/**
 * 金蝶云社区智能问答 — Token 管理 + SSE API 调用
 *
 * 移植自 kdclub-ai-product-qa/scripts/cosmic_qa.py v2.0
 * 纯 TypeScript 实现，零外部依赖，使用 Node.js 内置 fetch。
 *
 * API: GET https://vip.kingdee.com/aisapi/ai-search
 * 认证: Authorization: Bearer <kdt_xxx...>
 * 响应: SSE 流式
 */

import { existsSync, mkdirSync, readFileSync, writeFileSync } from "node:fs";
import { homedir } from "node:os";
import { join } from "node:path";
import { tryParseJson } from "@oh-my-pi/pi-utils";

// ─── Token 管理 ───────────────────────────────────────────

const TOKEN_DIR = join(homedir(), ".kdclub");
const TOKEN_FILE = join(TOKEN_DIR, "pat_token.json");
const LEGACY_TOKEN_FILES = [
	join(TOKEN_DIR, "token_vip_kingdee_com.json"),
	join(homedir(), ".qoderwork", "skills", "kdclub-login", "data", "token_vip_kingdee_com.json"),
];

export const TOKEN_NOT_FOUND_MSG =
	"未找到有效的 PAT Token。请按以下步骤获取并提供 token：\n" +
	"1. 打开浏览器访问 https://vip.kingdee.com\n" +
	"2. 登录您的金蝶云社区账号\n" +
	"3. 点击右上角头像 → 个人主页 → 编辑资料\n" +
	"4. 找到「个人访问令牌」区域 → 新建令牌\n" +
	"5. 复制生成的 token（格式如 kdt_xxxxxxxx...）\n" +
	"6. 使用 kd_cosmic_qa({ saveToken: 'kdt_xxx', query: '测试连接', communityProduct: 'enterprise' }) 保存 token；Cosmic 项目先让用户选择金蝶AI苍穹/金蝶AI星瀚/金蝶AI套件";

interface TokenData {
	token: string;
	domain: string;
	last_updated: string;
}

export function saveToken(token: string): string {
	const trimmed = token.trim();
	mkdirSync(TOKEN_DIR, { recursive: true });
	const data: TokenData = {
		token: trimmed,
		domain: "vip.kingdee.com",
		last_updated: new Date().toISOString(),
	};
	writeFileSync(TOKEN_FILE, `${JSON.stringify(data, null, 2)}\n`, "utf8");
	return `Token 已保存到 ${TOKEN_FILE}，后续会话无需重复提供。`;
}

export function loadToken(): { token: string } | { error: string } {
	// 1. 环境变量
	const envToken = (process.env.KDCLOUD_PAT_TOKEN ?? "").trim();
	if (envToken) return { token: envToken };

	// 2. 本地文件
	if (existsSync(TOKEN_FILE)) {
		try {
			const data = tryParseJson<TokenData>(readFileSync(TOKEN_FILE, "utf8"));
			const t = (data?.token ?? "").trim();
			if (t) {
				process.env.KDCLOUD_PAT_TOKEN = t;
				return { token: t };
			}
		} catch {
			/* fall through */
		}
	}

	for (const file of LEGACY_TOKEN_FILES) {
		if (!existsSync(file)) continue;
		try {
			const data = tryParseJson<TokenData>(readFileSync(file, "utf8"));
			const t = (data?.token ?? "").trim();
			if (t) {
				process.env.KDCLOUD_PAT_TOKEN = t;
				return { token: t };
			}
		} catch {
			/* fall through */
		}
	}

	return { error: TOKEN_NOT_FOUND_MSG };
}

// ─── 引用来源标题补全 ──────────────────────────────────────

export interface SearchSource {
	entityId: string;
	entityType: string;
	title: string;
	url: string;
}

export interface CosmicQaResult {
	answer: string;
	answerFormat: "html" | "markdown";
	thinkContent: string;
	sources: SearchSource[];
	sessionId: string;
}

// ─── 图片 URL 修复 ────────────────────────────────────────

function fixImageUrls(content: string): string {
	const base = "https://vip.kingdee.com";

	// 1. 补全相对路径（排除 // 开头的协议相对路径）
	content = content.replace(/src="(\/(?!\/)[^"]+)"/g, (_, p1) => `src="${base}${p1}"`);
	content = content.replace(/src='(\/(?!\/)[^']+)'/g, (_, p1) => `src='${base}${p1}'`);
	content = content.replace(/data-src="(\/(?!\/)[^"]+)"/g, (_, p1) => `data-src="${base}${p1}"`);
	content = content.replace(/data-src='(\/(?!\/)[^']+)'/g, (_, p1) => `data-src='${base}${p1}'`);

	// 2. 懒加载 data-src → src 提升
	content = content.replace(
		/<img\s([^>]*?)data-src=["']([^"']+)["']([^>]*?)\/?>/gi,
		(_match, before, dataSrc, after) => {
			const srcMatch = (before + after).match(/src=["']([^"']*)["']/);
			if (srcMatch) {
				const existingSrc = srcMatch[1].trim();
				if (!existingSrc || existingSrc.startsWith("data:") || /placeholder/i.test(existingSrc)) {
					return `<img ${before}src="${dataSrc}"${after.replace(/src=["'][^"']*["']/, "")}  />`;
				}
				return _match;
			}
			return `<img ${before}src="${dataSrc}" data-src="${dataSrc}"${after} />`;
		},
	);

	// 3. Markdown 图片相对路径补全
	content = content.replace(/!\[([^\]]*)\]\((\/(?!\/)[^)]+)\)/g, (_, alt, p2) => `![${alt}](${base}${p2})`);

	return content;
}

// ─── 引用来源标题补全 ──────────────────────────────────────

function needsTitleFetch(title: string): boolean {
	if (!title) return true;
	const t = title.trim();
	if (/^\d+$/.test(t)) return true;
	const generic = [
		"点击查看完整文档",
		"查看完整文档",
		"点击查看",
		"查看详情",
		"点击查看详情",
		"详情",
		"文档详情",
		"知识详情",
		"undefined",
		"null",
	];
	return generic.map(g => g.toLowerCase()).includes(t.toLowerCase());
}

async function fetchPageTitle(url: string, token: string, timeoutMs = 5000): Promise<string> {
	try {
		const controller = new AbortController();
		const timer = setTimeout(() => controller.abort(), timeoutMs);
		const resp = await fetch(url, {
			headers: {
				Authorization: `Bearer ${token}`,
				"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) Chrome/120.0.0.0",
				Accept: "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8",
			},
			signal: controller.signal,
		});
		clearTimeout(timer);
		const html = await resp.text();
		const m = html.match(/<title[^>]*>(.*?)<\/title>/is);
		if (m) {
			let title = m[1]
				.trim()
				.replace(/&amp;/g, "&")
				.replace(/&lt;/g, "<")
				.replace(/&gt;/g, ">")
				.replace(/&#39;/g, "'")
				.replace(/&quot;/g, '"')
				.replace(/&nbsp;/g, " ");
			for (const suffix of [" - 金蝶云社区", " - 金蝶社区", " | 金蝶云社区"]) {
				if (title.endsWith(suffix)) {
					title = title.slice(0, -suffix.length).trim();
					break;
				}
			}
			const generic = ["金蝶云社区", "金蝶社区", "金蝶云社区官网", "点击查看完整文档", "查看完整文档"];
			if (generic.includes(title)) return "";
			return title;
		}
	} catch {
		/* ignore */
	}
	return "";
}

async function enrichSearchSources(sources: SearchSource[], token: string): Promise<SearchSource[]> {
	if (!sources.length) return sources;
	const indices = sources.map((s, i) => (needsTitleFetch(s.title) ? i : -1)).filter(i => i >= 0);
	if (!indices.length) return sources;

	const tasks = indices.map(async idx => {
		const url = sources[idx].url;
		if (!url) return;
		const title = await fetchPageTitle(url, token);
		if (title) sources[idx].title = title;
	});
	await Promise.all(tasks);
	return sources;
}

// ─── 核心：流式调用金蝶云社区 API ──────────────────────────

export async function queryCosmicQa(
	question: string,
	productId: number,
	options?: {
		sessionId?: string;
		useDeepThink?: boolean;
		productLineId?: string;
	},
): Promise<CosmicQaResult> {
	const tokenResult = loadToken();
	if ("error" in tokenResult) {
		throw new Error(tokenResult.error);
	}
	const token = tokenResult.token;

	const params = new URLSearchParams({
		scene: "1",
		searchText: question,
		productId: String(productId),
		useDeepThink: options?.useDeepThink ? "true" : "false",
		useClarification: "false",
		productLineId: options?.productLineId || "35",
		channel_level: "Agent Skill",
	});
	if (options?.sessionId) {
		params.set("sessionId", options.sessionId);
	}

	const url = `https://vip.kingdee.com/aisapi/ai-search?${params.toString()}`;

	// 重试逻辑（401/403 时最多 3 次）
	let lastError: Error | undefined;
	for (let attempt = 0; attempt < 3; attempt++) {
		try {
			const result = await doStreamRequest(url, token);
			return result;
		} catch (e) {
			const msg = e instanceof Error ? e.message : String(e);
			if (msg.includes("401") || msg.includes("403") || msg.includes("未授权")) {
				// 重新加载 token（可能中途刷新了）
				const reloaded = loadToken();
				if ("token" in reloaded) {
					lastError = e instanceof Error ? e : new Error(msg);
					continue;
				}
			}
			lastError = e instanceof Error ? e : new Error(msg);
			break;
		}
	}

	throw lastError ?? new Error("请求金蝶云社区 API 失败");
}

async function doStreamRequest(url: string, token: string): Promise<CosmicQaResult> {
	const resp = await fetch(url, {
		headers: {
			Authorization: `Bearer ${token}`,
			Accept: "text/event-stream",
			"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) Chrome/120.0.0.0",
		},
	});

	if (resp.status === 401 || resp.status === 403) {
		throw new Error(`HTTP ${resp.status}: 未授权操作，PAT Token 可能已过期或无效。`);
	}
	if (!resp.ok) {
		throw new Error(`HTTP ${resp.status}: ${resp.statusText}`);
	}

	const body = resp.body;
	if (!body) {
		throw new Error("响应体为空");
	}

	// 解析 SSE 流
	let fullAnswer = "";
	let thinkContent = "";
	let sessionId = "";
	let searchSources: SearchSource[] = [];

	const reader = body.getReader();
	const decoder = new TextDecoder();
	let buffer = "";

	try {
		while (true) {
			const { done, value } = await reader.read();
			if (done) break;

			buffer += decoder.decode(value, { stream: true });
			const lines = buffer.split("\n");
			buffer = lines.pop() ?? ""; // 保留最后一行（可能不完整）

			for (const line of lines) {
				const trimmed = line.trim();
				if (!trimmed.startsWith("data:")) continue;

				const jsonStr = trimmed.slice(5).trim();
				let data: Record<string, unknown>;
				try {
					data = JSON.parse(jsonStr) as Record<string, unknown>;
				} catch {
					continue;
				}

				const msg = String(data.message ?? "");
				const isThink = Boolean(data.isThink);

				if (msg === "未授权操作") {
					throw new Error("未授权操作");
				}

				if (isThink && msg) {
					thinkContent += msg;
				} else if (msg) {
					fullAnswer += fixImageUrls(msg);
				}

				const sid = data.aiSearchSessionId;
				if (sid) sessionId = String(sid);

				const src = data.searchSources;
				if (Array.isArray(src) && src.length > 0) {
					searchSources = src as SearchSource[];
				}

				if (data.answerEnd) {
					// 对完整内容再做一次图片修复
					fullAnswer = fixImageUrls(fullAnswer);
					const answerFormat = fullAnswer.trim().startsWith("<") ? "html" : "markdown";
					searchSources = await enrichSearchSources(searchSources, token);
					return { answer: fullAnswer, answerFormat, thinkContent, sources: searchSources, sessionId };
				}
			}
		}
	} finally {
		reader.releaseLock();
	}

	// 流结束但未收到 answerEnd
	fullAnswer = fixImageUrls(fullAnswer);
	const answerFormat = fullAnswer.trim().startsWith("<") ? "html" : "markdown";
	searchSources = await enrichSearchSources(searchSources, token);
	return { answer: fullAnswer, answerFormat, thinkContent, sources: searchSources, sessionId };
}

// ─── 输出格式化 ────────────────────────────────────────────

export function formatCosmicQaResult(result: CosmicQaResult, question: string): string {
	const parts: string[] = [];

	parts.push(`## 金蝶云社区智能问答`);
	parts.push(`**问题**: ${question}`);
	parts.push("");

	if (result.thinkContent) {
		parts.push("<details>");
		parts.push("<summary>思考过程（点击展开）</summary>");
		parts.push("");
		parts.push(result.thinkContent);
		parts.push("");
		parts.push("</details>");
		parts.push("");
	}

	parts.push("### 回答");
	parts.push(result.answer);

	if (result.sources.length > 0) {
		parts.push("");
		parts.push("### 参考来源");
		for (const src of result.sources) {
			parts.push(`- [${src.title || "查看详情"}](${src.url})`);
		}
	}

	return parts.join("\n");
}