/**
 * Cursor Provider
 *
 * Loads configuration from Cursor's config directories.
 * Priority: 50 (tool-specific provider)
 *
 * Sources:
 * - User: ~/.cursor
 * - Project: .cursor/ (cwd only)
 *
 * Capabilities:
 * - rules: From rules/*.mdc files with MDC frontmatter (description, globs, alwaysApply)
 * - settings: From settings.json if present
 *
 * MCP servers are intentionally NOT inherited live from Cursor config: GJC owns
 * MCP runtime execution. Use `gjc mcp import cursor` to copy definitions into
 * GJC's own mcp.json instead.
 */

import { tryParseJson } from "@gajae-code/utils";
import { registerProvider } from "../capability";
import { readFile } from "../capability/fs";
import type { Rule } from "../capability/rule";
import { ruleCapability } from "../capability/rule";
import type { Settings } from "../capability/settings";
import { settingsCapability } from "../capability/settings";
import type { LoadContext, LoadResult, SourceMeta } from "../capability/types";
import { buildRuleFromMarkdown, createSourceMeta, getProjectPath, getUserPath, loadFilesFromDir } from "./helpers";

const PROVIDER_ID = "cursor";
const DISPLAY_NAME = "Cursor";
const PRIORITY = 50;

// =============================================================================
// Rules
// =============================================================================

async function loadRules(ctx: LoadContext): Promise<LoadResult<Rule>> {
	const items: Rule[] = [];
	const warnings: string[] = [];

	const userRulesPath = getUserPath(ctx, "cursor", "rules");

	const projectRulesPath = getProjectPath(ctx, "cursor", "rules");

	const [userResult, projectResult] = await Promise.all([
		userRulesPath
			? loadFilesFromDir<Rule>(ctx, userRulesPath, PROVIDER_ID, "user", {
					extensions: ["mdc", "md"],
					transform: transformMDCRule,
				})
			: Promise.resolve({ items: [] as Rule[], warnings: undefined }),
		projectRulesPath
			? loadFilesFromDir<Rule>(ctx, projectRulesPath, PROVIDER_ID, "project", {
					extensions: ["mdc", "md"],
					transform: transformMDCRule,
				})
			: Promise.resolve({ items: [] as Rule[], warnings: undefined }),
	]);

	items.push(...userResult.items);
	if (userResult.warnings) warnings.push(...userResult.warnings);

	items.push(...projectResult.items);
	if (projectResult.warnings) warnings.push(...projectResult.warnings);

	return { items, warnings };
}

function transformMDCRule(name: string, content: string, path: string, source: SourceMeta): Rule {
	return buildRuleFromMarkdown(name, content, path, source, { stripNamePattern: /\.(mdc|md)$/ });
}

// =============================================================================
// Settings
// =============================================================================

async function loadSettings(ctx: LoadContext): Promise<LoadResult<Settings>> {
	const items: Settings[] = [];
	const warnings: string[] = [];

	const userPath = getUserPath(ctx, "cursor", "settings.json");

	const [userContent, projectPath] = await Promise.all([
		userPath ? readFile(userPath) : Promise.resolve(null),
		getProjectPath(ctx, "cursor", "settings.json"),
	]);

	const projectContentPromise = projectPath ? readFile(projectPath) : Promise.resolve(null);

	if (userContent && userPath) {
		const parsed = tryParseJson<Record<string, unknown>>(userContent);
		if (parsed) {
			items.push({
				path: userPath,
				data: parsed,
				level: "user",
				_source: createSourceMeta(PROVIDER_ID, userPath, "user"),
			});
		} else {
			warnings.push(`${userPath}: invalid JSON`);
		}
	}

	const projectContent = await projectContentPromise;
	if (projectContent && projectPath) {
		const parsed = tryParseJson<Record<string, unknown>>(projectContent);
		if (parsed) {
			items.push({
				path: projectPath,
				data: parsed,
				level: "project",
				_source: createSourceMeta(PROVIDER_ID, projectPath, "project"),
			});
		} else {
			warnings.push(`${projectPath}: invalid JSON`);
		}
	}

	return { items, warnings };
}

// =============================================================================
// Provider Registration
// =============================================================================

registerProvider(ruleCapability.id, {
	id: PROVIDER_ID,
	displayName: DISPLAY_NAME,
	description: "Load rules from .cursor/rules/*.mdc and legacy .cursorrules",
	priority: PRIORITY,
	load: loadRules,
});

registerProvider(settingsCapability.id, {
	id: PROVIDER_ID,
	displayName: DISPLAY_NAME,
	description: "Load settings from ~/.cursor/settings.json and .cursor/settings.json",
	priority: PRIORITY,
	load: loadSettings,
});