package charts

import (
	"fmt"
	"slices"
	"strings"

	"ruben/inventory2/server/ui/svg"
)

type (
	// TODO: rename to BarChart
	Bar struct {
		values  []BarValue
		classes barChartClasses
	}

	BarValue struct {
		Label string
		Value float64
	}

	barChartClasses struct {
		svg []string
		bar []string
	}
)

func NewBar(vs ...BarValue) *Bar {
	return &Bar{
		values: vs,
	}
}

func (c *Bar) WithSVGClass(classes ...string) *Bar {
	c.classes.svg = append(c.classes.svg, classes...)
	return c
}

func (c *Bar) WithBarClass(classes ...string) *Bar {
	c.classes.bar = append(c.classes.bar, classes...)
	return c
}

func (c *Bar) SVG() svg.MarshalerReader {
	const (
		minX   = 0
		minY   = 0
		maxX   = 100
		maxY   = 100
		rangeX = maxX - minX
		rangeY = maxY - minY
	)

	s := svg.NewSVG().
		Attr(
			svg.Style{
				"width":        "100%",
				"height":       "auto",
				"padding":      "1em",
				"border-width": "2px",
			},
			svg.ViewBox{
				X:      minX,
				Y:      minY,
				Width:  maxX - minX,
				Height: maxY - minY,
			},
			svg.Class(
				strings.Join(append(
					[]string{"rounded-lg", "border-border"},
					c.classes.bar...,
				), " "),
			),
		)

	if len(c.classes.svg) != 0 {
		s = s.Attr(svg.Class(strings.Join(c.classes.svg, " ")))
	}

	if len(c.values) > 0 {
		minV := slices.MinFunc(c.values, func(a, b BarValue) int {
			if a.Value < b.Value {
				return -1
			}
			if a.Value > b.Value {
				return 1
			}
			return 0
		})
		maxV := slices.MaxFunc(c.values, func(a, b BarValue) int {
			if a.Value < b.Value {
				return -1
			}
			if a.Value > b.Value {
				return 1
			}
			return 0
		})
		rangeV := maxV.Value - minV.Value

		spacePerBar := float64(rangeX) / float64(len(c.values))
		barPadding := 0.025 * spacePerBar
		barWidth := spacePerBar - (2 * barPadding)
		fontSize := barWidth / 2

		for i, v := range c.values {
			scaledV := (v.Value - minV.Value) * rangeY / rangeV
			barX := float64(i)*spacePerBar + barPadding
			s = s.Child(
				new(svg.Rect).
					Attr(
						svg.NewLength(barX).AsX(),
						svg.NewLength(maxY-scaledV).AsY(),
						svg.NewLength(barWidth).AsWidth(),
						svg.NewLength(scaledV).AsHeight(),
						svg.Class(
							strings.Join(append(
								[]string{"fill-accent"},
								c.classes.bar...,
							), " "),
						),
					),
				svg.NewText(fmt.Sprint(v.Value)).
					Attr(
						svg.NewLength(barX+(barWidth/2)).AsX(),
						svg.NewLength(maxY-scaledV+fontSize).AsY(),
						svg.Fill("var(--accent-foreground)"),
						svg.TextAnchorMiddle,
						// svg.NewLength(fontSize).AsFontSize(),
						svg.Style{
							"font-size": fmt.Sprintf("%vpx", fontSize),
						},
					),
			)

			if v.Label != "" {
				x := barX + (barWidth / 2)
				y := maxY - fontSize
				s = s.Child(
					svg.NewText(v.Label).
						Attr(
							svg.NewLength(x).AsX(),
							svg.NewLength(y).AsY(),
							svg.Fill("var(--accent-foreground)"),
							//svg.NewLength(fontSize).AsFontSize(),
							svg.Style{
								"font-size": fmt.Sprintf("%vpx", fontSize),
							},
							svg.DominantBaselineCentral,
							svg.TransformRotate(-90).About(x, y),
						),
				)
			}
		}
	}

	return s
}