FIX: improves search banner migration scripts (#36192)

After running migration scripts on multiple sites the following
improvements were added:
* avoid conflicting `background_image` and `background_image_light`
settings migration
* run db query once for `migrate_all` task
* match theme url with and without `.git` suffix
* abort the migration if more than one theme is installed

and code related:
* improve logging for cleaner output
* remove logging duplicates
* rename methods and vars to be more self-explanatory
* simplify logic for a clearer execution

lib/tasks/migrate_advanced_search_banner_to_welcome_banner.rake

@@ -1,68 +1,73 @@
 # frozen_string_literal: true
 # rubocop:disable Lint/OrAssignmentToConstant
 
-THEME_GIT_URL ||= "https://github.com/discourse/discourse-search-banner.git"
+THEME_GIT_URL ||= "https://github.com/discourse/discourse-search-banner"
 REQUIRED_TRANSLATION_KEYS ||= %w[search_banner.headline search_banner.subhead]
 
 desc "Run all Advanced Search Banner migration tasks"
-task "themes:advanced_search_banner:migrate_all" => %w[
-       themes:advanced_search_banner:1_migrate_settings_to_welcome_banner
-       themes:advanced_search_banner:2_migrate_translations_to_welcome_banner
-       themes:advanced_search_banner:3_exclude_and_disable
-     ]
+task "themes:advanced_search_banner:migrate_all" => :environment do
+  components = find_component_in_all_dbs(includes: %i[theme_settings theme_translation_overrides])
+
+  if components.any?
+    puts "\n1. Migrating settings..."
+    puts "------------------------"
+    components.each { |c| process_theme_component_settings(c) }
+
+    puts "\n2. Migrating translations..."
+    puts "----------------------------"
+    components.each { |c| process_theme_component_translations(c) }
+
+    puts "\n3. Excluding and disabling..."
+    puts "-----------------------------"
+    components.each { |c| process_theme_component(c) }
+  end
+end
 
 desc "Migrate settings from Advanced Search Banner to core welcome banner"
 task "themes:advanced_search_banner:1_migrate_settings_to_welcome_banner" => :environment do
-  puts "\n1. Migrating settings..."
-  puts "------------------------"
-  components = find_all_components([:theme_settings])
+  components = find_component_in_all_dbs(includes: [:theme_settings])
 
-  if components.empty?
-    puts "\n\e[33m✗ No Advanced Search Banner theme components found\e[0m"
-    next
+  if components.any?
+    puts "\n1. Migrating settings..."
+    puts "------------------------"
+    components.each { |c| process_theme_component_settings(c) }
   end
-
-  components.each { |entry| process_theme_component_settings(entry[:theme]) }
 end
 
 desc "Migrate translations from Advanced Search Banner to core welcome banner"
 task "themes:advanced_search_banner:2_migrate_translations_to_welcome_banner" => :environment do
-  puts "\n2. Migrating translations..."
-  puts "----------------------------"
-  components = find_all_components([:theme_translation_overrides])
+  components = find_component_in_all_dbs(includes: [:theme_translation_overrides])
 
-  if components.empty?
-    puts "\n\e[33m✗ No Advanced Search Banner theme components found\e[0m"
-    next
+  if components.any?
+    puts "\n2. Migrating translations..."
+    puts "----------------------------"
+    components.each { |c| process_theme_component_translations(c) }
   end
-
-  components.each { |entry| process_theme_component_translations(entry[:theme]) }
 end
 
 desc "Exclude and disable Advanced Search Banner theme component"
 task "themes:advanced_search_banner:3_exclude_and_disable" => :environment do
-  puts "\n3. Excluding and disabling..."
-  puts "-----------------------------"
-  components = find_all_components
+  components = find_component_in_all_dbs
 
-  if components.empty?
-    puts "\n\e[33m✗ No Advanced Search Banner theme components found\e[0m"
-    next
+  if components.any?
+    puts "\n3. Excluding and disabling..."
+    puts "-----------------------------"
+    components.each { |c| process_theme_component(c) }
   end
-
-  components.each { |entry| process_theme_component(entry[:theme]) }
 end
 
 # Common helper methods
-def find_all_components(includes = [])
+def find_component_in_all_dbs(includes: [])
   if ENV["RAILS_DB"].present?
     db = validate_and_get_db(ENV["RAILS_DB"])
     RailsMultisite::ConnectionManagement.establish_connection(db: db)
-    wrap_themes_with_db(find_components_in_db(db, includes), db)
+    component = find_component_in_db(db, includes)
+    component ? [component] : []
   else
     components = []
     RailsMultisite::ConnectionManagement.each_connection do |db|
-      components.concat(wrap_themes_with_db(find_components_in_db(db, includes), db))
+      component = find_component_in_db(db, includes)
+      components << component if component
     end
     components
   end
@@ -77,19 +82,29 @@ def validate_and_get_db(db)
   default_db
 end
 
-def wrap_themes_with_db(themes, db)
-  themes.map { |theme| { db: db, theme: theme } }
-end
-
-def find_components_in_db(db, additional_includes)
+def find_component_in_db(db, additional_includes)
   puts "Accessing database: \e[1;104m[#{db}]\e[0m"
-  puts "  Searching for Advanced Search Banner components..."
+  puts "  Searching for Advanced Search Banner theme component..."
 
   includes = [{ parent_theme_relation: :parent_theme }] + Array(additional_includes)
-  themes = RemoteTheme.where(remote_url: THEME_GIT_URL).includes(theme: includes).map(&:theme)
+  themes =
+    RemoteTheme
+      .where(remote_url: [THEME_GIT_URL, "#{THEME_GIT_URL}.git"])
+      .includes(theme: includes)
+      .map(&:theme)
 
-  themes.each { |theme| puts "  \e[1;34mFound: #{theme_identifier(theme)}" }
-  themes
+  if themes.length > 1
+    puts "  \e[33mMultiple (#{themes.length}) Advanced Search Banner theme components found:\e[0m"
+    themes.each { |theme| puts "    - #{theme_identifier(theme)}" }
+    puts "  \e[33mMake sure a single instance is installed before running migrations.\e[0m"
+    return nil
+  elsif themes.length == 1
+    puts "  \e[1;34m✓ Found: #{theme_identifier(themes.first)}\e[0m"
+  else
+    puts "  \e[33m✗ Not found.\e[0m"
+  end
+
+  themes.first
 end
 
 def theme_identifier(theme)
@@ -103,7 +118,7 @@ def not_included_in_any_theme?(theme)
   true
 end
 
-# Settings migration methods
+# 1. Settings migration
 unless defined?(SETTINGS_MAPPING)
   SETTINGS_MAPPING = {
     "show_on" => {
@@ -153,18 +168,25 @@ end
 def migrate_theme_settings_to_site_settings(theme_settings, errors)
   migrated_count = 0
 
+  names = theme_settings.map(&:name).to_set
+
   theme_settings.each do |ts|
     mapping = SETTINGS_MAPPING[ts.name]
-    old_text = "\e[0;31m#{ts.name}: #{ts.value}\e[0m"
+    old_setting = "\e[0;31m#{ts.name}: #{ts.value}\e[0m"
 
     unless mapping
-      puts "    - #{old_text}\e[33m: is not supported by core welcome banner. Skipping\e[0m"
+      puts "    - #{old_setting}\e[33m: is not supported by core welcome banner. Skipping\e[0m"
+      next
+    end
+
+    if ts.name == "background_image" && names.include?("background_image_light")
+      puts "    - #{old_setting}\e[33m: using 'background_image_light' instead. Skipping\e[0m"
       next
     end
 
     site_setting_name = mapping[:site_setting]
     if ts.value.blank?
-      puts "    - '#{ts.name}' has no value. Skipping"
+      puts "    - \e[0;31m#{ts.name}\e[0m\e[33m: has no value. Skipping\e[0m"
       next
     end
 
@@ -183,9 +205,9 @@ def migrate_theme_settings_to_site_settings(theme_settings, errors)
       )
 
       arrow = "\e[0m=>\e[0m"
-      new_text = "\e[0;32m#{site_setting_name}: #{new_value}\e[0m"
+      new_setting = "\e[0;32m#{site_setting_name}: #{new_value}\e[0m"
 
-      puts "    - #{old_text} #{arrow} #{new_text}"
+      puts "    - #{old_setting} #{arrow} #{new_setting}"
       migrated_count += 1
     rescue StandardError => e
       errors << e
@@ -196,7 +218,7 @@ def migrate_theme_settings_to_site_settings(theme_settings, errors)
   migrated_count
 end
 
-# Translations migration methods
+# 2. Translations migration
 def process_theme_component_translations(theme)
   return if not_included_in_any_theme?(theme)
 
@@ -294,7 +316,7 @@ def map_translation_keys(translation_key)
   translations_mapping[translation_key] || []
 end
 
-# Exclude and disable methods
+# 3. Exclude and disable
 def process_theme_component(theme)
   enable_welcome_banner(theme)
   exclude_theme_component(theme)

spec/tasks/migrate_advanced_search_banner_to_welcome_banner_spec.rb

@@ -27,24 +27,6 @@ RSpec.describe "tasks/migrate_advanced_search_banner_to_welcome_banner" do
     end
   end
 
-  describe "#wrap_themes_with_db" do
-    it "wraps themes with database information" do
-      theme1 = Fabricate(:theme)
-      theme2 = Fabricate(:theme)
-      db = "default"
-
-      result = wrap_themes_with_db([theme1, theme2], db)
-
-      expect(result).to eq([{ db: db, theme: theme1 }, { db: db, theme: theme2 }])
-    end
-
-    it "returns empty array when no themes provided" do
-      result = wrap_themes_with_db([], "default")
-
-      expect(result).to eq([])
-    end
-  end
-
   describe "#theme_identifier" do
     it "returns formatted theme identifier" do
       theme = Fabricate(:theme, name: "Test Theme")