#!/usr/bin/env node

/**
 * Compile all TypeScript source + test files to dist-test/ using esbuild.
 * Run compiled JS directly with node --test (no per-file TS overhead).
 *
 * Usage: node scripts/compile-tests.mjs
 */

import { symlinkSync } from "node:fs";
import { cp, mkdir, readdir, readFile, writeFile } from "node:fs/promises";
import { createRequire } from "node:module";
import { join } from "node:path";
import { fileURLToPath } from "node:url";

const __dirname = fileURLToPath(new URL(".", import.meta.url));
const ROOT = join(__dirname, "..");

const require = createRequire(import.meta.url);
const esbuild = require(join(ROOT, "node_modules/esbuild"));

// Recursively collect files by extension (skip node_modules, templates, etc.)
// Directories to skip during file collection
const SKIP_DIRS = new Set([
	"node_modules",
	"templates",
	"__tests__",
	"integration",
]);

async function collectFiles(dir, exts = [".ts", ".mjs"]) {
	const results = [];
	let entries;
	try {
		entries = await readdir(dir, { withFileTypes: true });
	} catch {
		return results;
	}
	for (const entry of entries) {
		if (SKIP_DIRS.has(entry.name)) continue;
		const full = join(dir, entry.name);
		if (entry.isDirectory()) {
			results.push(...(await collectFiles(full, exts)));
		} else if (
			exts.some((ext) => entry.name.endsWith(ext)) &&
			!entry.name.endsWith(".d.ts")
		) {
			results.push(full);
		}
	}
	return results;
}

// Dirs to skip when copying assets (node_modules are never useful in dist-test)
const ASSET_SKIP_DIRS = new Set(["node_modules", "__tests__", "integration"]);

/**
 * Recursively copy files from srcDir to destDir.
 * Skips node_modules only. Copies everything: .ts/.tsx originals (for jiti),
 * .mjs helpers, .md/.yaml/.json assets, etc.
 * esbuild compiled .js output already lands in dist-test, so we just
 * overlay the asset files on top.
 */
async function copyAssets(srcDir, destDir) {
	let entries;
	try {
		entries = await readdir(srcDir, { withFileTypes: true });
	} catch {
		return; // directory doesn't exist, nothing to copy
	}
	for (const entry of entries) {
		if (ASSET_SKIP_DIRS.has(entry.name)) continue;
		const srcPath = join(srcDir, entry.name);
		const destPath = join(destDir, entry.name);
		if (entry.isDirectory()) {
			await copyAssets(srcPath, destPath);
		} else {
			await mkdir(destDir, { recursive: true });
			await cp(srcPath, destPath, { force: true });
		}
	}
}

async function main() {
	const start = Date.now();

	// Collect entry points from src/ and packages/*/src/
	const srcFiles = await collectFiles(join(ROOT, "src"));

	const packagesDir = join(ROOT, "packages");
	const pkgEntries = await readdir(packagesDir, { withFileTypes: true });
	const packageFiles = [];
	for (const entry of pkgEntries) {
		if (!entry.isDirectory()) continue;
		const pkgSrc = join(packagesDir, entry.name, "src");
		packageFiles.push(...(await collectFiles(pkgSrc)));
	}

	// Also compile web/lib/ — some tests import from ../../web/lib/
	const webLibFiles = await collectFiles(join(ROOT, "web", "lib"));

	const entryPoints = [...srcFiles, ...packageFiles, ...webLibFiles];
	console.log(`Compiling ${entryPoints.length} files to dist-test/...`);

	// bundle:false transforms TypeScript but keeps import specifiers verbatim.
	// We post-process the output to rewrite .ts → .js in import strings.
	await esbuild.build({
		entryPoints,
		outdir: join(ROOT, "dist-test"),
		outbase: ROOT,
		bundle: false,
		format: "esm",
		platform: "node",
		target: "node24",
		sourcemap: "inline",
		packages: "external",
		logLevel: "warning",
	});

	// Copy non-compiled assets from src/ to dist-test/src/ maintaining structure.
	// Tests use import.meta.url to resolve sibling .md, .yaml, .json, .ts etc.
	// Also copy original .ts files — jiti-based imports load .ts source directly.
	const srcDir = join(ROOT, "src");
	const distSrcDir = join(ROOT, "dist-test", "src");
	await copyAssets(srcDir, distSrcDir);
	console.log("Copied non-TS assets and .ts source files to dist-test/src/");

	// Copy packages/*/src/ assets as well
	for (const entry of pkgEntries) {
		if (!entry.isDirectory()) continue;
		const pkgSrc = join(packagesDir, entry.name, "src");
		const pkgDistSrc = join(ROOT, "dist-test", "packages", entry.name, "src");
		await copyAssets(pkgSrc, pkgDistSrc);
	}

	// Copy web/lib/ assets (tests import from ../../web/lib/ relative to dist-test/src/tests/)
	await copyAssets(
		join(ROOT, "web", "lib"),
		join(ROOT, "dist-test", "web", "lib"),
	);

	// Copy web/components/ assets (xterm-theme test reads shell-terminal.tsx via import.meta.dirname)
	await copyAssets(
		join(ROOT, "web", "components"),
		join(ROOT, "dist-test", "web", "components"),
	);

	// Copy scripts/ non-TS files (.cjs etc) — some tests require() scripts directly
	await copyAssets(join(ROOT, "scripts"), join(ROOT, "dist-test", "scripts"));

	// Copy root package.json — some tests read it to check version/engines fields
	await cp(
		join(ROOT, "package.json"),
		join(ROOT, "dist-test", "package.json"),
		{ force: true },
	);

	// Copy root dist/ into dist-test/dist/ — some tests compute projectRoot as
	// 3 levels up from dist-test/src/tests/ which lands at dist-test/, then
	// import from dist/mcp-server.js etc.
	const rootDistDir = join(ROOT, "dist");
	const distTestDistDir = join(ROOT, "dist-test", "dist");
	await copyAssets(rootDistDir, distTestDistDir);

	// Post-process: rewrite .ts import specifiers to .js in all compiled JS files.
	// esbuild with bundle:false preserves original specifiers; Node can't load .ts.
	const compiledJsFiles = await collectFiles(join(ROOT, "dist-test"), [".js"]);
	// Regex matches .ts in from/import() strings but not sourceMappingURL comments
	const tsImportRe = /(from\s+["'])(\.\.?\/[^"']*?)\.ts(["'])/g;
	const tsDynImportRe = /(import\(["'])(\.\.?\/[^"']*?)\.ts(["'])\)/g;

	let rewritten = 0;
	await Promise.all(
		compiledJsFiles.map(async (file) => {
			const src = await readFile(file, "utf-8");
			const out = src
				.replace(tsImportRe, (_, a, b, c) => `${a}${b}.js${c}`)
				.replace(tsDynImportRe, (_, a, b, c) => `${a}${b}.js${c})`);
			if (out !== src) {
				await writeFile(file, out, "utf-8");
				rewritten++;
			}
		}),
	);
	if (rewritten > 0) {
		console.log(`Rewrote .ts → .js imports in ${rewritten} files`);
	}

	// Remove stale compiled test files: dist-test entries whose source no longer exists
	// in a non-integration source directory (e.g. test moved to integration/).
	// Only cleans *.test.js and *.test.ts files to avoid touching non-test outputs.
	const { rm } = await import("node:fs/promises");
	const { existsSync } = await import("node:fs");
	const testDirsToClean = [
		[join(ROOT, "dist-test", "src", "tests"), join(ROOT, "src", "tests")],
		[
			join(ROOT, "dist-test", "src", "resources", "extensions", "sf", "tests"),
			join(ROOT, "src", "resources", "extensions", "sf", "tests"),
		],
	];
	let staleCleaned = 0;
	for (const [distDir, srcDir] of testDirsToClean) {
		let distEntries;
		try {
			distEntries = await readdir(distDir, { withFileTypes: true });
		} catch {
			continue;
		}
		for (const entry of distEntries) {
			if (!entry.isFile()) continue;
			if (!entry.name.match(/\.test\.(js|ts)$/)) continue;
			const stem = entry.name.replace(/\.(js|ts)$/, "");
			// Source could be .ts or .mjs (esbuild compiles both to .js)
			const hasTsSrc = existsSync(join(srcDir, stem + ".ts"));
			const hasMjsSrc = existsSync(join(srcDir, stem + ".mjs"));
			if (!hasTsSrc && !hasMjsSrc) {
				await rm(join(distDir, entry.name));
				staleCleaned++;
			}
		}
	}
	if (staleCleaned > 0) {
		console.log(
			`Removed ${staleCleaned} stale compiled test files from dist-test/`,
		);
	}

	// Ensure dist-test/node_modules exists so resource-loader.ts (which computes
	// packageRoot from import.meta.url) resolves sfNodeModules to a real path.
	// Without this, initResources creates dangling symlinks in test environments.
	const distNodeModules = join(ROOT, "dist-test", "node_modules");
	if (!existsSync(distNodeModules)) {
		symlinkSync(join(ROOT, "node_modules"), distNodeModules);
	}

	const elapsed = ((Date.now() - start) / 1000).toFixed(2);
	console.log(`Done in ${elapsed}s`);
}

main().catch((err) => {
	console.error(err);
	process.exit(1);
});