import { UserSettings, ChatSession, AppLanguage } from "../types";
import { DEFAULT_LANGUAGE } from "../constants";

const KEYS = {
  SETTINGS: "sociopal_settings",
  SESSIONS: "sociopal_sessions",
  CURRENT_SESSION: "sociopal_current_session_id"
};

export const loadSettings = (): UserSettings => {
  const stored = localStorage.getItem(KEYS.SETTINGS);
  if (stored) return JSON.parse(stored);
  return {
    language: DEFAULT_LANGUAGE,
    theme: 'light'
  };
};

export const saveSettings = (settings: UserSettings) => {
  localStorage.setItem(KEYS.SETTINGS, JSON.stringify(settings));
};

export const loadSessions = (): ChatSession[] => {
  const stored = localStorage.getItem(KEYS.SESSIONS);
  return stored ? JSON.parse(stored) : [];
};

export const saveSessions = (sessions: ChatSession[]) => {
  localStorage.setItem(KEYS.SESSIONS, JSON.stringify(sessions));
};

export const exportData = () => {
  const data = {
    settings: loadSettings(),
    sessions: loadSessions(),
    timestamp: Date.now()
  };
  const blob = new Blob([JSON.stringify(data, null, 2)], { type: "application/json" });
  const url = URL.createObjectURL(blob);
  const a = document.createElement('a');
  a.href = url;
  a.download = `sociopal_backup_${new Date().toISOString().slice(0, 10)}.json`;
  a.click();
};

export const importData = async (file: File): Promise<boolean> => {
  return new Promise((resolve) => {
    const reader = new FileReader();
    reader.onload = (e) => {
      try {
        const data = JSON.parse(e.target?.result as string);
        if (data.settings) saveSettings(data.settings);
        if (data.sessions) saveSessions(data.sessions);
        resolve(true);
      } catch (err) {
        console.error("Import failed", err);
        resolve(false);
      }
    };
    reader.readAsText(file);
  });
};

export const clearData = () => {
  localStorage.removeItem(KEYS.SETTINGS);
  localStorage.removeItem(KEYS.SESSIONS);
  localStorage.removeItem(KEYS.CURRENT_SESSION);
};