package cos

import (
	"fmt"
	"strings"
	"testing"
	"unicode/utf8"
)

func checkChunks(text string, size int) (*ChunkOfSize, int, error) {
	chunk := NewChunkOfSize(text, size)
	if chunk == nil {
		return nil, -1, fmt.Errorf("Chunk is nil!")
	}

	count := 0

	for {
		text := chunk.Next()
		if text == "" {
			break
		}

		if utf8.RuneCountInString(text) > size {
			return chunk, -1, fmt.Errorf("'%s'\nis longer than %d", text, size)
		}

		count++
	}

	return chunk, count, nil
}

func Test4ChunksOf100(t *testing.T) {
	size := 100
	expectedChunks := 4

	chunk, count, err := checkChunks(testText, size)
	if err != nil {
		t.Fatal(err)
	}

	if count != expectedChunks {
		t.Fatal("There should be", expectedChunks, "chunks, but have", count)
	}

	if !chunk.Success() {
		t.Fatal("There were errors:\n", strings.Join(chunk.GetErrors(), "\n"))
	}
}

func TestWordBiggerThanLimit(t *testing.T) {
	size := 4
	chunk := NewChunkOfSize(testText, size)

	text := chunk.Next()
	if text != "" {
		t.Fatal("Chunk should be empty, but is:", text)
	}

	if chunk.Success() || len(chunk.GetErrors()) == 0 {
		t.Fatal("There should be errors!")
	}
}

func TestTextShorterThanLimit(t *testing.T) {
	size := 400
	chunk := NewChunkOfSize(shorterText, size)
	if chunk != nil {
		t.Fatal("Chunk should be nil!")
	}
}

func checkWord(word string) bool {
	for i := range validWords {
		if word == validWords[i] {
			return true
		}
	}

	return false
}

func TestWordsNotCut(t *testing.T) {
	size := 12
	chunk := NewChunkOfSize(shorterText, size)
	if chunk == nil {
		t.Fatal("Chunk shouldn't be nil!")
	}

	for {
		text := chunk.Next()
		if text == "" {
			break
		}

		words := strings.Split(text, " ")
		for i := range words {
			if !checkWord(words[i]) {
				t.Fatal(words[i], "isn't a valid word!")
			}
		}
	}
}