"use client"

import Link from './LocalizedLink'
import { useRouter } from 'next/navigation'
import { useEffect, useState } from 'react'
import { ChevronRight, Loader2, Package, Search } from 'lucide-react'

import { API_BASE } from '../lib/api'
import { useLang } from '../hooks/useLang'
import { getPathWithLocale } from '../lib/locales'
import { toneClass } from '../lib/theme'

type TrackResponse =
  | { success: true; orderId: number }
  | { error?: string }

function parseStoredOrders(value: string | null) {
  if (!value) return []

  try {
    const parsed = JSON.parse(value)
    return Array.isArray(parsed)
      ? parsed.map(Number).filter((id) => Number.isFinite(id) && id > 0)
      : []
  } catch {
    return []
  }
}

function orderLabel(id: number) {
  return `#${id.toString().padStart(4, '0')}`
}

export default function TrackOrderClient() {
  const router = useRouter()
  const lang = useLang()
  const [orderId, setOrderId] = useState('')
  const [phone, setPhone] = useState('')
  const [localOrders, setLocalOrders] = useState<number[]>([])
  const [loading, setLoading] = useState(false)
  const [error, setError] = useState<string | null>(null)

  useEffect(() => {
    const storedOrders = parseStoredOrders(localStorage.getItem('app_local_orders'))
    queueMicrotask(() => setLocalOrders(storedOrders))
  }, [])

  const saveLocalOrder = (id: number) => {
    setLocalOrders((current) => {
      const next = [id, ...current.filter((item) => item !== id)].slice(0, 12)
      localStorage.setItem('app_local_orders', JSON.stringify(next))
      return next
    })
  }

  const handleSubmit = async (event: React.FormEvent<HTMLFormElement>) => {
    event.preventDefault()
    setLoading(true)
    setError(null)

    const normalizedOrderId = Number.parseInt(orderId.replace(/[^0-9]/g, ''), 10)

    if (!Number.isFinite(normalizedOrderId) || normalizedOrderId <= 0) {
      setError('กรุณากรอกหมายเลขคำสั่งซื้อให้ถูกต้อง')
      setLoading(false)
      return
    }

    try {
      const response = await fetch(`${API_BASE}/orders/track`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          orderId: normalizedOrderId,
          phone,
        }),
      })
      const data = await response.json() as TrackResponse

      if (response.ok && 'success' in data && data.success) {
        saveLocalOrder(data.orderId)
        router.push(getPathWithLocale(`/order/${data.orderId}`, lang))
        return
      }

      setError('error' in data && data.error ? data.error : 'ไม่สามารถยืนยันข้อมูลคำสั่งซื้อได้')
    } catch (err) {
      setError(err instanceof Error ? err.message : 'เกิดข้อผิดพลาดในการเชื่อมต่อ กรุณาลองใหม่อีกครั้ง')
    } finally {
      setLoading(false)
    }
  }

  return (
    <div className="grid gap-10 md:grid-cols-2">
      <section className="ui-panel self-start p-8">
        <div className="mb-6 flex items-center gap-3 border-b border-line-primary/20 pb-4">
          <div className="flex h-10 w-10 items-center justify-center rounded-full bg-surface-page text-brand-primary">
            <Search className="h-5 w-5" />
          </div>
          <div>
            <p className="ui-eyebrow">Manual Search</p>
            <h2 className="text-xl font-semibold text-text-main">ค้นหาคำสั่งซื้อ</h2>
          </div>
        </div>

        <form className="space-y-5" onSubmit={handleSubmit}>
          {error && (
            <div className={`p-4 text-sm font-medium ${toneClass('error')}`}>
              {error}
            </div>
          )}

          <div className="space-y-2">
            <label htmlFor="orderId" className="ui-form-label">
              Order Number
            </label>
            <input
              id="orderId"
              required
              value={orderId}
              onChange={(event) => setOrderId(event.target.value)}
              className="ui-form-shell"
              placeholder="เช่น 1024"
              type="text"
            />
          </div>

          <div className="space-y-2">
            <label htmlFor="phone" className="ui-form-label">
              Phone Number
            </label>
            <input
              id="phone"
              required
              value={phone}
              onChange={(event) => setPhone(event.target.value)}
              className="ui-form-shell"
              placeholder="เบอร์โทรที่ใช้ตอนสั่งซื้อ"
              type="tel"
            />
          </div>

          <button
            type="submit"
            disabled={loading}
            className="ui-form-inline-button w-full"
          >
            {loading ? <Loader2 className="h-5 w-5 animate-spin" /> : 'Find Order'}
          </button>
        </form>
      </section>

      <section className="space-y-6">
        <div className="flex items-center gap-3 border-b border-line-primary/20 pb-4">
          <Package className="h-5 w-5 text-brand-primary" />
          <h2 className="text-xl font-semibold text-text-main">Recent Device Orders</h2>
        </div>

        {localOrders.length === 0 ? (
          <div className="ui-empty-panel p-10 text-center">
            <p className="text-sm font-semibold text-muted-text">ยังไม่มีประวัติคำสั่งซื้อบนอุปกรณ์นี้</p>
            <p className="mt-2 text-xs uppercase tracking-[0.18em] text-muted-text/70">ใช้ฟอร์มค้นหาด้านซ้ายเพื่อบันทึกออเดอร์</p>
          </div>
        ) : (
          <div className="space-y-3">
            {localOrders.map((id) => (
              <Link
                key={id}
                href={`/order/${id}`}
                className="ui-card ui-card-hover group flex items-center justify-between p-5"
              >
                <div>
                  <p className="text-xs font-bold uppercase tracking-[0.22em] text-muted-text/70">Order</p>
                  <p className="mt-1 font-mono text-2xl font-bold text-text-main">{orderLabel(id)}</p>
                </div>
                <div className="flex h-10 w-10 items-center justify-center rounded-full bg-surface-page text-text-main transition group-hover:bg-brand-primary group-hover:text-surface-card">
                  <ChevronRight className="h-5 w-5" />
                </div>
              </Link>
            ))}
          </div>
        )}
      </section>
    </div>
  )
}