package chart

import "github.com/wcharczuk/go-chart/drawing"

// ValueProvider is a type that produces values.
type ValueProvider interface {
	Len() int
	GetValue(index int) (float64, float64)
}

// BoundedValueProvider allows series to return a range.
type BoundedValueProvider interface {
	Len() int
	GetBoundedValue(index int) (x, y1, y2 float64)
}

// LastValueProvider is a special type of value provider that can return it's (potentially computed) last value.
type LastValueProvider interface {
	GetLastValue() (x, y float64)
}

// BoundedLastValueProvider is a special type of value provider that can return it's (potentially computed) bounded last value.
type BoundedLastValueProvider interface {
	GetBoundedLastValue() (x, y1, y2 float64)
}

// FullValueProvider is an interface that combines `ValueProvider` and `LastValueProvider`
type FullValueProvider interface {
	ValueProvider
	LastValueProvider
}

// FullBoundedValueProvider is an interface that combines `BoundedValueProvider` and `BoundedLastValueProvider`
type FullBoundedValueProvider interface {
	BoundedValueProvider
	BoundedLastValueProvider
}

// SizeProvider is a provider for integer size.
type SizeProvider func(xrange, yrange Range, index int, x, y float64) float64

// ColorProvider is a general provider for color ranges based on values.
type ColorProvider func(v, vmin, vmax float64) drawing.Color

// DotColorProvider is a provider for dot color.
type DotColorProvider func(xrange, yrange Range, index int, x, y float64) drawing.Color