package main

import (
	"bufio"
	"errors"
	"io"
	"log"
	"strings"

	"golang.org/x/exp/slices"
)

// NL New line constant
const NL = "\n"

type content [][]byte

func (c *content) Sort(reverse bool) {
	slices.SortFunc(*c, func(a, b []byte) int {
		if reverse {
			a, b = b, a
		}

		return slices.Compare(a, b)
	})
}

func (c *content) Uniques() {
	m := make(map[string]struct{}, len(*c))

	*c = slices.DeleteFunc[content, []byte](*c, func(line []byte) bool {
		if _, ok := m[string(line)]; !ok {
			m[string(line)] = struct{}{}

			return false
		}

		return true
	})
}

func (c *content) String() string {
	lines := *c

	var n int
	for _, line := range lines {
		n += len(line)
	}
	n += len(lines) * len(NL)

	var sb strings.Builder
	sb.Grow(n)

	for i, line := range lines {
		if i > 0 {
			sb.WriteString(NL)
		}

		for _, rn := range line {
			sb.WriteByte(rn)
		}
	}

	return sb.String()
}

func (c *content) Load(r io.Reader) {
	br := bufio.NewReader(r)

	for {
		line, _, err := br.ReadLine()
		if err != nil {
			if errors.Is(io.EOF, err) {
				*c = append(*c, line)

				break
			}

			log.Fatalf("can't read line: %s", err)
		}

		*c = append(*c, line)
	}
}