import React, { useEffect, useState, useRef } from 'react'
import { ArrowLeft, Plus, FileText, File as FileIcon, MoreVertical, Trash2, Edit2, MessageSquare, Eye, EyeOff, Database, Book } from 'lucide-react'
import ReactMarkdown from 'react-markdown'
import { KnowledgeGroup, KnowledgeFile } from '../../types'
import { noteService, Note } from '../../services/noteService'
import { knowledgeBaseService } from '../../services/knowledgeBaseService'
import { modelConfigService } from '../../services/modelConfigService'
import { uploadService } from '../../services/uploadService'
import { knowledgeGroupService } from '../../services/knowledgeGroupService'
import { useToast } from '../../contexts/ToastContext'
import { ModelType, RawFile, IndexingConfig, ModelConfig } from '../../types'
import IndexingModalWithMode from '../IndexingModalWithMode'
import { PDFPreview, PDFPreviewButton } from '../PDFPreview'
import { AICommandDrawer } from '../AICommandDrawer'
import { ImportFolderDrawer } from '../ImportFolderDrawer'
import { NotebookGlobalDragDropOverlay } from '../NotebookGlobalDragDropOverlay'
import { useLanguage } from '../../contexts/LanguageContext'
import { readFile } from '../../utils/fileUtils'
import { Sparkles } from 'lucide-react'
import remarkGfm from 'remark-gfm'
import remarkMath from 'remark-math'
import rehypeKatex from 'rehype-katex'
import mermaid from 'mermaid'
import { Prism as SyntaxHighlighter } from 'react-syntax-highlighter'
import { oneLight } from 'react-syntax-highlighter/dist/esm/styles/prism'

// mermaid の初期化
mermaid.initialize({
    startOnLoad: false,
    theme: 'default',
    securityLevel: 'loose',
})

const Mermaid = ({ chart }: { chart: string }) => {
    const [svg, setSvg] = useState('')
    const [error, setError] = useState('')
    const { t } = useLanguage()

    useEffect(() => {
        const renderChart = async () => {
            try {
                const id = `mermaid-${Math.random().toString(36).substr(2, 9)}`
                const { svg } = await mermaid.render(id, chart)
                setSvg(svg)
                setError('')
            } catch (err) {
                console.error('Mermaid render error:', err)
                setError(t('errorRenderFlowchart'))
            }
        }
        if (chart) renderChart()
    }, [chart])

    if (error) return <div className="text-red-500 text-sm bg-red-50 p-2 rounded">{error}</div>
    return <div className="mermaid-chart my-4 flex justify-center" dangerouslySetInnerHTML={{ __html: svg }} />
}

interface NotebookDetailViewProps {
    authToken: string;
    notebook: KnowledgeGroup;
    onBack: () => void;
    onChatWithContext?: (context: { selectedGroups?: string[], selectedFiles?: string[] }) => void;
    isAdmin?: boolean;
}

export const NotebookDetailView: React.FC<NotebookDetailViewProps> = ({ authToken, notebook, onBack, onChatWithContext, isAdmin = false }) => {
    const [activeTab, setActiveTab] = useState<'files' | 'notes'>('files')
    const [files, setFiles] = useState<KnowledgeFile[]>([])
    const [notes, setNotes] = useState<Note[]>([])
    const [isLoading, setIsLoading] = useState(false)
    const { showError, showSuccess } = useToast()
    const { t, language } = useLanguage()

    // メモエディタの状態
    const [isEditingNote, setIsEditingNote] = useState(false)
    const [currentNote, setCurrentNote] = useState<Partial<Note>>({})
    const [showPreview, setShowPreview] = useState(true)

    const [isUploading, setIsUploading] = useState(false)
    const fileInputRef = React.useRef<HTMLInputElement>(null)
    const [isImportDrawerOpen, setIsImportDrawerOpen] = useState(false)

    // インデックスモーダルの状態
    const [isIndexingModalOpen, setIsIndexingModalOpen] = useState(false)
    const [pendingFiles, setPendingFiles] = useState<RawFile[]>([])
    const [models, setModels] = useState<ModelConfig[]>([])

    // PDFプレビューの状態
    const [previewFile, setPreviewFile] = useState<{ id: string, name: string } | null>(null);

    // AIアシスタントの状態
    const [isAIModalOpen, setIsAIModalOpen] = useState(false)

    useEffect(() => {
        // モーダル用のモデルを取得
        const fetchModels = async () => {
            try {
                const res = await modelConfigService.getAll(authToken)
                setModels(res)
            } catch (error) {
                console.error('Failed to fetch models', error)
            }
        }
        if (authToken) fetchModels()
    }, [authToken])

    const loadData = async () => {
        setIsLoading(true)
        try {
            const [allFiles, notebookNotes] = await Promise.all([
                knowledgeBaseService.getAll(authToken),
                noteService.getAll(authToken, notebook.id)
            ])

            const notebookFiles = allFiles.filter(f => f.groups?.some(g => g.id === notebook.id))
            setFiles(notebookFiles)
            setNotes(notebookNotes)
        } catch (error) {
            console.error(error)
            showError(t('errorLoadData'))
        } finally {
            setIsLoading(false)
        }
    }

    useEffect(() => {
        loadData()
    }, [authToken, notebook.id, activeTab])

    const handleFileUpload = async (e: React.ChangeEvent<HTMLInputElement>) => {
        const file = e.target.files?.[0]
        if (!file) return

        try {
            // ファイルの有効性をチェック
            const ext = file.name.split('.').pop()?.toLowerCase()
            const allowedExts = ['pdf', 'doc', 'docx', 'txt', 'md', 'html', 'json']
            if (!ext || !allowedExts.includes(ext)) {
                if (!window.confirm(t('confirmUnsupportedFile', ext))) {
                    if (fileInputRef.current) fileInputRef.current.value = ''
                    return;
                }
            }

            // ファイルを読み込んでモーダルを開く
            const rawFile = await readFile(file)
            setPendingFiles([rawFile])
            setIsIndexingModalOpen(true)

        } catch (error) {
            console.error(error)
            showError(t('errorReadFile', error.message || t('unknownError')))
        } finally {
            if (fileInputRef.current) {
                fileInputRef.current.value = ''
            }
        }
    }

    const handleConfirmIndexing = async (config: IndexingConfig) => {
        setIsUploading(true)
        setIsIndexingModalOpen(false)

        try {
            for (const rawFile of pendingFiles) {
                let uploadRes;
                if (rawFile.isNote) {
                    uploadRes = await uploadService.uploadText(rawFile.textContent || rawFile.content, rawFile.name, config, authToken)
                } else {
                    uploadRes = await uploadService.uploadFileWithConfig(rawFile.file, config, authToken)
                }

                if (uploadRes && uploadRes.id) {
                    await knowledgeGroupService.addFileToGroups(uploadRes.id, [notebook.id])
                }
            }
            showSuccess(t('successUploadFile'))
            loadData()
        } catch (error) {
            console.error(error)
            showError(t('errorUploadFile', error.message || t('unknownError')))
        } finally {
            setIsUploading(false)
            setPendingFiles([])
        }
    }

    const handleIndexNote = async (note: Note) => {
        if (!note.title || !note.content) return;
        try {
            const file = new File([note.content], `${note.title}.md`, { type: 'text/markdown' });
            const rawFile = await readFile(file);
            rawFile.isNote = true;
            rawFile.textContent = note.content;
            setPendingFiles([rawFile]);
            setIsIndexingModalOpen(true);
        } catch (error) {
            console.error(error);
            showError(t('errorProcessFile'));
        }
    }

    const handleSaveNote = async () => {
        if (!currentNote.title || !currentNote.content) {
            showError(t('errorTitleContentRequired'))
            return
        }

        try {
            if (currentNote.id) {
                await noteService.update(authToken, currentNote.id, {
                    title: currentNote.title,
                    content: currentNote.content
                })
                showSuccess(t('successNoteUpdated'))
            } else {
                await noteService.create(authToken, {
                    title: currentNote.title,
                    content: currentNote.content,
                    groupId: notebook.id
                })
                showSuccess(t('successNoteCreated'))
            }
            setIsEditingNote(false)
            setCurrentNote({})
            loadData()
        } catch (error: any) {
            console.error('Save note error:', error)
            showError(t('errorSaveFailed', error.message || t('unknownError')))
        }
    }

    const handleDeleteNote = async (id: string) => {
        if (!window.confirm(t('confirmDeleteNote'))) return
        try {
            await noteService.delete(authToken, id)
            showSuccess(t('successNoteDeleted'))
            loadData()
        } catch (error) {
            showError(t('deleteFailed'))
        }
    }

    const handleRemoveFile = async (fileId: string, fileName: string) => {
        if (!window.confirm(t('confirmRemoveFileFromGroup', fileName))) return;

        try {
            const { knowledgeGroupService } = await import('../../services/knowledgeGroupService');

            await knowledgeGroupService.removeFileFromGroup(fileId, notebook.id);
            showSuccess(t('fileDeleted'));
            loadData();
        } catch (error) {
            console.error(error);
            showError(t('deleteFailed'));
        }
    }

    // メモエディタのレンダリング
    if (isEditingNote) {
        return (
            <div className="flex flex-col h-full bg-slate-50">
                {/* エディタヘッダー */}
                <div className="h-14 bg-white border-b border-slate-200 flex items-center px-4 justify-between shrink-0">
                    <div className="flex items-center gap-2">
                        <button onClick={() => setIsEditingNote(false)} className="p-2 hover:bg-slate-100 rounded-full">
                            <ArrowLeft size={20} className="text-slate-500" />
                        </button>
                        <h2 className="font-semibold text-slate-800">{currentNote.id ? t('editNote') : t('newNote')}</h2>
                    </div>
                    <div className="flex items-center gap-2">
                        <button
                            onClick={handleSaveNote}
                            className="px-4 py-1.5 bg-blue-600 text-white text-sm rounded-lg hover:bg-blue-700 shadow-sm"
                        >
                            {t('save')}
                        </button>
                        <div className="h-6 w-px bg-slate-200 mx-1"></div>
                        <button
                            onClick={() => setShowPreview(!showPreview)}
                            className={`p-2 rounded-lg transition-colors ${showPreview ? 'bg-blue-50 text-blue-600' : 'text-slate-400 hover:bg-slate-100 hover:text-slate-600'}`}
                            title={showPreview ? t('togglePreviewClose') : t('togglePreviewOpen')}
                        >
                            {showPreview ? <Eye size={20} /> : <EyeOff size={20} />}
                        </button>
                        <button
                            onClick={() => setIsAIModalOpen(true)}
                            className={`p-2 rounded-lg transition-colors ${isAIModalOpen ? 'bg-purple-100 text-purple-600' : 'text-slate-400 hover:text-purple-600 hover:bg-purple-50'}`}
                            title={t('aiAssistant')}
                        >
                            <Sparkles size={20} />
                        </button>
                    </div>
                </div>

                <div className="flex-1 overflow-hidden w-full max-w-[95%] mx-auto flex flex-col p-4">
                    <input
                        type="text"
                        placeholder={t('noteTitlePlaceholder')}
                        value={currentNote.title || ''}
                        onChange={e => setCurrentNote(prev => ({ ...prev, title: e.target.value }))}
                        className="w-full text-2xl font-bold border-none outline-none bg-transparent mb-4 placeholder-slate-300 shrink-0 px-2"
                    />

                    <div className="flex-1 flex gap-4 min-h-0">
                        {/* エディタ */}
                        <div className={`flex flex-col transition-all duration-300 ${showPreview ? 'w-1/2' : 'w-full'}`}>
                            <textarea
                                placeholder={t('noteContentPlaceholder')}
                                value={currentNote.content || ''}
                                onChange={e => setCurrentNote(prev => ({ ...prev, content: e.target.value }))}
                                className="w-full h-full resize-none border border-slate-200 rounded-lg bg-white p-4 text-base leading-relaxed placeholder-slate-300 font-mono focus:ring-2 focus:ring-blue-500 focus:border-transparent outline-none shadow-sm"
                            />
                        </div>

                        {/* プレビュー */}
                        {showPreview && (
                            <div className="w-1/2 bg-white border border-slate-200 rounded-lg p-6 overflow-y-auto shadow-sm prose prose-slate max-w-none">
                                {currentNote.content ? (
                                    <ReactMarkdown
                                        remarkPlugins={[remarkGfm, remarkMath]}
                                        rehypePlugins={[rehypeKatex]}
                                        components={{
                                            code({ node, inline, className, children, ...props }: any) {
                                                const match = /language-(\w+)/.exec(className || '')
                                                const isMermaid = match && match[1] === 'mermaid'

                                                if (!inline && isMermaid) {
                                                    return <Mermaid chart={String(children).replace(/\n$/, '')} />
                                                }

                                                return !inline && match ? (
                                                    <SyntaxHighlighter
                                                        style={oneLight}
                                                        language={match[1]}
                                                        PreTag="div"
                                                        {...props}
                                                    >
                                                        {String(children).replace(/\n$/, '')}
                                                    </SyntaxHighlighter>
                                                ) : (
                                                    <code className={className} {...props}>
                                                        {children}
                                                    </code>
                                                )
                                            }
                                        }}
                                    >
                                        {currentNote.content}
                                    </ReactMarkdown>
                                ) : (
                                    <div className="text-slate-300 text-center mt-10 italic">{t('markdownPreviewArea')}</div>
                                )}
                            </div>
                        )}
                    </div>
                </div>

                {/* AIコマンドドロワー - エディタ表示用 */}
                <AICommandDrawer
                    isOpen={isAIModalOpen}
                    onClose={() => setIsAIModalOpen(false)}
                    context={currentNote.content || ''}
                    authToken={authToken}
                    onApply={(newContent) => {
                        setCurrentNote(prev => ({ ...prev, content: newContent }))
                    }}
                />
            </div>
        )
    }

    return (
        <div className="flex flex-col h-full bg-slate-50">
            {/* ヘッダー */}
            <div className="bg-white border-b border-slate-200 px-6 py-4 flex items-center justify-between shrink-0 shadow-sm z-10">
                <div className="flex items-center gap-4">
                    <button onClick={onBack} className="p-2 -ml-2 hover:bg-slate-100 rounded-full transition-colors" title={t('back')}>
                        <ArrowLeft size={20} className="text-slate-500" />
                    </button>
                    <div>
                        <h1 className="font-bold text-slate-800 text-xl flex items-center gap-2">
                            <Book className="w-6 h-6 text-blue-600" />
                            <span className="bg-gradient-to-r from-blue-600 to-purple-600 text-transparent bg-clip-text">
                                {notebook.name}
                            </span>
                        </h1>
                        {notebook.description && <p className="text-sm text-slate-500 max-w-[300px] truncate mt-1">{notebook.description}</p>}
                    </div>

                    <div className="h-6 w-px bg-slate-200 mx-2"></div>

                    <button
                        onClick={() => onChatWithContext?.({ selectedGroups: [notebook.id] })}
                        className="flex items-center gap-2 px-3 py-1.5 text-blue-600 bg-blue-50 hover:bg-blue-100 rounded-lg transition-colors"
                        title={t('chatWithGroup')}
                    >
                        <MessageSquare size={18} />
                        <span className="text-sm font-medium">{t('chatWithGroup')}</span>
                    </button>
                </div>

                <div className="flex bg-slate-100 p-1 rounded-lg">
                    <button
                        onClick={() => setActiveTab('files')}
                        className={`px-4 py-1.5 text-sm font-medium rounded-md transition-all duration-200 ${activeTab === 'files'
                            ? 'bg-white text-slate-800 shadow-sm'
                            : 'text-slate-500 hover:text-slate-700'
                            }`}
                    >
                        {t('filesCountLabel', files.length)}
                    </button>
                    <button
                        onClick={() => setActiveTab('notes')}
                        className={`px-4 py-1.5 text-sm font-medium rounded-md transition-all duration-200 ${activeTab === 'notes'
                            ? 'bg-white text-slate-800 shadow-sm'
                            : 'text-slate-500 hover:text-slate-700'
                            }`}
                    >
                        {t('notesCountLabel', notes.length)}
                    </button>
                </div>
            </div>

            {/* コンテンツアクション */}
            <div className="p-4 flex justify-end">
                {activeTab === 'notes' && (
                    <button
                        onClick={() => {
                            setCurrentNote({})
                            setIsEditingNote(true)
                        }}
                        className="flex items-center gap-2 px-3 py-1.5 bg-blue-600 text-white text-sm rounded-lg hover:bg-blue-700"
                    >
                        <Plus size={16} />
                        <span>{t('newNote')}</span>
                    </button>
                )}
                {activeTab === 'files' && (
                    <>
                        {isAdmin && (
                            <input
                                type="file"
                                ref={fileInputRef}
                                className="hidden"
                                onChange={handleFileUpload}
                                disabled={isUploading}
                            />
                        )}
                        {isAdmin && (
                            <button
                                className="flex items-center gap-2 px-3 py-1.5 bg-white text-slate-600 border border-slate-200 text-sm rounded-lg hover:bg-slate-50 mr-2"
                                onClick={() => setIsImportDrawerOpen(true)}
                            >
                                <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="M4 20h16a2 2 0 0 0 2-2V8a2 2 0 0 0-2-2h-7.93a2 2 0 0 1-1.66-.9l-.82-1.2A2 2 0 0 0 7.93 2H4a2 2 0 0 0-2 2v13c0 1.1.9 2 2 2Z" /><path d="M12 10v6" /><path d="m9 13 3-3 3 3" /></svg>
                                <span>{t('importFolder')}</span>
                            </button>
                        )}
                        {isAdmin && (
                            <button
                                className="flex items-center gap-2 px-3 py-1.5 bg-blue-600 text-white text-sm rounded-lg hover:bg-blue-700 disabled:opacity-50"
                                onClick={() => fileInputRef.current?.click()}
                                disabled={isUploading}
                            >
                                <Plus size={16} />
                                <span>{isUploading ? t('uploading') : t('addFile')}</span>
                            </button>
                        )}
                    </>
                )}
            </div>

            {/* 笔记本全局拖拽上传覆盖层 */}
            <NotebookGlobalDragDropOverlay
                onFilesSelected={async (files) => {
                    // 处理拖拽上传的文件
                    for (let i = 0; i < files.length; i++) {
                        const file = files[i];

                        // 创建一个临时input元素来触发上传
                        const input = document.createElement('input');
                        input.type = 'file';

                        // 使用DataTransfer来创建一个包含单个文件的FileList
                        const dt = new DataTransfer();
                        dt.items.add(file);

                        // 创建自定义事件对象
                        const event = {
                            target: {
                                files: dt.files
                            }
                        } as React.ChangeEvent<HTMLInputElement>;

                        await handleFileUpload(event);
                    }
                }}
                isAdmin={isAdmin}
            />

            {/* リスト表示 */}
            <div className="flex-1 overflow-y-auto px-6 pb-6">
                {isLoading ? (
                    <div className="text-center py-10 text-slate-400">Loading...</div>
                ) : (
                    <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
                        {activeTab === 'files' && files.map(file => (
                            <div key={file.id} className="bg-white p-4 rounded-xl border border-slate-200 flex items-start gap-3 hover:shadow-md transition-shadow group relative">
                                <div className="p-2 bg-slate-100 rounded-lg text-slate-500">
                                    <FileIcon size={24} />
                                </div>
                                <div className="flex-1 min-w-0">
                                    <h3 className="font-medium text-slate-800 truncate" title={file.name}>{file.name}</h3>
                                    <p className="text-xs text-slate-400 mt-1">{(file.size / 1024 / 1024).toFixed(2)} MB</p>
                                </div>
                                <div className="absolute top-2 right-2 opacity-0 group-hover:opacity-100 transition-opacity flex items-center gap-1">
                                    <PDFPreviewButton
                                        fileId={file.id}
                                        fileName={file.name}
                                        onPreview={() => setPreviewFile({ id: file.id, name: file.name })}
                                    />
                                    <button
                                        onClick={(e) => {
                                            e.stopPropagation();
                                            onChatWithContext?.({ selectedGroups: [notebook.id], selectedFiles: [file.id] });
                                        }}
                                        className="p-1.5 text-slate-400 hover:text-purple-500 hover:bg-purple-50 rounded-lg transition-colors"
                                        title={t('chatWithFile')}
                                    >
                                        <MessageSquare size={16} />
                                    </button>
                                    <button
                                        onClick={(e) => {
                                            e.stopPropagation();
                                            handleRemoveFile(file.id, file.name);
                                        }}
                                        className="p-1.5 text-slate-400 hover:text-red-500 hover:bg-red-50 rounded-lg transition-colors"
                                        title={t('confirmRemoveFileFromGroup', '')}
                                    >
                                        <Trash2 size={16} />
                                    </button>
                                </div>
                            </div>
                        ))}

                        {activeTab === 'notes' && notes.map(note => (
                            <div key={note.id} className="bg-white p-5 rounded-xl border border-slate-200 hover:shadow-md transition-all group flex flex-col cursor-pointer" onClick={() => {
                                setCurrentNote(note)
                                setIsEditingNote(true)
                            }}>
                                <div className="flex justify-between items-start mb-2 flex-shrink-0">
                                    <h3 className="font-bold text-slate-800 line-clamp-1">{note.title}</h3>
                                    <div className="flex gap-1 opacity-0 group-hover:opacity-100 transition-opacity" onClick={e => e.stopPropagation()}>
                                        <button onClick={() => handleIndexNote(note)} className="p-1 hover:bg-blue-50 text-slate-400 hover:text-blue-500 rounded" title={t('indexIntoKB')}>
                                            <Database size={16} />
                                        </button>
                                        <button onClick={() => handleDeleteNote(note.id)} className="p-1 hover:bg-red-50 text-slate-400 hover:text-red-500 rounded">
                                            <Trash2 size={16} />
                                        </button>
                                    </div>
                                </div>
                                <p className="text-slate-500 text-sm line-clamp-3 mb-2 whitespace-pre-line flex-shrink-0">
                                    {note.content}
                                </p>
                                {note.screenshotPath && (
                                    <div className="mt-2 mb-2 rounded overflow-hidden border border-slate-100 flex-shrink-0 h-32">
                                        <img
                                            src={`/uploads/${note.screenshotPath}`}
                                            alt="Screenshot"
                                            className="w-full h-full object-cover"
                                        />
                                    </div>
                                )}
                                <div className="text-xs text-slate-400 mt-auto pt-3 border-t border-slate-100 flex-shrink-0">
                                    {new Date(note.updatedAt).toLocaleDateString()}
                                </div>
                            </div>
                        ))}

                        {((activeTab === 'files' && files.length === 0) || (activeTab === 'notes' && notes.length === 0)) && (
                            <div className="col-span-full text-center py-20 text-slate-400">
                                {t('noFilesOrNotes', activeTab === 'files' ? t('files') : t('notes'))}
                            </div>
                        )}
                    </div>
                )}
            </div>
            {/* インデックスモーダル */}
            <IndexingModalWithMode
                isOpen={isIndexingModalOpen}
                onClose={() => {
                    setIsIndexingModalOpen(false)
                    setPendingFiles([])
                }}
                onConfirm={handleConfirmIndexing}
                files={pendingFiles}
                embeddingModels={models.filter(m => m.type === ModelType.EMBEDDING)}
                defaultEmbeddingId={models.find(m => m.type === ModelType.EMBEDDING)?.id || ''}
            />

            {/* PDFプレビューモーダル */}
            {
                previewFile && (
                    <PDFPreview
                        fileId={previewFile.id}
                        fileName={previewFile.name}
                        authToken={authToken}
                        groupId={notebook.id}
                        onClose={() => setPreviewFile(null)}
                    />
                )
            }

            {/* AIコマンドドロワー */}
            <AICommandDrawer
                isOpen={isAIModalOpen}
                onClose={() => setIsAIModalOpen(false)}
                context={currentNote.content || ''}
                authToken={authToken}
                onApply={(newContent) => {
                    setCurrentNote(prev => ({ ...prev, content: newContent })) // 内容を置換（必要に応じて将来的に追加オプションを検討）
                }}
            />

            <ImportFolderDrawer
                isOpen={isImportDrawerOpen}
                onClose={() => setIsImportDrawerOpen(false)}
                authToken={authToken}
                initialGroupId={notebook.id}
                initialGroupName={notebook.name}
                onImportSuccess={loadData}
            />
        </div >
    )
}