"use client";

import { useState, useEffect, useCallback } from "react";
import { useStorage } from "@/core/storage";
import { v4 as uuid } from "uuid";
import type {
  RegistryEntry,
  RegistryDirection,
  RegistryStatus,
  DocumentType,
  TrackedDeadline,
  DeadlineResolution,
} from "../types";
import {
  getAllEntries,
  getFullEntry,
  saveEntry,
  deleteEntry,
  generateRegistryNumber,
} from "../services/registry-service";
import {
  createTrackedDeadline,
  resolveDeadline as resolveDeadlineFn,
} from "../services/deadline-service";
import { getDeadlineType } from "../services/deadline-catalog";

export interface RegistryFilters {
  search: string;
  direction: RegistryDirection | "all";
  status: RegistryStatus | "all";
  documentType: DocumentType | "all";
  company: string;
}

export function useRegistry() {
  const storage = useStorage("registratura");
  const [entries, setEntries] = useState<RegistryEntry[]>([]);
  const [loading, setLoading] = useState(true);
  const [filters, setFilters] = useState<RegistryFilters>({
    search: "",
    direction: "all",
    status: "all",
    documentType: "all",
    company: "all",
  });

  const refresh = useCallback(async () => {
    setLoading(true);
    const items = await getAllEntries(storage);
    setEntries(items);
    setLoading(false);
  }, [storage]);

  // eslint-disable-next-line react-hooks/set-state-in-effect
  useEffect(() => {
    refresh();
  }, [refresh]);

  const addEntry = useCallback(
    async (
      data: Omit<RegistryEntry, "id" | "number" | "createdAt" | "updatedAt">,
    ) => {
      // Fetch fresh entries to prevent duplicate numbers from stale state.
      // This single call replaces what was previously list() + N×get().
      const freshEntries = await getAllEntries(storage);
      const now = new Date().toISOString();
      const number = generateRegistryNumber(
        data.company,
        data.date,
        freshEntries,
      );
      const entry: RegistryEntry = {
        ...data,
        id: uuid(),
        number,
        registrationDate: new Date().toISOString().slice(0, 10),
        createdAt: now,
        updatedAt: now,
      };
      await saveEntry(storage, entry);
      // Update local state directly to avoid a second full fetch
      setEntries((prev) => [entry, ...prev]);
      return entry;
    },
    [storage],
  );

  const updateEntry = useCallback(
    async (id: string, updates: Partial<RegistryEntry>) => {
      const existing = entries.find((e) => e.id === id);
      if (!existing) return;
      const updated: RegistryEntry = {
        ...existing,
        ...updates,
        id: existing.id,
        number: existing.number,
        createdAt: existing.createdAt,
        updatedAt: new Date().toISOString(),
      };
      await saveEntry(storage, updated);
      await refresh();
    },
    [storage, refresh, entries],
  );

  const removeEntry = useCallback(
    async (id: string) => {
      await deleteEntry(storage, id);
      await refresh();
    },
    [storage, refresh],
  );

  /** Close an entry and optionally its linked entries.
   *  Batches all saves, then does a single refresh at the end.
   */
  const closeEntry = useCallback(
    async (id: string, closeLinked: boolean) => {
      const entry = entries.find((e) => e.id === id);
      if (!entry) return;
      // Save main entry as closed
      const now = new Date().toISOString();
      const closedMain: RegistryEntry = {
        ...entry,
        status: "inchis",
        updatedAt: now,
      };
      await saveEntry(storage, closedMain);
      // Close linked entries in parallel
      const linked = entry.linkedEntryIds ?? [];
      if (closeLinked && linked.length > 0) {
        const saves = linked
          .map((linkedId) => entries.find((e) => e.id === linkedId))
          .filter((e): e is RegistryEntry => !!e && e.status !== "inchis")
          .map((e) =>
            saveEntry(storage, { ...e, status: "inchis", updatedAt: now }),
          );
        await Promise.all(saves);
      }
      // Single refresh at the end
      await refresh();
    },
    [entries, storage, refresh],
  );

  const updateFilter = useCallback(
    <K extends keyof RegistryFilters>(key: K, value: RegistryFilters[K]) => {
      setFilters((prev) => ({ ...prev, [key]: value }));
    },
    [],
  );

  // ── Deadline operations ──

  const addDeadline = useCallback(
    async (
      entryId: string,
      typeId: string,
      startDate: string,
      chainParentId?: string,
    ) => {
      const entry = entries.find((e) => e.id === entryId);
      if (!entry) return null;
      const tracked = createTrackedDeadline(typeId, startDate, chainParentId);
      if (!tracked) return null;
      const existing = entry.trackedDeadlines ?? [];
      const updated: RegistryEntry = {
        ...entry,
        trackedDeadlines: [...existing, tracked],
        updatedAt: new Date().toISOString(),
      };
      await saveEntry(storage, updated);
      await refresh();
      return tracked;
    },
    [entries, storage, refresh],
  );

  const resolveDeadline = useCallback(
    async (
      entryId: string,
      deadlineId: string,
      resolution: DeadlineResolution,
      note?: string,
    ): Promise<TrackedDeadline | null> => {
      const entry = entries.find((e) => e.id === entryId);
      if (!entry) return null;
      const deadlines = entry.trackedDeadlines ?? [];
      const idx = deadlines.findIndex((d) => d.id === deadlineId);
      if (idx === -1) return null;
      const dl = deadlines[idx];
      if (!dl) return null;
      const resolved = resolveDeadlineFn(dl, resolution, note);
      const updatedDeadlines = [...deadlines];
      updatedDeadlines[idx] = resolved;
      const updated: RegistryEntry = {
        ...entry,
        trackedDeadlines: updatedDeadlines,
        updatedAt: new Date().toISOString(),
      };
      await saveEntry(storage, updated);

      // If the resolved deadline has a chain, automatically check for the next type
      const def = getDeadlineType(dl.typeId);
      await refresh();

      if (
        def?.chainNextTypeId &&
        (resolution === "completed" || resolution === "aprobat-tacit")
      ) {
        return resolved;
      }

      return resolved;
    },
    [entries, storage, refresh],
  );

  const removeDeadline = useCallback(
    async (entryId: string, deadlineId: string) => {
      const entry = entries.find((e) => e.id === entryId);
      if (!entry) return;
      const deadlines = entry.trackedDeadlines ?? [];
      const updated: RegistryEntry = {
        ...entry,
        trackedDeadlines: deadlines.filter((d) => d.id !== deadlineId),
        updatedAt: new Date().toISOString(),
      };
      await saveEntry(storage, updated);
      await refresh();
    },
    [entries, storage, refresh],
  );

  const filteredEntries = entries.filter((entry) => {
    if (filters.direction !== "all" && entry.direction !== filters.direction)
      return false;
    if (filters.status !== "all" && entry.status !== filters.status)
      return false;
    if (
      filters.documentType !== "all" &&
      entry.documentType !== filters.documentType
    )
      return false;
    if (filters.company !== "all" && entry.company !== filters.company)
      return false;
    if (filters.search) {
      const q = filters.search.toLowerCase();
      return (
        entry.subject.toLowerCase().includes(q) ||
        entry.sender.toLowerCase().includes(q) ||
        entry.recipient.toLowerCase().includes(q) ||
        entry.number.toLowerCase().includes(q)
      );
    }
    return true;
  });

  /**
   * Load a single entry WITH full attachment data (for editing).
   * The list uses lightweight mode that strips base64 data.
   */
  const loadFullEntry = useCallback(
    async (id: string): Promise<RegistryEntry | null> => {
      return getFullEntry(storage, id);
    },
    [storage],
  );

  return {
    entries: filteredEntries,
    allEntries: entries,
    loading,
    filters,
    updateFilter,
    addEntry,
    updateEntry,
    removeEntry,
    closeEntry,
    loadFullEntry,
    addDeadline,
    resolveDeadline,
    removeDeadline,
    refresh,
  };
}