// ============================================================================
// FocusGram — InjectionController
// ============================================================================

import '../scripts/core_injection.dart' as scripts;
import '../scripts/ui_hider.dart' as ui_hider;

class InjectionController {
  static const String iOSUserAgent =
      'Mozilla/5.0 (iPhone; CPU iPhone OS 18_6 like Mac OS X) '
      'AppleWebKit/605.1.15 (KHTML, like Gecko) '
      'Version/26.0 Mobile/15E148 Safari/604.1';

  static const String reelsMutationObserverJS =
      scripts.kReelsMutationObserverJS;
  static const String linkSanitizationJS = scripts.kLinkSanitizationJS;
  static String get notificationBridgeJS => scripts.kNotificationBridgeJS;

  static String _buildMutationObserver(String cssContent) =>
      '''
    (function fgApplyStyles() {
      const ID = 'focusgram-style';
      function inject() {
        let el = document.getElementById(ID);
        if (!el) {
          el = document.createElement('style');
          el.id = ID;
          (document.head || document.documentElement).appendChild(el);
        }
        el.textContent = ${_escapeJsString(cssContent)};
      }
      inject();
      new MutationObserver(() => { if (!document.getElementById(ID)) inject(); })
        .observe(document.documentElement, { childList: true, subtree: true });
    })();
  ''';

  static String _escapeJsString(String s) {
    final escaped = s.replaceAll(r'\', r'\\').replaceAll('`', r'\`');
    return '`$escaped`';
  }

  static String softNavigateJS(String path) =>
      '''
    (function() {
      const t = ${_escapeJsString(path)};
      if (window.location.pathname !== t) window.location.href = t;
    })();
  ''';

  static String buildSessionStateJS(bool active) =>
      'window.__focusgramSessionActive = $active;';

  static String buildInjectionJS({
    required bool sessionActive,
    required bool blurExplore,
    required bool blurReels,
    required bool tapToUnblur,
    required bool enableTextSelection,
    required bool hideSuggestedPosts, // JS-only, handled by InjectionManager
    required bool hideSponsoredPosts, // JS-only, handled by InjectionManager
    required bool hideLikeCounts,
    required bool hideFollowerCounts,
    // hideStoriesBar parameter removed per user request
    required bool hideExploreTab,
    required bool hideReelsTab,
    required bool hideShopTab,
    required bool disableReelsEntirely,
  }) {
    final css = StringBuffer()..writeln(scripts.kGlobalUIFixesCSS);
    if (!enableTextSelection) css.writeln(scripts.kDisableSelectionCSS);

    if (!sessionActive) {
      // Hide reel feed content when no session active
      css.writeln(scripts.kHideReelsFeedContentCSS);
    }

    // FIX: blurReels moved OUTSIDE `if (!sessionActive)`.
    // Previously it was inside that block alongside display:none on the parent —
    // you cannot blur children of a display:none element, making it dead code.
    // Now: when sessionActive=true, reel thumbnails are blurred as friction.
    //      when sessionActive=false, reels are hidden anyway (blur harmless).
    if (blurReels) css.writeln(scripts.kBlurReelsCSS);

    if (blurExplore) css.writeln(scripts.kBlurHomeFeedAndExploreCSS);

    if (hideLikeCounts) css.writeln(ui_hider.kHideLikeCountsCSS);
    if (hideFollowerCounts) css.writeln(ui_hider.kHideFollowerCountsCSS);
    // Stories hiding removed per user request
    if (hideExploreTab) css.writeln(ui_hider.kHideExploreTabCSS);
    if (hideReelsTab) css.writeln(ui_hider.kHideReelsTabCSS);
    if (hideShopTab) css.writeln(ui_hider.kHideShopTabCSS);

    return '''
      ${buildSessionStateJS(sessionActive)}
      window.__fgDisableReelsEntirely = $disableReelsEntirely;
      window.__fgTapToUnblur = $tapToUnblur;
      ${scripts.kTrackPathJS}
      ${_buildMutationObserver(css.toString())}
      ${scripts.kDismissAppBannerJS}
      ${!sessionActive ? scripts.kStrictReelsBlockJS : ''}
      ${scripts.kReelsMutationObserverJS}
      ${tapToUnblur ? scripts.kTapToUnblurJS : ''}
      ${scripts.kLinkSanitizationJS}
      ${scripts.kThemeDetectorJS}
      ${scripts.kBadgeMonitorJS}
    ''';
  }
}