import { initI18n, onLangChange, t, getLang } from "./i18n";
import { initSidebar } from "./sidebar";

interface Deadline {
  id: string;
  project_id: string;
  title: string;
  due_date: string;
  status: string;
  source: string;
  rule_id?: string;
  project_reference: string;
  project_title: string;
  projekt_office: string;
  rule_code?: string;
}

interface Project {
  id: string;
  reference?: string | null;
  title: string;
}

interface Summary {
  overdue: number;
  this_week: number;
  upcoming: number;
  completed: number;
  total: number;
}

let allDeadlines: Deadline[] = [];
let allProjects: Project[] = [];
let statusFilter = "pending";
let akteFilter = "";
let loadedOK = false;

function urlParams(): URLSearchParams {
  return new URLSearchParams(window.location.search);
}

async function loadAkten() {
  try {
    const resp = await fetch("/api/projects");
    if (resp.ok) allProjects = await resp.json();
  } catch {
    /* non-fatal */
  }
}

async function loadSummary() {
  try {
    const url = akteFilter
      ? `/api/deadlines/summary?project_id=${encodeURIComponent(akteFilter)}`
      : `/api/deadlines/summary`;
    const resp = await fetch(url);
    if (!resp.ok) return;
    const sum: Summary = await resp.json();
    setCount("sum-overdue", sum.overdue);
    setCount("sum-week", sum.this_week);
    setCount("sum-upcoming", sum.upcoming);
    setCount("sum-completed", sum.completed);
  } catch {
    /* non-fatal */
  }
}

function setCount(id: string, n: number) {
  const el = document.getElementById(id);
  if (el) el.textContent = String(n);
}

async function loadFristen() {
  const unavailable = document.getElementById("fristen-unavailable")!;
  const tableWrap = document.querySelector<HTMLElement>(".akten-table-wrap")!;
  try {
    const params = new URLSearchParams();
    if (statusFilter) params.set("status", statusFilter);
    if (akteFilter) params.set("project_id", akteFilter);
    const resp = await fetch(`/api/deadlines?${params.toString()}`);
    if (resp.status === 503) {
      unavailable.style.display = "block";
      tableWrap.style.display = "none";
      document.getElementById("fristen-empty")!.style.display = "none";
      return;
    }
    if (!resp.ok) {
      unavailable.style.display = "block";
      tableWrap.style.display = "none";
      return;
    }
    allFristen = await resp.json();
    loadedOK = true;
    render();
  } catch {
    unavailable.style.display = "block";
    tableWrap.style.display = "none";
  }
}

function urgencyClass(due: string, status: string): string {
  if (status === "completed") return "frist-urgency-done";
  const today = new Date();
  today.setHours(0, 0, 0, 0);
  const d = new Date(due + "T00:00:00");
  const diffDays = Math.floor((d.getTime() - today.getTime()) / 86400000);
  if (diffDays < 0) return "frist-urgency-overdue";
  if (diffDays <= 7) return "frist-urgency-soon";
  return "frist-urgency-later";
}

function fmtDate(iso: string): string {
  try {
    const d = new Date(iso + "T00:00:00");
    return d.toLocaleDateString(getLang() === "de" ? "de-DE" : "en-GB", {
      year: "numeric",
      month: "2-digit",
      day: "2-digit",
    });
  } catch {
    return iso;
  }
}

function esc(s: string): string {
  const d = document.createElement("div");
  d.textContent = s;
  return d.innerHTML;
}

function render() {
  if (!loadedOK) return;
  const tbody = document.getElementById("fristen-body")!;
  const empty = document.getElementById("fristen-empty")!;
  const emptyFiltered = document.getElementById("fristen-empty-filtered")!;
  const tableWrap = document.querySelector<HTMLElement>(".akten-table-wrap")!;

  if (allFristen.length === 0) {
    tbody.innerHTML = "";
    tableWrap.style.display = "none";
    if (statusFilter === "all" && !akteFilter) {
      empty.style.display = "block";
      emptyFiltered.style.display = "none";
    } else {
      empty.style.display = "none";
      emptyFiltered.style.display = "block";
    }
    return;
  }

  tableWrap.style.display = "";
  empty.style.display = "none";
  emptyFiltered.style.display = "none";

  tbody.innerHTML = allFristen
    .map((f) => {
      const urgency = urgencyClass(f.due_date, f.status);
      const statusLabel = t(`fristen.status.${f.status}`) || f.status;
      const ruleLabel = f.rule_code ? esc(f.rule_code) : "&mdash;";
      const checked = f.status === "completed" ? "checked" : "";
      const disabled = f.status === "completed" ? "disabled" : "";
      const titleClass = f.status === "completed" ? "frist-title-done" : "";
      return `<tr class="frist-row" data-id="${esc(f.id)}">
        <td class="frist-col-check">
          <input type="checkbox" class="frist-complete-cb" ${checked} ${disabled}
                 aria-label="${esc(t("fristen.complete.action"))}" />
        </td>
        <td class="frist-col-due ${urgency}"><span class="frist-due-dot"></span>${fmtDate(f.due_date)}</td>
        <td class="frist-col-title ${titleClass}">${esc(f.title)}</td>
        <td class="frist-col-project">
          <a class="akten-ref-link" href="/projects/${esc(f.project_id)}">${esc(f.project_reference)}</a>
          <span class="frist-project-title">${esc(f.project_title)}</span>
        </td>
        <td class="frist-col-rule">${ruleLabel}</td>
        <td><span class="akten-status-chip akten-status-${esc(f.status)}">${esc(statusLabel)}</span></td>
      </tr>`;
    })
    .join("");

  tbody.querySelectorAll<HTMLTableRowElement>(".frist-row").forEach((row) => {
    const id = row.dataset.id!;
    row.addEventListener("click", (e) => {
      // Don't navigate if clicking the checkbox or a link
      const target = e.target as HTMLElement;
      if (target.closest(".frist-complete-cb") || target.closest("a")) return;
      window.location.href = `/deadlines/${id}`;
    });
    const cb = row.querySelector<HTMLInputElement>(".frist-complete-cb");
    if (cb) {
      cb.addEventListener("change", async () => {
        if (!cb.checked) return;
        cb.disabled = true;
        try {
          const resp = await fetch(`/api/deadlines/${id}/complete`, { method: "PATCH" });
          if (resp.ok) {
            await Promise.all([loadFristen(), loadSummary()]);
          } else {
            cb.checked = false;
            cb.disabled = false;
          }
        } catch {
          cb.checked = false;
          cb.disabled = false;
        }
      });
    }
  });
}

function initFilters() {
  const status = document.getElementById("frist-filter-status") as HTMLSelectElement;
  const project = document.getElementById("frist-filter-project") as HTMLSelectElement;

  // Pre-fill from URL
  const params = urlParams();
  if (params.has("status")) statusFilter = params.get("status")!;
  if (params.has("project_id")) akteFilter = params.get("project_id")!;
  status.value = statusFilter;

  status.addEventListener("change", async () => {
    statusFilter = status.value;
    await Promise.all([loadFristen(), loadSummary()]);
  });
  project.addEventListener("change", async () => {
    akteFilter = project.value;
    await Promise.all([loadFristen(), loadSummary()]);
  });
}

function populateAkteFilter() {
  const sel = document.getElementById("frist-filter-project") as HTMLSelectElement;
  // Keep the first "all" option, then append sorted Akten.
  const options: string[] = [
    `<option value="" data-i18n="fristen.filter.akte.all">${esc(t("fristen.filter.akte.all"))}</option>`,
  ];
  for (const a of allProjects) {
    options.push(
      `<option value="${esc(a.id)}">${esc(a.reference || "")} \u2014 ${esc(a.title)}</option>`,
    );
  }
  sel.innerHTML = options.join("");
  if (akteFilter) sel.value = akteFilter;
}

function initSummaryCards() {
  document.querySelectorAll<HTMLButtonElement>(".frist-summary-card").forEach((card) => {
    card.addEventListener("click", async () => {
      const newStatus = card.dataset.status!;
      statusFilter = newStatus;
      (document.getElementById("frist-filter-status") as HTMLSelectElement).value = newStatus;
      await Promise.all([loadFristen(), loadSummary()]);
    });
  });
}

document.addEventListener("DOMContentLoaded", async () => {
  initI18n();
  initSidebar();
  initFilters();
  initSummaryCards();
  onLangChange(render);
  await loadAkten();
  populateAkteFilter();
  await Promise.all([loadFristen(), loadSummary()]);
});