"use client";

import { useEffect, useState } from "react";

export interface ActivityItem {
  id: string;
  namespace: string;
  moduleLabel: string;
  label: string;
  action: "creat" | "actualizat";
  timestamp: string; // ISO
}

export interface DashboardKpis {
  registraturaThisWeek: number;
  registraturaOpen: number;
  deadlinesThisWeek: number;
  overdueDeadlines: number;
  contactsThisMonth: number;
  inventoryActive: number;
}

const MODULE_LABELS: Record<string, string> = {
  registratura: "Registratură",
  "address-book": "Agendă",
  "it-inventory": "IT Inventory",
  "password-vault": "Parole",
  "digital-signatures": "Semnături",
  "word-templates": "Șabloane Word",
  "tag-manager": "Tag Manager",
  "prompt-generator": "Prompt Generator",
};

/** Extract a human-readable label from a stored entity */
function pickLabel(obj: Record<string, unknown>): string {
  const candidates = ["subject", "name", "label", "title", "number"];
  for (const key of candidates) {
    const val = obj[key];
    if (typeof val === "string" && val.trim()) return val.trim();
  }
  return "(fără titlu)";
}

function startOfWeek(): Date {
  const d = new Date();
  d.setHours(0, 0, 0, 0);
  d.setDate(d.getDate() - d.getDay() + 1); // Monday
  return d;
}

function startOfMonth(): Date {
  const d = new Date();
  d.setHours(0, 0, 0, 0);
  d.setDate(1);
  return d;
}

function readAllNamespaceItems(): Record<string, Record<string, unknown>[]> {
  if (typeof window === "undefined") return {};
  const PREFIX = "architools:";
  const result: Record<string, Record<string, unknown>[]> = {};

  for (let i = 0; i < window.localStorage.length; i++) {
    const fullKey = window.localStorage.key(i);
    if (!fullKey?.startsWith(PREFIX)) continue;
    const rest = fullKey.slice(PREFIX.length);
    const colonIdx = rest.indexOf(":");
    if (colonIdx === -1) continue;
    const ns = rest.slice(0, colonIdx);
    try {
      const raw = window.localStorage.getItem(fullKey);
      if (!raw) continue;
      const parsed = JSON.parse(raw) as unknown;
      if (parsed && typeof parsed === "object" && !Array.isArray(parsed)) {
        if (!result[ns]) result[ns] = [];
        result[ns].push(parsed as Record<string, unknown>);
      }
    } catch {
      // ignore malformed entries
    }
  }
  return result;
}

export function useDashboardData() {
  const [activity, setActivity] = useState<ActivityItem[]>([]);
  const [kpis, setKpis] = useState<DashboardKpis>({
    registraturaThisWeek: 0,
    registraturaOpen: 0,
    deadlinesThisWeek: 0,
    overdueDeadlines: 0,
    contactsThisMonth: 0,
    inventoryActive: 0,
  });

  useEffect(() => {
    const allItems = readAllNamespaceItems();
    const weekStart = startOfWeek();
    const monthStart = startOfMonth();
    const now = new Date();

    // --- Activity feed ---
    const activityItems: ActivityItem[] = [];

    for (const [ns, items] of Object.entries(allItems)) {
      const moduleLabel = MODULE_LABELS[ns] ?? ns;
      for (const item of items) {
        const updatedAt =
          typeof item.updatedAt === "string" ? item.updatedAt : null;
        const createdAt =
          typeof item.createdAt === "string" ? item.createdAt : null;
        const id =
          typeof item.id === "string" ? item.id : String(Math.random());
        if (!updatedAt && !createdAt) continue;
        const timestamp = updatedAt ?? createdAt ?? "";
        const created = createdAt ? new Date(createdAt) : null;
        const updated = updatedAt ? new Date(updatedAt) : null;
        const action: "creat" | "actualizat" =
          created &&
          updated &&
          Math.abs(updated.getTime() - created.getTime()) < 2000
            ? "creat"
            : "actualizat";

        activityItems.push({
          id: `${ns}:${id}`,
          namespace: ns,
          moduleLabel,
          label: pickLabel(item),
          action,
          timestamp,
        });
      }
    }

    activityItems.sort((a, b) => b.timestamp.localeCompare(a.timestamp));
    setActivity(activityItems.slice(0, 20));

    // --- KPIs ---
    const registraturaItems = allItems["registratura"] ?? [];
    const registraturaThisWeek = registraturaItems.filter((e) => {
      const d = typeof e.date === "string" ? new Date(e.date) : null;
      return d && d >= weekStart;
    }).length;

    const registraturaOpen = registraturaItems.filter(
      (e) => e.status === "deschis",
    ).length;

    // Deadlines
    let deadlinesThisWeek = 0;
    let overdueDeadlines = 0;
    for (const entry of registraturaItems) {
      const deadlines = Array.isArray(entry.trackedDeadlines)
        ? (entry.trackedDeadlines as Record<string, unknown>[])
        : [];
      for (const dl of deadlines) {
        if (dl.resolution !== "pending") continue;
        const dueDate =
          typeof dl.dueDate === "string" ? new Date(dl.dueDate) : null;
        if (!dueDate) continue;
        if (dueDate < now) overdueDeadlines++;
        if (
          dueDate >= weekStart &&
          dueDate <= new Date(weekStart.getTime() + 7 * 86400000)
        )
          deadlinesThisWeek++;
      }
    }

    const contactItems = allItems["address-book"] ?? [];
    const contactsThisMonth = contactItems.filter((c) => {
      const d = typeof c.createdAt === "string" ? new Date(c.createdAt) : null;
      return d && d >= monthStart;
    }).length;

    const inventoryItems = allItems["it-inventory"] ?? [];
    const inventoryActive = inventoryItems.filter(
      (i) => i.status === "active",
    ).length;

    setKpis({
      registraturaThisWeek,
      registraturaOpen,
      deadlinesThisWeek,
      overdueDeadlines,
      contactsThisMonth,
      inventoryActive,
    });
  }, []);

  return { activity, kpis };
}