#!/usr/bin/env node
// sfx-compose.mjs — build a track whose EVERY sound is generated by the
// ElevenLabs SFX endpoint (/api/sfx). No synths, no samples, no vocals:
// just text-prompted sound effects layered on a timeline and glued with
// a psychedelic ffmpeg FX chain.
//
// Counterpart to big-pictures/cli.mjs (which builds jeffrey-vocal
// tracks). Here the "score" is an arrangement file of sound prompts.
// Each cue is content-hash cached by bin/sfx.mjs, so reruns are free.
//
// Arrangement file format (`<slug>.sfx`):
//   @title  phosphene            # ID3 title (default: slug)
//   @glue   swirl                # psychedelic glue: swirl | dub | none
//   @duration 88                 # hard trim (seconds); omit = auto
//
//   # cue lines — head is key=val tokens, prompt follows the colon:
//   #   at=SEC gain=G dur=S [loop] fadein=S fadeout=S pan=-1..1 : prompt
//   at=0  gain=0.5 dur=26 loop fadein=5 fadeout=8 : deep warm analog drone, evolving
//   at=12 gain=0.6 dur=8  fadein=2 fadeout=4 pan=-0.5 : reverse cymbal swell rising
//
// Usage:
//   node bin/sfx-compose.mjs big-pictures/phosphene.sfx
//   node bin/sfx-compose.mjs phosphene                 # resolves big-pictures/<slug>.sfx
//   node bin/sfx-compose.mjs phosphene --force         # bust sfx + mix caches
//   node bin/sfx-compose.mjs phosphene --no-finalize   # stop at the raw mix

import { spawnSync } from "node:child_process";
import { readFileSync, copyFileSync, existsSync, mkdirSync, statSync } from "node:fs";
import { resolve, dirname, basename } from "node:path";
import { fileURLToPath } from "node:url";
import { homedir } from "node:os";

const HERE = dirname(fileURLToPath(import.meta.url));
const POP = resolve(HERE, "..");
const OUT = `${POP}/big-pictures/out`;

const argv = process.argv.slice(2);
const flags = {};
const positional = [];
for (let i = 0; i < argv.length; i++) {
  const a = argv[i];
  if (a.startsWith("--")) {
    const k = a.slice(2);
    const next = argv[i + 1];
    if (next !== undefined && !next.startsWith("--")) { flags[k] = next; i++; }
    else flags[k] = true;
  } else positional.push(a);
}

if (!positional[0]) {
  console.error("usage: node bin/sfx-compose.mjs <arrangement.sfx | slug> [--force] [--no-finalize]");
  process.exit(1);
}

// Resolve the arrangement file: explicit path, or big-pictures/<slug>.sfx.
let ARR = resolve(process.cwd(), positional[0]);
if (!existsSync(ARR)) {
  const alt = `${POP}/big-pictures/${positional[0].replace(/\.sfx$/, "")}.sfx`;
  if (existsSync(alt)) ARR = alt;
  else { console.error(`✗ arrangement not found: ${positional[0]}`); process.exit(1); }
}
const SLUG = basename(ARR).replace(/\.sfx$/, "");
const FORCE = flags.force === true;
const FINALIZE = flags["no-finalize"] !== true;

// ── parse arrangement ─────────────────────────────────────────────────
const meta = { title: SLUG, glue: "swirl", duration: null };
const cues = [];
for (const raw of readFileSync(ARR, "utf8").split("\n")) {
  const line = raw.trim();
  if (!line || line.startsWith("#")) continue;
  if (line.startsWith("@")) {
    const sp = line.indexOf(" ");
    const key = (sp === -1 ? line.slice(1) : line.slice(1, sp)).trim();
    const val = sp === -1 ? "" : line.slice(sp + 1).trim();
    if (key === "duration") meta.duration = Number(val) || null;
    else meta[key] = val;
    continue;
  }
  const ci = line.indexOf(":");
  if (ci === -1) continue;
  const prompt = line.slice(ci + 1).trim();
  if (!prompt) continue;
  const cue = { at: 0, gain: 0.7, dur: null, loop: false, fadein: 0, fadeout: 0, pan: 0, prompt };
  for (const tok of line.slice(0, ci).trim().split(/\s+/)) {
    if (!tok) continue;
    const [k, v] = tok.split("=");
    if (k === "at") cue.at = Number(v) || 0;
    else if (k === "gain") cue.gain = Number(v);
    else if (k === "dur") cue.dur = Math.max(0.5, Math.min(30, Number(v)));
    else if (k === "loop") cue.loop = true;
    else if (k === "fadein") cue.fadein = Number(v) || 0;
    else if (k === "fadeout") cue.fadeout = Number(v) || 0;
    else if (k === "pan") cue.pan = Math.max(-1, Math.min(1, Number(v) || 0));
  }
  cues.push(cue);
}
if (!cues.length) { console.error(`✗ no cues in ${ARR}`); process.exit(1); }

const TITLE = flags.title || meta.title;
const MIX = `${OUT}/${SLUG}-sfxmix.mp3`;
const FINAL = `${OUT}/${SLUG}-final.mp3`;
const DESK = `${homedir()}/Desktop/${SLUG}.mp3`;
const sfxDir = `${OUT}/sfx/${SLUG}`;
mkdirSync(sfxDir, { recursive: true });

function run(cmd, args, cwd = POP) {
  const r = spawnSync(cmd, args, { cwd, stdio: ["ignore", "inherit", "inherit"] });
  if (r.status !== 0) { console.error(`✗ ${cmd} ${args.join(" ")} failed (exit ${r.status})`); process.exit(1); }
}
function probeDur(p) {
  const r = spawnSync("ffprobe", ["-v", "error", "-show_entries", "format=duration",
                                  "-of", "default=nw=1:nk=1", p], { encoding: "utf8" });
  return Number((r.stdout || "0").trim()) || 0;
}

console.log(`━━━ ${SLUG} ━━━ ${cues.length} sfx cues · glue=${meta.glue}${meta.duration ? ` · trim ${meta.duration}s` : ""}\n`);

// ── 1 · render every cue through /api/sfx (cached) ───────────────────
console.log("▸ 1 · render sfx cues");
const stems = [];
cues.forEach((c, i) => {
  const p = `${sfxDir}/${String(i).padStart(2, "0")}.mp3`;
  const args = ["bin/sfx.mjs", "--text", c.prompt, "--out", p];
  if (c.dur != null) args.push("--duration", String(c.dur));
  if (c.loop) args.push("--loop");
  if (FORCE) args.push("--force");
  run("node", args);
  stems.push(p);
});

// ── 2 · lay cues on a timeline + glue ────────────────────────────────
console.log("\n▸ 2 · compose timeline + psychedelic glue");
const inputs = [];
for (const p of stems) inputs.push("-i", p);

const stemFilters = [];
const labels = [];
let trackEnd = 0;
cues.forEach((c, i) => {
  const len = c.dur != null ? c.dur : probeDur(stems[i]);
  trackEnd = Math.max(trackEnd, c.at + len);
  const d = Math.max(0, Math.round(c.at * 1000));
  const chain = [`adelay=${d}|${d}`, `volume=${c.gain}`];
  if (c.fadein > 0) chain.push(`afade=t=in:st=${c.at}:d=${c.fadein}`);
  if (c.fadeout > 0) chain.push(`afade=t=out:st=${(c.at + len - c.fadeout).toFixed(3)}:d=${c.fadeout}`);
  // Stereo placement: pan a copy of the (mono/stereo) stem across the field.
  if (c.pan !== 0) {
    const l = (1 - Math.max(0, c.pan)).toFixed(3);
    const rr = (1 + Math.min(0, c.pan)).toFixed(3);
    chain.push(`pan=stereo|c0=${l}*c0|c1=${rr}*c1`);
  }
  stemFilters.push(`[${i}:a]${chain.join(",")}[s${i}]`);
  labels.push(`[s${i}]`);
});

// Psychedelic glue presets applied to the full mix.
const GLUE = {
  swirl: "aphaser=in_gain=0.5:out_gain=0.8:delay=3.0:decay=0.5:speed=0.4," +
         "chorus=0.6:0.9:55|65|75:0.4|0.32|0.3:0.25|0.4|0.3:2|2.3|1.3," +
         "aecho=0.8:0.7:90|330:0.4|0.25",
  dub:   "aecho=0.8:0.85:180|420|760:0.5|0.3|0.18,aphaser=speed=0.3",
  none:  "anull",
}[meta.glue] || "anull";

const dur = meta.duration || (trackEnd + 1);
// mix → glue → gentle loudness normalize → trim → 44.1k stereo
const post = `amix=inputs=${cues.length}:duration=longest:dropout_transition=0:normalize=0[mix];` +
             `[mix]${GLUE},loudnorm=I=-15:TP=-1.5:LRA=11,atrim=duration=${dur.toFixed(2)},aresample=44100`;
const filter = `${stemFilters.join(";")};${labels.join("")}${post}`;

run("ffmpeg", ["-y", "-loglevel", "error", ...inputs,
               "-filter_complex", filter, "-c:a", "libmp3lame", "-q:a", "2", MIX]);
console.log(`  ✓ ${MIX}  (${(statSync(MIX).size / 1024 / 1024).toFixed(2)} MB · ~${dur.toFixed(0)}s)`);

// ── 3 · finalize (ID3 + auto cover) ──────────────────────────────────
let result = MIX;
if (FINALIZE) {
  console.log("\n▸ 3 · finalize (ID3 + cover)");
  run("node", ["bin/finalize.mjs", "--in", MIX.replace(POP + "/", ""),
               "--slug", SLUG, "--title", TITLE,
               "--out", FINAL.replace(POP + "/", ""), "--force"]);
  result = FINAL;
}

copyFileSync(result, DESK);
console.log(`\n✓ ~/Desktop/${SLUG}.mp3   ${(statSync(DESK).size / 1024 / 1024).toFixed(2)} MB`);