package slice

import "fmt"
import "html/template"
import "git.tebibyte.media/sashakoshka/step"

const hiddenPrefix = "."

var _ step.FuncProvider = new(Provider)

// Provider provides slice functions.
type Provider struct {
	
}

// FuncMap fulfills the step.FuncProvider interface.
func (this *Provider) FuncMap () template.FuncMap {
	return template.FuncMap {
		"sAppend": funcSAppend,
		"iAppend": funcIAppend,
		"fAppend": funcFAppend,
	}
}

func funcSAppend (slice any, addition string) []string {
	switch slice := slice.(type) {
	case []string:
		newSlice := make([]string, len(slice) + 1)
		copy(newSlice, slice)
		newSlice[len(slice)] = addition
		return newSlice
	case string:
		return []string { slice, addition }
	default:
		return funcSAppend(fmt.Sprint(slice), addition)
	}
}

func funcIAppend (slice any, addition int) []int {
	switch slice := slice.(type) {
	case []int:
		newSlice := make([]int, len(slice) + 1)
		copy(newSlice, slice)
		newSlice[len(slice)] = addition
		return newSlice
	case int:
		return []int { slice, addition }
	default:
		return funcIAppend(0, addition)
	}
}

func funcFAppend (slice any, addition float64) []float64 {
	switch slice := slice.(type) {
	case []float64:
		newSlice := make([]float64, len(slice) + 1)
		copy(newSlice, slice)
		newSlice[len(slice)] = addition
		return newSlice
	case float64:
		return []float64 { slice, addition }
	default:
		return funcFAppend(0, addition)
	}
}