package gime

import "fmt"

// TagCollection is a collection of strings for gomobile bindings
type TagCollection struct {
	list []string
}

// Length returns the number of tags in the collection
func (tc *TagCollection) Length() int {
	return len(tc.list)
}

// Get returns the string at idx or an empty string
func (tc *TagCollection) Get(idx int) string {
	if idx < tc.Length() {
		return tc.list[idx]
	}
	return ""
}

// Clear empties the list of Tags
func (tc *TagCollection) Clear() {
	tc.list = tc.list[:0]
}

// Index finds the index of the given string or -1 if not found
func (tc *TagCollection) Index(t string) int {
	for i, tst := range tc.list {
		if tst == t {
			return i
		}
	}
	return -1
}

// Insert inserts a string into the collection at i
func (tc *TagCollection) Insert(i int, t string) {
	if i < 0 || i > tc.Length() {
		fmt.Println("gime: Attempted to insert string at invalid index")
	}
	tc.list = append(tc.list, "")
	copy(tc.list[i+1:], tc.list[i:])
	tc.list[i] = t
}

// Remove removes the string at i from the collection
func (tc *TagCollection) Remove(i int) {
	if i < 0 || i >= tc.Length() {
		fmt.Println("gime: Attempted to remove tag at invalid index")
	}
	copy(tc.list[i:], tc.list[i+1:])
	tc.list[len(tc.list)-1] = ""
	tc.list = tc.list[:len(tc.list)-1]
}

// Push adds an element to the end of the collection
func (tc *TagCollection) Push(t string) {
	tc.Insert(tc.Length(), t)
}

// Pop removes the last element from the collection
func (tc *TagCollection) Pop() string {
	ret := tc.list[tc.Length()-1]
	tc.Remove(tc.Length() - 1)
	return ret
}

// Unshift adds an element to the front of the collection
func (tc *TagCollection) Unshift(t string) {
	tc.Insert(0, t)
}

// Shift removes an element from the front of the collection
func (tc *TagCollection) Shift() string {
	ret := tc.list[0]
	tc.Remove(0)
	return ret
}