[sortField]
      let bVal: number | string = b[sortField]

      if (typeof aVal === 'string') aVal = aVal.toLowerCase()
      if (typeof bVal === 'string') bVal = bVal.toLowerCase()

      if (aVal < bVal) return sortDirection === 'asc' ? -1 : 1
      if (aVal > bVal) return sortDirection === 'asc' ? 1 : -1
      return 0
    })
    return sorted
  }, [tlds, sortField, sortDirection])

  const getTrendIcon = (trend: string) => {
    switch (trend) {
      case 'up':
        return <TrendingUp className="w-4 h-4 text-[#f97316]" />
      case 'down':
        return <TrendingDown className="w-4 h-4 text-accent" />
      default:
        return <Minus className="w-4 h-4 text-foreground-subtle" />
    }
  }

  if (loading || authLoading) {
    return (
      <div className="min-h-screen flex items-center justify-center">
        <div className="w-5 h-5 border-2 border-accent border-t-transparent rounded-full animate-spin" />
      </div>
    )
  }

  return (
    <div className="min-h-screen bg-background relative flex flex-col">
      {/* Ambient glow */}
      <div className="fixed inset-0 pointer-events-none">
        <div className="absolute top-0 left-1/4 w-[500px] h-[400px] bg-accent/[0.02] rounded-full blur-3xl" />
      </div>

      <Header />

      <main className="relative pt-28 sm:pt-32 pb-16 sm:pb-20 px-4 sm:px-6 flex-1">
        <div className="max-w-7xl mx-auto">
          {/* Header */}
          <div className="text-center mb-12 sm:mb-16 animate-fade-in">
            <div className="inline-flex items-center gap-2 px-3 py-1.5 bg-background-secondary/80 backdrop-blur-sm border border-border rounded-full mb-6">
              <BarChart3 className="w-4 h-4 text-accent" />
              <span className="text-ui-sm text-foreground-muted">TLD Price Intelligence</span>
            </div>
            <h1 className="font-display text-[2rem] sm:text-[2.75rem] md:text-[3.5rem] lg:text-[4rem] leading-[1.1] tracking-[-0.03em] text-foreground mb-4">
              Domain Extension Pricing
            </h1>
            <p className="text-body sm:text-body-lg text-foreground-muted max-w-2xl mx-auto">
              Track price trends across all major TLDs. Compare prices and monitor trends over time.
            </p>
          </div>

          {/* Login Banner for non-authenticated users */}
          {!isAuthenticated && (
            <div className="mb-8 p-5 bg-accent-muted border border-accent/20 rounded-xl flex flex-col sm:flex-row items-center justify-between gap-4 animate-fade-in">
              <div className="flex items-center gap-3">
                <div className="w-10 h-10 bg-accent/20 rounded-xl flex items-center justify-center">
                  <Lock className="w-5 h-5 text-accent" />
                </div>
                <div>
                  <p className="text-body-sm font-medium text-foreground">Unlock Full TLD Data</p>
                  <p className="text-ui-sm text-foreground-muted">
                    Sign in to see detailed pricing and trends.
                  </p>
                </div>
              </div>
              <Link
                href="/register"
                className="shrink-0 px-5 py-2.5 bg-accent text-background text-ui font-medium rounded-lg
                           hover:bg-accent-hover transition-all duration-300"
              >
                Get Started Free
              </Link>
            </div>
          )}

          {/* Trending Section */}
          {trending.length > 0 && (
            <div className="mb-12 sm:mb-16 animate-slide-up">
              <h2 className="text-body-lg sm:text-heading-sm font-medium text-foreground mb-4 sm:mb-6 flex items-center gap-2">
                <TrendingUp className="w-5 h-5 text-accent" />
                Trending Now
              </h2>
              <div className="grid sm:grid-cols-2 lg:grid-cols-4 gap-3 sm:gap-4">
                {trending.map((item) => (
                  <Link
                    key={item.tld}
                    href={isAuthenticated ? `/tld-pricing/${item.tld}` : '/register'}
                    className="p-4 sm:p-5 bg-background-secondary/50 border border-border rounded-xl hover:border-border-hover hover:bg-background-secondary transition-all duration-300 text-left group"
                  >
                    <div className="flex items-center justify-between mb-3">
                      <span className="font-mono text-body-lg sm:text-heading-sm text-foreground">.{item.tld}</span>
                      {isAuthenticated ? (
                        <span className={clsx(
                          "text-ui-sm font-medium px-2 py-0.5 rounded-full",
                          item.price_change > 0 
                            ? "text-[#f97316] bg-[#f9731615]"
                            : "text-accent bg-accent-muted"
                        )}>
                          {item.price_change > 0 ? '+' : ''}{item.price_change.toFixed(1)}%
                        </span>
                      ) : (
                        <ShimmerBlock className="h-5 w-14" />
                      )}
                    </div>
                    <p className="text-body-sm text-foreground-muted mb-2 line-clamp-2">
                      {isAuthenticated ? item.reason : 'Sign in to view trend details'}
                    </p>
                    <div className="flex items-center justify-between">
                      {isAuthenticated ? (
                        <span className="text-body-sm text-foreground-subtle">
                          ${item.current_price.toFixed(2)}/yr
                        </span>
                      ) : (
                        <ShimmerBlock className="h-5 w-20" />
                      )}
                      <ChevronRight className="w-4 h-4 text-foreground-subtle group-hover:text-accent transition-colors" />
                    </div>
                  </Link>
                ))}
              </div>
            </div>
          )}

          {/* TLD Table */}
          <div className="bg-background-secondary/30 border border-border rounded-xl overflow-hidden animate-slide-up">
            <div className="overflow-x-auto">
              <table className="w-full">
                <thead>
                  <tr className="bg-background-secondary border-b border-border">
                    <th className="text-left px-4 sm:px-6 py-4">
                      <button
                        onClick={() => handleSort('tld')}
                        className="flex items-center gap-2 text-ui-sm text-foreground-subtle font-medium hover:text-foreground transition-colors"
                      >
                        TLD
                        <SortIcon field="tld" currentField={sortField} direction={sortDirection} />
                      </button>
                    </th>
                    <th className="text-left px-4 sm:px-6 py-4 hidden lg:table-cell">
                      <span className="text-ui-sm text-foreground-subtle font-medium">
                        Description
                      </span>
                    </th>
                    <th className="text-left px-4 sm:px-6 py-4 hidden md:table-cell">
                      <span className="text-ui-sm text-foreground-subtle font-medium">
                        12-Month Trend
                      </span>
                    </th>
                    <th className="text-right px-4 sm:px-6 py-4">
                      <button
                        onClick={() => handleSort('avg_registration_price')}
                        className="flex items-center gap-2 ml-auto text-ui-sm text-foreground-subtle font-medium hover:text-foreground transition-colors"
                      >
                        Avg. Price
                        <SortIcon field="avg_registration_price" currentField={sortField} direction={sortDirection} />
                      </button>
                    </th>
                    <th className="text-right px-4 sm:px-6 py-4 hidden sm:table-cell">
                      <button
                        onClick={() => handleSort('min_registration_price')}
                        className="flex items-center gap-2 ml-auto text-ui-sm text-foreground-subtle font-medium hover:text-foreground transition-colors"
                      >
                        From
                        <SortIcon field="min_registration_price" currentField={sortField} direction={sortDirection} />
                      </button>
                    </th>
                    <th className="text-center px-4 sm:px-6 py-4 hidden xl:table-cell">
                      <button
                        onClick={() => handleSort('registrar_count')}
                        className="flex items-center gap-2 mx-auto text-ui-sm text-foreground-subtle font-medium hover:text-foreground transition-colors"
                      >
                        Registrars
                        <SortIcon field="registrar_count" currentField={sortField} direction={sortDirection} />
                      </button>
                    </th>
                    <th className="text-center px-4 sm:px-6 py-4 hidden sm:table-cell">
                      <span className="text-ui-sm text-foreground-subtle font-medium">Trend</span>
                    </th>
                    <th className="px-4 sm:px-6 py-4"></th>
                  </tr>
                </thead>
                <tbody className="divide-y divide-border">
                  {sortedTlds.map((tld, idx) => (
                    <tr
                      key={tld.tld}
                      className="hover:bg-background-secondary/50 transition-colors group"
                    >
                      <td className="px-4 sm:px-6 py-4">
                        <span className="font-mono text-body-sm sm:text-body font-medium text-foreground">
                          .{tld.tld}
                        </span>
                      </td>
                      <td className="px-4 sm:px-6 py-4 hidden lg:table-cell">
                        <span className="text-body-sm text-foreground-muted line-clamp-1">
                          {tld.description}
                        </span>
                      </td>
                      <td className="px-4 sm:px-6 py-4 hidden md:table-cell">
                        <MiniChart tld={tld.tld} isAuthenticated={isAuthenticated} />
                      </td>
                      <td className="px-4 sm:px-6 py-4 text-right">
                        {isAuthenticated ? (
                          <span className="text-body-sm font-medium text-foreground">
                            ${tld.avg_registration_price.toFixed(2)}
                          </span>
                        ) : (
                          <span className="text-body-sm text-foreground-subtle">•••</span>
                        )}
                      </td>
                      <td className="px-4 sm:px-6 py-4 text-right hidden sm:table-cell">
                        {isAuthenticated ? (
                          <span className="text-body-sm text-accent">
                            ${tld.min_registration_price.toFixed(2)}
                          </span>
                        ) : (
                          <span className="text-body-sm text-foreground-subtle">•••</span>
                        )}
                      </td>
                      <td className="px-4 sm:px-6 py-4 text-center hidden xl:table-cell">
                        {isAuthenticated ? (
                          <span className="text-body-sm text-foreground-muted">
                            {tld.registrar_count}
                          </span>
                        ) : (
                          <span className="text-body-sm text-foreground-subtle">•</span>
                        )}
                      </td>
                      <td className="px-4 sm:px-6 py-4 text-center hidden sm:table-cell">
                        {isAuthenticated ? getTrendIcon(tld.trend) : <Minus className="w-4 h-4 text-foreground-subtle mx-auto" />}
                      </td>
                      <td className="px-4 sm:px-6 py-4">
                        <Link
                          href={isAuthenticated ? `/tld-pricing/${tld.tld}` : '/register'}
                          className="flex items-center gap-1 text-ui-sm text-accent hover:text-accent-hover transition-colors opacity-0 group-hover:opacity-100"
                        >
                          Details
                          <ArrowRight className="w-3 h-3" />
                        </Link>
                      </td>
                    </tr>
                  ))}
                </tbody>
              </table>
            </div>
          </div>

          {/* Stats */}
          <div className="mt-6 flex justify-center">
            <p className="text-ui-sm text-foreground-subtle">
              Showing {sortedTlds.length} TLDs
            </p>
          </div>
        </div>
      </main>

      <Footer />
    </div>
  )
}