package beeParser

import (
	"strings"
)

type Annotator interface {
	Annotate(string) map[string]interface{}
}

type Annotation struct {
}

func isWhitespace(ch byte) bool { return ch == ' ' || ch == '\t' || ch == '\r' }

func handleHeadWhitespace(s string) string {
	i := 0
	for i < len(s) && isWhitespace(s[i]) {
		i++
	}
	return s[i:]
}

func handleTailWhitespace(s string) string {
	i := len(s)
	for i > 0 && isWhitespace(s[i-1]) {
		i--
	}
	return s[0:i]
}

//handle value to remove head and tail space.
func handleWhitespaceValues(values []string) []string {
	res := make([]string, 0)
	for _, v := range values {
		v = handleHeadWhitespace(v)
		v = handleTailWhitespace(v)
		res = append(res, v)
	}
	return res
}

//parse annotation to generate array with key and values
//start with "@" as a key-value pair,key and values are separated by a space,wrap to distinguish values.
func (a *Annotation) Annotate(annotation string) map[string]interface{} {
	results := make(map[string]interface{})
	//split annotation with '@'
	lines := strings.Split(annotation, "@")
	//skip first line whitespace
	for _, line := range lines[1:] {
		kvs := strings.Split(line, " ")
		key := kvs[0]
		values := strings.Split(strings.TrimSpace(line[len(kvs[0]):]), "\n")
		results[key] = handleWhitespaceValues(values)
	}
	return results
}