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// Copyright 2014 Oleku Konko All rights reserved.
// Use of this source code is governed by a MIT
// license that can be found in the LICENSE file.

// This module is a Table Writer  API for the Go Programming Language.
// The protocols were written in pure Go and works on windows and unix systems

package tablewriter

import (
    "math"
    "strings"
    "unicode/utf8"
)

var (
    nl = "\n"
    sp = " "
)

const defaultPenalty = 1e5

// Wrap wraps s into a paragraph of lines of length lim, with minimal
// raggedness.
func WrapString(s string, lim int) ([]string, int) {
    words := strings.Split(strings.Replace(s, nl, sp, -1), sp)
    var lines []string
    max := 0
    for _, v := range words {
        max = len(v)
        if max > lim {
            lim = max
        }
    }
    for _, line := range WrapWords(words, 1, lim, defaultPenalty) {
        lines = append(lines, strings.Join(line, sp))
    }
    return lines, lim
}

// WrapWords is the low-level line-breaking algorithm, useful if you need more
// control over the details of the text wrapping process. For most uses,
// WrapString will be sufficient and more convenient.
//
// WrapWords splits a list of words into lines with minimal "raggedness",
// treating each rune as one unit, accounting for spc units between adjacent
// words on each line, and attempting to limit lines to lim units. Raggedness
// is the total error over all lines, where error is the square of the
// difference of the length of the line and lim. Too-long lines (which only
// happen when a single word is longer than lim units) have pen penalty units
// added to the error.
func WrapWords(words []string, spc, lim, pen int) [][]string {
    n := len(words)

    length := make([][]int, n)
    for i := 0; i < n; i++ {
        length[i] = make([]int, n)
        length[i][i] = utf8.RuneCountInString(words[i])
        for j := i + 1; j < n; j++ {
            length[i][j] = length[i][j-1] + spc + utf8.RuneCountInString(words[j])
        }
    }
    nbrk := make([]int, n)
    cost := make([]int, n)
    for i := range cost {
        cost[i] = math.MaxInt32
    }
    for i := n - 1; i >= 0; i-- {
        if length[i][n-1] <= lim {
            cost[i] = 0
            nbrk[i] = n
        } else {
            for j := i + 1; j < n; j++ {
                d := lim - length[i][j-1]
                c := d*d + cost[j]
                if length[i][j-1] > lim {
                    c += pen // too-long lines get a worse penalty
                }
                if c < cost[i] {
                    cost[i] = c
                    nbrk[i] = j
                }
            }
        }
    }
    var lines [][]string
    i := 0
    for i < n {
        lines = append(lines, words[i:nbrk[i]])
        i = nbrk[i]
    }
    return lines
}

// getLines decomposes a multiline string into a slice of strings.
func getLines(s string) []string {
    var lines []string

    for _, line := range strings.Split(s, nl) {
        lines = append(lines, line)
    }
    return lines
}