import { webExtApi as api } from '../browser-api';
import type { Tab, TabGroup } from '../types';
import { normalizeGroupColor, queryTabGroups } from '../core';
import type { SessionTab, StoredSession } from '../types';

export function buildSessionSnapshot(tabs: Tab[], groups: TabGroup[]): SessionTab[] {
  const groupById = new Map(groups.map(group => [group.id, group]));
  return tabs
    .filter(tab => Boolean(tab.url || tab.pendingUrl))
    .sort((a, b) => (a.windowId - b.windowId) || (a.index - b.index))
    .map(tab => {
      const entry: SessionTab = { url: tab.url || tab.pendingUrl };
      if (tab.pinned) entry.pinned = true;
      if (tab.groupId >= 0) {
        const group = groupById.get(tab.groupId);
        entry.group = {
          key: `${tab.windowId}:${tab.groupId}`,
          title: group?.title || "",
          color: normalizeGroupColor(group?.color),
          collapsed: Boolean(group?.collapsed),
        };
      }
      return entry;
    });
}

/**
 * Snapshot the current windows/tabs/groups into a ready-to-store session plus
 * its change-detection signature. Shared by session.save and the autosave path.
 */
export async function captureCurrentSession(): Promise<{ session: StoredSession; signature: string; tabCount: number }> {
  const tabs = await api.tabs.query({});
  const groups = await queryTabGroups({});
  const sessionTabs = buildSessionSnapshot(tabs, groups);
  const signature = sessionSignature(sessionTabs);
  const session: StoredSession = {
    tabs: sessionTabs,
    urls: sessionTabs.map(tab => tab.url),
    savedAt: Date.now(),
    signature,
  };
  return { session, signature, tabCount: sessionTabs.length };
}

export function sessionSignature(sessionTabs: SessionTab[]) {
  return JSON.stringify(sessionTabs.map(tab => ({
    url: tab.url,
    pinned: Boolean(tab.pinned),
    group: tab.group ? {
      key: tab.group.key || "",
      title: tab.group.title || "",
      color: normalizeGroupColor(tab.group.color),
      collapsed: Boolean(tab.group.collapsed),
    } : null,
  })));
}