// One image model per workflow, plus the models to try when it fails.
//
// A single model means a refusal, a rate limit or a model the gateway has since
// dropped ends as a missing picture. The chain is primary first, then each
// fallback in order, and it stops at the first one that produces an image —
// every hop being a paid request is why it is capped rather than open-ended.
import { imageJson } from '../generatedImages.js';

const WORKFLOWS = [
  { key: 'clinical_assistant', label: 'Clinical Assistant' },
  { key: 'learning_hub', label: 'Learning Hub' },
  { key: 'my_resources', label: 'My Resources' }
];

let loading = false;
let loaded = false;
let controls = {};
let save; let status; let maxModels = 3;

async function load() {
  const root = document.getElementById('workflow-image-settings');
  if (root && !root.children.length) loaded = false; // fresh DOM (test/re-import) re-renders
  if (!root || loaded || loading) return;
  loading = true;
  try {
    const [settings, models] = await Promise.all([
      imageJson('/api/admin/image-settings'),
      imageJson('/api/admin/config/image-models/discover').catch(() => ({ success: false }))
    ]);
    maxModels = Number(settings.maxModels) || 3;
    const discovered = Array.isArray(models.models) ? models.models : [];
    root.textContent = '';

    const form = document.createElement('form');
    const heading = document.createElement('h4');
    heading.textContent = 'Image models';
    const note = document.createElement('p');
    note.style.cssText = 'margin:2px 0 10px;font-size:12px;color:var(--g500);';
    note.textContent = 'Each workflow tries its model first, then its fallbacks in order, ' +
      'stopping at the first that produces an image. A fallback is only tried when another ' +
      'model has a real chance — a refusal, a rate limit, a provider fault, or a model the ' +
      'gateway does not have. Bad credentials and a malformed request stop immediately.';
    form.append(heading, note);

    controls = {};
    WORKFLOWS.forEach(workflow => {
      const saved = settings.workflows[workflow.key] || {};
      const group = document.createElement('fieldset');
      group.style.cssText = 'border:1px solid var(--g200);border-radius:8px;padding:12px;margin:0 0 12px;';
      const legend = document.createElement('legend');
      legend.style.cssText = 'font-size:12px;font-weight:600;color:var(--g700);padding:0 6px;';
      legend.textContent = workflow.label;
      group.appendChild(legend);

      // My Resources picks its model per request from the roster, so only the
      // Learning Hub and the Assistant name a primary here.
      const primary = makeSelect([saved.model], discovered);
      primary.disabled = workflow.key === 'my_resources';
      group.appendChild(row(workflow.key === 'my_resources' ? 'Model (set per request)' : 'Model', primary));

      const fallbacks = [];
      for (let i = 0; i < maxModels - 1; i++) {
        const select = makeSelect([(saved.fallbacks || [])[i] || ''], discovered, true);
        fallbacks.push(select);
        group.appendChild(row('Fallback ' + (i + 1), select));
      }

      const budget = makeBudget(saved.budget);
      group.appendChild(row('Image input budget', budget));

      controls[workflow.key] = { primary, fallbacks, budget };
      form.appendChild(group);
    });

    save = document.createElement('button');
    save.type = 'submit'; save.className = 'btn-sm btn-primary';
    save.textContent = 'Save image settings';
    status = document.createElement('p'); status.setAttribute('role', 'status');
    form.append(save, status);

    form.onsubmit = async e => {
      e.preventDefault();
      if (save.disabled) return;
      save.disabled = true;
      try {
        for (const workflow of WORKFLOWS) {
          const control = controls[workflow.key];
          const body = {
            budget: Number(control.budget.value),
            fallbacks: control.fallbacks.map(s => s.value).filter(Boolean)
          };
          // Only the workflows that own a primary send one; My Resources would
          // be overwriting a per-request choice with a form field.
          if (workflow.key !== 'my_resources') body.model = control.primary.value;
          await imageJson('/api/admin/image-settings/' + workflow.key,
            { method: 'PUT', body: JSON.stringify(body) });
        }
        status.textContent = 'Saved. New jobs use these settings; existing jobs are unchanged.';
      } catch (error) {
        status.textContent = error.message + ' Nothing was saved.';
      } finally { save.disabled = false; }
    };
    root.append(form);
    loaded = true;
  } catch (_) { /* Next tab entry retries; no drafts are touched. */ }
  finally { loading = false; }
}

function row(labelText, control) {
  const wrap = document.createElement('div');
  wrap.className = 'admin-row';
  const label = document.createElement('label');
  label.className = 'admin-row-label';
  label.textContent = labelText;
  wrap.append(label, control);
  return wrap;
}

function makeSelect(knownIds, models, optional) {
  const select = document.createElement('select');
  select.className = 'admin-control';
  if (optional) {
    const none = document.createElement('option');
    none.value = ''; none.textContent = 'None';
    select.appendChild(none);
  }
  const ids = new Set([...(Array.isArray(knownIds) ? knownIds : []).filter(Boolean),
    ...((Array.isArray(models) ? models : []).map(m => m && m.id).filter(Boolean))]);
  [...ids].sort().forEach(id => {
    const option = document.createElement('option');
    option.value = id; option.textContent = id;
    select.appendChild(option);
  });
  select.value = knownIds[0] || '';
  return select;
}

function makeBudget(value) {
  const input = document.createElement('input');
  input.className = 'admin-control';
  input.type = 'number'; input.min = '1000'; input.max = '32000'; input.required = true;
  input.value = value;
  return input;
}

export function initImageSettings() {
  document.addEventListener('tabChanged', e => { if (e.detail?.tab === 'admin') load(); });
  // A model added in the Models card has to show up in these dropdowns without
  // a page reload. `loaded` exists so a tab revisit does not refetch; a roster
  // change is the one case where refetching is the point.
  document.addEventListener('models-changed', () => {
    if (loading) return;
    loaded = false;
    load();
  });
}