Inceptum/launcher-gtk/src/main/kotlin/io/gitlab/jfronny/inceptum/gtk/menu/MenuBuilder.kt

package io.gitlab.jfronny.inceptum.gtk.menu

import io.github.jwharm.javagi.glib.types.VariantTypes
import io.gitlab.jfronny.commons.throwable.ThrowingRunnable
import io.gitlab.jfronny.inceptum.gtk.util.I18n
import io.gitlab.jfronny.inceptum.gtk.util.Log
import org.gnome.gio.*
import org.gnome.glib.Variant
import org.gnome.gtk.Application
import org.gnome.gtk.MenuButton
import org.gnome.gtk.PopoverMenu
import java.util.function.BiFunction
import java.util.function.Consumer

class MenuBuilder private constructor(map: ActionMap, menu: Menu, prefix: String, groupName: String) {
    private val map: ActionMap
    private val refs: MutableMap<String, Action> = LinkedHashMap()
    val menu: Menu
    private val prefix: String
    private val groupName: String

    constructor(menu: PopoverMenu, groupName: String) : this(
        insertMap(menu, groupName),
        menu.menuModel as Menu,
        "",
        groupName
    )

    @JvmOverloads
    constructor(app: Application, menu: Menu = getRootMenu(app), prefix: String = "") : this(app, menu, prefix, "app.")

    init {
        fun String.suffix() = if (isNotEmpty() && !endsWith(".")) "$this." else this

        this.map = map
        this.menu = menu
        this.prefix = prefix.suffix()
        this.groupName = groupName.suffix()
    }

    fun button(name: String, onClick: ThrowingRunnable<*>): BuiltButtonItem {
        return literalButton(name, I18n["menu.$prefix$name"], onClick)
    }

    fun literalButton(internalName: String, label: String?, onClick: ThrowingRunnable<*>): BuiltButtonItem {
        var internalName = internalName
        internalName = prefix + internalName
        val action = SimpleAction(internalName, null)
        addAction(internalName, action)
        action.onActivate { _ ->
            try {
                onClick.run()
            } catch (e: Throwable) {
                Log.error("Could not execute action", e)
            }
        }
        val menuItem = MenuItem(label, groupName + internalName)
        menu.appendItem(menuItem)
        action.enabled = true
        return BuiltButtonItem(action, menuItem)
    }

    fun toggle(name: String, initial: Boolean, onToggle: Consumer<Boolean?>): BuiltToggleItem {
        var name = name
        name = prefix + name
        val action = SimpleAction.newStateful(name, null, Variant.newBoolean(initial))
        addAction(name, action)
        action.onActivate { _ ->
            val state = !action.getState()!!.boolean
            action.state = Variant.newBoolean(state)
            onToggle.accept(state)
        }
        val menuItem = MenuItem(I18n["menu.$name"], groupName + name)
        menu.appendItem(menuItem)
        return BuiltToggleItem(action, menuItem)
    }

    fun <T> radio(name: String, initial: T, options: List<T>, onCheck: Consumer<T>): BuiltRadioItem<T> {
        return literalRadio(name, initial, options, { i, _ -> I18n["menu.$prefix$name", i] }, onCheck)
    }

    fun <T> literalRadio(
        name: String,
        initial: T,
        options: List<T>,
        stringifier: BiFunction<Int, T, String?>,
        onCheck: Consumer<T>
    ): BuiltRadioItem<T> {
        var name = name
        name = prefix + name
        val action = SimpleAction.newStateful(name, VariantTypes.INT32, Variant.newInt32(options.indexOf(initial)))
        addAction(name, action)
        action.onActivate { variant: Variant? ->
            action.state = variant
            onCheck.accept(options[variant!!.int32])
        }
        for ((i, option) in options.withIndex()) {
            menu.appendItem(MenuItem(stringifier.apply(i, option), "$groupName$name($i)"))
        }
        return BuiltRadioItem(action, options)
    }

    fun submenu(name: String): MenuBuilder {
        return literalSubmenu(name, I18n["menu.$prefix$name"])
    }

    fun literalSubmenu(name: String, label: String?): MenuBuilder {
        var name = name
        name = prefix + name
        val submenu = Menu()
        menu.appendSubmenu(label, submenu)
        return MenuBuilder(map, submenu, name, groupName)
    }

    fun section(name: String): MenuBuilder {
        return literalSection(name, I18n["section.$prefix$name"])
    }

    fun literalSection(name: String, label: String?): MenuBuilder {
        var name = name
        name = prefix + name
        val section = Menu()
        menu.appendSection(label, section)
        return MenuBuilder(map, section, name, groupName)
    }

    fun clear() {
        menu.removeAll()
        refs.forEach { (name, _) -> map.removeAction(name) }
        refs.clear()
    }

    private fun addAction(name: String, action: SimpleAction) {
        map.addAction(action)
        refs[name] = action
    }

    fun asPopover(): PopoverMenu {
        return PopoverMenu.newFromModel(menu)
    }

    companion object {
        private val LOCK = Any()
        private fun getRootMenu(app: Application): Menu {
            synchronized(LOCK) {
                val currentMenu = app.menubar
                return if (currentMenu == null) {
                    val menu = Menu()
                    app.menubar = menu
                    menu
                } else {
                    currentMenu as Menu
                }
            }
        }

        fun create(target: MenuButton, groupName: String): MenuBuilder {
            val menu = Menu()
            val pm = PopoverMenu.newFromModel(menu)
            target.setPopover(pm)
            return MenuBuilder(pm, groupName)
        }

        private fun insertMap(menu: PopoverMenu, groupName: String): ActionMap {
            val ag = SimpleActionGroup()
            menu.insertActionGroup(groupName, ag)
            return ag
        }
    }
}