// evaluate.js - Supervisor page (/evaluate)
//
// Lists submitted critiques (fetched from the server), lets a supervisor
// select one, review the question / answer / critique, then write an
// evaluation and grade the critique 1-5. The evaluation is saved as one
// record and the form locks after submission.

import { Utils } from './utils.js';

const userId = Utils.getMachineId();
const sessionId = Utils.generateSessionId();

const RATING_LABELS = { good: 'Good', bad: 'Bad', mixed: 'Mixed' };

// -------------------- State --------------------
let critiques = [];
let currentCritique = null;

// -------------------- Elements --------------------
const listView = document.getElementById('critique-list-view');
const detailView = document.getElementById('critique-detail-view');
const critiqueList = document.getElementById('critique-list');
const critiqueListStatus = document.getElementById('critique-list-status');
const backBtn = document.getElementById('back-btn');

const detailQuestion = document.getElementById('detail-question');
const detailAnswer = document.getElementById('detail-answer');
const detailAnswerGrade = document.getElementById('detail-answer-grade');
const detailGeneralComment = document.getElementById('detail-general-comment');
const detailHighlights = document.getElementById('detail-highlights');

const evaluationForm = document.getElementById('evaluation-form');
const evaluationDone = document.getElementById('evaluation-done');
const evaluationCommentInput = document.getElementById('evaluation-comment-input');
const submitEvaluationBtn = document.getElementById('submit-evaluation-btn');
const evaluationStatus = document.getElementById('evaluation-status');

// -------------------- Helpers --------------------
async function postJson(url, payload) {
  const res = await fetch(url, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(payload),
  });
  if (!res.ok) {
    throw new Error(`HTTP ${res.status}`);
  }
  return res;
}

function renderMarkdown(target, markdownText) {
  const text = markdownText || '';
  if (window.marked && window.DOMPurify) {
    target.innerHTML = DOMPurify.sanitize(marked.parse(text));
  } else {
    target.textContent = text;
  }
}

function truncate(text, maxLength) {
  return text.length > maxLength ? `${text.slice(0, maxLength)}…` : text;
}

function getSelectedGrade() {
  const checked = document.querySelector('input[name="critique-grade"]:checked');
  return checked ? Number(checked.value) : null;
}

// -------------------- Load critique list --------------------
async function loadCritiques() {
  critiqueListStatus.textContent = 'Loading critiques…';
  try {
    const res = await fetch('/critiques');
    if (!res.ok) throw new Error(`HTTP ${res.status}`);
    const data = await res.json();
    critiques = data.critiques || [];
    renderCritiqueList();
  } catch (err) {
    critiqueListStatus.textContent = 'Could not load critiques. Please refresh the page.';
  }
}

function renderCritiqueList() {
  critiqueList.innerHTML = '';

  if (critiques.length === 0) {
    critiqueListStatus.textContent = 'No critiques have been submitted yet.';
    return;
  }
  critiqueListStatus.textContent = '';

  critiques.forEach((critique) => {
    const item = document.createElement('li');
    const btn = document.createElement('button');
    btn.type = 'button';
    btn.className = 'critique-select-btn';

    const question = document.createElement('span');
    question.textContent = truncate(critique.question || '(question unavailable)', 120);

    const meta = document.createElement('span');
    const count = (critique.highlights || []).length;
    meta.textContent = ` — grade ${critique.answer_grade ?? '?'}/5, ${count} highlight review(s)`;

    btn.append(question, meta);
    btn.addEventListener('click', () => selectCritique(critique));
    item.appendChild(btn);
    critiqueList.appendChild(item);
  });
}

// -------------------- Select a critique --------------------
function selectCritique(critique) {
  currentCritique = critique;

  detailQuestion.textContent = critique.question || '';
  renderMarkdown(detailAnswer, critique.answer);
  detailAnswerGrade.textContent = critique.answer_grade ?? '?';
  detailGeneralComment.textContent = critique.general_comment || '(no general comment)';

  detailHighlights.innerHTML = '';
  const highlights = critique.highlights || [];
  if (highlights.length === 0) {
    const empty = document.createElement('li');
    empty.textContent = '(no highlight reviews)';
    detailHighlights.appendChild(empty);
  } else {
    highlights.forEach((hl) => {
      const item = document.createElement('li');
      const label = document.createElement('span');
      label.textContent = `${RATING_LABELS[hl.rating] || hl.rating} — `;
      const quote = document.createElement('q');
      quote.textContent = truncate(hl.highlighted_text || '', 200);
      item.append(label, quote);
      if (hl.comment) {
        item.append(` : ${hl.comment}`);
      }
      detailHighlights.appendChild(item);
    });
  }

  // Reset the evaluation form.
  evaluationForm.hidden = false;
  evaluationDone.hidden = true;
  evaluationCommentInput.value = '';
  submitEvaluationBtn.disabled = false;
  evaluationStatus.textContent = '';
  document
    .querySelectorAll('input[name="critique-grade"]')
    .forEach((radio) => (radio.checked = false));

  listView.hidden = true;
  detailView.hidden = false;
  window.scrollTo(0, 0);
}

backBtn.addEventListener('click', () => {
  currentCritique = null;
  detailView.hidden = true;
  listView.hidden = false;
});

// -------------------- Submit evaluation --------------------
submitEvaluationBtn.addEventListener('click', async () => {
  if (!currentCritique) return;

  const grade = getSelectedGrade();
  if (grade === null) {
    evaluationStatus.textContent = 'Please grade the critique (1–5) before submitting.';
    return;
  }

  submitEvaluationBtn.disabled = true;
  evaluationStatus.textContent = 'Submitting…';

  try {
    await postJson('/evaluations', {
      user_id: userId,
      session_id: sessionId,
      critique_id: currentCritique.critique_id,
      critique_grade: grade,
      comment: evaluationCommentInput.value.trim(),
    });

    // Lock the evaluation.
    evaluationForm.hidden = true;
    evaluationDone.hidden = false;
  } catch (err) {
    submitEvaluationBtn.disabled = false;
    evaluationStatus.textContent = 'Could not submit the evaluation. Please try again.';
  }
});

// -------------------- Init --------------------
loadCritiques();