'use client'

import Link from 'next/link'
import { Star, Paperclip } from 'lucide-react'
import { cn } from '@/lib/utils'
import { Skeleton } from '@/components/ui/skeleton'

export interface MessageListItem {
  uid: number
  from: { name: string; address: string } | null
  subject: string
  date: string
  flags: string[]
  preview: string
}

interface MessageListProps {
  messages: MessageListItem[]
  folder: string
  loading?: boolean
  selectedUid?: number
}

function formatDate(dateStr: string): string {
  const date = new Date(dateStr)
  const now = new Date()
  const diffMs = now.getTime() - date.getTime()
  const diffDays = Math.floor(diffMs / (1000 * 60 * 60 * 24))

  if (diffDays === 0) {
    return date.toLocaleTimeString(undefined, { hour: '2-digit', minute: '2-digit' })
  }
  if (diffDays === 1) return 'Yesterday'
  if (diffDays < 7) {
    return date.toLocaleDateString(undefined, { weekday: 'short' })
  }
  return date.toLocaleDateString(undefined, { month: 'short', day: 'numeric' })
}

function senderDisplay(from: { name: string; address: string } | null): string {
  if (!from) return 'Unknown'
  return from.name || from.address
}

function senderInitial(from: { name: string; address: string } | null): string {
  const display = senderDisplay(from)
  return display.charAt(0).toUpperCase()
}

export function MessageList({ messages, folder, loading, selectedUid }: MessageListProps) {
  if (loading) {
    return (
      <div className="divide-y">
        {Array.from({ length: 8 }).map((_, i) => (
          <div key={i} className="flex items-start gap-3 p-4">
            <Skeleton className="h-9 w-9 rounded-full shrink-0" />
            <div className="flex-1 space-y-2">
              <Skeleton className="h-4 w-32" />
              <Skeleton className="h-4 w-48" />
              <Skeleton className="h-3 w-64" />
            </div>
            <Skeleton className="h-3 w-12" />
          </div>
        ))}
      </div>
    )
  }

  if (messages.length === 0) {
    return (
      <div className="flex flex-col items-center justify-center py-16 text-muted-foreground">
        <p className="text-sm">No messages</p>
      </div>
    )
  }

  return (
    <div className="divide-y">
      {messages.map((msg) => {
        const isRead = msg.flags.includes('\\Seen')
        const isStarred = msg.flags.includes('\\Flagged')
        const encodedFolder = encodeURIComponent(folder)

        return (
          <Link
            key={msg.uid}
            href={`/email/${encodedFolder}/${msg.uid}`}
            className={cn(
              'flex items-start gap-3 p-4 transition-colors hover:bg-accent/50',
              !isRead && 'bg-accent/20',
              selectedUid === msg.uid && 'bg-accent'
            )}
          >
            <div
              className={cn(
                'flex h-9 w-9 items-center justify-center rounded-full shrink-0 text-sm font-medium',
                isRead
                  ? 'bg-muted text-muted-foreground'
                  : 'bg-primary text-primary-foreground'
              )}
            >
              {senderInitial(msg.from)}
            </div>

            <div className="flex-1 min-w-0">
              <div className="flex items-center gap-2">
                <span
                  className={cn(
                    'text-sm truncate',
                    !isRead && 'font-semibold'
                  )}
                >
                  {senderDisplay(msg.from)}
                </span>
                {isStarred && (
                  <Star className="h-3.5 w-3.5 fill-yellow-400 text-yellow-400 shrink-0" />
                )}
              </div>
              <p
                className={cn(
                  'text-sm truncate',
                  !isRead ? 'font-medium text-foreground' : 'text-muted-foreground'
                )}
              >
                {msg.subject}
              </p>
              {msg.preview && (
                <p className="text-xs text-muted-foreground truncate mt-0.5">
                  {msg.preview}
                </p>
              )}
            </div>

            <span className="text-xs text-muted-foreground whitespace-nowrap shrink-0">
              {formatDate(msg.date)}
            </span>
          </Link>
        )
      })}
    </div>
  )
}