/**
 *  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/>.
 */

.pragma library

.import "utils.js" as Utils
.import "mathlib.js" as MathLib



function getNewName(allowedLetters, category) {
    if(Object.keys(currentObjects).indexOf(category) == -1) return allowedLetters[0]
    var newid = currentObjects[category].length
    var letter = allowedLetters[newid % allowedLetters.length]
    var num = Math.round((newid - (newid % allowedLetters.length)) / allowedLetters.length)
    return letter + (num > 0 ? Utils.textsup(num) : '')
}

class DrawableObject {
    static type(){return 'Unknown'}
    static properties() {return {}}
    
    constructor(name, visible = true, color = null, labelContent = 'name + value') {
        if(color == null) color = this.getRandomColor()
        this.type = 'Unknown'
        this.name = name
        this.visible = visible
        this.color = color
        this.labelContent = labelContent // "null", "name", "name + value"
        this.requiredBy = []
    }
    
    getRandomColor() {
        var x = '0123456789ABCDEF';
        var color = '#';
        for (var i = 0; i < 6; i++) {
            color += x[Math.floor(Math.random() * 16)];
        }
        return color;
    }
    
    getReadableString() {
        return `${this.name} = Unknown`
    }
    
    getLabel() {
        switch(this.labelContent) {
            case 'name':
                return this.name
            case 'name + value':
                return this.getReadableString()
            case 'null':
                return ''
                
        }
    }
    
    export() {
        return [this.name, this.visible, this.color.toString(), this.labelContent]
    }
    
    draw(canvas, ctx) {}
}

class Point extends DrawableObject  {
    static type(){return 'Point'}
    static properties() {return {
        'x': 'Expression',
        'y': 'Expression',
        'labelPos': ['top', 'bottom', 'left', 'right'],
        'pointStyle': ['dot', 'diagonal cross', 'vertical cross'],
    }}
    
    constructor(name = null, visible = true, color = null, labelContent = 'name + value', 
                x = 1, y = 0, labelPos = 'top', pointStyle = 'dot') {
        if(name == null) name = getNewName('ABCDEFJKLMNOPQRSTUVW', 'Point')
        super(name, visible, color, labelContent)
        this.type = 'Point'
        if(typeof x == 'number' || typeof x == 'string') x = new MathLib.Expression(x.toString())
        this.x = x
        if(typeof y == 'number' || typeof y == 'string') y = new MathLib.Expression(y.toString())
        this.y = y
        this.labelPos = labelPos
        this.pointStyle = pointStyle
    }
    
    getReadableString() {
        return `${this.name} = (${this.x}, ${this.y})`
    }
    
    export() {
        return [this.name, this.visible, this.color.toString(), this.labelContent, this.x.toEditableString(), this.y.toEditableString(), this.labelPos, this.pointStyle]
    }
    
    draw(canvas, ctx) {
        var [canvasX, canvasY] = [canvas.x2px(this.x.evaluate()), canvas.y2px(this.y.evaluate())]
        var pointSize = 8
        switch(this.pointStyle) {
            case 'dot':
                ctx.fillStyle = this.color
                ctx.beginPath();
                ctx.ellipse(canvasX-pointSize/2, canvasY-pointSize/2, pointSize, pointSize)
                ctx.fill();
                break;
            case 'diagonal cross':
                ctx.strokeStyle = this.color
                canvas.drawLine(ctx, canvasX-pointSize/2, canvasY-pointSize/2, canvasX+pointSize/2, canvasY+pointSize/2)
                canvas.drawLine(ctx, canvasX-pointSize/2, canvasY+pointSize/2, canvasX-pointSize/2, canvasY+pointSize/2)
                break;
            case 'vertical cross':
                ctx.strokeStyle = this.color
                canvas.drawLine(ctx, canvasX, canvasY-pointSize/2, canvasX, canvasY+pointSize/2)
                canvas.drawLine(ctx, canvasX-pointSize/2, canvasY, canvasX+pointSize/2, canvasY)
                break;
        }
        var text = this.getLabel()
        ctx.font = "14px sans-serif"
        var textSize = ctx.measureText(text).width
        ctx.fillStyle = this.color
        switch(this.labelPos) {
            case 'top':
                canvas.drawVisibleText(ctx, text, canvasX-textSize/2, canvasY-16)
                break;
            case 'bottom':
                canvas.drawVisibleText(ctx, text, canvasX-textSize/2, canvasY+16)
                break;
            case 'left':
                canvas.drawVisibleText(ctx, text, canvasX-textSize-10, canvasY+4)
                break;
            case 'right':
                canvas.drawVisibleText(ctx, text, canvasX+10, canvasY+4)
                break;
                
        }
    }
}

class Function extends DrawableObject {
    static type(){return 'Function'}
    static properties() {return {
        'expression': 'Expression',
        'inDomain': 'Domain',
        'outDomain': 'Domain',
        'labelPos': ['above', 'below'],
        'displayMode': ['application', 'function'],
        'labelX': 'number'
    }}
    
    constructor(name = null, visible = true, color = null, labelContent = 'name + value', 
                expression = 'x', inDomain = 'RPE', outDomain = 'R', displayMode = 'application', labelPos = 'above', labelX = 1) {
        if(name == null) name = getNewName('fghjqlmnopqrstuvwabcde', 'Function')
        super(name, visible, color, labelContent)
        if(typeof expression == 'number' || typeof expression == 'string') expression = new MathLib.Expression(expression.toString())
        this.expression = expression
        if(typeof inDomain == 'string') inDomain = MathLib.parseDomain(inDomain)
        this.inDomain = inDomain
        if(typeof outDomain == 'string') outDomain = MathLib.parseDomain(outDomain)
        this.outDomain = outDomain
        this.displayMode = displayMode
        this.labelPos = labelPos
        this.labelX = labelX
    }
    
    getReadableString() {
        if(this.displayMode == 'application') {
            return `${this.name}: ${this.inDomain} ⸺˃ ${this.outDomain}\n    x ⸺˃ ${this.expression.toString()}`
        } else {
            return `${this.name}(x) = ${this.expression.toString()}`
        }
    }
    
    export() {
        return [this.name, this.visible, this.color.toString(), this.labelContent, 
        this.expression.toEditableString(), this.inDomain.toString(), this.outDomain.toString(), 
        this.displayMode, this.labelPos, this.labelX]
    }
    
    draw(canvas, ctx) {
        ctx.strokeStyle = this.color
        ctx.fillStyle = this.color
        // Drawing small traits every 2px
        var pxprecision = 2
        var previousX = canvas.px2x(0)
        var previousY = this.expression.evaluate(previousX)
        for(var px = pxprecision; px < canvas.canvasSize.width; px += pxprecision) {
            var currentX = canvas.px2x(px)
            var currentY = this.expression.evaluate(currentX)
            if(this.inDomain.includes(currentX) && this.inDomain.includes(previousX) &&
                this.outDomain.includes(currentY) && this.outDomain.includes(previousY) &&
                Math.abs(previousY-currentY)<100) { // 100 per 2px is a lot (probably inf to inf issue)
                    canvas.drawLine(ctx, canvas.x2px(previousX), canvas.y2px(previousY), canvas.x2px(currentX), canvas.y2px(currentY))
                }
            previousX = currentX
            previousY = currentY
        }
        // Label
        var text = this.getLabel()
        ctx.font = "14px sans-serif"
        var textSize = canvas.measureText(ctx, text)
        ctx.fillStyle = this.color
        var posX = canvas.x2px(this.labelX)
        var posY = canvas.y2px(this.expression.evaluate(this.labelX))
        switch(this.labelPos) {
            case 'above':
                canvas.drawVisibleText(ctx, text, posX-textSize.width/2, posY-textSize.height)
                break;
            case 'below':
                canvas.drawVisibleText(ctx, text, posX-textSize.width/2, posY+textSize.height)
                break;
                
        }
    }
}

const drawableTypes = {
    'Point': Point,
    'Function': Function
}

var currentObjects = {}