package lorem

import (
	"rand"
	"time"
	"strings"
)

var src = rand.New(rand.NewSource(time.Nanoseconds()))

// Generate a natural word len.
func genWordLen() int {
	f := src.Float32() * 100

	// a table of word lengths and their frequencies.
	switch {
	case f < 1.939:
		return 1
	case f < 19.01:
		return 2
	case f < 38.00:
		return 3
	case f < 50.41:
		return 4
	case f < 61.00:
		return 5
	case f < 70.09:
		return 6
	case f < 78.97:
		return 7
	case f < 85.65:
		return 8
	case f < 90.87:
		return 9
	case f < 95.05:
		return 10
	case f < 97.27:
		return 11
	case f < 98.67:
		return 12
	case f < 100.0:
		return 13
	}
	return 2 // shouldn't get here
}

func intRange(min, max int) int {
	n := src.Int() % (max - min)
	return n + min
}

func word(wordLen int) string {	
	if wordLen < 1 {
		wordLen = 1
	}
	if wordLen > 13 {
		wordLen = 13 
	}

	n := src.Int() % len(wordlist)
	for {
		if n >= len(wordlist)-1 {
			n = 0
		}
		if len(wordlist[n]) == wordLen {
			return wordlist[n]
		}
		n++		
	}
	return ""
}

// Generate a word in a specfied range of letters.
func Word(min, max int) string {
	n := intRange(min, max)
	return word(n)
}

// Generate a sentence with a specified range of words.
func Sentence(min, max int) string {
	n := intRange(min, max)

	// grab some words
	ws := []string{}
	maxcommas := 2
	numcomma := 0
	for i := 0; i < n; i++ {
		// maybe insert a comma, if there's less than two and
		// the current word is not the last or first
		if (src.Int()%n == 0) && numcomma < maxcommas && i < n-1 && i > 2 {
			ws[len(ws)-1] += ","
			numcomma += 1
		}
		ws = append(ws, (word(genWordLen())))
	}

	sentence := strings.Join(ws, " ") + "."
	sentence = strings.ToUpper(sentence[:1]) + sentence[1:]
	return sentence
}

// Generate a paragraph with a specified range of sentenences.
const (
	minwords = 5
	maxwords = 22
)

func Paragraph(min, max int) string {
	n := intRange(min, max)

	p := []string{}
	for i := 0; i < n; i++ {
		p = append(p, Sentence(minwords, maxwords))
	}
	return strings.Join(p, "  ")
}


// Generate a random URL
func Url() string {
	n := intRange(0, 3)
	
	base := `http://www.` + Host()

	switch n { 
	case 0: break		
	case 1: base += "/" + Word(2,8) 
	case 2: base += "/" + Word(2,8) + "/" + Word(2,8) + ".html"
	}
	return base
}

// Host
func Host() string {
	n := intRange(0, 3)
	tld := ""
	switch n {
	case 0: tld = ".com"
	case 1: tld = ".net"
	case 2: tld = ".org"
	}

	parts := []string{Word(2,8), Word(2,8), tld}
	return strings.Join(parts, ``)
}

// Email
func Email() string {
	return Word(4,10) + `@` + Host()
}