import Note from '@joplin/lib/models/Note';
import Folder from '@joplin/lib/models/Folder';
import time from '@joplin/lib/time';

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

/**
 * 纯前端 GB2312 汉字首字母转换，支持拼音首字母模糊检索中文笔记（例如 gzzb -> 工作周报）
 */
export const getChinesePinyinInitials = (str: string): string => {
	const boundaries = [
		{ p: 'a', c: '啊' }, { p: 'b', c: '芭' }, { p: 'c', c: '擦' }, { p: 'd', c: '搭' },
		{ p: 'e', c: '蛾' }, { p: 'f', c: '发' }, { p: 'g', c: '噶' }, { p: 'h', c: '哈' },
		{ p: 'j', c: '击' }, { p: 'k', c: '喀' }, { p: 'l', c: '垃' }, { p: 'm', c: '妈' },
		{ p: 'n', c: '拿' }, { p: 'o', c: '哦' }, { p: 'p', c: '啪' }, { p: 'q', c: '期' },
		{ p: 'r', c: '然' }, { p: 's', c: '撒' }, { p: 't', c: '塌' }, { p: 'w', c: '挖' },
		{ p: 'x', c: '昔' }, { p: 'y', c: '压' }, { p: 'z', c: '匝' },
	];
	return str.split('').map(ch => {
		if (/[a-zA-Z0-9]/.test(ch)) return ch.toLowerCase();
		if (!/[\u4e00-\u9fa5]/.test(ch)) return '';
		for (let i = boundaries.length - 1; i >= 0; i--) {
			if (ch.localeCompare(boundaries[i].c, 'zh-Hans-CN') >= 0) {
				return boundaries[i].p;
			}
		}
		return '';
	}).join('');
};

/**
 * 中国地区标准日期星期格式化（统一 星期一 ~ 星期日）
 */
export const formatChineseDateTitle = (ms: number): string => {
	const weekdaysZh = ['星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六'];
	const datePrefix = time.formatMsToLocal(ms, 'YYYY-MM-DD');
	const d = new Date(ms);
	return `${datePrefix} ${weekdaysZh[d.getDay()]}`;
};

/**
 * 双链与 @ 快速提及的笔记查询与推荐算法
 * 同时服务于 Markdown 编辑器（CodeMirror 6）与富文本编辑器（TinyMCE）
 */
export const searchNotesForMention = async (query: string): Promise<MentionNoteItem[]> => {
	const trimmed = query.trim();
	const lowerQuery = trimmed.toLowerCase();

	const isDateSearch = (keywords: string[]) => {
		return keywords.some(k => k === lowerQuery || k.includes(lowerQuery) || lowerQuery.includes(k));
	};

	const matchesToday = !trimmed || isDateSearch(['今天', '今日', 'jt', 'jr', 'today', '日志', '日记', 'rz', 'rj']);
	const matchesYesterday = !trimmed || isDateSearch(['昨天', '昨日', 'zt', 'zr', 'yesterday']);
	const matchesTomorrow = !trimmed || isDateSearch(['明天', '明日', 'mt', 'mr', 'tomorrow']);
	const matchesDayBefore = isDateSearch(['前天', '前日', 'qt']);
	const matchesDayAfter = isDateSearch(['后天', '后日', 'ht']);

	const now = Date.now();
	const oneDayMs = 24 * 60 * 60 * 1000;

	const targetDates: Array<{ offsetDays: number; label: string; createLabel: string }> = [];
	if (matchesToday) targetDates.push({ offsetDays: 0, label: '📅 今日日志', createLabel: '✨ 新建今日日志' });
	if (matchesYesterday) targetDates.push({ offsetDays: -1, label: '📅 昨日日志', createLabel: '✨ 新建昨日日志' });
	if (matchesTomorrow) targetDates.push({ offsetDays: 1, label: '📅 明日日志', createLabel: '✨ 新建明日日志' });
	if (matchesDayBefore) targetDates.push({ offsetDays: -2, label: '📅 前天日志', createLabel: '✨ 新建前天日志' });
	if (matchesDayAfter) targetDates.push({ offsetDays: 2, label: '📅 后天日志', createLabel: '✨ 新建后天日志' });

	const specialItems: Array<MentionNoteItem> = [];
	for (const item of targetDates) {
		const targetMs = now + item.offsetDays * oneDayMs;
		const prefix = time.formatMsToLocal(targetMs, 'YYYY-MM-DD');
		const dateTitle = formatChineseDateTitle(targetMs);

		const row = await Note.db().selectOne(
			'SELECT id, title FROM notes WHERE is_conflict = 0 AND (deleted_time = 0 OR deleted_time IS NULL) AND title LIKE ? ORDER BY updated_time DESC LIMIT 1',
			[`${prefix}%`],
		);
		if (row && typeof row.id === 'string' && typeof row.title === 'string') {
			specialItems.push({
				id: row.id,
				title: row.title,
				parentTitle: item.label,
				section: '📅 日志推荐',
			});
		} else {
			specialItems.push({
				id: `__CREATE_${prefix}__`,
				title: dateTitle,
				parentTitle: item.createLabel,
				section: '📅 日志推荐',
			});
		}
	}

	// 识别直接输入的指定日期数字（如 2026-11-05、2026/11/5、20261105）
	const dateRegex = /^(\d{4})[-/.]?(\d{1,2})[-/.]?(\d{1,2})$/;
	const directDateMatch = trimmed.match(dateRegex);
	if (directDateMatch) {
		const year = parseInt(directDateMatch[1], 10);
		const month = parseInt(directDateMatch[2], 10);
		const day = parseInt(directDateMatch[3], 10);
		if (month >= 1 && month <= 12 && day >= 1 && day <= 31) {
			const d = new Date(year, month - 1, day);
			if (!isNaN(d.getTime())) {
				const prefix = time.formatMsToLocal(d.getTime(), 'YYYY-MM-DD');
				const dateTitle = formatChineseDateTitle(d.getTime());
				if (!specialItems.some(s => s.id.includes(prefix))) {
					const row = await Note.db().selectOne(
						'SELECT id, title FROM notes WHERE is_conflict = 0 AND (deleted_time = 0 OR deleted_time IS NULL) AND title LIKE ? ORDER BY updated_time DESC LIMIT 1',
						[`${prefix}%`],
					);
					if (row && typeof row.id === 'string' && typeof row.title === 'string') {
						specialItems.push({
							id: row.id,
							title: row.title,
							parentTitle: `📅 ${prefix} 日志`,
							section: '📅 日志推荐',
						});
					} else {
						specialItems.push({
							id: `__CREATE_${prefix}__`,
							title: dateTitle,
							parentTitle: `✨ 新建 ${prefix} 日志`,
							section: '📅 日志推荐',
						});
					}
				}
			}
		}
	}

	// 查询笔记标题匹配
	const likeQuery = `%${trimmed}%`;
	const rows = await Note.db().selectAll<{ id: string; title: string; parent_id: string }>(
		`SELECT id, title, parent_id FROM notes
		 WHERE is_conflict = 0 AND (deleted_time = 0 OR deleted_time IS NULL)
		   AND title LIKE ?
		 ORDER BY updated_time DESC LIMIT 15`,
		[likeQuery],
	);

	const folders = await Folder.all();
	const folderMap = new Map(folders.map(f => [f.id, f.title]));

	const existingSpecialIds = new Set(specialItems.map(s => s.id));
	const noteResults: Array<MentionNoteItem> = [];

	for (const r of rows) {
		if (!existingSpecialIds.has(r.id)) {
			noteResults.push({
				id: r.id,
				title: r.title,
				parentTitle: folderMap.get(r.parent_id),
				section: '📝 关联笔记',
			});
		}
	}

	// 若输入为英文字母且普通模糊搜索无果或结果较少，尝试拼音首字母反查
	if (trimmed && /^[a-zA-Z]+$/.test(trimmed) && noteResults.length < 5) {
		const recentRows = await Note.db().selectAll<{ id: string; title: string; parent_id: string }>(
			`SELECT id, title, parent_id FROM notes
			 WHERE is_conflict = 0 AND (deleted_time = 0 OR deleted_time IS NULL)
			 ORDER BY updated_time DESC LIMIT 60`,
		);
		for (const r of recentRows) {
			if (!existingSpecialIds.has(r.id) && !noteResults.some(n => n.id === r.id)) {
				const initials = getChinesePinyinInitials(r.title);
				if (initials.includes(lowerQuery)) {
					noteResults.push({
						id: r.id,
						title: r.title,
						parentTitle: folderMap.get(r.parent_id),
						section: '📝 关联笔记',
					});
				}
			}
		}
	}

	return [...specialItems, ...noteResults];
};

export default searchNotesForMention;