// Editable design settings for the generated application documents.
//
// Same contract as lib/prompts.js: the defaults live here, an override is a row
// in the `design` table, and deleting the row restores the default. What stays
// in code is the *layout* — the sidebar grid, the DIN-5008 letter, the one-page
// auto-scaling. What the user picks is a narrow, curated set of knobs.
//
// The palette is deliberately closed. A free colour picker invites a neon CV,
// which makes an application worse, not better; every option here is a muted
// tone that survives being printed in greyscale by an HR department.

// Accent colours. `ink`/`sub`/`hair` stay neutral in every theme — the accent
// only carries the name, section labels, company names and markers, exactly as
// the monochrome original did.
const AKZENTE = [
  { key: 'anthrazit', label: 'Anthrazit (Standard)', rgb: [23, 23, 23] },
  { key: 'tiefblau', label: 'Tiefblau', rgb: [30, 58, 95] },
  { key: 'bordeaux', label: 'Bordeaux', rgb: [122, 31, 47] },
  { key: 'waldgruen', label: 'Waldgrün', rgb: [27, 67, 50] },
  { key: 'stahlblau', label: 'Stahlblau', rgb: [51, 65, 85] },
  { key: 'kupfer', label: 'Kupfer', rgb: [124, 62, 24] },
];

const SIDEBAR_VARIANTEN = [
  { key: 'neutral', label: 'Neutral grau (Standard)' },
  { key: 'getoent', label: 'Im Akzent getönt' },
  { key: 'weiss', label: 'Weiß (ohne Band)' },
];

const FOTO_FORMEN = [
  { key: 'eckig', label: 'Eckig (Standard)' },
  { key: 'rund', label: 'Rund' },
];

const SCHRIFT_STUFEN = [
  { key: '90', label: '90 % (kompakt)' },
  { key: '95', label: '95 %' },
  { key: '100', label: '100 % (Standard)' },
  { key: '105', label: '105 %' },
  { key: '110', label: '110 % (groß)' },
];

// Layout is fixed for now; the field exists so a second variant can be added
// later without another migration.
const LAYOUTS = [
  { key: 'sidebar', label: 'Sidebar (Standard)' },
];

const DEFAULTS = {
  layout: 'sidebar',
  akzent: 'anthrazit',
  sidebar: 'neutral',
  foto_anzeigen: '1',
  foto_form: 'eckig',
  schrift: '100',
};

const FELDER = [
  { key: 'layout', label: 'Layout', optionen: LAYOUTS },
  { key: 'akzent', label: 'Akzentfarbe', optionen: AKZENTE },
  { key: 'sidebar', label: 'Sidebar-Hintergrund', optionen: SIDEBAR_VARIANTEN },
  { key: 'foto_form', label: 'Form des Bewerberfotos', optionen: FOTO_FORMEN },
  { key: 'schrift', label: 'Schriftgröße', optionen: SCHRIFT_STUFEN },
];

const NEUTRAL_SIDEBAR = [242, 243, 245];

// Mix a colour towards white. amount = 0 -> white, 1 -> the colour itself.
function tint(rgb, amount) {
  return rgb.map((c) => Math.round(c * amount + 255 * (1 - amount)));
}

function findOption(list, key, fallbackKey) {
  return list.find((o) => o.key === key) || list.find((o) => o.key === fallbackKey);
}

// A checkbox paired with a hidden fallback submits *both* values, which Express
// hands over as an array — the last entry is the effective one.
function one(v) {
  return Array.isArray(v) ? v[v.length - 1] : v;
}

// Fold the stored overrides onto the defaults, dropping unknown keys/values so a
// stale row, a hand-crafted query string or a checkbox pair can never produce an
// invalid theme.
function settings(overrides = {}) {
  const out = { ...DEFAULTS };
  for (const f of FELDER) {
    const v = one(overrides[f.key]);
    if (v && f.optionen.some((o) => o.key === String(v))) out[f.key] = String(v);
  }
  const foto = one(overrides.foto_anzeigen);
  if (foto === '0' || foto === '1') out.foto_anzeigen = foto;
  return out;
}

// Build the concrete theme the renderer draws with. Everything the PDF code
// needs to know about the user's choices is in here — the renderer itself has
// no idea these are configurable.
function resolve(overrides = {}) {
  const s = settings(overrides);
  const accent = findOption(AKZENTE, s.akzent, 'anthrazit').rgb;

  let sidebarBg;
  if (s.sidebar === 'weiss') sidebarBg = [255, 255, 255];
  else if (s.sidebar === 'getoent') sidebarBg = tint(accent, 0.08);
  else sidebarBg = NEUTRAL_SIDEBAR;

  return {
    layout: s.layout,
    // Résumé palette — neutral base, configurable accent.
    rc: {
      ink: [33, 33, 33],
      sub: [92, 96, 100],
      hair: [208, 210, 214],
      accent,
      sidebarBg,
      track: [199, 202, 208],
      onSide: [38, 40, 44],
      onSideSub: [96, 100, 106],
    },
    // Cover-letter palette — same accent, so both documents read as one set.
    lc: {
      ink: [26, 26, 26],
      muted: [92, 96, 100],
      hair: [206, 208, 212],
      accent,
    },
    foto: {
      anzeigen: s.foto_anzeigen !== '0',
      rund: s.foto_form === 'rund',
    },
    // Starting scale for the one-page fit. The auto-scaler may still shrink
    // below this when there is a lot of content — it never grows past it.
    scale: (Number(s.schrift) || 100) / 100,
  };
}

// Field list for the Vorlagen UI, with the current selection marked.
function list(overrides = {}) {
  const s = settings(overrides);
  return FELDER.map((f) => ({
    key: f.key,
    label: f.label,
    aktuell: s[f.key],
    optionen: f.optionen.map((o) => ({ key: o.key, label: o.label, gewaehlt: o.key === s[f.key] })),
  }));
}

// True when the user deviates from the shipped defaults.
function isAngepasst(overrides = {}) {
  const s = settings(overrides);
  return Object.keys(DEFAULTS).some((k) => s[k] !== DEFAULTS[k]);
}

module.exports = {
  DEFAULTS, AKZENTE, FELDER,
  settings, resolve, list, isAngepasst,
  // The default theme, for callers that pass no overrides at all.
  defaultTheme: () => resolve({}),
};