import {
	autocompletion,
	CompletionContext,
	CompletionResult,
	CompletionSource,
	startCompletion,
	completionKeymap,
} from '@codemirror/autocomplete';
import { Extension } from '@codemirror/state';
import { EditorView, keymap } from '@codemirror/view';
import { RenderedContentContext } from './rendering/types';

export interface WikiLinkMatch {
	query: string;
	matchLength: number;
	trigger: '[[' | '@';
}

export interface WikiNoteItem {
	id: string;
	title: string;
	parentTitle?: string;
	section?: string;
}

/**
 * 匹配光标前的 [[ / 【【 或 @ / ＠ 触发词及后续跟随的关键词
 * 支持：
 * 1. [[关键词 或 【【关键词（全角中文括号）
 * 2. @关键词 或 ＠关键词（全角中文@，前置必须为行首、空格或常用中文/西文开标点，严格防止误伤普通邮箱如 test@domain.com）
 */
export const matchWikiLinkTrigger = (textBefore: string): WikiLinkMatch | null => {
	// 匹配 [[ 或 【【 语法
	const bracketMatch = textBefore.match(/(?:\[\[|【【)([^\]】\n]*)$/);
	if (bracketMatch) {
		return {
			query: bracketMatch[1],
			matchLength: bracketMatch[0].length,
			trigger: '[[',
		};
	}

	// 匹配 @ 或 ＠ 语法（必须位于行首或前置为空格/常见开标点）
	const atMatch = textBefore.match(/(?:^|[\s([{\'"‘“（《「『【〔〖〘〚])([@＠])([^\s@＠\n)}\]\'"’”》」』】〕〗〙㛛]*)$/);
	if (atMatch) {
		const fullMatch = atMatch[0];
		const atChar = atMatch[1];
		const atOffset = fullMatch.lastIndexOf(atChar);
		return {
			query: atMatch[2],
			matchLength: fullMatch.length - atOffset,
			trigger: '@',
		};
	}

	return null;
};

/**
 * 创建双链与 @ 快速提及补全数据源
 */
export const createWikiLinkCompletionSource = (
	searchNotes: (query: string) => Promise<Array<WikiNoteItem>>,
	createNote?: (title: string) => Promise<{ id: string; title: string } | null>,
): CompletionSource => {
	return async (context: CompletionContext): Promise<CompletionResult | null> => {
		const line = context.state.doc.lineAt(context.pos);
		const textBefore = context.state.doc.sliceString(line.from, context.pos);
		const match = matchWikiLinkTrigger(textBefore);
		if (!match) return null;

		const from = context.pos - match.matchLength;
		const notes = await searchNotes(match.query);
		if (!notes || notes.length === 0) return null;

		return {
			from,
			options: notes.map((note, index) => {
				const noteTitle = note.title || '无标题笔记';
				const isCreate = note.id.startsWith('__CREATE_');
				const isJournal = note.parentTitle?.includes('日志') || note.parentTitle?.includes('日记') || note.title.match(/^\d{4}-\d{2}-\d{2}/);

				let optionType = 'text';
				if (isCreate) optionType = 'create';
				else if (isJournal) optionType = 'journal';

				return {
					label: noteTitle,
					detail: note.parentTitle ? (note.parentTitle.startsWith('📅') || note.parentTitle.startsWith('📁') || note.parentTitle.startsWith('✨') ? note.parentTitle : `📁 ${note.parentTitle}`) : undefined,
					type: optionType,
					section: note.section,
					boost: 100 - index,
					apply: (view, _completion, applyFrom, applyTo) => {
						if (isCreate && createNote) {
							void (async () => {
								const created = await createNote(noteTitle);
								const targetId = created ? created.id : '';
								const targetTitle = created ? created.title : noteTitle;
								if (targetId) {
									const replacement = `[${targetTitle}](:/${targetId})`;
									view.dispatch({
										changes: { from: applyFrom, to: applyTo, insert: replacement },
										selection: { anchor: applyFrom + replacement.length },
										userEvent: 'input.complete',
									});
								}
							})();
						} else {
							const replacement = `[${noteTitle}](:/${note.id})`;
							view.dispatch({
								changes: { from: applyFrom, to: applyTo, insert: replacement },
								selection: { anchor: applyFrom + replacement.length },
								userEvent: 'input.complete',
							});
						}
					},
				};
			}),
			filter: false,
		};
	};
};

const wikiLinkAutocompleteExtension = (context: RenderedContentContext): Extension => {
	if (!context.searchNotes) return [];

	const source = createWikiLinkCompletionSource(
		context.searchNotes.bind(context),
		context.createNote ? context.createNote.bind(context) : undefined,
	);

	return [
		autocompletion({
			override: [source],
			activateOnTyping: true,
			maxRenderedOptions: 15,
		}),
		keymap.of(completionKeymap),
		// 监听普通输入法字符触发
		EditorView.inputHandler.of((view, _from, _to, text) => {
			if (text === '@' || text === '＠' || text === '[' || text === '【') {
				setTimeout(() => {
					startCompletion(view);
				}, 20);
			}
			return false;
		}),
		// 监听中文输入法完成（compositionend），输入例如「今天」确认后即刻触发补全
		EditorView.domEventHandlers({
			compositionend: (_event, view) => {
				setTimeout(() => {
					const pos = view.state.selection.main.head;
					const line = view.state.doc.lineAt(pos);
					const textBefore = view.state.doc.sliceString(line.from, pos);
					if (matchWikiLinkTrigger(textBefore)) {
						startCompletion(view);
					}
				}, 40);
			},
		}),
		// 监听文本变化（包括拼音输入法、粘贴、撤销等）
		EditorView.updateListener.of(update => {
			if (update.docChanged) {
				const pos = update.state.selection.main.head;
				const line = update.state.doc.lineAt(pos);
				const textBefore = update.state.doc.sliceString(line.from, pos);
				if (matchWikiLinkTrigger(textBefore)) {
					setTimeout(() => {
						startCompletion(update.view);
					}, 20);
				}
			}
		}),
		// 现代化 macOS / Apple Notes / Raycast 风格浮窗样式设计
		EditorView.theme({
			'.cm-tooltip-autocomplete': {
				border: '1px solid var(--joplin-divider-color, rgba(0, 0, 0, 0.12))',
				borderRadius: '12px',
				boxShadow: '0 18px 42px rgba(0, 0, 0, 0.15), 0 3px 10px rgba(0, 0, 0, 0.05), 0 0 0 1px rgba(0, 0, 0, 0.03)',
				padding: '6px',
				backgroundColor: 'var(--joplin-background-color3, #ffffff)',
				backdropFilter: 'blur(24px) saturate(180%)',
				WebkitBackdropFilter: 'blur(24px) saturate(180%)',
				zIndex: '1000 !important',
				minWidth: '280px',
				maxWidth: '440px',
				fontFamily: '-apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif',
			},
			'.cm-tooltip-autocomplete ul': {
				maxHeight: '300px',
				listStyle: 'none',
				margin: '0',
				padding: '0',
				overflowY: 'auto',
			},
			'.cm-tooltip-autocomplete ul li': {
				borderRadius: '8px',
				padding: '7px 10px',
				margin: '1px 0',
				display: 'flex',
				justifyContent: 'space-between',
				alignItems: 'center',
				fontSize: '13px',
				cursor: 'pointer',
				lineHeight: '1.4',
				transition: 'background-color 0.12s ease',
			},
			'.cm-tooltip-autocomplete ul li[aria-selected]': {
				backgroundColor: 'var(--joplin-selected-color2, #007aff) !important',
				color: '#ffffff !important',
			},
			'.cm-tooltip-autocomplete ul li[aria-selected] .cm-completionDetail': {
				backgroundColor: 'rgba(255, 255, 255, 0.22) !important',
				color: '#ffffff !important',
			},
			'.cm-tooltip-autocomplete ul li[aria-selected] .cm-completionMatchedText': {
				color: '#ffffff !important',
				textDecoration: 'underline',
			},
			'.cm-tooltip-autocomplete .cm-completionLabel': {
				fontWeight: '500',
				overflow: 'hidden',
				textOverflow: 'ellipsis',
				whiteSpace: 'nowrap',
				flex: '1',
			},
			'.cm-tooltip-autocomplete .cm-completionDetail': {
				fontStyle: 'normal',
				fontSize: '11px',
				fontWeight: '500',
				padding: '2px 7px',
				borderRadius: '6px',
				backgroundColor: 'var(--joplin-background-color-hover3, rgba(0, 0, 0, 0.05))',
				color: 'var(--joplin-color-faded, #666)',
				marginLeft: '8px',
				whiteSpace: 'nowrap',
				flexShrink: '0',
			},
			'.cm-tooltip-autocomplete completion-section': {
				display: 'block',
				fontSize: '11px',
				fontWeight: '600',
				color: 'var(--joplin-color-faded, #888)',
				padding: '6px 8px 3px 8px',
				letterSpacing: '0.03em',
			},
			'.cm-tooltip-autocomplete::after': {
				content: '"↑↓ 切换 · ↵ 引用 · Esc 关闭"',
				display: 'block',
				fontSize: '10.5px',
				color: 'var(--joplin-color-faded, #999)',
				borderTop: '1px solid var(--joplin-divider-color, rgba(0, 0, 0, 0.08))',
				padding: '6px 6px 2px 6px',
				marginTop: '4px',
				textAlign: 'right',
				letterSpacing: '0.02em',
			},
		}),
	];
};

export default wikiLinkAutocompleteExtension;