import type { FeishuCredentials } from "./contracts.js";

export const REQUIRED_APP_SCOPES = [
	"im:message.p2p_msg:readonly",
	"im:message.group_at_msg:readonly",
	"im:message:send_as_bot",
	"im:message:update",
	"im:message.reactions:read",
	"im:message.reactions:write_only",
	"im:chat",
	"im:chat:read",
	"application:application:self_manage",
] as const;

export const SENSITIVE_GROUP_MSG_SCOPE = "im:message.group_msg";

export interface ScopeProbeResult {
	grantedScopes?: string[];
}

export function missingScopes(granted: readonly string[] | undefined, required: readonly string[]): string[] {
	if (!granted) return [...required];
	const set = new Set(granted);
	return required.filter((scope) => !set.has(scope));
}

export function hasScope(granted: readonly string[] | undefined, scope: string): boolean {
	return Boolean(granted?.includes(scope));
}

export function buildScopeApplyUrl(params: { appId: string; scopes: readonly string[] }): string {
	const url = new URL(`https://open.feishu.cn/app/${params.appId}/auth`);
	if (params.scopes.length > 0 && params.scopes.length < 20) url.searchParams.set("q", params.scopes.join(","));
	url.searchParams.set("op_from", "pi-feishu");
	url.searchParams.set("token_type", "tenant");
	return url.toString();
}

export function buildPermissionPageUrl(appId: string): string {
	return `https://open.feishu.cn/app/${appId}/permission`;
}

export function buildEventSubUrl(appId: string): string {
	return `https://open.feishu.cn/app/${appId}/event-sub`;
}

export async function probeGrantedScopes(credentials: FeishuCredentials): Promise<ScopeProbeResult> {
	const tokenResponse = await fetch("https://open.feishu.cn/open-apis/auth/v3/tenant_access_token/internal", {
		method: "POST",
		headers: { "Content-Type": "application/json" },
		body: JSON.stringify({ app_id: credentials.appId, app_secret: credentials.appSecret }),
	});
	const tokenResult = (await tokenResponse.json()) as { code?: number; msg?: string; tenant_access_token?: string };
	if (!tokenResponse.ok || tokenResult.code !== 0 || !tokenResult.tenant_access_token) {
		throw new Error(`获取飞书 tenant token 失败：${tokenResult.msg ?? tokenResponse.statusText}`);
	}

	const scopeResponse = await fetch("https://open.feishu.cn/open-apis/application/v6/applications/me?lang=zh_cn", {
		headers: { Authorization: `Bearer ${tokenResult.tenant_access_token}` },
	});
	const scopeResult = (await scopeResponse.json()) as {
		code?: number;
		app?: ScopeApp;
		data?: ScopeApp & { app?: ScopeApp };
	};
	if (!scopeResponse.ok || scopeResult.code !== 0) return {};
	const app = scopeResult.data?.app ?? scopeResult.app ?? scopeResult.data ?? {};
	const rawScopes = app.scopes ?? app.online_version?.scopes ?? [];
	return {
		grantedScopes: rawScopes.map((entry) => entry.scope).filter((scope): scope is string => Boolean(scope)),
	};
}

interface ScopeApp {
	scopes?: Array<{ scope?: string }>;
	online_version?: { scopes?: Array<{ scope?: string }> };
}

export function buildGroupPermissionReminder(params: {
	appId: string;
	groupName: string;
	grantedScopes?: readonly string[];
}): string | null {
	const missingRequired = missingScopes(params.grantedScopes, REQUIRED_APP_SCOPES);
	const missingGroupMsg = !hasScope(params.grantedScopes, SENSITIVE_GROUP_MSG_SCOPE);
	const unknown = !params.grantedScopes;
	if (!unknown && missingRequired.length === 0 && !missingGroupMsg) return null;

	const requiredForLink = unknown ? REQUIRED_APP_SCOPES : missingRequired;
	const lines = ["💬 **【重要体验提示 — 飞书项目群权限】**", "", `您刚才成功创建了项目群「${params.groupName}」。`, ""];
	if (unknown) {
		lines.push(
			"ℹ️ 当前应用还不能读取自身已开通 scope 列表（通常缺少 `application:application:self_manage`），无法自动确认权限完整性。",
			"",
		);
	}
	if (missingRequired.length > 0 || unknown) {
		lines.push(
			"⚠️ **基础权限可能未完整开通**，缺失时会影响私聊/群聊接收、回复、更新卡片和已读表情。",
			`👉 一键申请基础权限：${buildScopeApplyUrl({ appId: params.appId, scopes: requiredForLink })}`,
			"",
		);
	}
	if (missingGroupMsg || unknown) {
		lines.push(
			`⚠️ **免 @ 权限未确认**：如果不开通 \`${SENSITIVE_GROUP_MSG_SCOPE}\`，群里普通消息可能不会触发机器人；请在群里 @ 机器人，或申请免 @ 权限。`,
			`👉 一键申请免 @ 权限：${buildScopeApplyUrl({ appId: params.appId, scopes: [SENSITIVE_GROUP_MSG_SCOPE] })}`,
			"",
		);
	}
	lines.push(
		"还需要确认事件订阅与发布：",
		`1️⃣ 事件订阅页确认订阅 \`im.message.receive_v1\`：${buildEventSubUrl(params.appId)}`,
		`2️⃣ 权限管理页申请版本发布使权限生效：${buildPermissionPageUrl(params.appId)}`,
		"",
		"权限生效前，群里请先使用 `@机器人 你的问题`。",
	);
	return lines.join("\n");
}

/**
 * Bot 被拉进一个未托管的新群时，私聊 Owner 的引导：
 * 说明 /bind 用法，并附群聊相关权限的体检结果。
 */
export function buildBotAddedGuidance(params: {
	groupName: string;
	appId: string;
	grantedScopes?: readonly string[];
}): string {
	const missingRequired = missingScopes(params.grantedScopes, [
		"im:message.group_at_msg:readonly",
		"im:message:send_as_bot",
	]);
	const missingGroupMsg = !hasScope(params.grantedScopes, SENSITIVE_GROUP_MSG_SCOPE);
	const unknown = !params.grantedScopes;

	const lines = [
		"📥 **机器人已被加入新群聊**",
		"",
		`群聊「${params.groupName}」还没有绑定到 Pi。如需在该群使用，请在群里直接发送：`,
		"",
		"    /bind",
		"",
		"绑定后该群会获得独立的 Pi 会话，只有你和授权成员的消息会被处理。",
		"",
	];
	if (unknown) {
		lines.push("ℹ️ 暂时无法读取应用已开通的权限列表，无法自动完成权限体检。", "");
	} else if (missingRequired.length > 0) {
		lines.push(
			"⚠️ 群聊基础权限缺失，群里 @机器人 可能收不到消息或无法回复：",
			`   缺失：${missingRequired.join("、")}`,
			`👉 一键申请：${buildScopeApplyUrl({ appId: params.appId, scopes: missingRequired })}`,
			"",
		);
	}
	if ((missingGroupMsg || unknown) && missingRequired.length === 0) {
		lines.push(
			`💬 该群暂未开通「免 @ 响应」权限（${SENSITIVE_GROUP_MSG_SCOPE}，敏感权限需人工审核）：群内请先 @机器人 触发。`,
			`👉 一键申请：${buildScopeApplyUrl({ appId: params.appId, scopes: [SENSITIVE_GROUP_MSG_SCOPE] })}`,
			"",
		);
	}
	lines.push(`🔄 权限变更后需发布新版本生效：${buildPermissionPageUrl(params.appId)}`);
	return lines.join("\n");
}

/** 每个 scope 的用途说明，用于欢迎语中的权限清单。 */
export const SCOPE_DESCRIPTIONS: Record<string, string> = {
	"im:message.p2p_msg:readonly": "接收私聊消息",
	"im:message.group_at_msg:readonly": "接收群内 @机器人 的消息",
	"im:message:send_as_bot": "以机器人身份发送/回复消息",
	"im:message:update": "持续更新交互卡片（流式回复）",
	"im:message.reactions:read": "读取表情回复（❌ 取消排队消息）",
	"im:message.reactions:write_only": "添加表情回复（思考中已读回执）",
	"im:chat": "创建群聊并邀请 Owner",
	"im:chat:read": "读取群信息（群名等）",
	"application:application:self_manage": "读取应用已开通权限，自动完成权限体检",
	[SENSITIVE_GROUP_MSG_SCOPE]: "群内免 @ 直接响应所有消息（敏感权限，需人工审核）",
};

function renderScopeInventory(): string[] {
	return [...REQUIRED_APP_SCOPES, SENSITIVE_GROUP_MSG_SCOPE].map((scope) => {
		const description = SCOPE_DESCRIPTIONS[scope];
		return description ? `- \`${scope}\`（${description}）` : `- \`${scope}\``;
	});
}

/**
 * 权限体检段落：grantedScopes 未知时返回 null（不猜）；
 * 全部就绪时返回 ✅ 段落 + 完整依赖清单（便于逐项核对），
 * 否则返回缺失清单 + 一键申请链接。
 */
export function buildScopeHealthSection(appId: string, grantedScopes?: readonly string[]): string | null {
	if (!grantedScopes) return null;
	const missing = missingScopes(grantedScopes, REQUIRED_APP_SCOPES);
	const hasGroupMsg = hasScope(grantedScopes, SENSITIVE_GROUP_MSG_SCOPE);
	if (missing.length === 0 && hasGroupMsg) {
		return [
			"✅ 应用权限配置完整，所有功能均可正常使用。",
			"",
			"本 Bot 依赖以下权限（均已开通）：",
			...renderScopeInventory(),
		].join("\n");
	}
	const lines = ["⚠️ 以下应用权限尚未开通，对应功能会受限："];
	if (missing.length > 0) {
		lines.push(`📋 缺失 ${missing.length} 项基础权限，点击一键申请：`);
		lines.push(`👉 ${buildScopeApplyUrl({ appId, scopes: missing })}`);
		lines.push("   缺失明细：");
		for (const scope of missing) {
			const description = SCOPE_DESCRIPTIONS[scope];
			lines.push(`   - \`${scope}\`${description ? `（${description}）` : ""}`);
		}
	}
	if (!hasGroupMsg) {
		lines.push("💬 「免 @ 响应」权限未开：群内需 @机器人 才能触发，点击开通：");
		lines.push(`👉 ${buildScopeApplyUrl({ appId, scopes: [SENSITIVE_GROUP_MSG_SCOPE] })}`);
	}
	lines.push("🔄 权限生效（需发布应用版本）：");
	lines.push(`👉 ${buildPermissionPageUrl(appId)}`);
	return lines.join("\n");
}

/**
 * 对齐 easycodeclient：Bot 上线后私聊 Owner 的欢迎语，
 * 包含工作目录、使用提示和权限体检结果。
 */
export function buildStartupWelcome(params: { cwd?: string; healthSection?: string | null }): string {
	const lines = ["👋 Pi 飞书 Bot 已上线，随时待命。"];
	if (params.cwd) {
		lines.push("", "**📂 主会话工作目录**", `\`${params.cwd}\``);
	}
	lines.push(
		"",
		"**💡 使用提示**",
		"- 私聊直接发送问题即可",
		"- Owner 在群里发送 /bind 可把群绑定到独立 Pi 会话",
		"",
		"**❓ 需要帮助**：发送 /help 查看所有可用命令",
	);
	if (params.healthSection) {
		lines.push("", "---", "", params.healthSection);
	}
	return lines.join("\n");
}