/**
 * Commit Guard Extension
 *
 * WHAT: On `git commit -m …`, validates the message against Conventional
 *       Commits and scans it for secrets. Invalid/secret → confirm (UI) or
 *       block (no UI). Non-`-m` commits (editor) are left alone.
 *
 * CONFIGURE: edit COMMIT_TYPES below. Secret patterns live in
 *       extensions/lib/secrets.ts.
 *
 * DISABLE: remove/rename this file from the package `extensions/` folder.
 */

import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
import { scanSecrets } from "./lib/secrets.ts";
import { audit } from "./lib/audit.ts";

// Conventional Commits types accepted in the header. Extend as needed.
const COMMIT_TYPES = ["feat", "fix", "chore", "docs", "refactor", "test", "perf", "build", "ci", "style", "revert"];
const HEADER_RE = new RegExp(`^(${COMMIT_TYPES.join("|")})(\\(.+\\))?!?: .+`);

/** Extract the -m / --message value from a `git commit` command, if present. */
function extractCommitMessage(command: string): string | null {
	// Matches -m "msg", -m 'msg', --message=msg, -m msg (best effort).
	const m =
		command.match(/(?:-m|--message)[=\s]+"([^"]*)"/) ??
		command.match(/(?:-m|--message)[=\s]+'([^']*)'/) ??
		command.match(/(?:-m|--message)[=\s]+(\S+)/);
	return m ? m[1] : null;
}

export default function commitGuardExtension(pi: ExtensionAPI) {
	pi.on("tool_call", async (event, ctx) => {
		if (event.toolName !== "bash") return undefined;
		const command = (event.input.command as string | undefined) ?? "";
		if (!/\bgit\s+commit\b/.test(command)) return undefined;

		const message = extractCommitMessage(command);
		if (message === null) return undefined; // editor-based commit; not our concern

		const problems: string[] = [];
		if (!HEADER_RE.test(message)) problems.push("не Conventional Commits");
		const secretHits = scanSecrets(message);
		if (secretHits.length > 0) problems.push(`секрет (${secretHits.join(", ")})`);

		if (problems.length === 0) return undefined;

		audit({ kind: "guardrail_block", guardrail: "commit-guard", problems, hasSecret: secretHits.length > 0 });

		if (ctx.hasUI) {
			const choice = await ctx.ui.select(
				`⚠️ Проблема с сообщением коммита: ${problems.join("; ")}.\nФормат: type(scope): описание. Всё равно закоммитить?`,
				["Нет", "Да"],
			);
			if (choice === "Да") return undefined;
		}

		return { block: true, reason: `Commit message rejected: ${problems.join("; ")}` };
	});
}