pedrolopesme/s3tools

// MIT License
//
// Copyright (c) 2018 Pedro Mendes
//
// 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.

package utils

import (
    "bufio"
    "bytes"
    "fmt"
    . "github.com/logrusorgru/aurora"
    "regexp"
)

type s3File interface {
    GetBucket() string
    GetPath() string
    GetBufferedContent() ([]byte, error)
}

// colorizeMatches highlight all matches in a line
func colorizeMatches(line string, matches [][]int) string {
    output := ""
    pointer := 0
    for _, match := range matches {
        start := match[0]
        end := match[1]

        if start >= pointer {
            output += line[pointer:start]
        }

        output += Bold(Red(line[start:end])).String()
        pointer = end
    }

    if pointer < (len(line) - 1) {
        output += line[pointer:]
    }
    return output
}

// GrepLine search for a string pattern in a line
func GrepLine(filePath string, line string, pattern string) {
    // Avoiding patterns beginning with wildcard due to
    // regex violations.
    if string(pattern)[0] == '*' {
        pattern = pattern[1 : len(pattern)-1]
    }

    re := regexp.MustCompile(pattern)
    matches := re.FindAllStringIndex(line, -1)

    if len(matches) > 0 {
        line = colorizeMatches(line, matches)
        fmt.Println(Bold(Cyan(filePath)), ":", line)
        return
    }
}

// GrepFile scans an entire file and search
// for a pattern line by line
func GrepFile(file s3File, pattern string) {
    if file == nil {
        fmt.Println("File parameter cannot be blank")
        return
    }

    if pattern == "" {
        fmt.Println("Pattern parameter cannot be blank")
        return
    }

    buff, err := file.GetBufferedContent()
    if err != nil {
        return
    }

    reader := bytes.NewReader(buff)
    scanner := bufio.NewScanner(reader)
    for scanner.Scan() {
        line := scanner.Text()
        GrepLine(file.GetPath(), line, pattern)
    }
}

// GrepFiles identifies occurrences of a given string or pattern
// on files stored in a S3 bucket
func GrepFiles(bucket string, pattern string, path string) {
    if bucket == "" {
        fmt.Println("Bucket parameter cannot be blank")
        return
    }

    if pattern == "" {
        fmt.Println("Pattern parameter cannot be blank")
        return
    }

    files, err := ListObjects(bucket, path)
    if err != nil {
        fmt.Println("It was impossible retrieve files from bucket", err)
        return
    }

    for _, file := range files {
        GrepFile(file, pattern)
    }
    fmt.Println("GrepFiles finished.")
}