import { createReadStream } from "node:fs";
import { inspectExportStream } from "../db/export/inspect.js";
import { isExportKind } from "../db/export/filter.js";
import type { ExportKind } from "../db/types/ExportImport.js";

const args = process.argv.slice(2);

function printUsage(err: boolean | string = false): never {
  const log = (err ? console.error : console.log).bind(console);
  if (typeof err === "string") {
    log(`Error: ${err}`);
    log("");
  }
  log("Usage:");
  log("\tabode-inspect --help");
  log("\tabode-inspect <input-file|-> [--stop-after=note,...]");
  process.exit(err ? 1 : 0);
}

if (["-h", "--help", "help"].some((x) => args.includes(x))) printUsage();

let input: string | undefined;
const flags = new Map<string, string>();
for (const arg of args) {
  if (arg.startsWith("--")) {
    const eq = arg.indexOf("=");
    if (eq === -1) printUsage(`invalid flag: ${arg}`);
    flags.set(arg.slice(2, eq), arg.slice(eq + 1));
  } else if (input === undefined) {
    input = arg;
  } else {
    printUsage("too many arguments");
  }
}
if (!input) printUsage("missing <input-file|->");

for (const key of flags.keys()) {
  if (key !== "stop-after") printUsage(`unknown flag: --${key}`);
}

let stopAfterKinds: ExportKind[] | undefined;
const rawStop = flags.get("stop-after");
if (rawStop !== undefined) {
  const list = rawStop.split(",").filter(Boolean);
  const bad = list.filter((k) => !isExportKind(k));
  if (bad.length) printUsage(`invalid kind(s): ${bad.join(", ")}`);
  stopAfterKinds = list.filter(isExportKind);
}

const source = input === "-" ? process.stdin : createReadStream(input);

const { counts, meta } = await inspectExportStream(source, { stopAfterKinds });

if (meta) {
  console.log("Meta:");
  console.log(`- format version: ${meta.v ?? "?"}`);
  console.log(`- exported at: ${meta.exportedAt ?? "?"}`);
  console.log(`- source backend: ${meta.source ?? "?"}`);
  if (meta.filter && Object.keys(meta.filter).length) {
    console.log(`- effective filter: ${JSON.stringify(meta.filter)}`);
  }
}
console.log("Counts:");
const entries = Object.entries(counts);
if (!entries.length) console.log("(none)");
for (const [kind, count] of entries) console.log(`- ${kind}: ${count}`);

process.exit(0);