import { readdir, readFile } from "node:fs/promises";
import { basename, extname, join, resolve } from "node:path";

const root = resolve(process.argv[2] || ".");
const ignoredDirectories = new Set([
    ".git",
    "dist",
    "node_modules",
    "secrets",
    "state",
]);
const plainTextExtensions = new Set([".json", ".md", ".txt", ".yaml", ".yml"]);
const failures = [];

await inspect(root);

if (failures.length) {
    for (const failure of failures) console.error(failure);
    process.exitCode = 1;
} else {
    console.log("Layout constraints passed.");
}

async function inspect(directory) {
    const entries = await readdir(directory, { withFileTypes: true });
    const files = entries.filter((entry) => entry.isFile());
    const directories = entries.filter(
        (entry) => entry.isDirectory() && !ignoredDirectories.has(entry.name),
    );
    const relative = directory.slice(root.length + 1) || ".";

    if (files.length > 3) {
        failures.push(
            `${relative}: ${files.length} files exceeds the limit of 3`,
        );
    }
    if (directories.length > 4) {
        failures.push(
            `${relative}: ${directories.length} folders exceeds the limit of 4`,
        );
    }

    await Promise.all(
        files.map((file) => inspectFile(join(directory, file.name))),
    );
    await Promise.all(
        directories.map((child) => inspect(join(directory, child.name))),
    );
}

async function inspectFile(path) {
    const name = basename(path);
    if (name.includes(".test.") || plainTextExtensions.has(extname(name)))
        return;
    const content = await readFile(path, "utf8");
    const lines = content.split("\n").length;
    if (lines > 250) {
        failures.push(
            `${path.slice(root.length + 1)}: ${lines} lines exceeds 250`,
        );
    }
}