/*
Copyright © 2022 Seednode <seednode@seedno.de>
*/

package cmd

import (
	"bufio"
	"os"
	"strings"
)

type Exit struct{ Code int }

func Chunks(s string, chunkSize int) []string {
	if len(s) == 0 {
		return nil
	}

	if chunkSize >= len(s) {
		return []string{s}
	}

	var chunks []string = make([]string, 0, (len(s)-1)/chunkSize+1)

	currentLen := 0
	currentStart := 0

	for i := range s {
		if currentLen == chunkSize {
			chunks = append(chunks, s[currentStart:i])
			currentLen = 0
			currentStart = i
		}

		currentLen++
	}

	chunks = append(chunks, s[currentStart:])

	return chunks
}

func CollectOutputs(output chan string, outputs chan<- []string) {
	o := []string{}

	for r := range output {
		o = append(o, r)
	}

	outputs <- o

	close(outputs)
}

func FirstN(s string, n int) string {
	i := 0
	for j := range s {
		if i == n {
			return s[:j]
		}
		i++
	}
	return s
}

func HandleExit() {
	if e := recover(); e != nil {
		if exit, ok := e.(Exit); ok == true {
			os.Exit(exit.Code)
		}
		panic(e)
	}
}

func ScanFile(dbfile string) (func(), *bufio.Scanner, error) {
	readFile, err := os.Open(dbfile)
	if err != nil {
		return func() {}, nil, err
	}

	fileScanner := bufio.NewScanner(readFile)
	buffer := make([]byte, 0, 64*1024)
	fileScanner.Buffer(buffer, 1024*1024)

	return func() { _ = readFile.Close() }, fileScanner, nil
}

func Strip(s string) string {
	var result strings.Builder
	for i := 0; i < len(s); i++ {
		b := s[i]

		if ('a' <= b && b <= 'z') ||
			('A' <= b && b <= 'Z') ||
			('0' <= b && b <= '9') {
			result.WriteByte(b)
		}
	}

	return result.String()
}