// Diagnostic logging (frontend side)
// Maintains a client-side ring buffer, fetches server logs, and wires UI controls.

import { getDiagLog, setDiagLevel, clearDiagLog } from "./api.js";

const UI_MAX = 500;
const uiBuffer = [];
let uiEnabled = false;
let uiLevel = "normal";
let clickListenerAttached = false;

function appendUi(level, msg, meta = null) {
  if (!uiEnabled) return;
  if (level === "debug" && uiLevel !== "debug") return;
  const ts = new Date().toISOString();
  const entry = { ts, level, msg, meta, source: "ui" };
  uiBuffer.unshift(entry);
  if (uiBuffer.length > UI_MAX) uiBuffer.length = UI_MAX;
}

function attachClickTracker() {
  if (clickListenerAttached) return;
  clickListenerAttached = true;
  document.addEventListener(
    "click",
    (e) => {
      if (!uiEnabled || uiLevel !== "debug") return;
      const el = e.target.closest("button,input,select,textarea,label");
      if (!el) return;
      const label =
        el.getAttribute("aria-label") ||
        el.getAttribute("title") ||
        el.textContent?.trim()?.slice(0, 60) ||
        el.id ||
        el.tagName.toLowerCase();
      appendUi("debug", `UI click: ${label || el.tagName}`, {
        id: el.id || null,
        type: el.tagName.toLowerCase(),
      });
    },
    true,
  );
}

export function logUi(msg, level = "info", meta) {
  appendUi(level, msg, meta);
}

export async function initDiagUI({ elements, toast }) {
  const { enableToggle, debugToggle, refreshBtn, clearBtn, copyBtn, downloadBtn, logBox, statusEl } =
    elements;

  async function syncState() {
    const data = await getDiagLog();
    const state = data.state || {};
    uiEnabled = !!state.enabled;
    uiLevel = state.level || "normal";
    if (enableToggle) enableToggle.checked = uiEnabled;
    if (debugToggle) debugToggle.checked = uiLevel === "debug";
    return data.entries || [];
  }

  function render(entries) {
    if (!logBox) return;
    const merged = [
      ...(entries || []).map((e) => ({ ...e, source: "api" })),
      ...uiBuffer,
    ].sort((a, b) => (a.ts < b.ts ? 1 : -1));
    logBox.textContent = merged
      .map((e) => `${new Date(e.ts).toLocaleTimeString()} [${e.source || "api"} ${e.level}] ${e.msg}`)
      .join("\n");
    if (statusEl) statusEl.textContent = `${merged.length} entries`;
  }

  async function refresh() {
    try {
      const entries = await syncState();
      render(entries);
      toast?.("Diagnostics refreshed", "success");
    } catch (e) {
      toast?.(e.error || "Failed to load diagnostics", "error");
    }
  }

  enableToggle?.addEventListener("change", async () => {
    try {
      uiEnabled = enableToggle.checked;
      await setDiagLevel({ enabled: uiEnabled, level: uiLevel });
      appendUi("info", `Diagnostics ${uiEnabled ? "enabled" : "disabled"}`);
      if (uiEnabled) attachClickTracker();
      await refresh();
    } catch (e) {
      toast?.(e.error || "Failed to save diagnostics setting", "error");
      enableToggle.checked = !enableToggle.checked;
    }
  });

  debugToggle?.addEventListener("change", async () => {
    try {
      uiLevel = debugToggle.checked ? "debug" : "normal";
      await setDiagLevel({ enabled: uiEnabled, level: uiLevel });
      appendUi("info", `Diagnostics level set to ${uiLevel}`);
      if (uiEnabled) attachClickTracker();
      await refresh();
    } catch (e) {
      toast?.(e.error || "Failed to save level", "error");
      debugToggle.checked = uiLevel === "debug";
    }
  });

  refreshBtn?.addEventListener("click", refresh);

  clearBtn?.addEventListener("click", async () => {
    try {
      await clearDiagLog();
      uiBuffer.length = 0;
      appendUi("info", "Cleared diagnostics");
      await refresh();
    } catch (e) {
      toast?.(e.error || "Failed to clear log", "error");
    }
  });

  copyBtn?.addEventListener("click", async () => {
    try {
      const text = logBox?.textContent || "";
      if (navigator.clipboard && window.isSecureContext) {
        await navigator.clipboard.writeText(text || "No log entries.");
      } else {
        const ta = document.createElement("textarea");
        ta.value = text || "No log entries.";
        ta.style.position = "fixed";
        ta.style.opacity = "0";
        document.body.appendChild(ta);
        ta.select();
        document.execCommand("copy");
        document.body.removeChild(ta);
      }
      toast?.("Diagnostics copied", "success");
    } catch (e) {
      toast?.("Copy failed", "error");
    }
  });

  downloadBtn?.addEventListener("click", () => {
    try {
      const blob = new Blob([logBox?.textContent || "No log entries."], { type: "text/plain" });
      const url = URL.createObjectURL(blob);
      const a = document.createElement("a");
      a.href = url;
      a.download = "pikit-diagnostics.txt";
      a.click();
      URL.revokeObjectURL(url);
    } catch (e) {
      toast?.("Download failed", "error");
    }
  });

  // initial load
  attachClickTracker();
  await refresh();

  return {
    logUi,
    refresh,
  };
}