// The RenderModel→DOM boundary, statically: a projected field that nothing
// paints is the bug four widgets shared. See context/code/clients.md.

import { test } from "node:test";
import assert from "node:assert/strict";
import { readFileSync } from "node:fs";
import { fileURLToPath } from "node:url";

const read = (rel) => readFileSync(fileURLToPath(new URL(rel, import.meta.url)), "utf8");

/// Comments name model fields routinely, so a field mentioned only in one
/// would read as painted. Strip them before asking what the code touches.
const code = (rel) =>
  read(rel)
    .replace(/\/\*[\s\S]*?\*\//g, " ")
    .replace(/(^|[^:"'`])\/\/.*$/gm, "$1");

/// Fields the page deliberately does not read, each with the reason. A field
/// belongs here only with an argument; the list is the debt, written down.
// improvise-z754 put the title bar's facts in one shared cache and taught
// `src/draw.rs::draw_title` to fold it; this page never learned to. That is
// improvise-5jna, open, and this list is what stops it being forgotten.
const UNPAINTED = {
  doc_name: "improvise-5jna: the title bar is drawn by the TUI and not here",
  doc_dirty: "improvise-5jna",
  doc_stored_as: "improvise-5jna",
};

/// The `pub` fields of `RenderModel`, read off the Rust that defines it.
function renderModelFields() {
  const src = read("../../crates/improvise-wasm-client/src/render.rs");
  const start = src.indexOf("pub struct RenderModel {");
  assert.ok(start > 0, "RenderModel moved — this test reads the struct itself");
  const body = src.slice(start, src.indexOf("\n}", start));
  const fields = [...body.matchAll(/\n {4}pub ([a-z_0-9]+):/g)].map((m) => m[1]);
  assert.ok(fields.length > 10, `found only ${fields.length} fields`);
  return fields;
}

test("every field the render model projects is painted, or named as debt", () => {
  // Both halves of the page: `app.js` paints, `shell.js` plans the grid.
  const page = code("../app.js") + code("../shell.js");
  const unpainted = renderModelFields().filter((field) => !page.includes(`model.${field}`));
  assert.deepEqual(
    unpainted.sort(),
    Object.keys(UNPAINTED).sort(),
    "a projected field reaches no element — paint it, or add it to UNPAINTED with the reason",
  );
});

test("every element the page looks up exists in the page", () => {
  const app = read("../app.js");
  const html = read("../index.html");
  const ids = [...app.matchAll(/getElementById\("([^"]+)"\)/g)].map((m) => m[1]);
  assert.ok(ids.length >= 8, `found only ${ids.length} element lookups`);
  for (const id of ids) {
    assert.ok(html.includes(`id="${id}"`), `app.js looks up #${id}, which index.html has not got`);
  }
});