Утилита командной строки для переноса пользовательских данных с MUBI.com на letterboxd.com

Сделайте обзор кода утилиты командной строки для переноса пользовательских данных с MUBI.com на letterboxd.com. Утилита заставляет Get HTTP-запрос скачивать json-данные, анализирует их и сохраняет в виде CSV-файла.

Можно найти на github

// mubi2letterboxd is a simple command line utility for user data migration from MUBI to letterboxd.
// With the utility, you can create a .csv file suitable for manual import to Letterboxd.
//
// inspired by the reddit entry by jcunews1
// https://www.reddit.com/r/learnjavascript/comments/auwynr/export_mubi_data/ehcx2zf/

package main

import (
    "bufio"
    "encoding/csv"
    "encoding/json"
    "errors"
    "fmt"
    "io/ioutil"
    "log"
    "net/http"
    "os"
    "path/filepath"
    "strconv"
    "strings"
    "time"
)

type MovieRecord struct {
    Id        int    `json:"id"`
    Review    string `json:"body"`
    WatchedAt int64  `json:"updated_at"`
    Rating    int    `json:"overall"`
    Film      struct {
        Title     string `json:"title"`
        Year      int    `json:"year"`
        Directors []struct {
            Name string `json:"name"`
        } `json:"directors"`
    } `json:"film"`
}

const (
    url                   = "https://mubi.com/services/api/ratings"
    perPage               = "1000"
    letterboxdCsvFileName = "letterboxd.csv"
)

func main() {
    fmt.Print("Input MUBI userID and press Enter: ")
    var mubiUserId string
    if _, err := fmt.Scanf("%s", &mubiUserId); err == nil {
        if _, err := strconv.ParseUint(mubiUserId, 10, 64); err == nil {
            if err := process(mubiUserId); err != nil {
                fmt.Fprintf(os.Stderr, "Error occurred: %sn", err)
            }
        } else {
            fmt.Fprintf(os.Stderr,"%q is not a valid UserIdn", mubiUserId)
        }
    } else {
        fmt.Fprintf(os.Stderr, "Error reading UserID: %sn", err)
    }

    fmt.Print("Press Enter to exit")
    bufio.NewReader(os.Stdin).ReadBytes('n')
}

func process(mubiUserId string) error {

    var movieRecords []MovieRecord
    var csvRows [][]string

    client := &http.Client{}
    req, err := http.NewRequest("GET", url, nil)
    if err != nil {
        return err
    }
    query := req.URL.Query()
    query.Set("user_id", mubiUserId)
    query.Set("per_page", perPage)

    fmt.Printf("Data for UserID %s will be requested from MUBI servern", mubiUserId)
    for i := 1; ; i++ {
        fmt.Printf("Requesting for chunk #%d... ", i)
        query.Set("page", strconv.Itoa(i))
        req.URL.RawQuery = query.Encode()

        response, err := client.Do(req)
        if err != nil {
            return err
        }

        if response.StatusCode != http.StatusOK {
            return errors.New(fmt.Sprintf("Server returned status code %d", response.StatusCode))
        }

        jsonFile, err := ioutil.ReadAll(response.Body)
        if err != nil {
            return err
        }

        if err := json.Unmarshal(jsonFile, &movieRecords); err != nil {
            return err
        }
        fmt.Printf("downloaded %d recordsn", len(movieRecords))

        if len(movieRecords) == 0 {
            break
        }

        for _, item := range movieRecords {
            csvRows = append(csvRows, generateCsvRow(item))
        }
    }

    if len(csvRows) == 0 {
        fmt.Printf("nNo records found at MUBI server for UserID %sn", mubiUserId)
        return nil
    }

    outFile, err := os.Create(letterboxdCsvFileName)
    if err != nil {
        return err
    }
    defer func() {
        err := outFile.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()

    csvwriter := csv.NewWriter(outFile)
    defer csvwriter.Flush()
    if err := csvwriter.Write([]string{"tmdbID", "Title", "Year", "Directors", "Rating", "WatchedDate", "Review"}); err != nil {
        return err
    }
    if err := csvwriter.WriteAll(csvRows); err != nil {
        return err
    }

    absPath, err := filepath.Abs(outFile.Name())
    if err != nil {
        return err
    }
    fmt.Printf("n%d records are saved to %qn", len(csvRows), absPath)

    return outFile.Sync()
}

func generateCsvRow(r MovieRecord) []string {
    idOut := strconv.Itoa(r.Id)
    titleOut := r.Film.Title
    yearOut := strconv.Itoa(r.Film.Year)

    directors := make([]string, len(r.Film.Directors))
    for i, director := range r.Film.Directors {
        directors[i] = director.Name
    }
    directorsOut := strings.Join(directors, ", ")

    ratingOut := strconv.Itoa(r.Rating)
    timeOut := time.Unix(r.WatchedAt, 0).Format("2006-01-02")
    reviewOut := r.Review

    return []string{idOut, titleOut, yearOut, directorsOut, ratingOut, timeOut, reviewOut}
}