package context

import (
	"errors"
)

/* (1) Definitions
---------------------------------------------------------*/
/* (1) Default values */
const DefaultMin = 0x00f0
const DefaultMax = 0x0fff
const DefaultThr = 0x000a


/* (2) Struct attributes */
type T struct {
	win float64; // 'timeid' window size
	min uint16;  // minimum scha depth
	max uint16;  // maximum scha depth
	thr uint16;  // scha depth threshold
}

/* (3) Constructor
*
* @win<float64>						Window size for 'timeid' package
* @min<uint16>						[OPT] Minimum scha depth
* @thr<uint16>						[OPT] scha depth threshold before renewal
* @max<uint16>						[OPT] Maximum scha depth
*
* @return outName<outType>			outDesc
*
---------------------------------------------------------*/
func Create(win float64, optional... uint16) (*T, error) {

	var inst = new(T);

	/* (1) Window size error */
	if win < 0 { return nil, errors.New("Window size must be positive and is negative") }
	inst.win = win;

	/* (2) Default values */
	inst.min = DefaultMin
	inst.thr = DefaultThr
	inst.max = DefaultMax

	/* (3) Optional 'min' */
	if len(optional) > 0 {

		if optional[0] < 0x0f {
			return nil, errors.New("Minimum depth must be greater than 0x0f (decimal 15) for consistency issues")
		}
		inst.min = optional[0];

	}

	/* (4) Optional 'thr' */
	if len(optional) > 1 {
		inst.thr = optional[1];
	}

	/* (5) Optional 'max' */
	if len(optional) > 2 {

		if optional[2] <= inst.min+inst.thr {
			return nil, errors.New("Minimum depth must be greater than 0x0f (decimal 15) for consistency issues")
		}
		inst.max = optional[2];

	}

	return inst, nil
}

/* (4) Getters */
func (c T) Window()         float64 { return c.win }
func (c T) MinDepth()       uint16  { return c.min }
func (c T) MaxDepth()       uint16  { return c.max }
func (c T) DepthThreshold() uint16  { return c.thr }