/* ==========================================================================
   librus-tui frontend - grades view
   ========================================================================== */

"use strict";

async function renderGrades(token) {
  const data = await api("/api/grades");
  if (token !== state.loadToken) return;

  const subjects = data.subjects || {};
  const sorted = Object.entries(subjects).sort((a, b) =>
    String(a[0]).localeCompare(String(b[0]), "pl")
  );

  state.gradesFlat = [];
  state.gradeGroups = sorted.map(([subject, grades]) => {
    const items = (grades || []).map((grade) => {
      const item = { ...grade, _subject: subject, _index: state.gradesFlat.length };
      state.gradesFlat.push(item);
      return item;
    });
    return { subject, grades: items };
  });

  const overall = averageLabel(state.gradesFlat);
  const gradeCount = state.gradesFlat.length;

  $("#view").innerHTML = `
    <div class="view-inner">
      <div class="toolbar">
        <span>filter</span>
        <input class="tool-input" id="grade-filter" type="text"
               placeholder="subject or category…" spellcheck="false" autocomplete="off">
        <button class="btn btn-sm" type="button" data-action="grades-clear">[ clear ]</button>
        <span class="grow"></span>
        <span class="grades-summary">
          <span>average <b>${esc(overall)}</b></span>
          <span><b>${gradeCount}</b> grades</span>
          <span><b>${state.gradeGroups.length}</b> subjects</span>
        </span>
      </div>
      <div class="grades-grid" id="grades-list"></div>
      <div class="toolbar" style="margin-top:12px">
        <div class="legend">
          <span><span class="swatch green"></span>5 / 6</span>
          <span><span class="swatch cyan"></span>4</span>
          <span><span class="swatch amber"></span>3</span>
          <span><span class="swatch red"></span>1 / 2</span>
          <span class="dim">dashed chip = final · outlined = semester</span>
        </div>
      </div>
    </div>
  `;

  const input = $("#grade-filter");
  if (input) {
    input.value = state.gradeFilter;
    input.addEventListener("input", () => {
      state.gradeFilter = input.value;
      renderGradesList();
    });
  }

  renderGradesList();
}

function gradeWeightLabel(weight) {
  const raw = String(weight ?? "").toLowerCase();
  if (!raw || raw === "none" || raw === "null") return "";
  return `w${raw}`;
}

function renderGradesList() {
  const container = $("#grades-list");
  if (!container) return;

  const query = state.gradeFilter.trim().toLowerCase();
  const groups = state.gradeGroups.filter((group) => {
    if (!query) return true;
    if (group.subject.toLowerCase().includes(query)) return true;
    return group.grades.some((grade) =>
      `${grade.Category || ""} ${grade.Grade || ""}`.toLowerCase().includes(query)
    );
  });

  if (!groups.length) {
    container.innerHTML = `<div class="empty" style="grid-column:1/-1">no matching grades</div>`;
    return;
  }

  container.innerHTML = groups
    .map((group) => {
      const average = averageLabel(group.grades);
      const chips = group.grades.length
        ? group.grades
            .map((grade) => {
              const weight = gradeWeightLabel(grade.Weight);
              const classes = ["grade-chip", gradeClass(grade.Grade)];
              if (grade.isFinal) classes.push("final");
              if (grade.isSemester) classes.push("semester");
              const label = `${group.subject} · ${grade.Grade} · ${grade.Category || "grade"} · ${fmtDate(grade.AddDate)}`;
              return `
                <button class="${classes.join(" ")}" type="button" data-grade="${grade._index}" title="${esc(label)}">
                  ${weight ? `<span class="g-weight">${esc(weight)}</span>` : ""}
                  <span class="g">${esc(grade.Grade)}</span>
                  <span class="g-meta">${esc(grade.Category || "—")}</span>
                </button>`;
            })
            .join("")
        : `<span class="dim" style="font-size:10.5px">— no grades yet —</span>`;

      return `
        <section class="panel subject-card">
          <div class="panel-title">
            <span>${esc(group.subject)}</span>
            <span class="subject-average">avg ${esc(average)}</span>
          </div>
          <div class="panel-body">
            <div class="grade-chips">${chips}</div>
          </div>
        </section>`;
    })
    .join("");
}

function focusGradeFilter() {
  const input = $("#grade-filter");
  if (input) {
    input.focus();
    input.select();
  }
}

function openGradeDetail(index) {
  const grade = state.gradesFlat[index];
  if (!grade) return;

  const flags = [];
  if (grade.isFinal) flags.push("final");
  if (grade.isSemester) flags.push("semester");
  if (grade.Weight && String(grade.Weight).toLowerCase() !== "none") {
    flags.push(`weight ${grade.Weight}`);
  }

  const comment =
    grade.Comment && grade.Comment !== "No comment"
      ? `<div class="detail-comment">${esc(grade.Comment)}</div>`
      : "";

  const body = `
    <dl class="detail-grid">
      <dt>subject</dt><dd>${esc(grade._subject)}</dd>
      <dt>grade</dt><dd>${esc(grade.Grade)}</dd>
      <dt>category</dt><dd>${esc(grade.Category || "—")}</dd>
      <dt>weight</dt><dd>${esc(grade.Weight ?? "—")}</dd>
      <dt>added</dt><dd>${esc(fmtDate(grade.AddDate))}</dd>
      <dt>teacher</dt><dd>${esc(personName(grade.AddedBy) || "—")}</dd>
      <dt>semester</dt><dd>${esc(grade.Semester ?? "—")}${flags.length ? ` · ${esc(flags.join(" · "))}` : ""}</dd>
    </dl>
    ${comment}
  `;

  openModal(`grade ${grade.Grade} · ${grade._subject}`, body, [
    { label: "[ close ]", close: true },
  ]);
}