import { useState } from 'react'
import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query'
import {
  Plus,
  MailCheck,
  Trash2,
  Edit,
  TestTube,
  AlertCircle,
  CheckCircle,
  Clock,
  RefreshCw,
} from 'lucide-react'
import toast from 'react-hot-toast'
import { useForm } from 'react-hook-form'
import { Button } from '@/components/ui/Button'
import { Input } from '@/components/ui/Input'
import { Label } from '@/components/ui/Label'
import {
  Dialog,
  DialogContent,
  DialogHeader,
  DialogTitle,
  DialogFooter,
} from '@/components/ui/Dialog'
import { mailboxesApi } from '@/api/mailboxes.api'
import { getErrorMessage } from '@/api/client'
import { formatDate, MAILBOX_STATUS_LABELS } from '@/lib/utils'
import { cn } from '@/lib/utils'
import type { MailboxCreateRequest, MailboxResponse } from '@/types/api.types'

const STATUS_COLORS = {
  active: 'text-green-700 bg-green-100',
  paused: 'text-yellow-700 bg-yellow-100',
  error: 'text-red-700 bg-red-100',
  deleted: 'text-gray-700 bg-gray-100',
}

const STATUS_ICONS = {
  active: CheckCircle,
  paused: Clock,
  error: AlertCircle,
  deleted: Trash2,
}

export function MailboxesPage() {
  const queryClient = useQueryClient()
  const [showCreateDialog, setShowCreateDialog] = useState(false)
  const [editingMailbox, setEditingMailbox] = useState<MailboxResponse | null>(null)
  const [testingId, setTestingId] = useState<string | null>(null)
  const [testResult, setTestResult] = useState<{ success: boolean; message: string } | null>(null)

  const { data: mailboxesData, isLoading } = useQuery({
    queryKey: ['mailboxes'],
    queryFn: () => mailboxesApi.list(1, 200),
  })

  const deleteMutation = useMutation({
    mutationFn: mailboxesApi.delete,
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['mailboxes'] })
      toast.success('Casella eliminata')
    },
    onError: (e) => toast.error(getErrorMessage(e)),
  })

  const handleTest = async (mailbox: MailboxResponse) => {
    setTestingId(mailbox.id)
    setTestResult(null)
    try {
      const result = await mailboxesApi.testConnection(mailbox.id, 'imap')
      setTestResult(result)
      toast[result.success ? 'success' : 'error'](result.message)
    } catch (e) {
      toast.error(getErrorMessage(e))
    } finally {
      setTestingId(null)
    }
  }

  const handleDelete = async (mailbox: MailboxResponse) => {
    if (!confirm(`Eliminare la casella ${mailbox.email_address}? L'operazione è irreversibile.`)) return
    deleteMutation.mutate(mailbox.id)
  }

  const mailboxes = mailboxesData?.items || []

  return (
    <div className="flex flex-col h-full">
      {/* Header */}
      <div className="border-b bg-background px-6 py-4 flex items-center justify-between">
        <div className="flex items-center gap-2">
          <MailCheck className="h-5 w-5 text-primary" />
          <h1 className="text-xl font-semibold">Caselle PEC</h1>
          <span className="text-sm text-muted-foreground">({mailboxes.length})</span>
        </div>
        <Button onClick={() => setShowCreateDialog(true)}>
          <Plus className="h-4 w-4 mr-2" />
          Aggiungi casella
        </Button>
      </div>

      {/* Contenuto */}
      <div className="flex-1 overflow-y-auto p-6">
        {isLoading ? (
          <div className="flex justify-center py-12">
            <div className="h-8 w-8 animate-spin rounded-full border-4 border-primary border-t-transparent" />
          </div>
        ) : mailboxes.length === 0 ? (
          <div className="flex flex-col items-center justify-center py-12 text-center">
            <MailCheck className="h-12 w-12 text-muted-foreground/30 mb-3" />
            <p className="text-muted-foreground font-medium">Nessuna casella PEC configurata</p>
            <p className="text-sm text-muted-foreground/70 mt-1">
              Aggiungi una casella per iniziare a gestire le PEC
            </p>
            <Button className="mt-4" onClick={() => setShowCreateDialog(true)}>
              <Plus className="h-4 w-4 mr-2" />
              Aggiungi casella
            </Button>
          </div>
        ) : (
          <div className="grid gap-4">
            {mailboxes.map((mailbox) => {
              const StatusIcon = STATUS_ICONS[mailbox.status] || AlertCircle
              return (
                <div
                  key={mailbox.id}
                  className="rounded-lg border bg-card p-5 flex items-start justify-between gap-4"
                >
                  <div className="flex items-start gap-4 min-w-0">
                    <div className="h-10 w-10 rounded-lg bg-primary/10 flex items-center justify-center flex-shrink-0">
                      <MailCheck className="h-5 w-5 text-primary" />
                    </div>
                    <div className="min-w-0">
                      <div className="flex items-center gap-2 flex-wrap">
                        <h3 className="font-semibold text-foreground">
                          {mailbox.display_name || mailbox.email_address}
                        </h3>
                        <span
                          className={cn(
                            'inline-flex items-center gap-1 rounded-full px-2 py-0.5 text-xs font-medium',
                            STATUS_COLORS[mailbox.status],
                          )}
                        >
                          <StatusIcon className="h-3 w-3" />
                          {MAILBOX_STATUS_LABELS[mailbox.status]}
                        </span>
                        {mailbox.provider && (
                          <span className="text-xs text-muted-foreground bg-muted px-2 py-0.5 rounded">
                            {mailbox.provider}
                          </span>
                        )}
                      </div>
                      <p className="text-sm text-muted-foreground mt-0.5">{mailbox.email_address}</p>
                      <div className="flex gap-4 mt-2 text-xs text-muted-foreground">
                        <span>IMAP: {mailbox.imap_host}:{mailbox.imap_port}</span>
                        <span>SMTP: {mailbox.smtp_host}:{mailbox.smtp_port}</span>
                        {mailbox.last_sync_at && (
                          <span>Ultima sync: {formatDate(mailbox.last_sync_at)}</span>
                        )}
                      </div>
                      {mailbox.status === 'error' && mailbox.sync_error_msg && (
                        <p className="text-xs text-red-600 mt-1 flex items-center gap-1">
                          <AlertCircle className="h-3 w-3" />
                          {mailbox.sync_error_msg}
                        </p>
                      )}
                    </div>
                  </div>

                  <div className="flex items-center gap-2 flex-shrink-0">
                    {/* Test connessione */}
                    <Button
                      variant="outline"
                      size="sm"
                      onClick={() => handleTest(mailbox)}
                      isLoading={testingId === mailbox.id}
                      title="Testa connessione IMAP"
                    >
                      <TestTube className="h-4 w-4 mr-1" />
                      Test
                    </Button>

                    {/* Modifica */}
                    <Button
                      variant="outline"
                      size="sm"
                      onClick={() => setEditingMailbox(mailbox)}
                    >
                      <Edit className="h-4 w-4" />
                    </Button>

                    {/* Elimina */}
                    <Button
                      variant="outline"
                      size="sm"
                      onClick={() => handleDelete(mailbox)}
                      className="text-destructive hover:bg-destructive hover:text-destructive-foreground"
                    >
                      <Trash2 className="h-4 w-4" />
                    </Button>
                  </div>
                </div>
              )
            })}
          </div>
        )}
      </div>

      {/* Dialog crea/modifica casella */}
      <MailboxFormDialog
        open={showCreateDialog || editingMailbox !== null}
        onClose={() => {
          setShowCreateDialog(false)
          setEditingMailbox(null)
        }}
        editingMailbox={editingMailbox}
        onSaved={() => {
          queryClient.invalidateQueries({ queryKey: ['mailboxes'] })
          setShowCreateDialog(false)
          setEditingMailbox(null)
        }}
      />
    </div>
  )
}

// ─── Dialog creazione/modifica casella ───────────────────────────────────────

interface MailboxFormDialogProps {
  open: boolean
  onClose: () => void
  editingMailbox: MailboxResponse | null
  onSaved: () => void
}

function MailboxFormDialog({ open, onClose, editingMailbox, onSaved }: MailboxFormDialogProps) {
  const {
    register,
    handleSubmit,
    reset,
    formState: { errors },
  } = useForm<MailboxCreateRequest>({
    defaultValues: editingMailbox
      ? {
          email_address: editingMailbox.email_address,
          display_name: editingMailbox.display_name || '',
          provider: editingMailbox.provider || '',
          imap_host: editingMailbox.imap_host,
          imap_port: editingMailbox.imap_port,
          imap_user: editingMailbox.email_address,
          imap_use_ssl: editingMailbox.imap_use_ssl,
          smtp_host: editingMailbox.smtp_host,
          smtp_port: editingMailbox.smtp_port,
          smtp_user: editingMailbox.email_address,
          smtp_use_tls: editingMailbox.smtp_use_tls,
        }
      : {
          imap_port: 993,
          smtp_port: 465,
          imap_use_ssl: true,
          smtp_use_tls: true,
        },
  })

  const createMutation = useMutation({
    mutationFn: mailboxesApi.create,
    onSuccess: () => {
      toast.success('Casella creata con successo')
      onSaved()
      reset()
    },
    onError: (e) => toast.error(getErrorMessage(e)),
  })

  const updateMutation = useMutation({
    mutationFn: ({ id, data }: { id: string; data: MailboxCreateRequest }) =>
      mailboxesApi.update(id, data),
    onSuccess: () => {
      toast.success('Casella aggiornata')
      onSaved()
    },
    onError: (e) => toast.error(getErrorMessage(e)),
  })

  const onSubmit = (data: MailboxCreateRequest) => {
    if (editingMailbox) {
      updateMutation.mutate({ id: editingMailbox.id, data })
    } else {
      createMutation.mutate(data)
    }
  }

  const isLoading = createMutation.isPending || updateMutation.isPending

  return (
    <Dialog open={open} onOpenChange={(o) => !o && onClose()}>
      <DialogContent className="max-w-2xl max-h-[90vh] overflow-y-auto">
        <DialogHeader>
          <DialogTitle>
            {editingMailbox ? 'Modifica casella PEC' : 'Aggiungi casella PEC'}
          </DialogTitle>
        </DialogHeader>

        <form onSubmit={handleSubmit(onSubmit)} className="space-y-4 mt-4">
          {/* Info generali */}
          <div className="grid grid-cols-2 gap-4">
            <div className="col-span-2 space-y-2">
              <Label>Indirizzo PEC *</Label>
              <Input
                type="email"
                placeholder="casella@pec.it"
                disabled={!!editingMailbox}
                {...register('email_address', { required: 'Obbligatorio' })}
              />
            </div>
            <div className="space-y-2">
              <Label>Nome visualizzato</Label>
              <Input placeholder="Es: Casella principale" {...register('display_name')} />
            </div>
            <div className="space-y-2">
              <Label>Provider</Label>
              <Input placeholder="aruba, namirial..." {...register('provider')} />
            </div>
          </div>

          {/* Separatore IMAP */}
          <div className="space-y-3 rounded-lg border p-4">
            <h4 className="text-sm font-semibold">Configurazione IMAP (ricezione)</h4>
            <div className="grid grid-cols-2 gap-3">
              <div className="space-y-1.5">
                <Label className="text-xs">Server IMAP *</Label>
                <Input placeholder="imap.pec.it" {...register('imap_host', { required: true })} />
              </div>
              <div className="space-y-1.5">
                <Label className="text-xs">Porta</Label>
                <Input type="number" {...register('imap_port', { valueAsNumber: true })} />
              </div>
              <div className="space-y-1.5">
                <Label className="text-xs">Utente IMAP *</Label>
                <Input placeholder="casella@pec.it" {...register('imap_user', { required: true })} />
              </div>
              <div className="space-y-1.5">
                <Label className="text-xs">Password IMAP *</Label>
                <Input
                  type="password"
                  placeholder={editingMailbox ? '(invariata)' : ''}
                  {...register('imap_pass', {
                    required: !editingMailbox ? 'Obbligatoria' : false,
                  })}
                />
              </div>
            </div>
          </div>

          {/* Separatore SMTP */}
          <div className="space-y-3 rounded-lg border p-4">
            <h4 className="text-sm font-semibold">Configurazione SMTP (invio)</h4>
            <div className="grid grid-cols-2 gap-3">
              <div className="space-y-1.5">
                <Label className="text-xs">Server SMTP *</Label>
                <Input placeholder="smtp.pec.it" {...register('smtp_host', { required: true })} />
              </div>
              <div className="space-y-1.5">
                <Label className="text-xs">Porta</Label>
                <Input type="number" {...register('smtp_port', { valueAsNumber: true })} />
              </div>
              <div className="space-y-1.5">
                <Label className="text-xs">Utente SMTP *</Label>
                <Input placeholder="casella@pec.it" {...register('smtp_user', { required: true })} />
              </div>
              <div className="space-y-1.5">
                <Label className="text-xs">Password SMTP *</Label>
                <Input
                  type="password"
                  placeholder={editingMailbox ? '(invariata)' : ''}
                  {...register('smtp_pass', {
                    required: !editingMailbox ? 'Obbligatoria' : false,
                  })}
                />
              </div>
            </div>
          </div>

          <DialogFooter>
            <Button type="button" variant="outline" onClick={onClose}>
              Annulla
            </Button>
            <Button type="submit" isLoading={isLoading}>
              {editingMailbox ? 'Salva modifiche' : 'Crea casella'}
            </Button>
          </DialogFooter>
        </form>
      </DialogContent>
    </Dialog>
  )
}