package sws

import (
	"fmt"
	"io"
	"time"

	gochart "github.com/wcharczuk/go-chart"
	"github.com/wcharczuk/go-chart/drawing"
)

type counted interface {
	Counts() []int
}
type labelled interface {
	Labels() []string
}
type timed interface {
	Times() []time.Time
}
type timeCounted interface {
	counted
	timed
}
type labelCounted interface {
	counted
	labelled
}

type chart struct {
	width, height int
	data          HitSet
}

func NewChart(data HitSet, opts ...ChartOption) (*chart, error) {
	out := &chart{data: data}
	for _, o := range opts {
		if err := o(out); err != nil {
			return nil, err
		}
	}
	return out, nil
}

type ChartOption func(*chart) error

func Dimensions(height, width int) ChartOption {
	return func(c *chart) error {
		if height < 0 || width < 0 {
			return fmt.Errorf("invalid chart dimensions")
		}
		c.height = height
		c.width = width
		return nil
	}
}

func SparklineSVG(w io.Writer, data *HitSet, d time.Duration) error {
	hits := gochart.TimeSeries{
		//Name: "Hits",
		Style: gochart.Style{
			Show:        true,
			StrokeWidth: 2.0,
			StrokeColor: drawing.Color{R: 0, G: 0, B: 255, A: 100},
		},
	}
	//data, _ = NewHitSet(FromHits(data.Hits()), Duration(d))
	//data.SortByDate()

	var xVals []time.Time
	var yVals []float64
	tmp := data.XSeries()
	direction := 0
	lastV := float64(0)
	for i := range tmp {
		v := tmp[i].Count()
		switch {
		case i == 0:
			fallthrough
		case v > tmp[i-1].Count():
			direction = 1
		case v < tmp[i-1].Count():
			direction = -1
		default:
			direction = 0
		}
		if direction != 0 {
			yVals = append(yVals, float64(v))
			lastV = float64(v)
		} else {
			yVals = append(yVals, lastV)
		}
		xVals = append(xVals, tmp[i].Time())
	}
	hits.XValues, hits.YValues = xVals, yVals

	graph := gochart.Chart{
		Width:  600,
		Height: 50,
		Series: []gochart.Series{hits},
		// Background: gochart.Style{
		// 	Padding: gochart.Box{Top: 10, Right: 10, Bottom: 10, Left: 27},
		// },
		// XAxis: gochart.XAxis{
		// 	Style: gochart.Style{Show: true},
		// 	ValueFormatter: func(v interface{}) string {
		// 		return time.Unix(0, int64(v.(float64))).Format("Jan 02")
		// 	},
		// },
		// YAxis: gochart.YAxis{
		// 	NameStyle: gochart.StyleShow(),
		// 	Style:     gochart.Style{Show: true},
		// 	ValueFormatter: func(v interface{}) string {
		// 		return fmt.Sprintf("%.0f", v.(float64))
		// 	},
		// },
	}
	//graph.YAxis.Range.SetMin(0)

	graph.Render(gochart.SVG, w)
	return nil
}

func HitChartSVG(w io.Writer, data *HitSet, d time.Duration) error {
	hits := gochart.TimeSeries{
		Name: "Hits",
		Style: gochart.Style{
			Show:        true,
			StrokeWidth: 2.0,
			StrokeColor: drawing.Color{R: 0, G: 0, B: 255, A: 100},
			DotColorProvider: func(_, _ gochart.Range, _ int, _, _ float64) drawing.Color {
				return drawing.Color{R: 21, G: 198, B: 148, A: 100}
			},
			DotWidthProvider: func(_, _ gochart.Range, _ int, _, _ float64) float64 {
				return 5
			},
		},
		//YAxis:   gochart.YAxisSecondary,
	}

	hits.XValues, hits.YValues = data.XYValues()

	graph := gochart.Chart{
		Width:  400,
		Height: 200,
		Series: []gochart.Series{hits},
		Background: gochart.Style{
			Padding: gochart.Box{Top: 10, Right: 10, Bottom: 10, Left: 27},
		},
		XAxis: gochart.XAxis{
			Style: gochart.Style{Show: true},
			ValueFormatter: func(v interface{}) string {
				return time.Unix(0, int64(v.(float64))).Format("2015-01-02 15:04")
			},
		},
		YAxis: gochart.YAxis{
			//NameStyle: gochart.StyleShow(),
			Style: gochart.Style{Show: true},
			ValueFormatter: func(v interface{}) string {
				return fmt.Sprintf("%.0f", v.(float64))
			},
		},
		// YAxis: gochart.YAxis{
		// 	Name:      "Unique visitors",
		// 	NameStyle: gochart.StyleShow(),
		// 	Style:     gochart.Style{Show: true},
		// 	ValueFormatter: func(v interface{}) string {
		// 		return fmt.Sprintf("%.1f", v.(float64))
		// 	},
		// },
	}
	//graph.YAxis.Range.SetMin(0)
	// graph.Elements = []gochart.Renderable{
	// 	gochart.Legend(&graph),
	// }

	graph.Render(gochart.SVG, w)
	return nil
}

func PieChartSVG(w io.Writer, data labelCounted) error {
	labels := data.Labels()
	counts := data.Counts()
	values := make([]gochart.Value, len(labels))
	for i := 0; i < len(labels); i++ {
		values[i] = gochart.Value{
			Value: float64(counts[i]),
			Label: labels[i],
		}
	}
	pie := gochart.PieChart{
		Width:  400,
		Height: 400,
		Values: values,
	}
	pie.Render(gochart.SVG, w)
	return nil
}