'use client'

/**
 * Shared link-attribute resolver for every entity card.
 *
 * Pure-presentation cards (BlogCard, OnboardingGuideCard, etc.)
 * historically required callers to pre-compute `target`/`rel` via a
 * hub-side `useNavLink` wrapper because the same-tab-vs-new-tab
 * decision depends on `currentPlatform()` and the cross-platform
 * URL topology — neither of which the lib knows.
 *
 * This hook moves that decision INTO the card via the
 * `ChatRuntime.navigation.decideNewTab` callback already wired by
 * `HubRuntimeProvider` (and overridable per-embedder). The wrapping
 * `*-card-item.tsx` files in the hub become unnecessary — every card
 * derives its own `target`/`rel` from runtime.
 *
 * Backwards compat: explicit `target` / `rel` props always WIN over
 * runtime-derived values. Chat dispatcher callsites that already pass
 * pre-resolved attributes are unaffected.
 *
 * No runtime mounted? Returns `{ target: undefined, rel: undefined }`
 * (same-tab) — matches the documented embed-shim fallback.
 */

import { useMemo } from 'react'
import { useChatRuntime } from '../../../contexts/chat-runtime-context'
import { computeIsNewTab } from '../utils/nav-anchor-props'

export interface UseEntityCardLinkArgs {
  href: string
  targetPlatform?: string | null
  /** Explicit override. When set, runtime decision is skipped. */
  target?: '_blank'
  /** Explicit override. When set, runtime decision is skipped. */
  rel?: 'noopener noreferrer'
}

export interface EntityCardLinkProps {
  target: '_blank' | undefined
  rel: 'noopener noreferrer' | undefined
}

export function useEntityCardLink({
  href,
  targetPlatform,
  target,
  rel,
}: UseEntityCardLinkArgs): EntityCardLinkProps {
  const runtime = useChatRuntime()
  return useMemo(() => {
    // Explicit prop wins — preserves the chat-dispatcher path that
    // pre-computes attrs from `computeIsNewTab`. When `target='_blank'`
    // is passed without `rel`, auto-pair with `noopener noreferrer`
    // to close the tabnabbing vector (window.opener access from the
    // new tab back to the parent).
    if (target !== undefined || rel !== undefined) {
      const safeRel =
        rel ?? (target === '_blank' ? 'noopener noreferrer' : undefined)
      return { target, rel: safeRel }
    }
    // Use the UNIFIED new-tab decision so the rendered anchor's target/rel ALWAYS
    // agrees with the click handler (executeNavigation also calls computeIsNewTab) —
    // including the embed-mode short-circuit + the origin/platform fallback.
    // Previously this used `decideNewTab ?? false`, which diverged from the click
    // when decideNewTab was unwired (embed mode rendered a same-tab anchor that
    // clicked into a new tab). Hub behavior is unchanged: it wires decideNewTab,
    // which computeIsNewTab consumes identically.
    const newTab = runtime ? computeIsNewTab(runtime, href, targetPlatform ?? null) : false
    return newTab
      ? { target: '_blank' as const, rel: 'noopener noreferrer' as const }
      : { target: undefined, rel: undefined }
  }, [target, rel, href, targetPlatform, runtime])
}