'use client'

import { useEffect, useState } from 'react'
import { trpc } from '@/lib/trpc/client'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import { Label } from '@/components/ui/label'
import { Textarea } from '@/components/ui/textarea'
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from '@/components/ui/dialog'
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from '@/components/ui/select'
import { Loader2 } from 'lucide-react'
import { toast } from 'sonner'
import type { VisaStatus } from '@prisma/client'

const STATUS_OPTIONS: { value: VisaStatus; label: string }[] = [
  { value: 'NOT_NEEDED', label: 'Not needed' },
  { value: 'REQUESTED', label: 'Requested' },
  { value: 'INVITATION_SENT', label: 'Invitation sent' },
  { value: 'APPOINTMENT_BOOKED', label: 'Appointment booked' },
  { value: 'GRANTED', label: 'Granted' },
  { value: 'DENIED', label: 'Denied' },
]

function toDateInputValue(d: Date | null | undefined): string {
  if (!d) return ''
  const dt = new Date(d)
  if (Number.isNaN(dt.getTime())) return ''
  // YYYY-MM-DD for <input type="date">
  return dt.toISOString().slice(0, 10)
}

function fromDateInputValue(s: string): Date | null {
  if (!s) return null
  const dt = new Date(s)
  return Number.isNaN(dt.getTime()) ? null : dt
}

export type VisaEditTarget = {
  id: string
  status: VisaStatus
  nationality: string | null
  invitationSentAt: Date | null
  appointmentAt: Date | null
  decisionAt: Date | null
  notes: string | null
  attendeeName: string
  projectTitle: string
}

export function VisaEditDialog({
  open,
  target,
  programId,
  onOpenChange,
}: {
  open: boolean
  target: VisaEditTarget | null
  programId: string
  onOpenChange: (next: boolean) => void
}) {
  const utils = trpc.useUtils()
  const [status, setStatus] = useState<VisaStatus>('REQUESTED')
  const [nationality, setNationality] = useState('')
  const [invitationSent, setInvitationSent] = useState('')
  const [appointment, setAppointment] = useState('')
  const [decision, setDecision] = useState('')
  const [notes, setNotes] = useState('')

  useEffect(() => {
    if (target && open) {
      setStatus(target.status)
      setNationality(target.nationality ?? '')
      setInvitationSent(toDateInputValue(target.invitationSentAt))
      setAppointment(toDateInputValue(target.appointmentAt))
      setDecision(toDateInputValue(target.decisionAt))
      setNotes(target.notes ?? '')
    }
  }, [target, open])

  const mutation = trpc.logistics.updateVisaApplication.useMutation({
    onSuccess: () => {
      toast.success('Visa application updated')
      utils.logistics.listVisaApplications.invalidate({ programId })
      onOpenChange(false)
    },
    onError: (e) => toast.error(e.message),
  })

  const handleSave = () => {
    if (!target) return
    mutation.mutate({
      id: target.id,
      status,
      nationality: nationality.trim() || null,
      invitationSentAt: fromDateInputValue(invitationSent),
      appointmentAt: fromDateInputValue(appointment),
      decisionAt: fromDateInputValue(decision),
      notes: notes.trim() || null,
    })
  }

  return (
    <Dialog
      open={open}
      onOpenChange={(next) => {
        if (!mutation.isPending) onOpenChange(next)
      }}
    >
      <DialogContent className="sm:max-w-md">
        <DialogHeader>
          <DialogTitle>Update visa application</DialogTitle>
          <DialogDescription>
            {target
              ? `${target.attendeeName} · ${target.projectTitle}`
              : 'Loading…'}
          </DialogDescription>
        </DialogHeader>

        <div className="space-y-4">
          <div className="space-y-2">
            <Label htmlFor="visa-status">Status</Label>
            <Select value={status} onValueChange={(v) => setStatus(v as VisaStatus)}>
              <SelectTrigger id="visa-status">
                <SelectValue />
              </SelectTrigger>
              <SelectContent>
                {STATUS_OPTIONS.map((o) => (
                  <SelectItem key={o.value} value={o.value}>
                    {o.label}
                  </SelectItem>
                ))}
              </SelectContent>
            </Select>
          </div>

          <div className="space-y-2">
            <Label htmlFor="visa-nationality">Nationality</Label>
            <Input
              id="visa-nationality"
              value={nationality}
              onChange={(e) => setNationality(e.target.value)}
              placeholder="Self-declared, optional"
            />
          </div>

          <div className="grid grid-cols-1 gap-3 sm:grid-cols-3">
            <div className="space-y-2">
              <Label htmlFor="visa-invitation">Invitation sent</Label>
              <Input
                id="visa-invitation"
                type="date"
                value={invitationSent}
                onChange={(e) => setInvitationSent(e.target.value)}
              />
            </div>
            <div className="space-y-2">
              <Label htmlFor="visa-appointment">Appointment</Label>
              <Input
                id="visa-appointment"
                type="date"
                value={appointment}
                onChange={(e) => setAppointment(e.target.value)}
              />
            </div>
            <div className="space-y-2">
              <Label htmlFor="visa-decision">Decision</Label>
              <Input
                id="visa-decision"
                type="date"
                value={decision}
                onChange={(e) => setDecision(e.target.value)}
              />
            </div>
          </div>

          <div className="space-y-2">
            <Label htmlFor="visa-notes">Notes</Label>
            <Textarea
              id="visa-notes"
              value={notes}
              onChange={(e) => setNotes(e.target.value)}
              rows={3}
              placeholder="Free-text notes — embassy, contact, follow-ups, etc. No documents."
            />
          </div>
        </div>

        <DialogFooter>
          <Button
            variant="outline"
            onClick={() => onOpenChange(false)}
            disabled={mutation.isPending}
          >
            Cancel
          </Button>
          <Button onClick={handleSave} disabled={!target || mutation.isPending}>
            {mutation.isPending && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
            Save
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  )
}