"use client";

import type {
  BankingData,
  Account,
  Transaction,
  Folder,
  Category,
} from "./types";
import { defaultCategories, defaultRootFolder } from "./defaults";

const STORAGE_KEY = "banking-app-data";

// Convertir les CategoryDefinition en Category pour le localStorage
function buildCategoriesFromDefaults(): Category[] {
  const slugToId = new Map<string, string>();
  const categories: Category[] = [];

  // D'abord les parents
  const parents = defaultCategories.filter((c) => c.parentSlug === null);
  parents.forEach((cat, index) => {
    const id = `cat-${index + 1}`;
    slugToId.set(cat.slug, id);
    categories.push({
      id,
      name: cat.name,
      color: cat.color,
      icon: cat.icon,
      keywords: cat.keywords,
      parentId: null,
    });
  });

  // Puis les enfants
  const children = defaultCategories.filter((c) => c.parentSlug !== null);
  children.forEach((cat, index) => {
    const id = `cat-${parents.length + index + 1}`;
    slugToId.set(cat.slug, id);
    categories.push({
      id,
      name: cat.name,
      color: cat.color,
      icon: cat.icon,
      keywords: cat.keywords,
      parentId: cat.parentSlug ? slugToId.get(cat.parentSlug) || null : null,
    });
  });

  return categories;
}

const defaultData: BankingData = {
  accounts: [],
  transactions: [],
  folders: [defaultRootFolder],
  categories: buildCategoriesFromDefaults(),
};

export function loadData(): BankingData {
  if (typeof window === "undefined") return defaultData;

  const stored = localStorage.getItem(STORAGE_KEY);
  if (!stored) {
    saveData(defaultData);
    return defaultData;
  }

  try {
    return JSON.parse(stored);
  } catch {
    return defaultData;
  }
}

export function saveData(data: BankingData): void {
  if (typeof window === "undefined") return;
  localStorage.setItem(STORAGE_KEY, JSON.stringify(data));
}

export function addAccount(account: Account): BankingData {
  const data = loadData();
  data.accounts.push(account);
  saveData(data);
  return data;
}

export function updateAccount(account: Account): BankingData {
  const data = loadData();
  const index = data.accounts.findIndex((a) => a.id === account.id);
  if (index !== -1) {
    data.accounts[index] = account;
    saveData(data);
  }
  return data;
}

export function deleteAccount(accountId: string): BankingData {
  const data = loadData();
  data.accounts = data.accounts.filter((a) => a.id !== accountId);
  data.transactions = data.transactions.filter(
    (t) => t.accountId !== accountId,
  );
  saveData(data);
  return data;
}

export function addTransactions(transactions: Transaction[]): BankingData {
  const data = loadData();

  // Filter out duplicates based on fitId
  const existingFitIds = new Set(
    data.transactions.map((t) => `${t.accountId}-${t.fitId}`),
  );
  const newTransactions = transactions.filter(
    (t) => !existingFitIds.has(`${t.accountId}-${t.fitId}`),
  );

  data.transactions.push(...newTransactions);
  saveData(data);
  return data;
}

export function updateTransaction(transaction: Transaction): BankingData {
  const data = loadData();
  const index = data.transactions.findIndex((t) => t.id === transaction.id);
  if (index !== -1) {
    data.transactions[index] = transaction;
    saveData(data);
  }
  return data;
}

export function addFolder(folder: Folder): BankingData {
  const data = loadData();
  data.folders.push(folder);
  saveData(data);
  return data;
}

export function updateFolder(folder: Folder): BankingData {
  const data = loadData();
  const index = data.folders.findIndex((f) => f.id === folder.id);
  if (index !== -1) {
    data.folders[index] = folder;
    saveData(data);
  }
  return data;
}

export function deleteFolder(folderId: string): BankingData {
  const data = loadData();
  // Move accounts to root
  data.accounts = data.accounts.map((a) =>
    a.folderId === folderId ? { ...a, folderId: "folder-root" } : a,
  );
  // Move subfolders to parent
  const folder = data.folders.find((f) => f.id === folderId);
  if (folder) {
    data.folders = data.folders.map((f) =>
      f.parentId === folderId ? { ...f, parentId: folder.parentId } : f,
    );
  }
  data.folders = data.folders.filter((f) => f.id !== folderId);
  saveData(data);
  return data;
}

export function addCategory(category: Category): BankingData {
  const data = loadData();
  data.categories.push(category);
  saveData(data);
  return data;
}

export function updateCategory(category: Category): BankingData {
  const data = loadData();
  const index = data.categories.findIndex((c) => c.id === category.id);
  if (index !== -1) {
    data.categories[index] = category;
    saveData(data);
  }
  return data;
}

export function deleteCategory(categoryId: string): BankingData {
  const data = loadData();
  data.categories = data.categories.filter((c) => c.id !== categoryId);
  // Remove category from transactions
  data.transactions = data.transactions.map((t) =>
    t.categoryId === categoryId ? { ...t, categoryId: null } : t,
  );
  saveData(data);
  return data;
}

// Auto-categorize a transaction based on keywords
export function autoCategorize(
  description: string,
  categories: Category[],
): string | null {
  const lowerDesc = description.toLowerCase();

  for (const category of categories) {
    for (const keyword of category.keywords) {
      if (lowerDesc.includes(keyword.toLowerCase())) {
        return category.id;
      }
    }
  }

  return null;
}

export function generateId(): string {
  return `${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
}