import type { ActiveRun, GateResult, KdQuestion } from "./types.ts";

export type KdActionIntent =
	| "answer-question"
	| "revise-fact"
	| "stop-or-reset"
	| "advance-phase"
	| "verify-result"
	| "read-context"
	| "write-code"
	| "ask-question"
	| "phase-input";

export interface KdActionRoute {
	intent: KdActionIntent;
	allowed: boolean;
	reason: string;
	requiredAction: string;
}

export function routeHarnessAction(input: {
	run: ActiveRun;
	gate: GateResult;
	openQuestion?: KdQuestion;
	userText: string;
}): KdActionRoute {
	const text = input.userText.trim();
	const openQuestion = input.openQuestion;
	const inferred = inferIntent(text);

	if (openQuestion) {
		if (inferred === "stop-or-reset") {
			return {
				intent: inferred,
				allowed: true,
				reason: `当前存在 ${openQuestion.id}，但用户输入表达停止、废弃或重开。`,
				requiredAction: "先确认是否废弃当前断点；若继续当前 run，必须先回答 open question。",
			};
		}
		if (inferred === "revise-fact") {
			return {
				intent: inferred,
				allowed: true,
				reason: `当前存在 ${openQuestion.id}，用户输入可能是事实更正。`,
				requiredAction: "使用 kd_answer_user action=revise 记录更正事实和原因，或要求用户明确更正对象。",
			};
		}
		if (looksLikeQuestionAnswer(text)) {
			return {
				intent: "answer-question",
				allowed: true,
				reason: `当前唯一允许的正常动作是回答 ${openQuestion.id}。`,
				requiredAction: `调用 kd_answer_user action=answer id=${openQuestion.id} answer=<本轮输入>。`,
			};
		}
		return {
			intent: inferred,
			allowed: false,
			reason: `当前存在 open blocking question ${openQuestion.id}，本轮输入不能解释为 ${inferred}。`,
			requiredAction: `先判断本轮输入是否回答 ${openQuestion.id}；不是答案时要求用户回答、修订事实或明确停止当前 run。`,
		};
	}

	if (!input.gate.passed && inferred === "write-code") {
		return {
			intent: inferred,
			allowed: false,
			reason: `当前门禁阻塞：${input.gate.reason ?? "未知阻塞"}。`,
			requiredAction: input.gate.reason ? `只处理门禁阻塞：${input.gate.reason}` : "刷新门禁并处理唯一阻塞项。",
		};
	}

	if (input.run.phase !== "execute" && inferred === "write-code") {
		return {
			intent: inferred,
			allowed: false,
			reason: `当前阶段是 ${input.run.phase}，不能写代码。`,
			requiredAction: "完成当前阶段和门禁后推进到 execute；事实不足时使用 kd_ask_user 登记当前事实组问题。",
		};
	}

	return {
		intent: inferred,
		allowed: true,
		reason: "本轮输入可按当前 control frame 焦点处理。",
		requiredAction: defaultActionForIntent(inferred),
	};
}

function inferIntent(text: string): KdActionIntent {
	if (!text) return "phase-input";
	if (/^(停止|暂停|废弃|取消|重开|重新开始|stop|cancel|reset)\b/i.test(text)) return "stop-or-reset";
	if (/修订|更正|改成|不是.*而是|应为|应该是|revise/i.test(text)) return "revise-fact";
	if (isPlainAdvanceRequest(text)) return "advance-phase";
	if (/^(推进|下一阶段|继续推进|advance)\b|^\/kd\s+(next|phase|advance)\b/i.test(text)) return "advance-phase";
	if (/验证|测试|构建|release:check|npm test|npm run|exit\s*code|kd_verify_result|verify/i.test(text)) return "verify-result";
	if (/读取|查看|搜索|查找|定位|打开|read|grep|find|rg|get-content|ls\b|dir\b/i.test(text)) return "read-context";
	if (/写代码|编码|实现|修改|修复|新增|生成|提交代码|write|edit|patch|implement|fix/i.test(text)) return "write-code";
	if (/[?？]$|请问|确认.*什么|是什么/.test(text)) return "ask-question";
	return "phase-input";
}

export function isPlainAdvanceRequest(text: string): boolean {
	const normalized = text
		.trim()
		.replace(/[。.!！]+$/g, "")
		.replace(/\s+/g, " ")
		.toLowerCase();
	return [
		"继续",
		"继续推进",
		"继续下一步",
		"下一步",
		"下一阶段",
		"下个阶段",
		"推进",
		"开始下一步",
		"advance",
		"continue",
		"next",
	].includes(normalized);
}

function looksLikeQuestionAnswer(text: string): boolean {
	if (!text || text.startsWith("/")) return false;
	if (text.length > 300) return false;
	if (/[?？]/.test(text)) return false;
	if (/^(先|暂停|等等|不用|不要|继续|开始|实现|修改|修复|提交|发布|push)\b/i.test(text)) return false;
	if (/(然后|同时|顺便|接着|写代码|编码|提交|发布|push)/i.test(text)) return false;
	return true;
}

function defaultActionForIntent(intent: KdActionIntent): string {
	if (intent === "answer-question") return "记录 open question 答案。";
	if (intent === "revise-fact") return "记录结构化事实修订。";
	if (intent === "advance-phase") return "刷新门禁，通过后推进阶段。";
	if (intent === "verify-result") return "运行或记录真实验证命令和 evidence。";
	if (intent === "read-context") return "读取当前项目真实文件并记录结论。";
	if (intent === "write-code") return "仅在 execute 阶段写 PLAN.md 批准文件。";
	if (intent === "ask-question") return "使用 kd_ask_user 登记当前事实组问题。";
	if (intent === "stop-or-reset") return "确认停止、废弃或重开当前 run 的后果。";
	return "按当前阶段协议处理输入。";
}