package ui

import (
	"strings"
	"unicode"

	"github.com/mattn/go-runewidth"
)

// The following code is modified from github.com/fogleman/gg/wrap.go

// Copyright (C) 2016 Michael Fogleman
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

func splitOnSpace(x string) []string {
	var result []string
	var pi int
	var ps bool
	for i, c := range x {
		s := unicode.IsSpace(c)
		if s != ps && i > 0 {
			result = append(result, x[pi:i])
			pi = i
		}
		ps = s
	}
	result = append(result, x[pi:])
	return result
}

// WordWrap wraps s to the provided width.
func WordWrap(s string, width int) []string {
	var result []string
	var line string
	fields := splitOnSpace(s)
	for i, field := range fields {
		if i != 0 {
			if runewidth.StringWidth(line+field) > width {
				// Only move to the next line if the field is not longer than an entire line
				if runewidth.StringWidth(field) < width {
					result = append(result, line)
					line = ""
					field = strings.TrimLeftFunc(field, unicode.IsSpace)
				}
			}
		}
		line += field
		w := runewidth.StringWidth(line)
		if w > width {
			// Wrap line
			for {
				left, right := Splice(line, width)
				result = append(result, left)
				line = right
				line = strings.TrimLeftFunc(line, unicode.IsSpace)
				if runewidth.StringWidth(line) <= width {
					break
				}
			}
		}
	}

	result = append(result, line)
	return result
}