Add tags blacklist option for suggestions

app/src/main/java/org/koitharu/kotatsu/core/prefs/AppSettings.kt

@@ -165,6 +165,18 @@ class AppSettings(context: Context) {
 			else -> SimpleDateFormat(format, Locale.getDefault())
 		}
 
+	fun getSuggestionsTagsBlacklistRegex(): Regex? {
+		val string = prefs.getString(KEY_SUGGESTIONS_EXCLUDE_TAGS, null)?.trimEnd(' ', ',')
+		if (string.isNullOrEmpty()) {
+			return null
+		}
+		val tags = string.split(',')
+		val regex = tags.joinToString(prefix = "(", separator = "|", postfix = ")") { tag ->
+			Regex.escape(tag.trim())
+		}
+		return Regex(regex, RegexOption.IGNORE_CASE)
+	}
+
 	fun getMangaSources(includeHidden: Boolean): List<MangaSource> {
 		val list = MangaSource.values().toMutableList()
 		list.remove(MangaSource.LOCAL)
@@ -247,6 +259,7 @@ class AppSettings(context: Context) {
 		const val KEY_PAGES_PRELOAD = "pages_preload"
 		const val KEY_SUGGESTIONS = "suggestions"
 		const val KEY_SUGGESTIONS_EXCLUDE_NSFW = "suggestions_exclude_nsfw"
+		const val KEY_SUGGESTIONS_EXCLUDE_TAGS = "suggestions_exclude_tags"
 		const val KEY_SEARCH_SINGLE_SOURCE = "search_single_source"
 
 		// About

app/src/main/java/org/koitharu/kotatsu/settings/SuggestionsSettingsFragment.kt

@@ -4,10 +4,13 @@ import android.content.SharedPreferences
 import android.os.Bundle
 import androidx.lifecycle.lifecycleScope
 import kotlinx.coroutines.launch
+import org.koin.android.ext.android.get
 import org.koin.android.ext.android.inject
 import org.koitharu.kotatsu.R
 import org.koitharu.kotatsu.base.ui.BasePreferenceFragment
 import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.settings.utils.MultiAutoCompleteTextViewPreference
+import org.koitharu.kotatsu.settings.utils.TagsAutoCompleteProvider
 import org.koitharu.kotatsu.suggestions.domain.SuggestionRepository
 import org.koitharu.kotatsu.suggestions.ui.SuggestionsWorker
 
@@ -23,6 +26,11 @@ class SuggestionsSettingsFragment : BasePreferenceFragment(R.string.suggestions)
 
 	override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
 		addPreferencesFromResource(R.xml.pref_suggestions)
+
+		findPreference<MultiAutoCompleteTextViewPreference>(AppSettings.KEY_SUGGESTIONS_EXCLUDE_TAGS)?.run {
+			autoCompleteProvider = TagsAutoCompleteProvider(get())
+			summaryProvider = MultiAutoCompleteTextViewPreference.SimpleSummaryProvider(summary)
+		}
 	}
 
 	override fun onDestroy() {

app/src/main/java/org/koitharu/kotatsu/settings/utils/MultiAutoCompleteTextViewPreference.kt

@@ -0,0 +1,118 @@
+package org.koitharu.kotatsu.settings.utils
+
+import android.content.Context
+import android.util.AttributeSet
+import android.widget.ArrayAdapter
+import android.widget.EditText
+import android.widget.Filter
+import android.widget.MultiAutoCompleteTextView
+import androidx.annotation.AttrRes
+import androidx.annotation.MainThread
+import androidx.annotation.StyleRes
+import androidx.annotation.WorkerThread
+import androidx.preference.EditTextPreference
+import kotlinx.coroutines.runBlocking
+import org.koitharu.kotatsu.R
+import org.koitharu.kotatsu.parsers.util.replaceWith
+
+class MultiAutoCompleteTextViewPreference @JvmOverloads constructor(
+	context: Context,
+	attrs: AttributeSet? = null,
+	@AttrRes defStyleAttr: Int = R.attr.multiAutoCompleteTextViewPreferenceStyle,
+	@StyleRes defStyleRes: Int = R.style.Preference_MultiAutoCompleteTextView,
+) : EditTextPreference(context, attrs, defStyleAttr, defStyleRes) {
+
+	private val autoCompleteBindListener = AutoCompleteBindListener()
+
+	var autoCompleteProvider: AutoCompleteProvider? = null
+
+	init {
+		super.setOnBindEditTextListener(autoCompleteBindListener)
+	}
+
+	override fun setOnBindEditTextListener(onBindEditTextListener: OnBindEditTextListener?) {
+		autoCompleteBindListener.delegate = onBindEditTextListener
+	}
+
+	private inner class AutoCompleteBindListener : OnBindEditTextListener {
+
+		var delegate: OnBindEditTextListener? = null
+
+		override fun onBindEditText(editText: EditText) {
+			delegate?.onBindEditText(editText)
+			if (editText !is MultiAutoCompleteTextView) {
+				return
+			}
+			editText.setTokenizer(MultiAutoCompleteTextView.CommaTokenizer())
+			editText.setAdapter(
+				autoCompleteProvider?.let {
+					CompletionAdapter(editText.context, it, ArrayList())
+				}
+			)
+			editText.threshold = 1
+		}
+	}
+
+	interface AutoCompleteProvider {
+
+		suspend fun getSuggestions(query: String): List<String>
+	}
+
+	class SimpleSummaryProvider(
+		private val emptySummary: CharSequence?,
+	) : SummaryProvider<MultiAutoCompleteTextViewPreference> {
+
+		override fun provideSummary(preference: MultiAutoCompleteTextViewPreference): CharSequence? {
+			return if (preference.text.isNullOrEmpty()) {
+				emptySummary
+			} else {
+				preference.text?.trimEnd(' ', ',')
+			}
+		}
+	}
+
+	private class CompletionAdapter(
+		context: Context,
+		private val completionProvider: AutoCompleteProvider,
+		private val dataset: MutableList<String>,
+	) : ArrayAdapter<String>(context, android.R.layout.simple_dropdown_item_1line, dataset) {
+
+		override fun getFilter(): Filter {
+			return CompletionFilter(this, completionProvider)
+		}
+
+		fun publishResults(results: List<String>) {
+			dataset.replaceWith(results)
+			notifyDataSetChanged()
+		}
+	}
+
+	private class CompletionFilter(
+		private val adapter: CompletionAdapter,
+		private val provider: AutoCompleteProvider,
+	) : Filter() {
+
+		@WorkerThread
+		override fun performFiltering(constraint: CharSequence?): FilterResults {
+			val query = constraint?.toString().orEmpty()
+			val suggestions = runBlocking { provider.getSuggestions(query) }
+			return CompletionResults(suggestions)
+		}
+
+		@MainThread
+		override fun publishResults(constraint: CharSequence?, results: FilterResults) {
+			val completions = (results as CompletionResults).completions
+			adapter.publishResults(completions)
+		}
+
+		private class CompletionResults(
+			val completions: List<String>,
+		) : FilterResults() {
+
+			init {
+				values = completions
+				count = completions.size
+			}
+		}
+	}
+}

app/src/main/java/org/koitharu/kotatsu/settings/utils/TagsAutoCompleteProvider.kt

@@ -0,0 +1,23 @@
+package org.koitharu.kotatsu.settings.utils
+
+import org.koitharu.kotatsu.core.db.MangaDatabase
+
+class TagsAutoCompleteProvider(
+	private val db: MangaDatabase,
+) : MultiAutoCompleteTextViewPreference.AutoCompleteProvider {
+
+	override suspend fun getSuggestions(query: String): List<String> {
+		if (query.isEmpty()) {
+			return emptyList()
+		}
+		val tags = db.tagsDao.findTags(query = "$query%", limit = 6)
+		val set = HashSet<String>()
+		val result = ArrayList<String>(tags.size)
+		for (tag in tags) {
+			if (set.add(tag.title)) {
+				result.add(tag.title)
+			}
+		}
+		return result
+	}
+}

app/src/main/java/org/koitharu/kotatsu/suggestions/ui/SuggestionsWorker.kt

@@ -76,7 +76,10 @@ class SuggestionsWorker(appContext: Context, params: WorkerParameters) :
 			suggestionRepository.clear()
 			return 0
 		}
-		val allTags = historyRepository.getPopularTags(TAGS_LIMIT)
+		val blacklistTagRegex = appSettings.getSuggestionsTagsBlacklistRegex()
+		val allTags = historyRepository.getPopularTags(TAGS_LIMIT).filterNot {
+			blacklistTagRegex?.containsMatchIn(it.title) ?: false
+		}
 		if (allTags.isEmpty()) {
 			return 0
 		}
@@ -102,6 +105,11 @@ class SuggestionsWorker(appContext: Context, params: WorkerParameters) :
 		if (appSettings.isSuggestionsExcludeNsfw) {
 			rawResults.removeAll { it.isNsfw }
 		}
+		if (blacklistTagRegex != null) {
+			rawResults.removeAll {
+				it.tags.any { x -> blacklistTagRegex.containsMatchIn(x.title) }
+			}
+		}
 		if (rawResults.isEmpty()) {
 			return 0
 		}