"use client";

import Image from 'next/image'
import Link from './LocalizedLink'
import { useEffect, useState } from 'react'
import {
  Award,
  Check,
  Edit3,
  ExternalLink,
  Loader2,
  LogOut,
  Mail,
  MapPin,
  Package,
  Phone,
  Plus,
  Settings,
  Trash2,
  User,
  type LucideIcon,
} from 'lucide-react'
import { formatPrice, type CustomerAddress, type Order } from '@homaroma/types'

import { API_BASE } from '../lib/api'
import { orderStatusBadgeClass, toneClass } from '../lib/theme'
import { useAuthStore, type Customer } from '../store/authStore'

type ProfileTab = 'orders' | 'addresses' | 'settings'

type ProfileTabItem = {
  tab: ProfileTab
  label: string
  icon: LucideIcon
  count: number | null
}

type ProfileCustomer = Customer & {
  points?: number
  addresses?: CustomerAddress[]
}

type AddressFormState = {
  recipientName: string
  phone: string
  addressLine: string
  subdistrict: string
  district: string
  province: string
  zipcode: string
  isDefault: boolean
}

const emptyAddressForm: AddressFormState = {
  recipientName: '',
  phone: '',
  addressLine: '',
  subdistrict: '',
  district: '',
  province: '',
  zipcode: '',
  isDefault: false,
}

function statusLabel(status: string) {
  const labels: Record<string, string> = {
    PENDING_PAYMENT: 'รอการชำระเงิน',
    PAID: 'ชำระเงินสำเร็จ',
    PROCESSING: 'กำลังจัดเตรียมสินค้า',
    SHIPPED: 'จัดส่งแล้ว',
    DELIVERED: 'จัดส่งสำเร็จ',
    CANCELLED: 'ยกเลิกแล้ว',
  }

  return labels[status] ?? status.replaceAll('_', ' ')
}

function formatAddress(address: CustomerAddress) {
  return `${address.addressLine} ต.${address.subdistrict} อ.${address.district} จ.${address.province} ${address.zipcode}`
}

function toAddressForm(address: CustomerAddress): AddressFormState {
  return {
    recipientName: address.recipientName,
    phone: address.phone,
    addressLine: address.addressLine,
    subdistrict: address.subdistrict,
    district: address.district,
    province: address.province,
    zipcode: address.zipcode,
    isDefault: address.isDefault,
  }
}

async function readJson<T>(path: string, init?: RequestInit): Promise<T> {
  const response = await fetch(`${API_BASE}${path}`, init)
  const data = await response.json()

  if (!response.ok) {
    const message = data && typeof data === 'object' && 'error' in data && typeof data.error === 'string'
      ? data.error
      : `${path} returned ${response.status}`
    throw new Error(message)
  }

  return data as T
}

export default function ProfileClient() {
  const { token, customer, setAuth, logout } = useAuthStore()
  const [activeTab, setActiveTab] = useState<ProfileTab>('orders')
  const [dbCustomer, setDbCustomer] = useState<ProfileCustomer | null>(null)
  const [orders, setOrders] = useState<Order[]>([])
  const [addresses, setAddresses] = useState<CustomerAddress[]>([])
  const [loading, setLoading] = useState(false)
  const [error, setError] = useState<string | null>(null)
  const [showAddressForm, setShowAddressForm] = useState(false)
  const [editingAddress, setEditingAddress] = useState<CustomerAddress | null>(null)
  const [addressForm, setAddressForm] = useState<AddressFormState>(emptyAddressForm)
  const [submittingAddress, setSubmittingAddress] = useState(false)
  const [settingsForm, setSettingsForm] = useState({ email: '', phone: '' })
  const [submittingSettings, setSubmittingSettings] = useState(false)
  const [settingsSuccess, setSettingsSuccess] = useState(false)

  const loadProfileData = async (currentCustomer: Customer) => {
    setLoading(true)
    setError(null)

    try {
      const [profileData, orderData, addressData] = await Promise.all([
        readJson<ProfileCustomer>(`/profile/${currentCustomer.id}`),
        readJson<Order[]>(`/orders/customer/${currentCustomer.id}`),
        readJson<CustomerAddress[]>(`/profile/${currentCustomer.id}/addresses`),
      ])

      setDbCustomer(profileData)
      setOrders(Array.isArray(orderData) ? orderData : [])
      setAddresses(Array.isArray(addressData) ? addressData : [])
      setSettingsForm({
        email: profileData.email ?? '',
        phone: profileData.phone ?? '',
      })
    } catch (err) {
      setError(err instanceof Error ? err.message : 'ไม่สามารถโหลดข้อมูลสมาชิกได้')
    } finally {
      setLoading(false)
    }
  }

  useEffect(() => {
    if (!customer) return
    queueMicrotask(() => {
      void loadProfileData(customer)
    })
  }, [customer])

  const resetAddressForm = () => {
    setAddressForm(emptyAddressForm)
    setEditingAddress(null)
    setShowAddressForm(false)
  }

  const updateAddressForm = (key: keyof AddressFormState, value: string | boolean) => {
    setAddressForm((current) => ({ ...current, [key]: value }))
  }

  const handleStartAddress = (address?: CustomerAddress) => {
    if (address) {
      setEditingAddress(address)
      setAddressForm(toAddressForm(address))
    } else {
      setEditingAddress(null)
      setAddressForm(emptyAddressForm)
    }
    setShowAddressForm(true)
  }

  const reloadAddresses = async (customerId: number) => {
    const data = await readJson<CustomerAddress[]>(`/profile/${customerId}/addresses`)
    setAddresses(Array.isArray(data) ? data : [])
  }

  const handleAddressSubmit = async (event: React.FormEvent<HTMLFormElement>) => {
    event.preventDefault()
    if (!customer) return

    setSubmittingAddress(true)
    setError(null)

    try {
      await readJson<CustomerAddress>(
        editingAddress
          ? `/profile/${customer.id}/addresses/${editingAddress.id}`
          : `/profile/${customer.id}/addresses`,
        {
          method: editingAddress ? 'PUT' : 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify(addressForm),
        },
      )
      resetAddressForm()
      await reloadAddresses(customer.id)
    } catch (err) {
      setError(err instanceof Error ? err.message : 'ไม่สามารถบันทึกที่อยู่ได้')
    } finally {
      setSubmittingAddress(false)
    }
  }

  const handleDeleteAddress = async (addressId: number) => {
    if (!customer) return
    if (!window.confirm('ยืนยันที่จะลบที่อยู่จัดส่งนี้?')) return

    setError(null)
    try {
      await readJson<{ success: boolean }>(`/profile/${customer.id}/addresses/${addressId}`, { method: 'DELETE' })
      await reloadAddresses(customer.id)
    } catch (err) {
      setError(err instanceof Error ? err.message : 'ไม่สามารถลบที่อยู่ได้')
    }
  }

  const handleSetDefaultAddress = async (addressId: number) => {
    if (!customer) return

    setError(null)
    try {
      await readJson<CustomerAddress>(`/profile/${customer.id}/addresses/${addressId}/default`, { method: 'PATCH' })
      await reloadAddresses(customer.id)
    } catch (err) {
      setError(err instanceof Error ? err.message : 'ไม่สามารถตั้งค่าที่อยู่เริ่มต้นได้')
    }
  }

  const handleSettingsSubmit = async (event: React.FormEvent<HTMLFormElement>) => {
    event.preventDefault()
    if (!customer) return

    setSubmittingSettings(true)
    setSettingsSuccess(false)
    setError(null)

    try {
      const updatedCustomer = await readJson<ProfileCustomer>(`/profile/${customer.id}`, {
        method: 'PUT',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          email: settingsForm.email || null,
          phone: settingsForm.phone || null,
        }),
      })

      setDbCustomer(updatedCustomer)
      if (token) setAuth(token, updatedCustomer)
      setSettingsSuccess(true)
      setTimeout(() => setSettingsSuccess(false), 3000)
    } catch (err) {
      setError(err instanceof Error ? err.message : 'ไม่สามารถบันทึกข้อมูลติดต่อได้')
    } finally {
      setSubmittingSettings(false)
    }
  }

  const handleLineLogin = () => {
    const maybeWindow = window as Window & {
      liff?: {
        login: (options?: { redirectUri?: string }) => void
      }
    }

    if (maybeWindow.liff) {
      maybeWindow.liff.login({ redirectUri: window.location.href })
      return
    }

    setError('ยังไม่พบ LINE LIFF ในหน้า website นี้ กรุณาเปิดผ่าน LINE OA หรือรอให้ทีมตั้งค่า LIFF สำหรับ website')
  }

  if (!customer) {
    return (
      <section className="ui-panel mx-auto max-w-md p-10 text-center">
        <div className="ui-avatar-shell mx-auto mb-6 text-brand-primary">
          <User className="h-10 w-10" />
        </div>
        <h1 className="text-3xl font-semibold text-text-main">เข้าสู่ระบบสมาชิก</h1>
        <p className="mt-3 text-sm leading-relaxed text-muted-text">
          ล็อกอินเพื่อตรวจสอบประวัติคำสั่งซื้อ สะสมคะแนนสมาชิก และบันทึกสมุดที่อยู่จัดส่งสินค้า
        </p>
        {error && (
          <p className={`mt-5 p-4 text-sm ${toneClass('warning')}`}>
            {error}
          </p>
        )}
        <button
          type="button"
          onClick={handleLineLogin}
          className="mt-8 flex w-full items-center justify-center gap-3 rounded-full bg-line-primary px-6 py-4 text-sm font-bold uppercase tracking-[0.16em] text-surface-card transition hover:bg-line-primary-hover"
        >
          <Award className="h-5 w-5" />
          เข้าสู่ระบบผ่าน LINE
        </button>
        <Link href="/shop" className="mt-5 inline-flex text-sm font-semibold text-brand-primary">
          กลับไปเลือกซื้อสินค้า
        </Link>
      </section>
    )
  }

  const displayCustomer = dbCustomer ?? customer
  const tabs: ProfileTabItem[] = [
    { tab: 'orders', label: 'ออเดอร์', icon: Package, count: orders.length },
    { tab: 'addresses', label: 'ที่อยู่', icon: MapPin, count: addresses.length },
    { tab: 'settings', label: 'ตั้งค่า', icon: Settings, count: null },
  ]

  return (
    <section className="space-y-8">
      {error && (
        <div className={`p-5 text-sm font-medium ${toneClass('error')}`}>
          {error}
        </div>
      )}

      <div className="ui-panel relative overflow-hidden p-6">
        <div className="absolute inset-x-0 top-0 h-1 bg-gradient-to-r from-brand-primary via-brand-accent to-brand-primary-hover" />
        <div className="flex flex-col gap-5 sm:flex-row sm:items-center sm:justify-between">
          <div className="flex min-w-0 items-center gap-4">
            <div className="ui-avatar-shell-sm relative shrink-0">
              <Image
                src={displayCustomer.pictureUrl || `https://ui-avatars.com/api/?name=${encodeURIComponent(displayCustomer.displayName || 'Member')}`}
                alt={displayCustomer.displayName || 'LINE Profile'}
                fill
                unoptimized
                className="h-full w-full object-cover"
              />
            </div>
            <div className="min-w-0">
              <h1 className="truncate text-2xl font-semibold text-text-main">{displayCustomer.displayName || 'Member'}</h1>
              <div className="mt-2 flex flex-wrap gap-x-4 gap-y-1 text-xs font-semibold text-muted-text">
                {displayCustomer.phone && <span className="inline-flex items-center gap-1"><Phone className="h-3 w-3" />{displayCustomer.phone}</span>}
                {displayCustomer.email && <span className="inline-flex items-center gap-1"><Mail className="h-3 w-3" />{displayCustomer.email}</span>}
              </div>
            </div>
          </div>
          <div className="ui-panel-muted flex items-center justify-between gap-4 px-4 py-3">
            <Award className="h-6 w-6 text-brand-primary" />
            <div>
              <p className="text-[10px] font-bold uppercase tracking-[0.2em] text-muted-text">คะแนนสะสม</p>
              <p className="text-xl font-black text-text-main">{displayCustomer.points ?? 0} คะแนน</p>
            </div>
          </div>
        </div>
      </div>

      <div className="flex gap-2 overflow-x-auto border-b border-line-primary/20">
        {tabs.map(({ tab, label, icon: Icon, count }) => (
          <button
            key={tab}
            type="button"
            onClick={() => setActiveTab(tab)}
            className={`ui-tab-button ${activeTab === tab ? 'ui-tab-button-active' : 'ui-tab-button-inactive'}`}
          >
            <Icon className="h-4 w-4" />
            {label}
            {typeof count === 'number' && (
              <span className="ui-tab-count">{count}</span>
            )}
            {activeTab === tab && <span className="absolute inset-x-0 bottom-0 h-0.5 rounded-full bg-brand-primary" />}
          </button>
        ))}
      </div>

      {loading ? (
        <div className="ui-panel flex items-center justify-center py-24">
          <Loader2 className="h-8 w-8 animate-spin text-brand-primary" />
        </div>
      ) : (
        <>
          {activeTab === 'orders' && (
            <div className="space-y-5">
              {orders.length === 0 ? (
                <EmptyPanel icon={Package} title="ไม่มีประวัติการสั่งซื้อ" description="คุณยังไม่ได้ทำการสั่งซื้อสินค้าใด ๆ " actionHref="/shop" actionText="ไปหน้าช้อปปิ้ง" />
              ) : (
                orders.map((order) => (
                  <article key={order.id} className="ui-panel p-6">
                    <div className="flex flex-col gap-3 border-b border-line-primary/20 pb-4 md:flex-row md:items-center md:justify-between">
                      <div>
                        <p className="text-xs font-semibold text-muted-text">เลขออเดอร์ #{order.id.toString().padStart(4, '0')}</p>
                        <p className="mt-1 text-[11px] text-muted-text/70">
                          สั่งเมื่อ {new Date(order.createdAt).toLocaleDateString('th-TH', { year: 'numeric', month: 'long', day: 'numeric' })}
                        </p>
                      </div>
                      <div className="flex items-center gap-3">
                        <span className={orderStatusBadgeClass(order.status)}>
                          {statusLabel(order.status)}
                        </span>
                        <Link href={`/order/${order.id}`} className="rounded-full border border-line-primary/20 p-2 text-muted-text transition hover:text-brand-primary">
                          <ExternalLink className="h-4 w-4" />
                        </Link>
                      </div>
                    </div>

                    <div className="mt-4 space-y-3">
                      {order.items.map((item) => (
                        <div key={item.id} className="flex items-center gap-3 text-sm">
                          <div className="relative h-11 w-11 shrink-0 overflow-hidden rounded-xl bg-surface-page">
                            <Image src={item.productImage || '/images/fallback-product.svg'} alt={item.productName} fill unoptimized className="h-full w-full object-cover" />
                          </div>
                          <div className="min-w-0 flex-1">
                            <p className="truncate font-semibold text-text-main">{item.productName}</p>
                            <p className="text-xs text-muted-text">{item.variantSize ? `${item.variantSize} · ` : ''}x {item.quantity}</p>
                          </div>
                          <p className="font-bold text-brand-primary">{formatPrice(item.priceAtPurchase * item.quantity)}</p>
                        </div>
                      ))}
                    </div>

                    <div className="mt-5 flex flex-col gap-3 border-t border-line-primary/20 pt-4 text-sm md:flex-row md:items-center md:justify-between">
                      <p className="text-muted-text">
                        {order.trackingNo ? <>เลขพัสดุ: <span className="font-mono font-bold text-text-main">{order.trackingNo}</span></> : 'ยังไม่มีเลขพัสดุ'}
                      </p>
                      <p className="font-bold text-text-main">ยอดรวมสุทธิ: <span className="text-brand-primary">{formatPrice(order.totalAmount)}</span></p>
                    </div>
                  </article>
                ))
              )}
            </div>
          )}

          {activeTab === 'addresses' && (
            <div className="space-y-6">
              <div className="flex flex-col gap-3 border-b border-line-primary/20 pb-4 sm:flex-row sm:items-center sm:justify-between">
                <h2 className="flex items-center gap-2 text-xl font-semibold text-text-main">
                  <MapPin className="h-5 w-5 text-brand-primary" />
                  สมุดที่อยู่จัดส่ง
                </h2>
                {!showAddressForm && (
                  <button type="button" onClick={() => handleStartAddress()} className="inline-flex items-center justify-center gap-2 rounded-full bg-text-main px-5 py-3 text-xs font-bold uppercase tracking-[0.16em] text-surface-card transition hover:bg-brand-primary">
                    <Plus className="h-4 w-4" />
                    เพิ่มที่อยู่ใหม่
                  </button>
                )}
              </div>

              {showAddressForm && (
                <form onSubmit={handleAddressSubmit} className="ui-panel space-y-5 p-6">
                  <h3 className="text-sm font-bold uppercase tracking-[0.2em] text-brand-primary">
                    {editingAddress ? 'แก้ไขที่อยู่จัดส่ง' : 'เพิ่มที่อยู่จัดส่งใหม่'}
                  </h3>

                  <div className="grid gap-4 md:grid-cols-2">
                    <TextInput label="ชื่อผู้รับ" value={addressForm.recipientName} onChange={(value) => updateAddressForm('recipientName', value)} required />
                    <TextInput label="เบอร์โทรศัพท์ผู้รับ" value={addressForm.phone} onChange={(value) => updateAddressForm('phone', value)} required />
                  </div>
                  <TextInput label="ที่อยู่" value={addressForm.addressLine} onChange={(value) => updateAddressForm('addressLine', value)} required />
                  <div className="grid gap-4 md:grid-cols-4">
                    <TextInput label="ตำบล/แขวง" value={addressForm.subdistrict} onChange={(value) => updateAddressForm('subdistrict', value)} required />
                    <TextInput label="อำเภอ/เขต" value={addressForm.district} onChange={(value) => updateAddressForm('district', value)} required />
                    <TextInput label="จังหวัด" value={addressForm.province} onChange={(value) => updateAddressForm('province', value)} required />
                    <TextInput label="รหัสไปรษณีย์" value={addressForm.zipcode} onChange={(value) => updateAddressForm('zipcode', value)} required />
                  </div>

                  <label className="flex items-center gap-3 text-sm font-semibold text-muted-text">
                    <input
                      type="checkbox"
                      checked={addressForm.isDefault}
                      onChange={(event) => updateAddressForm('isDefault', event.target.checked)}
                      className="ui-form-checkbox"
                    />
                    ตั้งเป็นที่อยู่จัดส่งเริ่มต้น
                  </label>

                  <div className="flex justify-end gap-3 border-t border-line-primary/20 pt-4">
                    <button type="button" onClick={resetAddressForm} className="ui-form-secondary-button">
                      ยกเลิก
                    </button>
                    <button type="submit" disabled={submittingAddress} className="inline-flex items-center gap-2 rounded-full bg-brand-primary px-5 py-2 text-sm font-semibold text-surface-card disabled:opacity-60">
                      {submittingAddress && <Loader2 className="h-4 w-4 animate-spin" />}
                      บันทึกที่อยู่
                    </button>
                  </div>
                </form>
              )}

              {addresses.length === 0 ? (
                <EmptyPanel icon={MapPin} title="ไม่มีข้อมูลที่อยู่จัดส่ง" description="เพิ่มที่อยู่เพื่อใช้ในขั้นตอน checkout รอบถัดไป" />
              ) : (
                <div className="grid gap-4 md:grid-cols-2">
                  {addresses.map((address) => (
                    <article key={address.id} className={`ui-panel p-5 ${address.isDefault ? 'ring-2 ring-brand-primary/30' : ''}`}>
                      <div className="flex items-start justify-between gap-4">
                        <div>
                          <div className="flex flex-wrap items-center gap-2">
                            <p className="font-semibold text-text-main">{address.recipientName}</p>
                            {address.isDefault && <span className="rounded-full bg-surface-page px-2 py-0.5 text-[10px] font-bold text-brand-primary">เริ่มต้น</span>}
                          </div>
                          <p className="mt-1 text-xs font-semibold text-muted-text">{address.phone}</p>
                        </div>
                        <div className="flex gap-1">
                          <button type="button" onClick={() => handleStartAddress(address)} className="rounded-full border border-line-primary/20 p-2 text-muted-text hover:text-brand-primary">
                            <Edit3 className="h-4 w-4" />
                          </button>
                          <button type="button" onClick={() => void handleDeleteAddress(address.id)} className="ui-form-danger-button">
                            <Trash2 className="h-4 w-4" />
                          </button>
                        </div>
                      </div>
                      <p className="mt-4 text-sm leading-relaxed text-muted-text">{formatAddress(address)}</p>
                      {!address.isDefault && (
                        <button type="button" onClick={() => void handleSetDefaultAddress(address.id)} className="mt-4 w-full rounded-full border border-line-primary/20 px-4 py-2 text-xs font-bold uppercase tracking-[0.16em] text-muted-text hover:text-brand-primary">
                          ตั้งเป็นที่อยู่เริ่มต้น
                        </button>
                      )}
                    </article>
                  ))}
                </div>
              )}
            </div>
          )}

          {activeTab === 'settings' && (
            <div className="space-y-6">
              <h2 className="flex items-center gap-2 border-b border-line-primary/20 pb-4 text-xl font-semibold text-text-main">
                <Settings className="h-5 w-5 text-brand-primary" />
                ข้อมูลติดต่อสมาชิก
              </h2>

              <form onSubmit={handleSettingsSubmit} className="ui-panel max-w-xl space-y-5 p-6">
                {settingsSuccess && (
                <div className={`flex items-center justify-center gap-2 p-4 text-sm font-bold ${toneClass('success')}`}>
                  <Check className="h-4 w-4" />
                  บันทึกข้อมูลติดต่อสำเร็จแล้ว
                </div>
                )}
                <TextInput label="อีเมล" value={settingsForm.email} onChange={(email) => setSettingsForm((current) => ({ ...current, email }))} type="email" />
                <TextInput label="เบอร์โทรศัพท์" value={settingsForm.phone} onChange={(phone) => setSettingsForm((current) => ({ ...current, phone }))} type="tel" />
                <button type="submit" disabled={submittingSettings} className="inline-flex w-full items-center justify-center gap-2 rounded-full bg-brand-primary px-6 py-3 text-sm font-bold uppercase tracking-[0.16em] text-surface-card disabled:opacity-60">
                  {submittingSettings ? <Loader2 className="h-4 w-4 animate-spin" /> : <Check className="h-4 w-4" />}
                  บันทึกข้อมูลติดต่อ
                </button>
              </form>
            </div>
          )}
        </>
      )}

      <button type="button" onClick={logout} className="inline-flex items-center gap-2 text-sm font-semibold text-muted-text transition hover:text-rose-500">
        <LogOut className="h-4 w-4" />
        ออกจากระบบบนอุปกรณ์นี้
      </button>
    </section>
  )
}

function TextInput({
  label,
  value,
  onChange,
  required = false,
  type = 'text',
}: {
  label: string
  value: string
  onChange: (value: string) => void
  required?: boolean
  type?: string
}) {
  return (
    <label className="space-y-1.5">
      <span className="ui-form-label block text-[10px] tracking-[0.2em]">{label}</span>
      <input
        type={type}
        required={required}
        value={value}
        onChange={(event) => onChange(event.target.value)}
        className="ui-form-shell"
      />
    </label>
  )
}

function EmptyPanel({
  icon: Icon,
  title,
  description,
  actionHref,
  actionText,
}: {
  icon: typeof Package
  title: string
  description: string
  actionHref?: string
  actionText?: string
}) {
  return (
    <div className="ui-empty-panel">
      <Icon className="mx-auto mb-5 h-12 w-12 text-muted-text/40" />
      <h3 className="text-xl font-semibold text-text-main">{title}</h3>
      <p className="mx-auto mt-2 max-w-md text-sm text-muted-text">{description}</p>
      {actionHref && actionText && (
        <Link href={actionHref} className="mt-6 inline-flex rounded-full bg-brand-primary px-6 py-3 text-sm font-bold text-surface-card">
          {actionText}
        </Link>
      )}
    </div>
  )
}