import { parseArgs } from "node:util";
import { addSong, loadSong, readAlignment, trackKeys, writeAlignment } from "../ref/manifest.ts";
import { parseSmf } from "./smf.ts";
import { autoAlign } from "./auto.ts";
import { fitSummary } from "./fit.ts";
import { SF2_PATH, startServer } from "./server.ts";

const USAGE = `usage:
  bun run align [serve] [--host 127.0.0.1] [--port 5180] [--url-host <host shown in the URL>] [--root reference]
  bun run align add <audio> <midi> --id <id> [--title <t>] [--capo "<track name>=9"]...
  bun run align auto <id> [--root reference]`;

async function add(argv: string[]) {
  const { values, positionals } = parseArgs({ args: argv, allowPositionals: true, options: { id: { type: "string" }, title: { type: "string" }, capo: { type: "string", multiple: true } } });
  const [audio, midi] = positionals;
  if (!audio || !midi || !values.id) throw new Error(USAGE);
  const smf = parseSmf(new Uint8Array(await Bun.file(midi).arrayBuffer()));
  const keys = new Set(trackKeys(smf.tracks));
  const capo: Record<string, number> = {};
  for (const c of values.capo ?? []) {
    const i = c.lastIndexOf("=");
    const k = c.slice(0, i), n = Number(c.slice(i + 1));
    if (i < 0 || !Number.isInteger(n) || n < 0) throw new Error(`bad --capo ${JSON.stringify(c)}; expected "<track name>=<fret>"`);
    if (!keys.has(k)) throw new Error(`--capo: no track named ${JSON.stringify(k)}; tracks: ${[...keys].map((x) => JSON.stringify(x)).join(", ")}`);
    capo[k] = n;
  }
  const e = await addSong({ id: values.id, title: values.title ?? values.id, audio, midi, capo });
  console.log(`added ${e.id} (${e.title})`);
  for (const [k, r] of Object.entries(e.roles)) console.log(`  ${JSON.stringify(k)} -> ${r ?? "unmapped"}`);
}

async function serve(argv: string[]) {
  const { values } = parseArgs({ args: argv, options: { host: { type: "string" }, port: { type: "string" }, "url-host": { type: "string" }, root: { type: "string" } } });
  const port = values.port === undefined ? 5180 : Number(values.port);
  if (!Number.isInteger(port) || port < 0 || port > 65535) throw new Error(`bad --port ${values.port}`);
  const s = await startServer({ host: values.host ?? "127.0.0.1", port, urlHost: values["url-host"], root: values.root ?? "reference" });
  console.log(`Alignment page: ${s.url}`);
  console.log(`(listening on ${values.host ?? "127.0.0.1"}:${s.port}; the key in the URL is required and changes on every start)`);
}

async function auto(argv: string[]) {
  const { values, positionals } = parseArgs({ args: argv, allowPositionals: true, options: { root: { type: "string" } } });
  const root = values.root ?? "reference";
  const id = positionals[0];
  if (!id) throw new Error(USAGE);
  const s = await loadSong(id, root);
  const prev = await readAlignment(id, root);
  const manual = (prev?.anchors ?? []).filter((a) => a.kind === "manual");
  const keys = trackKeys(s.smf.tracks);
  const roles = Object.fromEntries(keys.map((k) => [k, s.entry.roles[k] ?? null]));
  const sf2 = new Uint8Array(await Bun.file(SF2_PATH).arrayBuffer());
  const t0 = performance.now();
  const r = autoAlign(s.audio, s.smf, roles, manual, sf2);
  await writeAlignment(id, { anchors: r.anchors, savedAt: new Date().toISOString(), fit: r.fit }, root);
  console.log(`${id}: ${r.anchors.length} anchors (${manual.length} manual kept) in ${((performance.now() - t0) / 1000).toFixed(1)} s -> ${root}/${id}/alignment.json`);
  console.log(`fit: ${fitSummary(r.fit)}`);
}

const [cmd, ...rest] = process.argv.slice(2);
try {
  if (cmd === "add") await add(rest);
  else if (cmd === "auto") await auto(rest);
  else if (cmd === "serve") await serve(rest);
  else if (cmd === undefined || cmd.startsWith("--")) await serve(process.argv.slice(2));
  else throw new Error(USAGE);
} catch (err) {
  console.error((err as Error).message);
  process.exit(1);
}