import { initI18n, t, type I18nKey } from "./i18n";
import { initSidebar } from "./sidebar";
import type { FilterSpec, RenderSpec, ViewRunResult, UserView, RenderShape } from "./views/types";
import { renderListShape } from "./views/shape-list";
import { renderCardsShape } from "./views/shape-cards";
import { renderCalendarShape } from "./views/shape-calendar";

// /views and /views/{slug} client. Loads the saved or system view, runs
// it via /api/views/{slug}/run, and dispatches to the matching render-
// shape component. Shape-switcher chips toggle the live render without
// re-fetching (the rows are already in memory).

initI18n();
initSidebar();

interface ViewMeta {
  // For saved views: identifies the row for touch/edit/delete.
  user_view_id?: string;
  // Display name + slug.
  name: string;
  slug: string;
  // Filter + render specs (may be overridden by slug detection).
  filter: FilterSpec;
  render: RenderSpec;
  // Whether this is a code-resident SystemView.
  is_system: boolean;
}

let currentMeta: ViewMeta | null = null;
let currentRows: ViewRunResult | null = null;

document.addEventListener("DOMContentLoaded", () => {
  bindShapeChips();
  bindToastClose();
  void hydrate();
});

async function hydrate(): Promise<void> {
  const slug = pathSlug();
  if (!slug) {
    // /views with no slug → empty / onboarding state.
    const onboarding = document.getElementById("views-onboarding");
    const loading = document.getElementById("views-loading");
    if (loading) loading.hidden = true;
    if (onboarding) onboarding.hidden = false;
    return;
  }
  // Resolve the view: try system first, then user.
  const meta = await resolveMeta(slug);
  if (!meta) {
    showError(t("views.error.not_found"));
    return;
  }
  currentMeta = meta;
  document.title = `${meta.name} — Paliad`;
  updateHeader(meta);
  await runAndRender(meta);
  if (meta.user_view_id) {
    fireAndForget(`/api/user-views/${meta.user_view_id}/touch`, "POST");
  }
}

async function resolveMeta(slug: string): Promise<ViewMeta | null> {
  // Try the system view list first — cheap, code-resident.
  try {
    const r = await fetch("/api/views/system", { credentials: "include" });
    if (r.ok) {
      const list = (await r.json()) as Array<{ Slug: string; Name: string; Filter: FilterSpec; Render: RenderSpec }>;
      const sys = list.find((sv) => sv.Slug === slug);
      if (sys) {
        return { name: sys.Name, slug: sys.Slug, filter: sys.Filter, render: sys.Render, is_system: true };
      }
    }
  } catch (_e) {
    // fall through to user lookup
  }
  // Try a saved user view.
  try {
    const r = await fetch("/api/user-views", { credentials: "include" });
    if (r.ok) {
      const list = (await r.json()) as UserView[];
      const v = list.find((uv) => uv.slug === slug);
      if (v) {
        return {
          user_view_id: v.id,
          name: v.name,
          slug: v.slug,
          filter: v.filter_spec,
          render: v.render_spec,
          is_system: false,
        };
      }
    }
  } catch (_e) { /* noop */ }
  return null;
}

async function runAndRender(meta: ViewMeta): Promise<void> {
  const loading = document.getElementById("views-loading");
  const empty = document.getElementById("views-empty");
  const errorEl = document.getElementById("views-error");
  const toolbar = document.getElementById("views-toolbar");
  if (loading) loading.hidden = false;
  if (empty) empty.hidden = true;
  if (errorEl) errorEl.hidden = true;
  if (toolbar) toolbar.hidden = false;

  let result: ViewRunResult;
  try {
    const r = await fetch(`/api/views/${encodeURIComponent(meta.slug)}/run`, {
      method: "POST",
      credentials: "include",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({}),
    });
    if (!r.ok) {
      showError(`${r.status}: ${r.statusText}`);
      return;
    }
    result = (await r.json()) as ViewRunResult;
  } catch (e) {
    showError(t("views.error.network"));
    return;
  }
  if (loading) loading.hidden = true;

  currentRows = result;
  if (result.inaccessible_project_ids && result.inaccessible_project_ids.length > 0) {
    showInaccessibleToast(result.inaccessible_project_ids.length);
  }

  if (result.rows.length === 0) {
    if (empty) {
      empty.hidden = false;
      const hint = document.getElementById("views-empty-hint");
      if (hint) hint.textContent = filterSummary(meta.filter);
    }
    return;
  }

  setActiveShape(meta.render.shape);
  renderShape(meta.render.shape, meta.render, result.rows);
}

function setActiveShape(shape: RenderShape): void {
  for (const host of ["views-shape-list", "views-shape-cards", "views-shape-calendar"]) {
    const el = document.getElementById(host);
    if (el) el.hidden = !host.endsWith("-" + shape);
  }
  document.querySelectorAll<HTMLButtonElement>("#views-shape-chips [data-shape]").forEach((btn) => {
    btn.classList.toggle("active", btn.dataset.shape === shape);
  });
}

function renderShape(shape: RenderShape, render: RenderSpec, rows: ViewRunResult["rows"]): void {
  const host = document.getElementById(`views-shape-${shape}`);
  if (!host) return;
  switch (shape) {
    case "list":
      renderListShape(host, rows, render);
      break;
    case "cards":
      renderCardsShape(host, rows, render);
      break;
    case "calendar":
      renderCalendarShape(host, rows, render);
      break;
  }
}

function bindShapeChips(): void {
  document.querySelectorAll<HTMLButtonElement>("#views-shape-chips [data-shape]").forEach((btn) => {
    btn.addEventListener("click", () => {
      const shape = (btn.dataset.shape ?? "list") as RenderShape;
      if (!currentMeta || !currentRows) return;
      // Override the shape transiently — doesn't mutate the saved spec.
      const overrideRender = { ...currentMeta.render, shape };
      setActiveShape(shape);
      renderShape(shape, overrideRender, currentRows.rows);
    });
  });
}

function updateHeader(meta: ViewMeta): void {
  const heading = document.getElementById("views-heading");
  if (heading) heading.textContent = meta.name;
  const subtitle = document.getElementById("views-subtitle");
  if (subtitle) subtitle.textContent = filterSummary(meta.filter);
  const actions = document.getElementById("views-header-actions");
  if (actions) {
    actions.innerHTML = "";
    if (!meta.is_system && meta.user_view_id) {
      const editLink = document.createElement("a");
      editLink.href = `/views/${encodeURIComponent(meta.slug)}/edit`;
      editLink.className = "btn-secondary btn-small";
      editLink.textContent = t("views.action.edit");
      actions.appendChild(editLink);
    }
  }
}

function filterSummary(filter: FilterSpec): string {
  const parts: string[] = [];
  // Sources
  parts.push(filter.sources.map((s) => t(("views.source." + s) as I18nKey)).join(" + "));
  // Time
  parts.push(t(("views.horizon." + filter.time.horizon) as I18nKey));
  // Scope
  if (filter.scope.personal_only) {
    parts.push(t("views.scope.personal_only"));
  } else if (filter.scope.projects.mode !== "all_visible") {
    parts.push(t(("views.scope." + filter.scope.projects.mode) as I18nKey));
  }
  return parts.join(" · ");
}

function showError(message: string): void {
  const loading = document.getElementById("views-loading");
  const errorEl = document.getElementById("views-error");
  const msg = document.getElementById("views-error-message");
  if (loading) loading.hidden = true;
  if (errorEl) errorEl.hidden = false;
  if (msg) msg.textContent = message;
}

function showInaccessibleToast(count: number): void {
  const toast = document.getElementById("views-toast");
  const text = document.getElementById("views-toast-text");
  if (!toast || !text) return;
  text.textContent = count === 1
    ? t("views.toast.inaccessible_one")
    : t("views.toast.inaccessible_n").replace("{n}", String(count));
  toast.hidden = false;
}

function bindToastClose(): void {
  const close = document.getElementById("views-toast-close");
  const toast = document.getElementById("views-toast");
  if (!close || !toast) return;
  close.addEventListener("click", () => { toast.hidden = true; });
}

function pathSlug(): string | null {
  const m = window.location.pathname.match(/^\/views\/([^\/]+)$/);
  if (!m) return null;
  return decodeURIComponent(m[1]);
}

function fireAndForget(url: string, method: string): void {
  fetch(url, { method, credentials: "include" }).catch(() => { /* noop */ });
}