// Render one filmstrip per song: N frames evenly across the track, tiled.
//
//   node tools/strip.js --songs drone,runner,dusk
//   node tools/strip.js --songs drone --cols 6 --rows 2 --w 480 --h 270
//
// Frames come from the same Run as a full render, and the sim is advanced
// through every frame in between, so a strip cannot show a world that the
// video would not have.

import { writeFileSync, mkdirSync } from 'node:fs';
import { resolve, dirname } from 'node:path';
import { fileURLToPath } from 'node:url';
import { loadSong } from './load.js';
import { Run } from '../src/film.js';
import { encodePNG, tile } from '../src/render/png.js';

const HERE = dirname(fileURLToPath(import.meta.url));
const ROOT = resolve(HERE, '..');
const BANK = resolve(ROOT, '../flow-state/test/songs');

function args(argv) {
    const out = {};
    for (let i = 2; i < argv.length; i += 2) out[argv[i].replace(/^--/, '')] = argv[i + 1];
    return out;
}

const opt = args(process.argv);
const names = (opt.songs || 'drone,runner,dusk').split(',').map((s) => s.trim()).filter(Boolean);
const seed = Number(opt.seed || 12345);
const cols = Number(opt.cols || 4);
const rows = Number(opt.rows || 3);
const width = Number(opt.w || 480);
const height = Number(opt.h || 270);
const fps = 30;
const everything = opt.combined === '1';
const outDir = resolve(ROOT, opt.out || 'out');
mkdirSync(outDir, { recursive: true });

const count = cols * rows;
const all = [];

for (const name of names) {
    const { song, analysis } = loadSong(resolve(BANK, `${name}.wav`), { fps, seed });
    const run = new Run(song, { fps, width, height, seed });
    const frames = [];
    for (let i = 0; i < count; i++) {
        const t = (0.10 + 0.85 * (i / Math.max(1, count - 1))) * analysis.duration;
        frames.push(Math.min(analysis.frames - 1, Math.round(t * fps)));
    }
    const rendered = run.renderAt(frames);
    const shots = frames.map((f) => rendered.get(f));
    const zooms = shots.map((s) => `${s.cam.zoom.toFixed(1)}@${s.shot}`).join(' ');
    const sheet = tile(shots, cols, rows, 2);
    const file = resolve(outDir, `strip-${name}.png`);
    writeFileSync(file, encodePNG(sheet.w, sheet.h, sheet.data));
    const stats = run.world.stats();
    console.log(`${file}  ${sheet.w}x${sheet.h}  ${song.name}  peak=${stats.peak}  pop=${run.world.count}  hue=${song.palette.hue.toFixed(2)}  key=${song.summary.key}`);
    console.log(`  shots: ${zooms}`);
    all.push({ name, song, shots, stats });
}

if (everything) {
    // One row per song, same fractions of each track: the comparison sheet.
    const per = 4;
    const chosen = [];
    for (const entry of all) {
        for (let i = 0; i < per; i++) chosen.push(entry.shots[Math.round((i / (per - 1)) * (entry.shots.length - 1))]);
    }
    const sheet = tile(chosen, per, all.length, 3);
    const file = resolve(outDir, 'strip-all.png');
    writeFileSync(file, encodePNG(sheet.w, sheet.h, sheet.data));
    console.log(`${file}  ${sheet.w}x${sheet.h}`);
}