package com.unciv.models.translations

import com.badlogic.gdx.Gdx
import com.unciv.Constants
import com.unciv.UncivGame
import com.unciv.models.metadata.LocaleCode
import com.unciv.models.ruleset.RulesetCache
import com.unciv.models.ruleset.unique.Unique
import com.unciv.models.stats.Stat
import com.unciv.models.stats.Stats
import com.unciv.ui.components.fonts.DiacriticSupport
import com.unciv.ui.components.fonts.FontRulesetIcons
import com.unciv.utils.Log
import com.unciv.utils.debug
import java.util.Locale
import org.jetbrains.annotations.VisibleForTesting
import yairm210.purity.annotations.Immutable
import yairm210.purity.annotations.LocalState
import yairm210.purity.annotations.Pure
import yairm210.purity.annotations.Readonly

/**
 *  This collection holds all translations for the game.
 *
 *  The collection may be instantiated loading any number of languages, but normally it contains
 *  either one (player-selected) language or all of them for the translation file writer.
 *
 *  Translatables have two forms: normal or containing placeholders (delimited by square brackets).
 *  Translation _requests_ can have a third form: containing {subsentences} - these are split into their
 *  components and passed individually back into the translator, therefore they need no entry in this collection
 *
 *  @property keys:     The key is a copy of the translatable string in the normal case.
 *                       For the placeholder case, the key is modified: placeholders reduced to empty [] pairs.
 *  @property values:   Each a [TranslationEntry] containing the original translatable and 0..n translations.
 *  @property percentCompleteOfLanguages:   Holds the completion percentage for each language,
 *                      read from its file "completionPercentages.properties" which is generated
 *                      by the [TranslationFileWriter] utility.
 *
 *  @see    String.tr   for more explanations (below)
 */
class Translations : LinkedHashMap<String, TranslationEntry>() {

    var percentCompleteOfLanguages = HashMap<String,Int>()
            .apply { put(Constants.english, 100) } // So even if we don't manage to load the percentages, we can still pass the language screen

    internal var modsWithTranslations: HashMap<String, Translations> = hashMapOf() // key == mod name

    // used by tr() whenever GameInfo not initialized (allowing new game screen to use mod translations)
    var translationActiveMods = LinkedHashSet<String>()

    /**
     * Searches for the translation entry of a given [text] for a given [language].
     * This includes translations provided by mods from [activeMods]
     *
     * @param text the input text for the translate entry
     * @param language the inquired language
     * @param activeMods set of the active mods that should include in the search
     *
     * @return the translation entry or null when not available
     */
    @Readonly
    fun get(text: String, language: String, activeMods: HashSet<String>? = null): TranslationEntry? {
        if (activeMods != null)
            for (activeMod in activeMods) {
                val modTranslations = modsWithTranslations[activeMod] ?: continue
                val translationEntry = modTranslations[text]
                if (translationEntry?.get(language) != null)
                    return translationEntry
            }

        return this[text]
    }

    /**
     * @see get
     */
    @Readonly
    fun getText(text: String, language: String, activeMods: HashSet<String>? = null): String {
        return get(text, language, activeMods)?.get(language) ?: text
    }

    /** Get all languages present in `this`, used for [TranslationFileWriter] and `TranslationTests` */
    fun getLanguages() = linkedSetOf<String>().apply {
            for (entry in values)
                for (languageName in entry.keys)
                    add(languageName)
        }

    /** This reads all translations for a specific language, including _all_ installed mods.
     *  Vanilla translations go into `this` instance, mod translations into [modsWithTranslations].
     */
    private fun tryReadTranslationForLanguage(language: String, noDiacritics: Boolean = false) {
        val translationStart = System.currentTimeMillis()

        val translationFileName = "jsons/translations/$language.properties"
        if (!Gdx.files.internal(translationFileName).exists()) return

        val languageTranslations: HashMap<String, String>
        try { // On some devices we get a weird UnsupportedEncodingException
            // which is super odd because everyone should support UTF-8
            languageTranslations = TranslationFileReader.read(Gdx.files.internal(translationFileName))
        } catch (ex: Exception) {
            Log.error("Exception reading translations for $language", ex)
            return
        }

        // try to load the translations from the mods
        for (modFolder in RulesetCache.values.mapNotNull { it.folderLocation }) {
            val modTranslationFile = modFolder.child(translationFileName)
            if (modTranslationFile.exists()) {
                var translationsForMod = modsWithTranslations[modFolder.name()]
                if (translationsForMod == null) {
                    translationsForMod = Translations()
                    modsWithTranslations[modFolder.name()] = translationsForMod
                }
                try {
                    translationsForMod.createTranslations(language, TranslationFileReader.read(modTranslationFile), noDiacritics)
                } catch (ex: Exception) {
                    Log.error("Exception reading translations for ${modFolder.name()} $language", ex)
                }
            }
        }

        createTranslations(language, languageTranslations, noDiacritics)

        debug("Loading translation file for %s - %sms", language, System.currentTimeMillis() - translationStart)
    }

    @VisibleForTesting
    fun createTranslations(language: String, languageTranslations: HashMap<String, String>, noDiacritics: Boolean = false) {
        val diacriticSupport = if (noDiacritics) null
            else DiacriticSupport(languageTranslations).takeIf { it.isEnabled() }
        for ((key, value) in languageTranslations) {
            val hashKey = if (key.contains('[') && !key.contains('<'))
                key.getPlaceholderText()
            else key
            var entry = this[hashKey]
            if (entry == null) {
                entry = TranslationEntry(key)
                this[hashKey] = entry
            }
            entry[language] = diacriticSupport?.remapDiacritics(value) ?: value
        }
    }


    fun tryReadTranslationForCurrentLanguage() {
        DiacriticSupport.reset()
        tryReadTranslationForLanguage(UncivGame.Current.settings.language)
        DiacriticSupport.freeTranslationData()
    }

    /** Get a list of supported languages for [readAllLanguagesTranslation] */
    // This function is too strange for me, however, let's keep it "as is" for now. - JackRainy
    private fun getLanguagesWithTranslationFile(): List<String> {

        val languages = HashSet<String>()
        // So apparently the Locales don't work for everyone, which is horrendous
        // So for those players, which seem to be Android-y, we try to see what files exist directly...yeah =/
        try{
            for (file in Gdx.files.internal("jsons/translations").list())
                languages.add(file.nameWithoutExtension())
        }
        catch (ex: Exception) {
            Log.error("Failed to add languages", ex)
        } // Iterating on internal files will not work when running from a .jar

        languages.addAll(Locale.getAvailableLocales() // And this should work for Desktop, meaning from a .jar
                .map { it.getDisplayName(Locale.ENGLISH) }) // Maybe THIS is the problem, that the DISPLAY locale wasn't english
        // and then languages were displayed according to the player's locale... *sweatdrop*

        // These should probably be renamed
        languages.add("Simplified_Chinese")
        languages.add("Traditional_Chinese")

        languages.remove("template")
        languages.remove("completionPercentages")

        return languages.filter { Gdx.files.internal("jsons/translations/$it.properties").exists() }
    }

    /** Ensure _all_ languages are loaded, used by [TranslationFileWriter] and `TranslationTests` only.
     *
     *  #### Notes:
     *  -  Expects to run on a newly created instance.
     *  -  Loads the translations with no diacritic mapping, so what we read will be what we write
     *     (otherwise we would write out the fake alphabet-conversions, a one-way destructive mistake).
     *  -  Relies on usage by TFW and tests only, if the result is ever meant to support translations that are actually displayed, a refactor will be needed.
     *  -  Does not clear the fake alphabet possibly present in DiacriticSupport, but will not use it either.
     */
    fun readAllLanguagesTranslation() {
        // Apparently you can't iterate over the files in a directory when running out of a .jar...
        // https://www.badlogicgames.com/forum/viewtopic.php?f=11&t=27250
        // which means we need to list everything manually =/

        val translationStart = System.currentTimeMillis()

        for (language in getLanguagesWithTranslationFile()) {
            tryReadTranslationForLanguage(language, noDiacritics = true)
        }

        debug("Loading translation files - %sms", System.currentTimeMillis() - translationStart)
    }

    fun loadPercentageCompleteOfLanguages() {
        val startTime = System.currentTimeMillis()

        percentCompleteOfLanguages = TranslationFileReader.readLanguagePercentages()

        debug("Loading percent complete of languages - %sms", System.currentTimeMillis() - startTime)
    }
    @Readonly
    fun getConditionalOrder(language: String): String {
        return getText(englishConditionalOrderingString, language, null)
    }

    @Readonly
    fun placeConditionalsAfterUnique(language: String) =
        get(conditionalUniqueOrderString, language, null)?.get(language) != "before"

    /** Returns the equivalent of a space in the given language
     * Defaults to a space if no translation is provided
     */
    @Readonly
    fun getSpaceEquivalent(language: String): String {
        val translation = getText("\" \"", language, null)
        return translation.substring(1, translation.length-1)
    }

    @Readonly
    fun shouldCapitalize(language: String): Boolean {
        return get(shouldCapitalizeString, language, null)?.get(language)?.toBoolean() ?: true
    }

    @Readonly
    fun triggerNotificationEffectBeforeCause(language: String): Boolean{
        return get(effectBeforeCause, language, null)?.get(language)?.toBoolean() ?: true
    }

    companion object {
        // Whenever this string is changed, it should also be changed in the translation files!
        // It is mostly used as the template for translating the order of conditionals
        const val englishConditionalOrderingString =
            "<with a garrison> <for [mapUnitFilter] units> <above [amount] HP> <below [amount] HP> <vs cities> <vs [mapUnitFilter] units> <when fighting in [tileFilter] tiles> <when attacking> <when defending> <if this city has at least [amount] specialists> <when at war> <when not at war> <while the empire is happy> <during a Golden Age> <during the [era]> <starting from the [era]> <before the [era]> <with [techOrPolicy]> <without [techOrPolicy]>"
        const val conditionalUniqueOrderString = "ConditionalsPlacement"
        const val shouldCapitalizeString = "StartWithCapitalLetter"
        const val effectBeforeCause = "EffectBeforeCause"
    }
}


// We don't need to allocate different memory for these every time we .tr() - or recompile them.
// Please note: The extra \] and \} are NOT removable, despite what Android Studio might recommend -
//   they are necessary for Android Java 6 phones to parse the regex properly!

// Expect a literal [ followed by a captured () group and a literal ].
// The group may contain any number of any character except ] - pattern [^]]
@Suppress("RegExpRedundantEscape") // Some Android versions need ]}) escaped
val squareBraceRegex = Regex("""\[([^]]*)\]""")

// Analogous as above: Expect a {} pair with any chars but } in between and capture that
@Suppress("RegExpRedundantEscape") // Some Android versions need ]}) escaped
val curlyBraceRegex = Regex("""\{([^}]*)\}""")

// Analogous as above: Expect a <> pair with any chars but > in between and capture that
@Suppress("RegExpRedundantEscape") // Some Android versions need ]}) escaped
val pointyBraceRegex = Regex("""\<([^>]*)\>""")

// Used to match continous digits 0, 12, 1232 etc
@Suppress("RegExpRedundantEscape") // Some Android versions need ]}) escaped
val digitsRegex = Regex("""\d""")

object TranslationActiveModsCache {
    private var cachedHash = Int.MIN_VALUE

    var activeMods: HashSet<String> = hashSetOf()
        get() {
            val hash = getCurrentHash()
            if (hash != cachedHash) {
                cachedHash = hash
                field = getCurrentSet()
            }
            return field
        }
        private set

    private fun getCurrentHash(): Int {
        val gameInfo = UncivGame.Current.gameInfo
        return if (gameInfo != null) {
            gameInfo.gameParameters.mods.hashCode() + gameInfo.gameParameters.baseRuleset.hashCode() * 31
        } else {
            UncivGame.Current.translations.translationActiveMods.hashCode() * 31 * 31
        }
    }

    private fun getCurrentSet(): LinkedHashSet<String> {
        val gameInfo = UncivGame.Current.gameInfo
        return if (gameInfo != null) {
            val par = gameInfo.gameParameters
            // This is equivalent to (par.mods + par.baseRuleset) without the cast down to `Set`
            LinkedHashSet<String>(par.mods.size + 1).apply {
                addAll(par.mods)
                add(par.baseRuleset)
            }
        } else {
            UncivGame.Current.translations.translationActiveMods
        }
    }
}

/**
 *  This function does the actual translation work,
 *      using an instance of [Translations] stored in UncivGame.Current
 *
 *  @receiver   The string to be translated, can take three forms:
 *                  plain - translated directly by hashset lookup
 *                  placeholders - contains at least one '[' - see below
 *                  sentences - contains at least one '{'
 *                  - phrases between curly braces are translated individually
 *                  Additionally, they may contain conditionals between '<' and '>'
 *  @param      hideIcons disables auto-inserting icons for ruleset objects (but not Stats)
 *  @param      hideStats disables auto-inserting icons for Stats (but not rulset objects)
 *  @return     The translated string
 *                  defaults to the input string if no translation is available,
 *                  but with placeholder or sentence brackets removed.
 */
@Readonly
fun String.tr(hideIcons: Boolean = false, hideStats: Boolean = false): String {
    val language: String = UncivGame.Current.settings.language

    // '<' and '>' checks for quick 'no' answer, regex to ensure that no one accidentally put '><' and ruined things
    if (contains('<') && contains('>') && pointyBraceRegex.containsMatchIn(this)) {
        return translateConditionals(hideIcons, language)
    }

    // curly and square brackets can be nested inside of each other so find the leftmost curly/square
    // bracket then process that first
    val indexSquare = this.indexOf('[')
    val indexCurly = this.indexOf('{')

    val squareBracketsEncounteredFirst = indexSquare >= 0 && (indexCurly < 0 || indexSquare < indexCurly)
    val curlyBracketsEncounteredFirst =  indexCurly >= 0 && (indexSquare < 0 || indexCurly < indexSquare)

    if (squareBracketsEncounteredFirst)
        return translatePlaceholders(language, hideIcons)

    if (curlyBracketsEncounteredFirst) // Translating partial sentences
        return curlyBraceRegex.replace(this) { it.groups[1]!!.value.tr(hideIcons) }

    return translateIndividualWord(language, hideIcons, hideStats)
}


@Readonly
private fun String.translateConditionals(hideIcons: Boolean, language: String): String {
    /**
     * So conditionals can contain placeholders, such as <vs [unitFilter] units>, which themselves
     * can contain multiple filters, such as <vs [{Military} {Water}] units>.
     * Moreover, we can have any amount of conditionals in any order, and translations
     * can reorder these conditionals in any way they like, even putting them in front
     * of the rest of the translatable string.
     * All of this nesting makes it quite difficult to translate, and is the reason we check
     * for these first.
     *
     * The plan: First translate each of the conditionals on its own, and then combine them
     * together into the final fully translated string.
     */

    var translatedBaseUnique = this.removeConditionals().tr(hideIcons)

    val conditionals = this.getModifiers().map { it.placeholderText }
    val conditionsWithTranslation: LinkedHashMap<String, String> = linkedMapOf()

    for (conditional in this.getModifiers())
        conditionsWithTranslation[conditional.placeholderText] = conditional.text.tr(hideIcons)

    val translatedConditionals: MutableList<String> = mutableListOf()

    // Somewhere, we asked the translators to reorder all possible conditionals in a way that
    // makes sense in their language. We get this ordering, and than extract each of the
    // translated conditionals, removing the <> surrounding them, and removing param values
    // where it exists.
    val conditionalOrdering = UncivGame.Current.translations.getConditionalOrder(language)
    for (placedConditional in pointyBraceRegex.findAll(conditionalOrdering)
        .map { it.value.substring(1, it.value.length - 1).getPlaceholderText() }) {
        if (placedConditional in conditionals) {
            translatedConditionals.add(conditionsWithTranslation[placedConditional]!!)
            conditionsWithTranslation.remove(placedConditional)
        }
    }

    // If the translated string that should contain all conditionals doesn't contain
    // a few conditionals used here, just add the translations of these to the end.
    // We do test for this, but just in case.
    translatedConditionals.addAll(conditionsWithTranslation.values)

    // After that, add the translation of the base unique either before or after these conditionals
    if (UncivGame.Current.translations.placeConditionalsAfterUnique(language)) {
        translatedConditionals.add(0, translatedBaseUnique)
    } else {
        if (UncivGame.Current.translations.shouldCapitalize(language) && translatedBaseUnique[0].isUpperCase())
            translatedBaseUnique = translatedBaseUnique.replaceFirstChar { it.lowercase() }
        translatedConditionals.add(translatedBaseUnique)
    }

    var fullyTranslatedString = translatedConditionals.joinToString(
        UncivGame.Current.translations.getSpaceEquivalent(language)
    )
    if (UncivGame.Current.translations.shouldCapitalize(language))
        fullyTranslatedString = fullyTranslatedString.replaceFirstChar { it.uppercase() }
    return fullyTranslatedString
}

@Readonly
private fun String.translatePlaceholders(language: String, hideIcons: Boolean): String {
    /**
     * I'm SURE there's an easier way to do this but I can't think of it =\
     * So what's all this then?
     * Well, not all languages are like English. So say I want to say "work on Library has completed in Akkad",
     * but in a completely different language like Japanese or German,
     * It could come out "Akkad hast die worken onner Library gerfinishen" or whatever,
     * basically, the order of the words in the sentence is not guaranteed.
     * So to translate this, I give a sentence like "work on [building] has completed in [city]"
     * and the german can put those placeholders where he wants, so  "[city] hast die worken onner [building] gerfinishen"
     * The string on which we call tr() will look like "work on [library] has completed in [Akkad]"
     * We will find the german placeholder text, and replace the placeholders with what was filled in the text we got!
     */

    // Convert "work on [building] has completed in [city]" to "work on [] has completed in []"
    val translationStringWithSquareBracketsOnly = this.getPlaceholderText()
    // That is now the key into the translation HashMap!
    val translationEntry = UncivGame.Current.translations
        .get(translationStringWithSquareBracketsOnly, language, TranslationActiveModsCache.activeMods)

    var languageSpecificPlaceholder: String
    val originalEntry: String
    if (translationEntry == null || !translationEntry.containsKey(language)) {
        // Translation placeholder doesn't exist for this language, default to English
        languageSpecificPlaceholder = this
        originalEntry = this
    } else {
        languageSpecificPlaceholder = translationEntry[language]!!
        originalEntry = translationEntry.entry
    }

    // Take the terms in the message, WITHOUT square brackets
    val termsInMessage = this.getPlaceholderParameters()
    // Take the terms from the placeholder
    val termsInTranslationPlaceholder = originalEntry.getPlaceholderParameters()
    if (termsInMessage.size != termsInTranslationPlaceholder.size)
        throw Exception("Message $this has a different number of terms than the placeholder $translationEntry!")

    for (i in termsInMessage.indices) {
        languageSpecificPlaceholder = languageSpecificPlaceholder.replace(
            "[${termsInTranslationPlaceholder[i]}]", // re-add square brackets to placeholder terms
            termsInMessage[i].tr(hideIcons)
        )
    }
    return languageSpecificPlaceholder      // every component is already translated
}


/** No brackets of any kind, just a single word */
@Readonly
private fun String.translateIndividualWord(language: String, hideIcons: Boolean, hideStats: Boolean): String {
    if (Stats.isStats(this)) return Stats.parse(this).toString()

    val translation = UncivGame.Current.translations.getText(
        this, language, TranslationActiveModsCache.activeMods
    ).replace(digitsRegex) {
        it.value.toLong().tr(language)
    }

    val stat = Stat.safeValueOf(this)
    if (!hideStats && stat != null) return stat.character + translation

    if (!hideIcons && FontRulesetIcons.rulesetObjectNameToChar.containsKey(this))
        return FontRulesetIcons.rulesetObjectNameToChar[this]!! + translation

    return translation
}


/**
 * Finds the parameters in a string while IGNORING the lower-leveled braces.
 * For example, a string like 'The city of [New [York]]' will return ['New [York]'],
 * allowing us to have nested translations!
 */
@Pure
fun String.getPlaceholderParameters(): List<String> {
    if (!this.contains('[')) return emptyList()

    val stringToParse = this.removeConditionals()
    
    val parameters = ArrayList<String>()
    var depthOfBraces = 0
    var startOfCurrentParameter = -1
    stringToParse.indices.forEach { i ->
        if (stringToParse[i] == '[') {
            if (depthOfBraces == 0) startOfCurrentParameter = i+1
            depthOfBraces++
        }
        if (stringToParse[i] == ']' && depthOfBraces > 0) {
            depthOfBraces--
            if (depthOfBraces == 0) parameters.add(substring(startOfCurrentParameter,i))
        }
    }
    return parameters
}

@Pure
fun String.getPlaceholderText(): String {
    var stringToReturn = this.removeConditionals()
    @LocalState val placeholderParameters = stringToReturn.getPlaceholderParameters()
    placeholderParameters.forEach { placeholderParameter ->
        stringToReturn = stringToReturn.replaceFirst("[$placeholderParameter]", "[]")
    }
    return stringToReturn
}

@Pure
fun String.equalsPlaceholderText(str: String): Boolean {
    if (isEmpty()) return str.isEmpty()
    if (str.isEmpty()) return false // Empty strings have no .first()
    if (first() != str.first()) return false // for quick negative return 95% of the time
    return this.getPlaceholderText() == str
}

@Pure
fun String.hasPlaceholderParameters(): Boolean {
    if (!this.contains('[')) return false
    return squareBraceRegex.containsMatchIn(this.removeConditionals())
}

/** Substitutes placeholders with [strings], respecting order of appearance. */
@Pure
fun String.fillPlaceholders(vararg strings: String): String {
    @Immutable val keys = this.getPlaceholderParameters()
    if (keys.size > strings.size)
        throw Exception("String $this has a different number of placeholders ${keys.joinToString()} (${keys.size}) than the substitutive strings ${strings.joinToString()} (${strings.size})!")

    var filledString = this.replace(squareBraceRegex, "[]")
    keys.indices.forEach { i ->
        filledString = filledString.replaceFirst("[]", "[${strings[i]}]")
    }
    return filledString
}

@Pure
fun String.getModifiers(): List<Unique> {
    if (!this.contains('<')) return emptyList()
    @Immutable val matchResults = pointyBraceRegex.findAll(this)
    @Immutable val uniques = matchResults.map { Unique(it.groups[1]!!.value) }
    return uniques.toList()
}

@Pure
fun String.removeConditionals(): String {
    if (!this.contains('<')) return this // no need to regex search
    return this
        .replace(pointyBraceRegex, "")
        // So, this is a quick hack, but it works as long as nobody uses word separators different from " " (space) and "" (none),
        // and no translations start or end with a space.
        // According to https://linguistics.stackexchange.com/questions/6131/is-there-a-long-list-of-languages-whose-writing-systems-dont-use-spaces
        // This is a reasonable but not fully correct assumption to make.
        // By doing it like this, we exclude languages such as Tibetan, Dzongkha (Bhutan), and Ethiopian.
        // If we ever start getting translations for these, we'll work something out then.
        .replace("  ", " ")
        .trim()
}

/** Formats number according to current language
 *
 *  Note: The inverse operation is UncivGame.Current.settings.getCurrentNumberFormat().parse(string), handled in the [UncivTextField.Numeric][com.unciv.ui.components.widgets.UncivTextField.Numeric] widget.
 *
 *  @return locale-dependent String representation of receiver, may contain formatting like thousands separators
 */
@Readonly
fun Number.tr(): String {
    return UncivGame.Current.settings.getCurrentNumberFormat().format(this)
}

/** Formats number according to a specific [language]
 *
 *  Note: The inverse operation is `LocaleCode.getNumberFormatFromLanguage(language).parse(string)`.
 *
 *  @return locale-dependent String representation of receiver, may contain formatting like thousands separators
 */
@Readonly
fun Number.tr(language: String): String {
    return LocaleCode.getNumberFormatFromLanguage(language).format(this)
}
