import React, { useState, useEffect } from "react";
import * as d3 from 'd3';

function getlength(number) {
    return number.toString().length;
}

function drawGraphInner(list, quantitativeComparisons){
    if(true){
        // Build the graph object
        let nodes = list.map((x,i) => ({id: i, name: x}))
        let links = quantitativeComparisons.map(([element1, element2, weight]) => ({source: list.indexOf(element1), target: list.indexOf(element2), weight: weight}))
        console.log("Links")
        console.log(links)

        let data = ({
            nodes,
            links: links
        })
        console.log(data)

        // Build the d3 graph
        let margin = {top: 0, right: 30, bottom: 20, left: 30};
        let width = 900 - margin.left - margin.right;
        let height = 400 - margin.top - margin.bottom;

        var svg = d3.select("#graph")
            .append("svg")
            .attr("width", width + margin.left + margin.right)
            .attr("height", height + margin.top + margin.bottom)
            .append("g")
            .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

        console.log(data)
        // List of node names
        var nodeNames = data.nodes.map(function(d){return d.name})
        
        // A linear scale to position the nodes on the X axis
        var x = d3.scalePoint()
            .range([0, width])
            .domain(nodeNames)
        
        // Add the circle for the nodes
        svg
            .selectAll("mynodes")
            .data(data.nodes)
            .enter()
            .append("circle")
            .attr("cx", function(d){ return(x(d.name))})
            .attr("cy", height-30)
            .attr("r", 8)
            .style("fill", "#69b3a2")
        
        // And give them a label
        svg
            .selectAll("mylabels")
            .data(data.nodes)
            .enter()
            .append("text")
            .attr("x", function(d){ return(x(d.name))})
            .attr("y", height-10)
            .text(function(d){ return(d.name)})
            .style("text-anchor", "middle")
        

        
        // Add links between nodes.
        // In the input data, links are provided between nodes -id-, not between node names.
        // So one has to link ids and names
        // Note Nuño: This is inefficient, and we could have built the data object to avoid this. However, every time I try to refactor this, the thing breaks. 
        var nodesById = {};
        data.nodes.forEach(function (n) {
            nodesById[n.id] = n;
        });
        
        // Cool, now if I do nodesById["2"].name I've got the name of the node with id 2
        
        // Add the links
        svg
            .selectAll('mylinks')
            .data(data.links)
            .enter()
            .append('path')
            .attr('d', function (d) {
                let start = x(nodesById[d.source].name)    
                    // X position of start node on the X axis
                let end = x(nodesById[d.target].name)      
                    // X position of end node
                return ['M', 
                    start, 
                    height-30,    
                        // the arc starts at the coordinate x=start, y=height-30 (where the starting node is)
                    'A',                            
                        // This means we're gonna build an elliptical arc
                    (start - end)/2, ',',    
                        // Next 2 lines are the coordinates of the inflexion point. Height of this point is proportional with start - end distance
                    (start - end)/2, 0, 0, ',',
                    start < end ? 1 : 0, end, ',', height-30] 
                        // We always want the arc on top. So if end is before start, putting 0 here turn the arc upside down.
                .join(' ');
            })
            .style("fill", "none")
            .attr("stroke", "black")
        
        // labels for links
        svg
            .selectAll('mylinks')
            .data(data.links)
            .enter()
            .append("text")
            .attr("x", function(d){ 
                let start = x(nodesById[d.source].name)    
                    // X position of start node on the X axis
                let end = x(nodesById[d.target].name)      
                    // X position of end node
                return start + (end-start)/2 -4*getlength(d.weight)
            })
            .attr("y", function(d){ 
                let start = x(nodesById[d.source].name)    
                    // X position of start node on the X axis
                let end = x(nodesById[d.target].name)      
                    // X position of end node
                return height-32-(Math.abs(start-end)/2)//height-30
            })
            .text(function(d){ return(`${d.weight}`)})
            .style("text-anchor", "top")

    }


}

export function DrawGraph({list, quantitativeComparisons, isListOrdered}) {
    // list is just an array
    // arrows is an array of arrows
    
    if(isListOrdered){
        drawGraphInner(list, quantitativeComparisons);
    }
    
    return (
        <div>
            <div id="graph">
            </div>
        </div>
    );

}