/**
 *  Logarithm Graph Creator - Create graphs with logarithm scales.
 *  Copyright (C) 2020  Ad5001
 * 
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 * 
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 * 
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

// This library helps containing actions to be undone or redone (in other words, editing history)
// Each type of event is repertoried as an action that can be listed for everything that's undoable.
.pragma library

.import "objects.js" as Objects
.import "utils.js" as Utils

class Action {
    // Type of the action done.
    static type(){return 'Unknown'}
    
    // TargetName is the name of the object that's targeted by the event.
    constructor(targetName = "", targetType = "Point") {
        this.targetName = targetName
        this.targetType = targetType
    }
    
    undo() {}
    
    redo() {}
    
    getReadableString() {
        return 'Unknown action'
    }
}

class CreateNewObject extends Action {
    // Action used for the creation of an object
    static type(){return 'CreateNewObject'}
    
    constructor(targetName = "", targetType = "Point", properties = []) {
        super(targetName, targetType)
        this.targetProperties = properties
    }
    
    undo() {
        var targetIndex = Objects.getObjectsName(this.targetType).indexOf(this.targetName)
        Objects.currentObjects[this.targetType][targetIndex].delete()
        Objects.currentObjects[this.targetType].splice(targetIndex, 1)
    }
    
    redo() {
        Objects.createNewRegisteredObject(this.targetType, this.targetProperties)
    }
    
    getReadableString() {
        return `New ${this.targetType} ${this.targetName} created.`
    }
}

class DeleteObject extends CreateNewObject {
    // Action used at the deletion of an object. Basicly the same thing as creating a new object, except Redo & Undo are reversed.
    static type(){return 'DeleteObject'}
    
    undo() {
        super.redo()
    }
    
    redo() {
        super.undo()
    }
    
    getReadableString() {
        return `${this.targetType} ${this.targetName} deleted.`
    }
}

class EditedProperty extends Action {
    // Action used everytime an object's property has been changed
    static type(){return 'EditedProperty'}
    
    constructor(targetName = "", targetType = "Point", targetProperty = "visible", previousValue = false, newValue = true) {
        super(targetName, targetType)
        this.targetProperty = targetProperty
        this.targetPropertyReadable = Utils.camelCase2readable(this.targetProperty)
        this.previousValue = previousValue
        this.newValue = newValue
    }
    
    undo() {
        Objects.getObjectByName(this.targetName, this.targetType)[this.targetProperty] = this.previousValue
    }
    
    redo() {
        Objects.getObjectByName(this.targetName, this.targetType)[this.targetProperty] = this.newValue
    }
    
    getReadableString() {
        var prev = this.previousValue == null ? ""+this.previousValue : this.previousValue.toString()
        var next = this.newValue == null ? ""+this.newValue : this.newValue.toString()
        return `${this.targetPropertyReadable} of ${this.targetType} ${this.targetName} changed from "${prev}" to "${next}".`
    }
}

class EditedVisibility extends EditedProperty {
    // Action used everytime an object's property has been changed
    static type(){return 'EditedVisibility'}
    
    constructor(targetName = "", targetType = "Point", newValue = true) {
        super(targetName, targetType, "visible", !newValue, newValue)
    }
    
    getReadableString() {
        if(this.newValue) {
            return `${this.targetType} ${this.targetName} shown.`
        } else {
            return `${this.targetType} ${this.targetName} hidden.`
        }
    }
}