import { ChevronDown, ChevronRight, Mail, ExternalLink } from 'lucide-react'
import { useState } from 'react'
import { useNavigate } from 'react-router-dom'
import { PecTypeBadge, PecStateBadge } from '@/components/PecBadge/PecBadge'
import { formatDate } from '@/lib/utils'
import type { MessageResponse } from '@/types/api.types'

interface ReceiptTreeProps {
  message: MessageResponse
  receipts: MessageResponse[]
}

/**
 * Visualizza la gerarchia delle ricevute PEC collegate a un messaggio.
 * Mostra in ordine cronologico: accettazione → consegna (o anomalia).
 * Le ricevute sono cliccabili e navigano al dettaglio del messaggio ricevuta.
 */
export function ReceiptTree({ message, receipts }: ReceiptTreeProps) {
  const [expanded, setExpanded] = useState(true)
  const navigate = useNavigate()

  if (receipts.length === 0) {
    if (message.direction === 'outbound') {
      return (
        <div className="rounded-lg border border-dashed border-muted-foreground/30 p-4 text-sm text-muted-foreground">
          <Mail className="mb-1 inline h-4 w-4 mr-1" />
          Nessuna ricevuta ancora ricevuta per questo messaggio.
        </div>
      )
    }
    return null
  }

  return (
    <div className="space-y-2">
      <button
        className="flex items-center gap-2 text-sm font-medium text-foreground hover:text-primary"
        onClick={() => setExpanded(!expanded)}
      >
        {expanded ? (
          <ChevronDown className="h-4 w-4" />
        ) : (
          <ChevronRight className="h-4 w-4" />
        )}
        Ricevute ({receipts.length})
      </button>

      {expanded && (
        <div className="ml-4 space-y-2 border-l-2 border-muted pl-4">
          {/* Messaggio originale */}
          <ReceiptNode
            label="Messaggio inviato"
            date={message.sent_at || message.created_at}
            state={message.state}
            isRoot
          />

          {/* Ricevute in ordine cronologico */}
          {[...receipts]
            .sort(
              (a, b) =>
                new Date(a.received_at || a.created_at).getTime() -
                new Date(b.received_at || b.created_at).getTime(),
            )
            .map((receipt) => (
              <ReceiptNode
                key={receipt.id}
                label={receipt.subject || 'Ricevuta'}
                date={receipt.received_at || receipt.created_at}
                type={receipt.pec_type}
                messageId={receipt.id}
                onClick={() => navigate(`/messages/${receipt.id}`)}
              />
            ))}
        </div>
      )}
    </div>
  )
}

interface ReceiptNodeProps {
  label: string
  date: string | null
  state?: MessageResponse['state']
  type?: MessageResponse['pec_type']
  messageId?: string
  isRoot?: boolean
  onClick?: () => void
}

function ReceiptNode({ label, date, state, type, isRoot, onClick }: ReceiptNodeProps) {
  const isClickable = !!onClick

  const content = (
    <div className="flex items-start gap-3">
      {/* Indicatore timeline */}
      <div className="mt-1 flex flex-col items-center">
        <div
          className={`h-3 w-3 rounded-full border-2 ${
            isRoot
              ? 'border-primary bg-primary/20'
              : isClickable
                ? 'border-blue-500 bg-blue-100'
                : 'border-muted-foreground bg-muted'
          }`}
        />
      </div>

      <div className="flex-1 min-w-0">
        <div className="flex items-center gap-2 flex-wrap">
          <span
            className={`text-sm font-medium truncate ${
              isClickable ? 'text-blue-600 group-hover:underline' : ''
            }`}
          >
            {label}
          </span>
          {state && !isRoot && <PecStateBadge state={state} />}
          {type && type !== 'posta_certificata' && <PecTypeBadge type={type} />}
          {isClickable && (
            <ExternalLink className="h-3.5 w-3.5 text-blue-400 group-hover:text-blue-600 flex-shrink-0" />
          )}
        </div>
        {date && (
          <p className="text-xs text-muted-foreground mt-0.5">{formatDate(date)}</p>
        )}
      </div>
    </div>
  )

  if (isClickable) {
    return (
      <button
        type="button"
        onClick={onClick}
        className="w-full text-left group rounded-md px-2 py-1 -mx-2 hover:bg-muted/50 transition-colors cursor-pointer"
        title="Apri dettaglio ricevuta"
      >
        {content}
      </button>
    )
  }

  return <div>{content}</div>
}