/* Idle Fantasy Save Viewer – client UI */

let state = {
  data: null,
  snapshots: [],
  timeline: [],
  inventory: { search: "", categories: new Set(), sort: "category", highlightEquipped: false, collapsedGroups: new Set() },
  skills: { search: "", sort: "level", sortAsc: false },
  quests: { tab: "story", filter: "all" },
  history: { olderId: null, newerId: null, diff: null },
  charts: {},
};

const CATEGORY_ORDER = [
  "Currency", "Ores & Mining", "Bars & Smithing", "Wood & Planks", "Runes",
  "Raw Food", "Cooked Food", "Seeds & Farming", "Melee Weapons", "Ranged",
  "Magic", "Armor", "Bones & Hides", "Gems & Jewelry", "Potions & Brews", "Misc",
];

const CATEGORY_I18N_KEYS = {
  "Currency": "category.currency",
  "Ores & Mining": "category.ores_mining",
  "Bars & Smithing": "category.bars_smithing",
  "Wood & Planks": "category.wood_planks",
  "Runes": "category.runes",
  "Raw Food": "category.raw_food",
  "Cooked Food": "category.cooked_food",
  "Seeds & Farming": "category.seeds_farming",
  "Melee Weapons": "category.melee_weapons",
  "Ranged": "category.ranged",
  "Magic": "category.magic",
  "Armor": "category.armor",
  "Bones & Hides": "category.bones_hides",
  "Gems & Jewelry": "category.gems_jewelry",
  "Potions & Brews": "category.potions_brews",
  "Misc": "category.misc",
};

document.addEventListener("DOMContentLoaded", init);

function apiBase() {
  const vid = window.VIEWER_ID;
  return vid ? `/v/${vid}/api` : "/api";
}

function viewerPageUrl() {
  const vid = window.VIEWER_ID;
  if (!vid) return window.location.href;
  return `${window.location.origin}/v/${vid}/`;
}

async function init() {
  await I18n.init();
  applyStaticI18n();
  setupLanguage();
  setupViewerBanner();
  setupNav();
  setupUpload();
  await loadData();
}

function setupViewerBanner() {
  const vid = window.VIEWER_ID;
  if (!vid || vid === "local") return;

  const banner = document.getElementById("viewer-link-banner");
  const urlEl = document.getElementById("viewer-link-url");
  const copyBtn = document.getElementById("viewer-copy-link");
  const url = viewerPageUrl();

  banner.hidden = false;
  urlEl.textContent = url;

  copyBtn.addEventListener("click", async () => {
    try {
      await navigator.clipboard.writeText(url);
      const prev = copyBtn.textContent;
      copyBtn.textContent = t("viewer.copied");
      setTimeout(() => { copyBtn.textContent = prev; }, 2000);
    } catch {
      window.prompt(t("viewer.copyPrompt"), url);
    }
  });
}

function categoryLabel(cat) {
  const key = CATEGORY_I18N_KEYS[cat];
  return key ? t(key) : cat;
}

function applyStaticI18n() {
  document.querySelectorAll("[data-i18n]").forEach((el) => {
    el.textContent = t(el.dataset.i18n);
  });
}

function setupLanguage() {
  const sel = document.getElementById("locale-select");
  sel.value = I18n.getPreference();
  sel.addEventListener("change", async (e) => {
    await I18n.setPreference(e.target.value);
    applyStaticI18n();
    resetLocaleDependentPanels();
    if (state.data) renderAll();
    if (document.getElementById("tab-history").classList.contains("active")) {
      loadHistoryTab();
    }
  });
}

function resetLocaleDependentPanels() {
  ["tab-skills", "tab-inventory"].forEach((id) => {
    document.getElementById(id).innerHTML = "";
  });
}

function setupNav() {
  document.querySelectorAll(".nav-btn").forEach((btn) => {
    btn.addEventListener("click", () => {
      document.querySelectorAll(".nav-btn").forEach((b) => b.classList.remove("active"));
      document.querySelectorAll(".tab-panel").forEach((p) => p.classList.remove("active"));
      btn.classList.add("active");
      document.getElementById(`tab-${btn.dataset.tab}`).classList.add("active");
      if (btn.dataset.tab === "history") loadHistoryTab();
    });
  });
}

function setupUpload() {
  document.getElementById("file-upload").addEventListener("change", async (e) => {
    const file = e.target.files[0];
    if (!file) return;
    const fd = new FormData();
    fd.append("file", file);
    const res = await fetch(`${apiBase()}/import`, { method: "POST", body: fd });
    const result = await res.json();
    if (!res.ok || result.error) {
      showImportFailure(result);
      e.target.value = "";
      return;
    }
    if (result.imported) {
      await loadData();
      notifyImportSuccess(result);
    } else if (result.reason === "duplicate") {
      alert(t("import.duplicate"));
    }
    e.target.value = "";
  });
}

function showImportFailure(result) {
  const lines = [result.error || t("import.failed")];
  for (const item of result.import_report || []) {
    lines.push(`• ${I18n.translateIssue(item)}`);
  }
  alert(lines.join("\n"));
}

function notifyImportSuccess(result) {
  const summary = result.import_summary || {};
  const warnings = summary.warnings || 0;
  const infos = summary.infos || 0;
  if (warnings || infos) {
    alert(t("import.successWithNotes", {
      id: result.snapshot_id,
      warnings,
      infos,
    }));
  }
}

function renderImportReport(meta) {
  const el = document.getElementById("import-report");
  const report = meta?.import_report || [];
  const visible = report.filter((i) => i.level === "error" || i.level === "warning");
  const infos = report.filter((i) => i.level === "info");

  if (!report.length) {
    el.hidden = true;
    el.innerHTML = "";
    return;
  }

  const errors = report.filter((i) => i.level === "error");
  const warnings = report.filter((i) => i.level === "warning");
  const level = errors.length ? "error" : warnings.length ? "warning" : "info";
  const title = errors.length
    ? t("import.titleError")
    : warnings.length
      ? t("import.titleWarning")
      : t("import.titleInfo");

  el.hidden = false;
  el.className = `import-report import-report-${level}`;
  el.innerHTML = `
    <div class="import-report-header">
      <strong>${esc(title)}</strong>
      <span class="import-report-counts">
        ${errors.length ? t("import.countErrors", { count: errors.length }) : ""}
        ${warnings.length ? t("import.countWarnings", { count: warnings.length }) : ""}
        ${infos.length ? t("import.countInfos", { count: infos.length }) : ""}
      </span>
      <button type="button" class="import-report-dismiss" title="${esc(t("actions.dismiss"))}">×</button>
    </div>
    <ul class="import-report-list">
      ${visible.map((i) => `<li class="import-issue import-issue-${i.level}">${esc(I18n.translateIssue(i))}</li>`).join("")}
      ${infos.length ? `
        <li class="import-issue import-issue-info-collapsed">
          <details>
            <summary>${esc(t("import.newFieldsSummary", { count: infos.length }))}</summary>
            <ul>${infos.map((i) => `<li>${esc(I18n.translateIssue(i))}</li>`).join("")}</ul>
          </details>
        </li>` : ""}
    </ul>`;

  el.querySelector(".import-report-dismiss").addEventListener("click", () => {
    el.hidden = true;
  });
}

async function loadData() {
  try {
    const res = await fetch(`${apiBase()}/snapshot/latest`);
    if (!res.ok) {
      showEmpty(window.VIEWER_ID ? t("empty.noSaveWeb") : t("empty.noSave"));
      return;
    }
    state.data = await res.json();
    renderAll();
  } catch (err) {
    showEmpty(t("empty.loadError", { message: err.message }));
  }
}

function showEmpty(msg) {
  document.getElementById("character-header").innerHTML = `<span class="loading">${esc(msg)}</span>`;
}

function renderAll() {
  const d = state.data;
  if (!d) return;

  renderHeader(d);
  renderImportReport(d.meta);
  renderOverview(d);
  renderSkills(d);
  renderInventory(d);
  renderEquipment(d);
  renderQuests(d);
  renderCombat(d);
}

function renderHeader(d) {
  const c = d.character;
  const m = d.meta;
  document.getElementById("character-header").innerHTML = `
    <h2>${esc(c.name || t("empty.unknown"))}</h2>
    <div class="character-meta">
      ${esc(c.race || "")} · ${esc(c.gender || "")} · ${t("meta.export")}: ${formatTs(m.exported_at)}
    </div>`;

  document.getElementById("kpi-row").innerHTML = `
    <div class="kpi"><div class="kpi-label">${esc(t("kpi.coins"))}</div><div class="kpi-value">${fmt(m.coins)}</div></div>
    <div class="kpi"><div class="kpi-label">${esc(t("kpi.totalLevel"))}</div><div class="kpi-value">${m.total_level}</div></div>
    <div class="kpi"><div class="kpi-label">${esc(t("kpi.items"))}</div><div class="kpi-value">${m.item_count}</div></div>
    <div class="kpi"><div class="kpi-label">${esc(t("kpi.totalQty"))}</div><div class="kpi-value">${fmt(m.total_items)}</div></div>`;
}

function renderOverview(d) {
  const c = d.character;
  const queue = (d.session_queue || []).map((q) =>
    `<li><span>${esc(q.skill_display_name || q.skill_name)}</span><span>${esc(q.activity_key || "—")} · ${q.qty || 0}</span></li>`
  ).join("");

  const slayer = d.combat.slayer_task;
  const slayerHtml = slayer
    ? `<p><strong>${esc(slayer.display_name)}</strong>: ${slayer.kills_completed}/${slayer.target_kills} (${d.combat.slayer_points} ${esc(t("meta.points"))})</p>`
    : `<p class='empty-state'>${esc(t("overview.noSlayerTask"))}</p>`;

  const pets = (d.pets || []).map((p) =>
    `<li><span>${esc(p.id.replace(/_/g, " "))}</span><span>+${p.boost_percent}%</span></li>`
  ).join("");

  const farming = (d.farming || []).map((p) =>
    `<li><span>${esc(t("overview.patch", { n: p.patchNumber }))}</span><span>${esc(p.cropType || "—")}</span></li>`
  ).join("");

  document.getElementById("tab-overview").innerHTML = `
    <div class="grid-2">
      <div class="card">
        <h3>${esc(t("overview.character"))}</h3>
        <ul class="list-compact">
          <li><span>${esc(t("overview.hp"))}</span><span>${c.hp ?? "—"}</span></li>
          <li><span>${esc(t("overview.activePotion"))}</span><span>${esc(c.active_potion || "—")}</span></li>
          <li><span>${esc(t("overview.activeSpell"))}</span><span>${esc(c.active_spell || "—")}</span></li>
          <li><span>${esc(t("overview.weaponSlot"))}</span><span>${esc(c.active_weapon_slot || "—")}</span></li>
          <li><span>${esc(t("overview.blessing"))}</span><span>${esc(c.active_blessing || "—")}</span></li>
        </ul>
      </div>
      <div class="card">
        <h3>${esc(t("overview.sessionQueue"))}</h3>
        <ul class="list-compact">${queue || `<li><span>${esc(t("empty.empty"))}</span></li>`}</ul>
      </div>
      <div class="card">
        <h3>${esc(t("overview.slayer"))}</h3>
        ${slayerHtml}
      </div>
      <div class="card">
        <h3>${esc(t("overview.pets"))}</h3>
        <ul class="list-compact">${pets || `<li><span>${esc(t("empty.none"))}</span></li>`}</ul>
      </div>
      <div class="card">
        <h3>${esc(t("overview.farming"))}</h3>
        <ul class="list-compact">${farming || `<li><span>${esc(t("empty.none"))}</span></li>`}</ul>
      </div>
      <div class="card">
        <h3>${esc(t("overview.guildRep"))}</h3>
        <ul class="list-compact">${Object.entries(d.guild_reputation || {}).map(([k, v]) =>
          `<li><span>${esc(k)}</span><span>${fmt(v)}</span></li>`).join("")}</ul>
      </div>
    </div>`;
}

function renderSkills(d) {
  const panel = document.getElementById("tab-skills");
  const s = state.skills;

  if (!panel.querySelector("#skill-search")) {
    panel.innerHTML = `
      <div class="toolbar">
        <input class="search-input" id="skill-search" placeholder="" value="">
        <select class="select-input" id="skill-sort">
          <option value="level"></option>
          <option value="xp"></option>
          <option value="name"></option>
        </select>
      </div>
      <div class="card">
        <table>
          <thead><tr>
            <th data-sort="name"></th>
            <th data-sort="level"></th>
            <th data-sort="xp">XP</th>
            <th></th>
          </tr></thead>
          <tbody id="skill-tbody"></tbody>
        </table>
      </div>`;

    document.getElementById("skill-search").addEventListener("input", (e) => {
      state.skills.search = e.target.value;
      renderSkillsBody(state.data);
    });
    document.getElementById("skill-sort").addEventListener("change", (e) => {
      state.skills.sort = e.target.value;
      renderSkillsBody(state.data);
    });
    panel.querySelectorAll("th[data-sort]").forEach((th) => {
      th.addEventListener("click", () => {
        const key = th.dataset.sort;
        if (state.skills.sort === key) state.skills.sortAsc = !state.skills.sortAsc;
        else { state.skills.sort = key; state.skills.sortAsc = false; }
        renderSkillsBody(state.data);
      });
    });
  }

  document.getElementById("skill-search").placeholder = t("skills.search");
  document.getElementById("skill-sort").options[0].textContent = t("skills.sortLevel");
  document.getElementById("skill-sort").options[1].textContent = t("skills.sortXp");
  document.getElementById("skill-sort").options[2].textContent = t("skills.sortName");
  panel.querySelector('th[data-sort="name"]').textContent = t("skills.skill");
  panel.querySelector('th[data-sort="level"]').textContent = t("skills.level");
  panel.querySelector("thead tr th:last-child").textContent = t("skills.progress");

  document.getElementById("skill-search").value = s.search;
  document.getElementById("skill-sort").value = s.sort;
  renderSkillsBody(d);
}

function renderSkillsBody(d) {
  const s = state.skills;
  let items = [...d.skills];
  if (s.search) {
    const q = s.search.toLowerCase();
    items = items.filter((sk) => sk.name.toLowerCase().includes(q) || sk.key.includes(q));
  }
  items.sort((a, b) => {
    let cmp = 0;
    if (s.sort === "name") cmp = a.name.localeCompare(b.name);
    else if (s.sort === "level") cmp = a.level - b.level;
    else cmp = a.xp - b.xp;
    return s.sortAsc ? cmp : -cmp;
  });

  document.getElementById("skill-tbody").innerHTML = items.map((sk) => `
    <tr>
      <td>${esc(sk.name)}</td>
      <td>${sk.level}</td>
      <td>${fmt(sk.xp)}</td>
      <td style="min-width:140px">
        ${sk.progress_pct}%
        <div class="progress-bar"><div class="progress-fill" style="width:${sk.progress_pct}%"></div></div>
      </td>
    </tr>`).join("");
}

function getFilteredInventoryItems(d, inv) {
  let items = [...d.inventory];
  if (inv.search) {
    const q = inv.search.toLowerCase();
    items = items.filter((i) => i.name.toLowerCase().includes(q) || i.key.includes(q));
  }
  if (inv.categories.size > 0) {
    items = items.filter((i) => inv.categories.has(i.category));
  }
  items.sort((a, b) => {
    if (inv.sort === "qty") return b.qty - a.qty;
    if (inv.sort === "name") return a.name.localeCompare(b.name);
    const ca = CATEGORY_ORDER.indexOf(a.category);
    const cb = CATEGORY_ORDER.indexOf(b.category);
    return ca - cb || a.name.localeCompare(b.name);
  });
  return items;
}

function renderInventoryTable(d, inv) {
  const items = getFilteredInventoryItems(d, inv);
  const grouped = {};
  for (const item of items) {
    if (!grouped[item.category]) grouped[item.category] = [];
    grouped[item.category].push(item);
  }

  const groupRows = Object.entries(grouped).map(([cat, catItems]) => {
    const totalQty = catItems.reduce((s, i) => s + i.qty, 0);
    const expanded = !inv.collapsedGroups.has(cat);
    const catLabel = categoryLabel(cat);
    const header = `
      <tr class="inv-group-row" data-group="${esc(cat)}">
        <td colspan="3">
          <button type="button" class="inv-group-toggle" data-group="${esc(cat)}" aria-expanded="${expanded}">
            <span class="inv-group-title">${esc(catLabel)}</span>
            <span class="inv-group-meta">${esc(t("inventory.groupMeta", { count: catItems.length, qty: fmt(totalQty) }))}</span>
          </button>
        </td>
      </tr>`;
    const rows = catItems.map((i) => `
      <tr class="inv-item-row ${i.equipped && inv.highlightEquipped ? "item-equipped" : ""} ${expanded ? "" : "collapsed"}" data-group="${esc(cat)}">
        <td class="col-name">${esc(i.name)}${i.equipped ? `<span class="equipped-mark" title="${esc(t("inventory.equipped"))}">⚡</span>` : ""}</td>
        <td class="col-qty">${fmt(i.qty)}</td>
        <td class="col-key"><code>${esc(i.key)}</code></td>
      </tr>`).join("");
    return header + rows;
  }).join("");

  const results = document.getElementById("inv-results");
  if (!groupRows) {
    results.innerHTML = `<p class='empty-state'>${esc(t("empty.noItems"))}</p>`;
    return;
  }

  results.innerHTML = `
    <div class="inv-table-wrap">
      <table class="inv-table">
        <colgroup>
          <col class="col-name">
          <col class="col-qty">
          <col class="col-key">
        </colgroup>
        <thead>
          <tr>
            <th class="col-name">${esc(t("inventory.item"))}</th>
            <th class="col-qty">${esc(t("inventory.qty"))}</th>
            <th class="col-key">${esc(t("inventory.id"))}</th>
          </tr>
        </thead>
        <tbody>${groupRows}</tbody>
      </table>
    </div>`;

  results.querySelectorAll(".inv-group-toggle").forEach((btn) => {
    btn.addEventListener("click", () => {
      const group = btn.dataset.group;
      const expanded = btn.getAttribute("aria-expanded") === "true";
      btn.setAttribute("aria-expanded", expanded ? "false" : "true");
      if (expanded) inv.collapsedGroups.add(group);
      else inv.collapsedGroups.delete(group);
      results.querySelectorAll(`.inv-item-row[data-group="${group}"]`).forEach((row) => {
        row.classList.toggle("collapsed", expanded);
      });
    });
  });
}

function renderInventoryChips(d, inv) {
  const categories = [...new Set(d.inventory.map((i) => i.category))].sort(
    (a, b) => CATEGORY_ORDER.indexOf(a) - CATEGORY_ORDER.indexOf(b)
  );
  const chips = document.getElementById("inv-chips");
  chips.innerHTML = categories.map((c) => `
    <span class="chip ${inv.categories.has(c) ? "active" : ""}" data-cat="${esc(c)}">${esc(categoryLabel(c))}</span>`).join("");
  chips.querySelectorAll(".chip").forEach((chip) => {
    chip.addEventListener("click", () => {
      const cat = chip.dataset.cat;
      if (inv.categories.has(cat)) inv.categories.delete(cat);
      else inv.categories.add(cat);
      renderInventoryChips(d, inv);
      renderInventoryTable(d, inv);
    });
  });
}

function renderInventory(d) {
  const panel = document.getElementById("tab-inventory");
  const inv = state.inventory;

  if (!panel.querySelector("#inv-search")) {
    panel.innerHTML = `
      <div class="toolbar">
        <input class="search-input" id="inv-search" placeholder="" value="">
        <select class="select-input" id="inv-sort">
          <option value="category"></option>
          <option value="name"></option>
          <option value="qty"></option>
        </select>
        <label class="toggle-label">
          <input type="checkbox" id="inv-equipped">
          <span id="inv-equipped-label"></span>
        </label>
      </div>
      <div class="chip-row" id="inv-chips"></div>
      <div class="card inv-card" id="inv-results"></div>`;

    document.getElementById("inv-search").addEventListener("input", (e) => {
      state.inventory.search = e.target.value;
      renderInventoryTable(state.data, state.inventory);
    });
    document.getElementById("inv-sort").addEventListener("change", (e) => {
      state.inventory.sort = e.target.value;
      renderInventoryTable(state.data, state.inventory);
    });
    document.getElementById("inv-equipped").addEventListener("change", (e) => {
      state.inventory.highlightEquipped = e.target.checked;
      renderInventoryTable(state.data, state.inventory);
    });
  }

  document.getElementById("inv-search").placeholder = t("inventory.search");
  document.getElementById("inv-sort").options[0].textContent = t("inventory.sortCategory");
  document.getElementById("inv-sort").options[1].textContent = t("inventory.sortName");
  document.getElementById("inv-sort").options[2].textContent = t("inventory.sortQty");
  document.getElementById("inv-equipped-label").textContent = t("inventory.highlightEquipped");

  document.getElementById("inv-search").value = inv.search;
  document.getElementById("inv-sort").value = inv.sort;
  document.getElementById("inv-equipped").checked = inv.highlightEquipped;
  renderInventoryChips(d, inv);
  renderInventoryTable(d, inv);
}

function renderEquipment(d) {
  document.getElementById("tab-equipment").innerHTML = `
    <div class="card">
      <h3>${esc(t("equipment.title"))}</h3>
      <div class="equip-grid">
        ${d.equipment.map((eq) => `
          <div class="equip-slot ${eq.key ? "" : "empty"}">
            <div class="slot-name">${esc(eq.slot_name)}</div>
            <div class="item-name">${eq.name ? esc(eq.name) : "—"}</div>
          </div>`).join("")}
      </div>
    </div>`;
}

function renderQuests(d) {
  const panel = document.getElementById("tab-quests");
  const q = state.quests;
  const tabs = [
    { key: "story", label: t("quests.story") },
    { key: "daily", label: t("quests.daily") },
    { key: "weekly", label: t("quests.weekly") },
    { key: "guild", label: t("quests.guild") },
  ];

  let items = d.quests[q.tab] || [];
  if (q.tab === "story") {
    if (q.filter === "open") items = items.filter((x) => !x.completed);
    if (q.filter === "done") items = items.filter((x) => x.completed);
  } else {
    if (q.filter === "open") items = items.filter((x) => !x.claimed);
    if (q.filter === "done") items = items.filter((x) => x.claimed);
  }

  const isStory = q.tab === "story";
  panel.innerHTML = `
    <div class="quest-tabs">
      ${tabs.map((tab) => `<button class="quest-tab ${q.tab === tab.key ? "active" : ""}" data-tab="${tab.key}">${esc(tab.label)}</button>`).join("")}
    </div>
    <div class="toolbar">
      <select class="select-input" id="quest-filter">
        <option value="all" ${q.filter === "all" ? "selected" : ""}>${esc(t("quests.filterAll"))}</option>
        <option value="open" ${q.filter === "open" ? "selected" : ""}>${esc(t("quests.filterOpen"))}</option>
        <option value="done" ${q.filter === "done" ? "selected" : ""}>${esc(t("quests.filterDone"))}</option>
      </select>
    </div>
    <div class="card">
      <table>
        <thead><tr>
          <th>${esc(t("quests.quest"))}</th>
          <th>${esc(t("quests.progress"))}</th>
          <th>${esc(t("quests.status"))}</th>
        </tr></thead>
        <tbody>${items.map((quest) => {
          const done = isStory ? quest.completed : quest.claimed;
          return `<tr>
            <td>${esc(quest.name)}</td>
            <td>${fmt(quest.progress)}</td>
            <td><span class="badge ${done ? "badge-success" : "badge-warning"}">${esc(done ? t("quests.done") : t("quests.open"))}</span></td>
          </tr>`;
        }).join("")}</tbody>
      </table>
    </div>`;

  panel.querySelectorAll(".quest-tab").forEach((btn) => {
    btn.addEventListener("click", () => {
      state.quests.tab = btn.dataset.tab;
      renderQuests(state.data);
    });
  });
  document.getElementById("quest-filter").addEventListener("change", (e) => {
    state.quests.filter = e.target.value;
    renderQuests(state.data);
  });
}

function renderCombat(d) {
  const kills = Object.entries(d.combat.enemy_kills || {})
    .sort((a, b) => b[1] - a[1])
    .map(([k, v]) => `<li><span>${esc(k.replace(/_/g, " "))}</span><span>${fmt(v)}</span></li>`).join("");

  const dungeons = Object.entries(d.combat.dungeon_runs || {})
    .sort((a, b) => b[1] - a[1])
    .map(([k, v]) => `<li><span>${esc(k.replace(/_/g, " "))}</span><span>${esc(t("combat.runs", { count: fmt(v) }))}</span></li>`).join("");

  const recent = (d.recent_sessions || [])
    .map((s) => `<li><span>${esc(s.activity_display_name || s.activity_key)}</span><span>${esc(s.skill_name)}</span></li>`).join("");

  const active = (d.sessions || [])
    .map((s) => `<li><span>${esc(s.activity)}</span><span>${esc(s.skill)} · ${esc(s.completed ? t("combat.sessionDone") : t("combat.sessionRunning"))}</span></li>`).join("");

  const none = `<li>${esc(t("empty.none"))}</li>`;
  document.getElementById("tab-combat").innerHTML = `
    <div class="grid-2">
      <div class="card"><h3>${esc(t("combat.enemyKills"))}</h3><ul class="list-compact">${kills || none}</ul></div>
      <div class="card"><h3>${esc(t("combat.dungeonRuns"))}</h3><ul class="list-compact">${dungeons || none}</ul></div>
      <div class="card"><h3>${esc(t("combat.recentActivity"))}</h3><ul class="list-compact">${recent || none}</ul></div>
      <div class="card"><h3>${esc(t("combat.activeSessions"))}</h3><ul class="list-compact">${active || none}</ul></div>
    </div>`;
}

async function loadHistoryTab() {
  const panel = document.getElementById("tab-history");
  panel.innerHTML = `<p class='loading'>${esc(t("history.loading"))}</p>`;

  const [snapRes, tlRes] = await Promise.all([
    fetch(`${apiBase()}/snapshots`),
    fetch(`${apiBase()}/timeline`),
  ]);
  state.snapshots = await snapRes.json();
  state.timeline = await tlRes.json();

  if (state.snapshots.length === 0) {
    panel.innerHTML = `<p class='empty-state'>${esc(t("empty.noSnapshots"))}</p>`;
    return;
  }

  const h = state.history;
  if (!h.newerId) h.newerId = state.snapshots[0].id;
  if (!h.olderId && state.snapshots.length > 1) h.olderId = state.snapshots[1].id;

  panel.innerHTML = `
    <div class="grid-2">
      <div class="card">
        <h3>${esc(t("history.coinsChart"))}</h3>
        <div class="chart-wrap"><canvas id="chart-coins"></canvas></div>
      </div>
      <div class="card">
        <h3>${esc(t("history.levelChart"))}</h3>
        <div class="chart-wrap"><canvas id="chart-level"></canvas></div>
      </div>
    </div>
    <div class="card">
      <h3>${esc(t("history.snapshotCompare"))}</h3>
      <div class="toolbar">
        <select class="select-input" id="diff-older">
          ${state.snapshots.map((s) => option(s, h.olderId)).join("")}
        </select>
        <span>→</span>
        <select class="select-input" id="diff-newer">
          ${state.snapshots.map((s) => option(s, h.newerId)).join("")}
        </select>
        <button class="select-input" id="diff-run" style="background:var(--accent);border-color:var(--accent);color:#fff;font-weight:600">${esc(t("actions.compare"))}</button>
      </div>
      <div id="diff-result"></div>
    </div>
    <div class="card">
      <h3>${esc(t("history.allSnapshots"))}</h3>
      <table>
        <thead><tr>
          <th>ID</th>
          <th>${esc(t("history.character"))}</th>
          <th>${esc(t("kpi.coins"))}</th>
          <th>${esc(t("kpi.totalLevel"))}</th>
          <th>${esc(t("meta.export"))}</th>
          <th>${esc(t("history.file"))}</th>
        </tr></thead>
        <tbody>${state.snapshots.map((s) => `
          <tr>
            <td>${s.id}</td>
            <td>${esc(s.character_name || "—")}</td>
            <td>${fmt(s.coins)}</td>
            <td>${s.total_level}</td>
            <td>${formatTs(s.exported_at)}</td>
            <td>${esc(s.source_file)}</td>
          </tr>`).join("")}
        </tbody>
      </table>
    </div>`;

  renderTimelineCharts();
  document.getElementById("diff-older").addEventListener("change", (e) => { h.olderId = +e.target.value; });
  document.getElementById("diff-newer").addEventListener("change", (e) => { h.newerId = +e.target.value; });
  document.getElementById("diff-run").addEventListener("click", runDiff);
  if (h.olderId && h.newerId && h.olderId !== h.newerId) runDiff();
}

function option(s, selected) {
  const label = `#${s.id} · ${s.character_name || "?"} · ${formatTs(s.exported_at)}`;
  return `<option value="${s.id}" ${s.id === selected ? "selected" : ""}>${esc(label)}</option>`;
}

function renderTimelineCharts() {
  const tl = state.timeline;
  if (!tl.length) return;

  const labels = tl.map((s) => formatTs(s.exported_at));
  const coins = tl.map((s) => s.coins);
  const levels = tl.map((s) => s.total_level);

  destroyChart("coins");
  destroyChart("level");

  state.charts.coins = new Chart(document.getElementById("chart-coins"), {
    type: "line",
    data: { labels, datasets: [{ label: t("kpi.coins"), data: coins, borderColor: "#6c8cff", tension: 0.3, fill: false }] },
    options: chartOpts(),
  });
  state.charts.level = new Chart(document.getElementById("chart-level"), {
    type: "line",
    data: { labels, datasets: [{ label: t("kpi.totalLevel"), data: levels, borderColor: "#4ade80", tension: 0.3, fill: false }] },
    options: chartOpts(),
  });
}

function chartOpts() {
  return {
    responsive: true,
    maintainAspectRatio: false,
    plugins: { legend: { labels: { color: "#8b92a8" } } },
    scales: {
      x: { ticks: { color: "#8b92a8" }, grid: { color: "#2d3348" } },
      y: { ticks: { color: "#8b92a8" }, grid: { color: "#2d3348" } },
    },
  };
}

function destroyChart(key) {
  if (state.charts[key]) {
    state.charts[key].destroy();
    delete state.charts[key];
  }
}

async function runDiff() {
  const h = state.history;
  const el = document.getElementById("diff-result");
  if (!h.olderId || !h.newerId || h.olderId === h.newerId) {
    el.innerHTML = `<p class='empty-state'>${esc(t("empty.pickTwoSnapshots"))}</p>`;
    return;
  }
  const older = Math.min(h.olderId, h.newerId);
  const newer = Math.max(h.olderId, h.newerId);
  const res = await fetch(`${apiBase()}/snapshots/${older}/diff/${newer}`);
  const diff = await res.json();
  if (diff.error) {
    el.innerHTML = `<p class='empty-state'>${esc(diff.error)}</p>`;
    return;
  }

  const coinDelta = diff.summary.coins_delta;
  const coinCls = coinDelta >= 0 ? "delta-pos" : "delta-neg";
  const levelDelta = diff.summary.total_level_delta;

  const invRows = diff.inventory_changes.slice(0, 50).map((i) => `
    <tr>
      <td>${esc(i.name)}</td>
      <td>${fmt(i.old_qty)} → ${fmt(i.new_qty)}</td>
      <td class="${i.delta >= 0 ? "delta-pos" : "delta-neg"}">${i.delta >= 0 ? "+" : ""}${fmt(i.delta)}</td>
    </tr>`).join("");

  const skRows = diff.skill_changes
    .sort((a, b) => b.xp_delta - a.xp_delta)
    .slice(0, 20)
    .map((s) => `
    <tr>
      <td>${esc(s.name)}</td>
      <td>${s.old_level} → ${s.new_level}</td>
      <td class="${s.xp_delta >= 0 ? "delta-pos" : "delta-neg"}">${s.xp_delta >= 0 ? "+" : ""}${fmt(s.xp_delta)} XP</td>
    </tr>`).join("");

  const noChanges = `<tr><td colspan='3'>${esc(t("empty.noChanges"))}</td></tr>`;
  el.innerHTML = `
    <p>${esc(t("history.coinsSummary", {
      delta: `${coinDelta >= 0 ? "+" : ""}${fmt(coinDelta)}`,
      levelDelta: `${levelDelta >= 0 ? "+" : ""}${levelDelta}`,
    }))}</p>
    <h4 style="margin-top:16px">${esc(t("history.inventoryChanges", { count: diff.inventory_changes.length }))}</h4>
    <table><thead><tr>
      <th>${esc(t("inventory.item"))}</th>
      <th>${esc(t("inventory.qty"))}</th>
      <th>${esc(t("history.delta"))}</th>
    </tr></thead>
    <tbody>${invRows || noChanges}</tbody></table>
    <h4 style="margin-top:16px">${esc(t("history.skillChanges", { count: diff.skill_changes.length }))}</h4>
    <table><thead><tr>
      <th>${esc(t("skills.skill"))}</th>
      <th>${esc(t("skills.level"))}</th>
      <th>${esc(t("history.xpDelta"))}</th>
    </tr></thead>
    <tbody>${skRows || noChanges}</tbody></table>`;
}

function fmt(n) {
  if (n == null) return "—";
  return Number(n).toLocaleString(I18n.localeTag());
}

function formatTs(ts) {
  if (!ts) return "—";
  const d = new Date(Number(ts));
  return d.toLocaleString(I18n.localeTag(), { dateStyle: "short", timeStyle: "short" });
}

function esc(s) {
  if (s == null) return "";
  return String(s)
    .replace(/&/g, "&amp;")
    .replace(/</g, "&lt;")
    .replace(/>/g, "&gt;")
    .replace(/"/g, "&quot;");
}