import { useState } from 'react'
import type { MediaRef, Page } from '@/types/nostr'
import { uploadNip95Media } from '@/lib/nip95'
import { t } from '@/lib/i18n'

interface MarkdownEditorTwoColumnsProps {
  value: string
  onChange: (value: string) => void
  pages?: Page[]
  onPagesChange?: (pages: Page[]) => void
  onMediaAdd?: (media: MediaRef) => void
  onBannerChange?: (url: string) => void
}

export function MarkdownEditorTwoColumns({
  value,
  onChange,
  pages = [],
  onPagesChange,
  onMediaAdd,
  onBannerChange,
}: MarkdownEditorTwoColumnsProps): React.ReactElement {
  const [uploading, setUploading] = useState(false)
  const [error, setError] = useState<string | null>(null)

  const handleAddPage = (type: 'markdown' | 'image'): void => {
    if (!onPagesChange) {
      return
    }
    const newPage: Page = {
      number: pages.length + 1,
      type,
      content: type === 'markdown' ? '' : '',
    }
    onPagesChange([...pages, newPage])
  }

  const handlePageContentChange = (pageNumber: number, content: string): void => {
    if (!onPagesChange) {
      return
    }
    const updatedPages = pages.map((p) => (p.number === pageNumber ? { ...p, content } : p))
    onPagesChange(updatedPages)
  }

  const handlePageTypeChange = (pageNumber: number, type: 'markdown' | 'image'): void => {
    if (!onPagesChange) {
      return
    }
    const updatedPages = pages.map((p) => (p.number === pageNumber ? { ...p, type, content: '' } : p))
    onPagesChange(updatedPages)
  }

  const handleRemovePage = (pageNumber: number): void => {
    if (!onPagesChange) {
      return
    }
    const updatedPages = pages
      .filter((p) => p.number !== pageNumber)
      .map((p, index) => ({ ...p, number: index + 1 }))
    onPagesChange(updatedPages)
  }

  const handleImageUpload = async (file: File, pageNumber?: number): Promise<void> => {
    setError(null)
    setUploading(true)
    try {
      const media = await uploadNip95Media(file)
      if (media.type === 'image') {
        if (pageNumber !== undefined && onPagesChange) {
          handlePageContentChange(pageNumber, media.url)
        } else {
          onBannerChange?.(media.url)
        }
        onMediaAdd?.(media)
      }
    } catch (e) {
      setError(e instanceof Error ? e.message : t('upload.error.failed'))
    } finally {
      setUploading(false)
    }
  }

  return (
    <div className="space-y-4">
      <MarkdownToolbar
        onFileSelected={(file) => {
          void handleImageUpload(file)
        }}
        uploading={uploading}
        error={error}
        onAddPage={onPagesChange ? handleAddPage : undefined}
      />
      <div className="grid grid-cols-2 gap-4">
        <div className="space-y-2">
          <label className="block text-sm font-semibold text-gray-800">{t('markdown.editor')}</label>
          <textarea
            className="w-full border rounded p-3 h-96 font-mono text-sm"
            value={value}
            onChange={(e) => onChange(e.target.value)}
            placeholder={t('markdown.placeholder')}
          />
        </div>
        <div className="space-y-2">
          <label className="block text-sm font-semibold text-gray-800">{t('markdown.preview')}</label>
          <MarkdownPreview value={value} />
        </div>
      </div>
      {onPagesChange && (
        <PagesManager
          pages={pages}
          onPageContentChange={handlePageContentChange}
          onPageTypeChange={handlePageTypeChange}
          onRemovePage={handleRemovePage}
          onImageUpload={handleImageUpload}
        />
      )}
    </div>
  )
}

function MarkdownToolbar({
  onFileSelected,
  uploading,
  error,
  onAddPage,
}: {
  onFileSelected: (file: File) => void
  uploading: boolean
  error: string | null
  onAddPage?: (type: 'markdown' | 'image') => void
}): React.ReactElement {
  return (
    <div className="flex items-center gap-2 flex-wrap">
      <label className="px-3 py-1 text-sm rounded bg-blue-600 text-white cursor-pointer hover:bg-blue-700">
        {t('markdown.upload.media')}
        <input
          type="file"
          accept=".png,.jpg,.jpeg,.webp"
          className="hidden"
          onChange={(e) => {
            const file = e.target.files?.[0]
            if (file) {
              onFileSelected(file)
            }
          }}
        />
      </label>
      {onAddPage && (
        <>
          <button
            type="button"
            className="px-3 py-1 text-sm rounded bg-green-600 text-white hover:bg-green-700"
            onClick={() => onAddPage('markdown')}
          >
            {t('page.add.markdown')}
          </button>
          <button
            type="button"
            className="px-3 py-1 text-sm rounded bg-purple-600 text-white hover:bg-purple-700"
            onClick={() => onAddPage('image')}
          >
            {t('page.add.image')}
          </button>
        </>
      )}
      {uploading && <span className="text-sm text-gray-500">{t('markdown.upload.uploading')}</span>}
      {error && <span className="text-sm text-red-600">{error}</span>}
    </div>
  )
}

function MarkdownPreview({ value }: { value: string }): React.ReactElement {
  return (
    <div className="prose max-w-none border rounded p-3 bg-white h-96 overflow-y-auto whitespace-pre-wrap">
      {value || <span className="text-gray-400">{t('markdown.preview.empty')}</span>}
    </div>
  )
}

function PagesManager({
  pages,
  onPageContentChange,
  onPageTypeChange,
  onRemovePage,
  onImageUpload,
}: {
  pages: Page[]
  onPageContentChange: (pageNumber: number, content: string) => void
  onPageTypeChange: (pageNumber: number, type: 'markdown' | 'image') => void
  onRemovePage: (pageNumber: number) => void
  onImageUpload: (file: File, pageNumber: number) => Promise<void>
}): React.ReactElement {
  if (pages.length === 0) {
    return <div className="text-sm text-gray-500">{t('page.empty')}</div>
  }

  return (
    <div className="space-y-4">
      <h3 className="text-lg font-semibold">{t('page.title')}</h3>
      {pages.map((page) => (
        <PageEditor
          key={page.number}
          page={page}
          onContentChange={(content) => onPageContentChange(page.number, content)}
          onTypeChange={(type) => onPageTypeChange(page.number, type)}
          onRemove={() => onRemovePage(page.number)}
          onImageUpload={(file) => {
            void onImageUpload(file, page.number)
          }}
        />
      ))}
    </div>
  )
}

function PageEditor({
  page,
  onContentChange,
  onTypeChange,
  onRemove,
  onImageUpload,
}: {
  page: Page
  onContentChange: (content: string) => void
  onTypeChange: (type: 'markdown' | 'image') => void
  onRemove: () => void
  onImageUpload: (file: File) => Promise<void>
}): React.ReactElement {
  return (
    <div className="border rounded-lg p-4 space-y-3">
      <div className="flex items-center justify-between">
        <h4 className="font-semibold">
          {t('page.number', { number: page.number })} - {t(`page.type.${page.type}`)}
        </h4>
        <div className="flex items-center gap-2">
          <select
            value={page.type}
            onChange={(e) => onTypeChange(e.target.value as 'markdown' | 'image')}
            className="text-sm border rounded px-2 py-1"
          >
            <option value="markdown">{t('page.type.markdown')}</option>
            <option value="image">{t('page.type.image')}</option>
          </select>
          <button
            type="button"
            className="px-2 py-1 text-sm rounded bg-red-600 text-white hover:bg-red-700"
            onClick={onRemove}
          >
            {t('page.remove')}
          </button>
        </div>
      </div>
      {page.type === 'markdown' ? (
        <textarea
          className="w-full border rounded p-2 h-48 font-mono text-sm"
          value={page.content}
          onChange={(e) => onContentChange(e.target.value)}
          placeholder={t('page.markdown.placeholder')}
        />
      ) : (
        <div className="space-y-2">
          {page.content ? (
            <div className="relative">
              <img src={page.content} alt={t('page.image.alt', { number: page.number })} className="max-w-full h-auto rounded" />
              <button
                type="button"
                className="absolute top-2 right-2 px-2 py-1 text-sm rounded bg-red-600 text-white hover:bg-red-700"
                onClick={() => onContentChange('')}
              >
                {t('page.image.remove')}
              </button>
            </div>
          ) : (
            <label className="block px-3 py-2 text-sm rounded bg-blue-600 text-white cursor-pointer hover:bg-blue-700 text-center">
              {t('page.image.upload')}
              <input
                type="file"
                accept=".png,.jpg,.jpeg,.webp"
                className="hidden"
                onChange={(e) => {
                  const file = e.target.files?.[0]
                  if (file) {
                    void onImageUpload(file)
                  }
                }}
              />
            </label>
          )}
        </div>
      )}
    </div>
  )
}