var margin = {
    top: 20,
    right: 0,
    bottom: 20,
    left: 30
};
var width = 680 - margin.left - margin.right;
var height = 360 - margin.top - margin.bottom;

var x = d3.scale.ordinal()
    .rangeRoundBands([0, width]);

var y = d3.scale.linear()
    .rangeRound([height - 20, 0]);

var xLabel = d3.time.scale()
    .domain([new Date(1960, 0, 1), new Date(2014, 11, 31)])
    .range([0, width]);

var xAxis = d3.svg.axis()
    .scale(xLabel)
    .ticks(3)
    .tickFormat(d3.time.format("%Y"));

var yAxis = d3.svg.axis()
    .scale(y)
    .ticks(4)
    .orient("left");

var line = d3.svg.line()
    .defined(function(d) {
        if (!isNaN(d.value)) {
            return d.value;
        }
    })
    .interpolate("cardinal")
    .x(function(d) {
        return x(d.label) + x.rangeBand() / 2;
    })
    .y(function(d) {
        return y(d.value);
    });

    var colors = ["#fff7ec", "#fee8c8", "#fdd49e", "#fdbb84", "#fc8d59", "#ef6548", "#d7301f", "#b30000", "#7f0000", "#cc4c02", "#993404", "#662506"];

    var color = d3.scale.ordinal().range(colors);




var dateFormat = d3.time.format("%Y");

var svg = d3.select("#chart").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 + ")");

d3.csv("Global-ocean-land-temperatures.csv", function(error, data) {

    // console.log(data);

    var years = Object.keys(data[0]);
    years.sort();

    var labelVar = 'year';
    var varNames = d3.keys(data[0]).filter(function(key) {
        return key !== labelVar;
    });
    color.domain(varNames);

    var seriesData = varNames.map(function(name) {
        return {
            name: name,
            values: data.map(function(d) {
                return {
                    name: name,
                    label: d[labelVar],
                    value: +d[name]
                };
            })
        };
    });

    // console.log(seriesData);

    data.forEach(function(d) {
        d.year = +d.year;
    });

    x.domain(data.map(function(d) {
        return d.year;
    }));
    y.domain([d3.min(seriesData, function(c) {
        return d3.min(c.values, function(d) {
            return d.value;
        });
    }),
    d3.max(seriesData, function(c) {
        return d3.max(c.values, function(d) {
                return d.value;
            });
        })
    ]);

    svg.append("g")
        .attr("class", "x axis")
        .attr("transform", "translate(0," + height + ")")
        .call(xAxis);

    svg.append("g")
        .attr("class", "y axis")
        .call(yAxis)
        .append("text")
        .attr("x", 0)
        .attr("y", 0)
        .attr("dy", ".71em")
        .style("text-anchor", "end")
        .text("°C");

    var series = svg.selectAll(".series")
        .data(seriesData)
        .enter().append("g")
        .attr("class", "series")
        .attr("transform", "translate(-20,0)");

    series.append("path")
        .attr("class", "line")
        .attr("id", function(d) {
            return d.name
        })
        .attr("stroke", function(d, i){
            return colors[i];
        })
        .attr("opacity", 0)
        .transition()
        .delay(function(d, i) {
            return i * 550;
        })
        .duration(500)
        .attr("d", function(d, i) {
            return line(d.values);
        })
        .attr("opacity", 1);

});