'use client'

import { useEffect, useState } from 'react'
import { useParams, useRouter } from 'next/navigation'
import { authFetch, clearToken, getApiBase, getToken } from '../../lib/auth'
import AdminShell from '../../ui/AdminShell'

type UserStats = {
  total: number
  ready: number
  pending: number
  approved: number
  working: number
  partial: number
  declined: number
  in_progress: number
  last_request_at?: string | null
}

type AdminUser = {
  id?: number
  username: string
  role: string
  auth_provider?: string | null
  last_login_at?: string | null
  is_blocked?: boolean
  jellyseerr_user_id?: number | null
}

const formatDateTime = (value?: string | null) => {
  if (!value) return 'Never'
  const date = new Date(value)
  if (Number.isNaN(date.valueOf())) return value
  return date.toLocaleString()
}

const normalizeStats = (stats: any): UserStats => ({
  total: Number(stats?.total ?? 0),
  ready: Number(stats?.ready ?? 0),
  pending: Number(stats?.pending ?? 0),
  approved: Number(stats?.approved ?? 0),
  working: Number(stats?.working ?? 0),
  partial: Number(stats?.partial ?? 0),
  declined: Number(stats?.declined ?? 0),
  in_progress: Number(stats?.in_progress ?? 0),
  last_request_at: stats?.last_request_at ?? null,
})

export default function UserDetailPage() {
  const params = useParams()
  const router = useRouter()
  const idParam = Array.isArray(params?.id) ? params.id[0] : params?.id
  const [user, setUser] = useState<AdminUser | null>(null)
  const [stats, setStats] = useState<UserStats | null>(null)
  const [error, setError] = useState<string | null>(null)
  const [loading, setLoading] = useState(true)

  const loadUser = async () => {
    if (!idParam) return
    try {
      const baseUrl = getApiBase()
      const response = await authFetch(
        `${baseUrl}/admin/users/id/${encodeURIComponent(idParam)}`
      )
      if (!response.ok) {
        if (response.status === 401) {
          clearToken()
          router.push('/login')
          return
        }
        if (response.status === 403) {
          router.push('/')
          return
        }
        if (response.status === 404) {
          setError('User not found.')
          return
        }
        throw new Error('Could not load user.')
      }
      const data = await response.json()
      setUser(data?.user ?? null)
      setStats(normalizeStats(data?.stats))
      setError(null)
    } catch (err) {
      console.error(err)
      setError('Could not load user.')
    } finally {
      setLoading(false)
    }
  }

  const toggleUserBlock = async (blocked: boolean) => {
    if (!user) return
    try {
      const baseUrl = getApiBase()
      const response = await authFetch(
        `${baseUrl}/admin/users/${encodeURIComponent(user.username)}/${blocked ? 'block' : 'unblock'}`,
        { method: 'POST' }
      )
      if (!response.ok) {
        throw new Error('Update failed')
      }
      await loadUser()
    } catch (err) {
      console.error(err)
      setError('Could not update user access.')
    }
  }

  const updateUserRole = async (role: string) => {
    if (!user) return
    try {
      const baseUrl = getApiBase()
      const response = await authFetch(
        `${baseUrl}/admin/users/${encodeURIComponent(user.username)}/role`,
        {
          method: 'POST',
          headers: { 'Content-Type': 'application/json' },
          body: JSON.stringify({ role }),
        }
      )
      if (!response.ok) {
        throw new Error('Update failed')
      }
      await loadUser()
    } catch (err) {
      console.error(err)
      setError('Could not update user role.')
    }
  }

  useEffect(() => {
    if (!getToken()) {
      router.push('/login')
      return
    }
    void loadUser()
  }, [router, idParam])

  if (loading) {
    return <main className="card">Loading user...</main>
  }

  return (
    <AdminShell
      title={user?.username || 'User'}
      subtitle="User overview and request stats."
      actions={
        <button type="button" onClick={() => router.push('/users')}>
          Back to users
        </button>
      }
    >
      <section className="admin-section">
        {error && <div className="error-banner">{error}</div>}
        {!user ? (
          <div className="status-banner">No user data found.</div>
        ) : (
          <>
            <div className="user-detail-card">
              <div className="user-detail-header">
                <div>
                  <strong>{user.username}</strong>
                  <div className="user-detail-meta">
                    <span className="meta">Jellyseerr ID: {user.jellyseerr_user_id ?? user.id ?? 'Unknown'}</span>
                    <span className="meta">Role: {user.role}</span>
                    <span className="meta">Login type: {user.auth_provider || 'local'}</span>
                    <span className="meta">Last login: {formatDateTime(user.last_login_at)}</span>
                  </div>
                </div>
                <div className="user-actions">
                  <label className="toggle">
                    <input
                      type="checkbox"
                      checked={user.role === 'admin'}
                      onChange={(event) => updateUserRole(event.target.checked ? 'admin' : 'user')}
                    />
                    <span>Make admin</span>
                  </label>
                  <button
                    type="button"
                    className="ghost-button"
                    onClick={() => toggleUserBlock(!user.is_blocked)}
                  >
                    {user.is_blocked ? 'Allow access' : 'Block access'}
                  </button>
                </div>
              </div>
              <div className="user-detail-grid">
                <div>
                  <span className="label">Total</span>
                  <span className="value">{stats?.total ?? 0}</span>
                </div>
                <div>
                  <span className="label">Ready</span>
                  <span className="value">{stats?.ready ?? 0}</span>
                </div>
                <div>
                  <span className="label">Pending</span>
                  <span className="value">{stats?.pending ?? 0}</span>
                </div>
                <div>
                  <span className="label">Approved</span>
                  <span className="value">{stats?.approved ?? 0}</span>
                </div>
                <div>
                  <span className="label">Working</span>
                  <span className="value">{stats?.working ?? 0}</span>
                </div>
                <div>
                  <span className="label">Partial</span>
                  <span className="value">{stats?.partial ?? 0}</span>
                </div>
                <div>
                  <span className="label">Declined</span>
                  <span className="value">{stats?.declined ?? 0}</span>
                </div>
                <div>
                  <span className="label">In progress</span>
                  <span className="value">{stats?.in_progress ?? 0}</span>
                </div>
                <div>
                  <span className="label">Last request</span>
                  <span className="value">{formatDateTime(stats?.last_request_at)}</span>
                </div>
              </div>
            </div>
          </>
        )}
      </section>
    </AdminShell>
  )
}