/**
 * PlanPathPolicy — blocks writes to paths not in PLAN.md.
 *
 * Checkpoints: pre-write
 *
 * Logic migrated from:
 *   - src/harness/path-policy.ts: planWriteBlockReason, flagshipWriteBlockReason
 */

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

export const PLAN_PATH_POLICY_NAME = "plan-path-policy";

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

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

	if (!run) return findings;

	if (ctx.checkpoint === "pre-phase-transition") {
		if (ctx.phaseTarget === "execute" && (run?.profile?.product ?? run?.product) === "flagship") {
			const plan = readArtifact(cwd, run, "plan") ?? "";
			const flagshipProblem = flagshipPlanBlockReason(cwd, run, plan);
			if (flagshipProblem) {
				findings.push({
					id: "PPP-003",
					severity: "hard-deny",
					policy: PLAN_PATH_POLICY_NAME,
					message: flagshipProblem,
					nextAction: "旗舰版产品必须先在 PLAN.md 中规划 code/ 目录下的源码目标路径。",
				});
			}
		}
		return findings;
	}

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

	// Normalize path
	const normalized = normalizeRelativePath(cwd && isAbsolute(path) ? relative(cwd, path) : path);

	// Skip .pi/ paths
	if (normalized.startsWith(".pi/")) return findings;

	// Check flagship write block
	if ((run?.profile?.product ?? run?.product) === "flagship") {
		const flagshipReason = flagshipWriteBlockReason(run, normalized, cwd);
		if (flagshipReason) {
			findings.push({
				id: "PPP-002",
				severity: "hard-deny",
				policy: PLAN_PATH_POLICY_NAME,
				message: flagshipReason,
				nextAction: "旗舰版产品必须将源码放在 code/ 目录下。",
			});
			return findings;
		}
	}

	// Check plan write block (only in execute phase)
	if (run?.phase === "execute") {
		const plan = typeof payload === "string" ? payload : "";
		const planReason = planWriteBlockReason(normalized, plan);
		if (planReason) {
			findings.push({
				id: "PPP-001",
				severity: "soft-deny",
				policy: PLAN_PATH_POLICY_NAME,
				message: planReason,
				nextAction: "先在 PLAN.md 中声明要修改的文件路径，再执行写入。",
			});
		}
	}

	return findings;
}

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

function flagshipWriteBlockReason(run: ActiveRun, normalizedPath: string, cwd?: string): string | undefined {
	if ((run?.profile?.product ?? run?.product) !== "flagship") return undefined;
	if (!cwd || !hasWorkspaceCodeDir(cwd)) return undefined;
	if (!normalizedPath.startsWith("code/")) {
		return `旗舰版产品源码必须写入 code/ 目录，当前路径 ${normalizedPath} 不符合要求。`;
	}
	return undefined;
}

function planWriteBlockReason(normalizedPath: string, plan: string): string | undefined {
	if (!plan) return undefined;
	if (planMentionsPath(plan, normalizedPath)) return undefined;
	return `路径 ${normalizedPath} 未在 PLAN.md 中声明，禁止写入。`;
}

function planMentionsPath(plan: string, normalizedPath: string): boolean {
	const normalizedPlan = normalizeRelativePath(plan);
	const escaped = escapeRegExp(normalizedPath);
	return new RegExp(`(?:^|[\\s\`"'(])${escaped}(?:[\\s\`"')]|$)`, "i").test(normalizedPlan);
}

function hasWorkspaceCodeDir(cwd: string): boolean {
	try {
		const { existsSync } = require("node:fs");
		const { join } = require("node:path");
		return existsSync(join(cwd, "code"));
	} catch {
		return false;
	}
}

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(/^\/+/, "");
}

function escapeRegExp(value: string): string {
	return value.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
}

function flagshipPlanBlockReason(cwd: string, run: ActiveRun | undefined, plan: string): string | undefined {
	if ((run?.profile?.product ?? run?.product) !== "flagship") return undefined;

	if (hasWorkspaceCodeDir(cwd)) {
		if (/(?:^|[\s\`"'(])code[\\/][a-zA-Z0-9_\-\.\/]+/i.test(plan)) return undefined;
		return "不能进入 execute：星空旗舰版 PLAN.md 必须先记录当前项目 code/ 下的实际目标路径；不要按固定模块规则猜路径。";
	}

	if (planMentionsDiscoveredSourcePath(plan)) return undefined;
	return "不能进入 execute：PLAN.md 必须先记录已检查当前项目结构，并写明实际源码根或目标文件路径；当前项目没有 code/ 时更不能猜路径。";
}

function planMentionsDiscoveredSourcePath(plan: string): boolean {
	return /(?:^|[\s`"'(])(?:src[\\/]main[\\/]java|src[\\/]main[\\/]resources|[^`\n]*[\\/](?:src[\\/]main[\\/]java|src[\\/]main[\\/]resources)|[^`\n]*\.(?:java|xml|properties|yml|yaml|sql|ksql|py))(?:[\s`"')]|$)/i.test(
		plan,
	);
}

import { isAbsolute, relative } from "node:path";