import { api } from "./api.js";
import { renderArchive, setArchiveRender } from "./archive.js";
import { navigate, onRouteChange, parseHash } from "./router.js";
import { renderRenames, setRenamesRender } from "./renames.js";
import { renderUploads, setUploadsRender } from "./uploads.js";
import {
  renderAlbums,
  renderAnalyze,
  renderLibrary,
  renderSafety,
  renderStats,
  renderWorkflow,
  setRender,
} from "./views.js";

const root = document.getElementById("app");

// Tiny DOM helper — builds nodes without innerHTML injection.
function el(tag, attrs = {}, ...children) {
  const node = document.createElement(tag);
  for (const [key, value] of Object.entries(attrs)) {
    if (value == null || value === false) continue;
    if (key === "class") node.className = value;
    else if (key === "dataset") Object.assign(node.dataset, value);
    else if (key.startsWith("on") && typeof value === "function")
      node.addEventListener(key.slice(2).toLowerCase(), value);
    else node.setAttribute(key, value);
  }
  for (const child of children.flat()) {
    if (child == null || child === false) continue;
    node.appendChild(typeof child === "string" ? document.createTextNode(child) : child);
  }
  return node;
}

function show(...nodes) {
  root.replaceChildren(...nodes);
}

function setActiveNav(view) {
  document.querySelectorAll("nav a[data-nav]").forEach((a) => {
    if (a.dataset.nav === view) a.setAttribute("aria-current", "page");
    else a.removeAttribute("aria-current");
  });
}

function errorBanner(message) {
  return el("div", { class: "alert", role: "alert" }, message);
}

// ── Inventory view ──────────────────────────────────────────────────────────
async function renderInventory(params) {
  setActiveNav("inventory");
  const limit = Number(params.limit || 50);
  const offset = Number(params.offset || 0);
  let data;
  try {
    data = await api.listAssets({
      limit,
      offset,
      availability: params.availability || "",
      q: params.q || "",
    });
  } catch (error) {
    show(errorBanner(`Failed to load inventory: ${error.message}`));
    return;
  }

  const search = el("input", {
    type: "search",
    placeholder: "Filter by path…",
    value: params.q || "",
    "aria-label": "Filter by path",
    onchange: (e) => navigate("/inventory", { ...params, q: e.target.value, offset: 0 }),
  });
  const availability = el(
    "select",
    {
      "aria-label": "Availability",
      onchange: (e) =>
        navigate("/inventory", { ...params, availability: e.target.value, offset: 0 }),
    },
    el("option", { value: "" }, "All availability"),
    ...["active", "archived_offline", "archived_online"].map((v) =>
      el("option", { value: v, selected: params.availability === v ? "selected" : false }, v)
    )
  );

  const rows = data.items.map((asset, index) =>
    el(
      "tr",
      {
        "data-testid": "asset-row",
        "data-asset-id": asset.id,
        tabindex: "-1",
        role: "row",
        onclick: () => selectRow(index),
      },
      el("td", {}, asset.current_path || "(no path)"),
      el("td", {}, asset.availability_state),
      el("td", {}, asset.missing ? "missing" : "present"),
      el("td", { class: "muted" }, asset.byte_size != null ? String(asset.byte_size) : "—")
    )
  );

  const tbody = el("tbody", {}, ...rows);
  let selected = -1;
  function selectRow(index) {
    if (index < 0 || index >= rows.length) return;
    if (selected >= 0) rows[selected].setAttribute("aria-selected", "false");
    selected = index;
    rows[selected].setAttribute("aria-selected", "true");
    rows[selected].focus();
  }

  tbody.addEventListener("keydown", (event) => {
    if (event.key === "ArrowDown") {
      event.preventDefault();
      selectRow(Math.min(selected + 1, rows.length - 1) || 0);
    } else if (event.key === "ArrowUp") {
      event.preventDefault();
      selectRow(Math.max(selected - 1, 0));
    }
  });

  const table = el(
    "table",
    { "aria-label": "Inventory" },
    el(
      "thead",
      {},
      el("tr", {}, el("th", {}, "Path"), el("th", {}, "Availability"), el("th", {}, "State"), el("th", {}, "Bytes"))
    ),
    tbody
  );

  const start = data.total === 0 ? 0 : offset + 1;
  const end = Math.min(offset + limit, data.total);
  const pager = el(
    "div",
    { class: "pager" },
    el(
      "button",
      {
        "data-testid": "prev-page",
        disabled: offset === 0 ? "disabled" : false,
        onclick: () => navigate("/inventory", { ...params, offset: Math.max(offset - limit, 0) }),
      },
      "Previous"
    ),
    el("span", { class: "muted", "data-testid": "page-info" }, `${start}–${end} of ${data.total}`),
    el(
      "button",
      {
        "data-testid": "next-page",
        disabled: end >= data.total ? "disabled" : false,
        onclick: () => navigate("/inventory", { ...params, offset: offset + limit }),
      },
      "Next"
    )
  );

  show(
    el("h1", {}, "Inventory"),
    el("div", { class: "toolbar" }, search, availability),
    table,
    pager
  );
  if (rows.length) selectRow(0);
}

// ── Duplicate cluster list ───────────────────────────────────────────────────
async function renderClusters(params) {
  setActiveNav("duplicates");
  let data;
  try {
    data = await api.listClusters({ state: params.state || "", limit: 100 });
  } catch (error) {
    show(errorBanner(`Failed to load clusters: ${error.message}`));
    return;
  }

  const items = data.items.map((cluster) =>
    el(
      "div",
      { class: "card", "data-testid": "cluster-card" },
      el(
        "div",
        {},
        el("a", { class: "link", href: `#/duplicates/${cluster.id}` }, `Cluster ${cluster.id.slice(0, 8)}`),
        " ",
        el("span", { class: `badge ${cluster.method}` }, cluster.method),
        " ",
        el("span", { class: `badge ${cluster.state}` }, cluster.state)
      ),
      el("div", { class: "muted" }, `${cluster.members.length} members · confidence ${cluster.confidence}`)
    )
  );

  show(
    el("h1", {}, "Duplicate clusters"),
    data.items.length ? el("div", { class: "cluster-grid" }, ...items) : el("p", { class: "muted" }, "No clusters detected.")
  );
}

// ── Duplicate comparison ─────────────────────────────────────────────────────
async function renderClusterDetail(id, extra = {}) {
  setActiveNav("duplicates");
  let cluster;
  try {
    cluster = await api.getCluster(id);
  } catch (error) {
    show(errorBanner(`Failed to load cluster: ${error.message}`));
    return;
  }

  const zoom = el("input", {
    type: "range",
    min: "1",
    max: "3",
    step: "0.1",
    value: "1",
    "aria-label": "Synchronized zoom",
    "data-testid": "zoom",
  });

  const images = [];
  const members = cluster.members.map((member) => {
    const isCanonical = cluster.canonical_asset_id === member.asset_id;
    const img = el("img", {
      src: api.thumbnailUrl(member.asset_id, 512),
      alt: member.current_path || member.asset_id,
      loading: "lazy",
    });
    images.push(img);
    const actions =
      cluster.state === "decided" || cluster.state === "dismissed"
        ? []
        : [
            el(
              "button",
              {
                "data-testid": "make-canonical",
                onclick: () => decide(cluster, "canonical", member.asset_id),
              },
              "Keep this as canonical"
            ),
          ];
    return el(
      "div",
      { class: `member ${isCanonical ? "canonical" : ""}`, "data-testid": "member" },
      img,
      el(
        "dl",
        {},
        el("dt", {}, "Path"),
        el("dd", {}, member.current_path || "—"),
        el("dt", {}, "Role"),
        el("dd", {}, member.role),
        el("dt", {}, "pHash distance"),
        el("dd", {}, member.distance == null ? "—" : String(member.distance)),
        el("dt", {}, "Bytes"),
        el("dd", {}, member.byte_size == null ? "—" : String(member.byte_size))
      ),
      ...actions
    );
  });

  zoom.addEventListener("input", () => {
    const scale = zoom.value;
    images.forEach((img) => (img.style.transform = `scale(${scale})`));
  });

  const decisionBar = el(
    "div",
    { class: "decision-bar" },
    el("span", { "data-testid": "cluster-state", class: `badge ${cluster.state}` }, `state: ${cluster.state}`),
    el("span", { class: `badge ${cluster.confidence}` }, `confidence: ${cluster.confidence}`),
    cluster.requires_confirmation ? el("span", { class: "muted" }, "fuzzy — confirmation required") : null,
    el(
      "button",
      { class: "danger", "data-testid": "not-duplicate", onclick: () => decide(cluster, "not_duplicate") },
      "Not a duplicate"
    ),
    el("button", { "data-testid": "defer", onclick: () => decide(cluster, "deferred") }, "Defer")
  );

  const nodes = [
    el("p", {}, el("a", { class: "link", href: "#/duplicates" }, "← All clusters")),
    el("h1", {}, `Compare cluster ${cluster.id.slice(0, 8)}`),
  ];
  if (extra.conflict) {
    nodes.push(
      errorBanner("This cluster changed since you loaded it. Nothing was modified; showing the latest state.")
    );
  }
  nodes.push(el("div", { class: "toolbar" }, el("label", {}, "Zoom "), zoom));
  nodes.push(decisionBar);
  if (extra.pending) nodes.push(confirmPanel(cluster, extra.pending));
  nodes.push(el("div", { class: "cluster-grid" }, ...members));
  show(...nodes);
}

function confirmPanel(cluster, pending) {
  return el(
    "div",
    { class: "confirm", role: "dialog", "aria-label": "Confirm decision", "data-testid": "confirm" },
    el("p", {}, `Confirm "${pending.decision.replace("_", " ")}" for this fuzzy cluster?`),
    el(
      "div",
      { class: "decision-bar" },
      el(
        "button",
        {
          class: "primary",
          "data-testid": "confirm-yes",
          onclick: () => applyDecision(cluster, pending.decision, pending.canonicalId),
        },
        "Confirm"
      ),
      el(
        "button",
        { "data-testid": "confirm-no", onclick: () => renderClusterDetail(cluster.id) },
        "Cancel"
      )
    )
  );
}

// A fuzzy cluster needs explicit confirmation; exact/pixel apply immediately.
function decide(cluster, decision, canonicalId) {
  if (cluster.requires_confirmation) {
    renderClusterDetail(cluster.id, { pending: { decision, canonicalId } });
  } else {
    applyDecision(cluster, decision, canonicalId);
  }
}

async function applyDecision(cluster, decision, canonicalId) {
  try {
    await api.decide(cluster.id, {
      decision,
      expected_version: cluster.version,
      canonical_asset_id: canonicalId || null,
    });
    renderClusterDetail(cluster.id);
  } catch (error) {
    if (error.status === 409) {
      renderClusterDetail(cluster.id, { conflict: true });
    } else {
      show(errorBanner(`Decision failed: ${error.message}`));
    }
  }
}

// ── Router ───────────────────────────────────────────────────────────────────
function render() {
  const { path, params } = parseHash();
  const clusterMatch = path.match(/^\/duplicates\/(.+)$/);
  if (path === "/workflow" || path === "/") renderWorkflow(root, params);
  else if (path === "/inventory") renderInventory(params);
  else if (path === "/duplicates") renderClusters(params);
  else if (clusterMatch) renderClusterDetail(clusterMatch[1]);
  else if (path === "/safety") renderSafety(root, params);
  else if (path === "/library") renderLibrary(root, params);
  else if (path === "/analyze") renderAnalyze(root, params);
  else if (path === "/albums") renderAlbums(root, params);
  else if (path === "/renames") renderRenames(root, params);
  else if (path === "/uploads") renderUploads(root, params);
  else if (path === "/archive") renderArchive(root, params);
  else if (path === "/stats") renderStats(root, params);
  else show(errorBanner("Unknown view"));
}

// Let views re-render the current route after a mutation.
setRender(render);
setRenamesRender(render);
setUploadsRender(render);
setArchiveRender(render);
onRouteChange(render);
render();