/**
 * SourceWritePolicy — blocks source writes when not in execute phase,
 * when gate not passed, when plan not approved, etc.
 *
 * Checkpoints: pre-write
 *
 * Logic migrated from:
 *   - src/harness/action-policy.ts: sourceWriteBlockReason
 *   - src/harness/path-policy.ts: isSourceLikePath
 */

import type { GateContext, GateFinding } from "../findings.ts";
import type { ActiveRun } from "../../types.ts";

export const SOURCE_WRITE_POLICY_NAME = "source-write-policy";

const SOURCE_EXTENSIONS = new Set([
	".java", ".kt", ".kts", ".xml", ".properties", ".yml", ".yaml",
	".sql", ".ksql", ".cs", ".py",
]);

export function evaluateSourceWritePolicy(ctx: GateContext): GateFinding[] {
	const findings: GateFinding[] = [];
	const { path, run, cwd } = ctx;

	if (!path || !isSourceLikePath(path)) return findings;

	// No active run
	if (!run) {
		findings.push({
			id: "SWP-001",
			severity: "hard-deny",
			policy: SOURCE_WRITE_POLICY_NAME,
			message: "当前没有正在处理的需求，禁止直接写产品代码。",
			nextAction: "先用 /kd <需求> 开始；按当前流程完成计划并进入 execute 后再写生产源码。",
		});
		return findings;
	}

	// Not in execute phase
	if (run.phase !== "execute") {
		findings.push({
			id: "SWP-002",
			severity: "hard-deny",
			policy: SOURCE_WRITE_POLICY_NAME,
			message: `当前阶段是 ${run.phase}，禁止写产品代码。`,
			nextAction: "先完成当前阶段文档和检查，用 /kd phase execute 进入 execute；计划不完整时更新 PLAN.md，禁止直接写代码。",
		});
		return findings;
	}

	// Open blocking question
	const openQuestion = (run.questions ?? []).find((q) => q.status === "open" && q.blocking);
	if (openQuestion) {
		findings.push({
			id: "SWP-004",
			severity: "hard-deny",
			policy: SOURCE_WRITE_POLICY_NAME,
			message: `存在未回答阻断问题 ${openQuestion.id}，禁止写产品代码。`,
			nextAction: "先记录该问题答案，再重新检查门禁。",
		});
	}

	// Open resume snapshot
	if (run.resumeSnapshot?.status === "open") {
		findings.push({
			id: "SWP-005",
			severity: "hard-deny",
			policy: SOURCE_WRITE_POLICY_NAME,
			message: `存在 open resumeSnapshot，禁止写产品代码。`,
			nextAction: `先恢复断点并处理 ${run.resumeSnapshot.pendingQuestionId ?? "当前阻塞问题"}。`,
		});
	}

	return findings;
}

// ── Utility functions (reimplemented from src/harness/path-policy.ts) ────────

function isSourceLikePath(path: string): boolean {
	const normalized = normalizeRelativePath(path);
	const lastSegment = normalized.split("/").at(-1) ?? normalized;
	const dotIndex = lastSegment.lastIndexOf(".");
	if (dotIndex < 0) return false;
	return SOURCE_EXTENSIONS.has(lastSegment.slice(dotIndex).toLowerCase());
}

function normalizeRelativePath(path: string): string {
	return path.replace(/\\/g, "/").replace(/^\.\//, "").replace(/^\/+/, "");
}