// Build-time markup for the Neighbors page: its Markdown list of sites, drawn as lots on a plat map.

import { ITEM, text, trimStop, hash, findList, address } from './list.mjs';

export { address };

const MONTHS = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];

/** A plausible survey call for a lot's front line, from its owner's name: "N 04°12′ E · 82.5′". */
export function bearing(name) {
  const h = hash(name);
  const deg = String(h % 90).padStart(2, '0');
  const min = String((h >>> 7) % 60).padStart(2, '0');
  const dist = (70 + ((h >>> 13) % 350) / 10).toFixed(1);
  return `${h & 1 ? 'N' : 'S'} ${deg}°${min}′ ${h & 2 ? 'E' : 'W'} · ${dist}′`;
}

/** "Maggie Appleton" → "MA". */
export const initials = (name) => text(name).split(/\s+/).map((w) => w[0]).join('').toUpperCase().slice(0, 3);

/**
 * Parse one rendered list item, `<a href>Name</a>: line. Start here: piece. Elsewhere: piece, in Pub.`
 * @returns {{ href: string, name: string, line: string, start: string, elsewhere: string } | null}
 */
export function parseNeighbor(li) {
  const m = li.trim().match(ITEM);
  if (!m) return null;
  const [, href, name, rest] = m;
  const [before, after = ''] = rest.split(/Start here:/);
  const [start, elsewhere = ''] = after.split(/Elsewhere:/);
  const line = before.trim() === 'TK.' ? 'TK' : before.trim();
  return { href, name, line, start: trimStop(start), elsewhere: trimStop(elsewhere) };
}

/** One neighbor's lot on the plat: initials, a sprig, their name and address, and what to read first. */
function lot(n) {
  return [
    `<li class="plot" data-b="${bearing(text(n.name))}">`,
    `<span class="lot" aria-hidden="true">${initials(n.name)}</span>`,
    `<svg class="sprig" aria-hidden="true"><use href="#sprout-g"/></svg>`,
    `<h2><a href="${n.href}">${n.name}</a></h2>`,
    `<p class="address label">${address(n.href)}</p>`,
    n.line ? `<p>${n.line}</p>` : '',
    n.start ? `<p class="start"><span class="label">Start here</span> ${n.start}</p>` : '',
    n.elsewhere ? `<p class="elsewhere"><span class="label">Elsewhere</span> ${n.elsewhere}</p>` : '',
    '</li>',
  ].join('\n');
}

/**
 * Turn the first list in a rendered page body into the plat: a map key, one lot per neighbor,
 * a hatched lot for this garden and a title block. Leaves the body alone if the list doesn't parse.
 * @param {string} html
 * @param {string} [tended] YYYY-MM-DD, the survey date on the title block
 */
export function platMap(html, tended) {
  const list = findList(html ?? '');
  if (!list) return html;
  const items = list.items.map(parseNeighbor);
  if (!items.length || items.some((n) => !n)) return html;

  const [y, mo] = String(tended ?? '').split('-').map(Number);
  const surveyed = y && mo ? `<span>Surveyed ${MONTHS[mo - 1]} ${y} · Sheet 1 of 1</span>` : '<span>Sheet 1 of 1</span>';
  const plat = [
    '<p class="map-key label">',
    '<span class="here"><span class="hatch-swatch" aria-hidden="true"></span>Hatched lot: ohlin.co/notes, you are here</span>',
    `<span>${items.length} lots</span>`,
    '<span class="north"><svg width="16" height="22" viewBox="0 0 16 22" aria-hidden="true"><path d="M8 1l5 13-5-3-5 3z" fill="currentColor"/><path d="M5 21v-5l6 5v-5" fill="none" stroke="currentColor" stroke-width="1.4" stroke-linejoin="round"/></svg>North</span>',
    '<span class="scale"><span class="scale-bar" aria-hidden="true"></span>1 lot = 1 good read</span>',
    '</p>',
    '<ul class="plots">',
    ...items.map(lot),
    // This garden: drawn on the map, but not a neighbor, so the list doesn't announce it. The key says it in words.
    '<li class="plot home" aria-hidden="true"><span class="home-label label">You are here</span><span class="home-name">ohlin.co/notes</span></li>',
    '</ul>',
    `<p class="title-block label"><strong>Plat of the Neighborhood</strong><span>Kevin⚡Ohlin · Notes</span>${surveyed}</p>`,
  ].join('\n');
  return html.slice(0, list.start) + plat + html.slice(list.end);
}