hishtory/client/cmd/saveHistoryEntry.go

package cmd

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"os"
	"os/exec"
	"os/user"
	"regexp"
	"strconv"
	"strings"
	"syscall"
	"time"

	"github.com/ddworken/hishtory/client/data"
	"github.com/ddworken/hishtory/client/hctx"
	"github.com/ddworken/hishtory/client/lib"
	"github.com/ddworken/hishtory/shared"
	"github.com/spf13/cobra"
)

var saveHistoryEntryCmd = &cobra.Command{
	Use:                "saveHistoryEntry",
	Hidden:             true,
	Short:              "[Internal-only] The command used to save history entries",
	DisableFlagParsing: true,
	Run: func(cmd *cobra.Command, args []string) {
		ctx := hctx.MakeContext()
		lib.CheckFatalError(maybeUploadSkippedHistoryEntries(ctx))
		saveHistoryEntry(ctx)
	},
}

var presaveHistoryEntryCmd = &cobra.Command{
	Use:                "presaveHistoryEntry",
	Hidden:             true,
	Short:              "[Internal-only] The command used to pre-save history entries that haven't yet finished running",
	DisableFlagParsing: true,
	Run: func(cmd *cobra.Command, args []string) {
		ctx := hctx.MakeContext()
		presaveHistoryEntry(ctx)
	},
}

func maybeUploadSkippedHistoryEntries(ctx context.Context) error {
	config := hctx.GetConf(ctx)
	if !config.HaveMissedUploads {
		return nil
	}
	if config.IsOffline {
		return nil
	}

	// Upload the missing entries
	db := hctx.GetDb(ctx)
	query := fmt.Sprintf("after:%s", time.Unix(config.MissedUploadTimestamp, 0).Format("2006-01-02"))
	entries, err := lib.Search(ctx, db, query, 0)
	if err != nil {
		return fmt.Errorf("failed to retrieve history entries that haven't been uploaded yet: %w", err)
	}
	hctx.GetLogger().Infof("Uploading %d history entries that previously failed to upload (query=%#v)\n", len(entries), query)
	jsonValue, err := lib.EncryptAndMarshal(config, entries)
	if err != nil {
		return err
	}
	_, err = lib.ApiPost("/api/v1/submit?source_device_id="+config.DeviceId, "application/json", jsonValue)
	if err != nil {
		// Failed to upload the history entry, so we must still be offline. So just return nil and we'll try again later.
		return nil
	}

	// Mark down that we persisted it
	config.HaveMissedUploads = false
	config.MissedUploadTimestamp = 0
	err = hctx.SetConfig(config)
	if err != nil {
		return fmt.Errorf("failed to mark a history entry as uploaded: %w", err)
	}
	return nil
}

func presaveHistoryEntry(ctx context.Context) {
	config := hctx.GetConf(ctx)
	if !config.IsEnabled {
		return
	}
	if !config.BetaMode {
		return
	}

	// Build the basic entry with metadata retrieved from runtime
	entry, err := buildPreArgsHistoryEntry(ctx)
	lib.CheckFatalError(err)
	if entry == nil {
		return
	}

	// Augment it with os.Args
	entry.Command = trimTrailingWhitespace(os.Args[3])
	if strings.HasPrefix(" ", entry.Command) {
		// Don't save commands that start with a space
		return
	}
	startTime, err := parseCrossPlatformInt(os.Args[4])
	lib.CheckFatalError(err)
	entry.StartTime = time.Unix(startTime, 0).UTC()
	entry.EndTime = time.Unix(0, 0).UTC()

	// And persist it locally.
	db := hctx.GetDb(ctx)
	err = lib.ReliableDbCreate(db, *entry)
	lib.CheckFatalError(err)
	db.Commit()

	// Note that we aren't persisting these half-entries remotely,
	// since they should be updated with the rest of the information very soon. If they
	// are never updated (e.g. due to a long-running command that never finishes), then
	// they will only be available on this device. That isn't perfect since it means
	// history entries can get out of sync, but it is probably good enough.
	// TODO: Consider improving this
}

func saveHistoryEntry(ctx context.Context) {
	config := hctx.GetConf(ctx)
	if !config.IsEnabled {
		hctx.GetLogger().Infof("Skipping saving a history entry because hishtory is disabled\n")
		return
	}
	entry, err := buildHistoryEntry(ctx, os.Args)
	lib.CheckFatalError(err)
	if entry == nil {
		hctx.GetLogger().Infof("Skipping saving a history entry because we did not build a history entry (was the command prefixed with a space and/or empty?)\n")
		return
	}
	db := hctx.GetDb(ctx)

	// Drop any entries from pre-saving since they're no longer needed
	if config.BetaMode {
		tx, err := lib.MakeWhereQueryFromSearch(ctx, db, "cwd:"+entry.CurrentWorkingDirectory+" start_time:"+strconv.FormatInt(entry.StartTime.Unix(), 10))
		if err != nil {
			lib.CheckFatalError(fmt.Errorf("failed to query for pre-saved history entry: %w", err))
		}
		res := tx.Delete(&data.HistoryEntry{})
		if res.Error != nil {
			lib.CheckFatalError(fmt.Errorf("failed to delete pre-saved history entry (expected command=%#v): %w", entry.Command, res.Error))
		}
		if res.RowsAffected > 1 {
			lib.CheckFatalError(fmt.Errorf("attempted to delete pre-saved entry, but something went wrong since we deleted %d rows", res.RowsAffected))
		}
	}

	// Persist it locally
	err = lib.ReliableDbCreate(db, *entry)
	lib.CheckFatalError(err)

	// Persist it remotely
	if !config.IsOffline {
		jsonValue, err := lib.EncryptAndMarshal(config, []*data.HistoryEntry{entry})
		lib.CheckFatalError(err)
		_, err = lib.ApiPost("/api/v1/submit?source_device_id="+config.DeviceId, "application/json", jsonValue)
		if err != nil {
			if lib.IsOfflineError(err) {
				hctx.GetLogger().Infof("Failed to remotely persist hishtory entry because we failed to connect to the remote server! This is likely because the device is offline, but also could be because the remote server is having reliability issues. Original error: %v", err)
				if !config.HaveMissedUploads {
					config.HaveMissedUploads = true
					config.MissedUploadTimestamp = time.Now().Unix()
					lib.CheckFatalError(hctx.SetConfig(config))
				}
			} else {
				lib.CheckFatalError(err)
			}
		}
	}

	// Check if there is a pending dump request and reply to it if so
	dumpRequests, err := lib.GetDumpRequests(config)
	if err != nil {
		if lib.IsOfflineError(err) {
			// It is fine to just ignore this, the next command will retry the API and eventually we will respond to any pending dump requests
			dumpRequests = []*shared.DumpRequest{}
			hctx.GetLogger().Infof("Failed to check for dump requests because we failed to connect to the remote server!")
		} else {
			lib.CheckFatalError(err)
		}
	}
	if len(dumpRequests) > 0 {
		lib.CheckFatalError(lib.RetrieveAdditionalEntriesFromRemote(ctx))
		entries, err := lib.Search(ctx, db, "", 0)
		lib.CheckFatalError(err)
		var encEntries []*shared.EncHistoryEntry
		for _, entry := range entries {
			enc, err := data.EncryptHistoryEntry(config.UserSecret, *entry)
			lib.CheckFatalError(err)
			encEntries = append(encEntries, &enc)
		}
		reqBody, err := json.Marshal(encEntries)
		lib.CheckFatalError(err)
		for _, dumpRequest := range dumpRequests {
			if !config.IsOffline {
				_, err := lib.ApiPost("/api/v1/submit-dump?user_id="+dumpRequest.UserId+"&requesting_device_id="+dumpRequest.RequestingDeviceId+"&source_device_id="+config.DeviceId, "application/json", reqBody)
				lib.CheckFatalError(err)
			}
		}
	}

	// Handle deletion requests
	lib.CheckFatalError(lib.ProcessDeletionRequests(ctx))

	if config.BetaMode {
		db.Commit()
	}
}

func init() {
	rootCmd.AddCommand(saveHistoryEntryCmd)
	rootCmd.AddCommand(presaveHistoryEntryCmd)
}

func buildPreArgsHistoryEntry(ctx context.Context) (*data.HistoryEntry, error) {
	var entry data.HistoryEntry

	// user
	user, err := user.Current()
	if err != nil {
		return nil, fmt.Errorf("failed to build history entry: %w", err)
	}
	entry.LocalUsername = user.Username

	// cwd and homedir
	cwd, homedir, err := getCwd(ctx)
	if err != nil {
		return nil, fmt.Errorf("failed to build history entry: %w", err)
	}
	entry.CurrentWorkingDirectory = cwd
	entry.HomeDirectory = homedir

	// hostname
	hostname, err := os.Hostname()
	if err != nil {
		return nil, fmt.Errorf("failed to build history entry: %w", err)
	}
	entry.Hostname = hostname

	// device ID
	config := hctx.GetConf(ctx)
	entry.DeviceId = config.DeviceId

	// custom columns
	cc, err := buildCustomColumns(ctx)
	if err != nil {
		return nil, err
	}
	entry.CustomColumns = cc

	return &entry, nil
}

func buildHistoryEntry(ctx context.Context, args []string) (*data.HistoryEntry, error) {
	if len(args) < 6 {
		hctx.GetLogger().Warnf("buildHistoryEntry called with args=%#v, which has too few entries! This can happen in specific edge cases for newly opened terminals and is likely not a problem.", args)
		return nil, nil
	}
	shell := args[2]

	entry, err := buildPreArgsHistoryEntry(ctx)
	if err != nil {
		return nil, err
	}

	// exitCode
	exitCode, err := strconv.Atoi(args[3])
	if err != nil {
		return nil, fmt.Errorf("failed to build history entry: %w", err)
	}
	entry.ExitCode = exitCode

	// start time
	seconds, err := parseCrossPlatformInt(args[5])
	if err != nil {
		return nil, fmt.Errorf("failed to parse start time %s as int: %w", args[5], err)
	}
	entry.StartTime = time.Unix(seconds, 0).UTC()

	// end time
	entry.EndTime = time.Now().UTC()

	// command
	if shell == "bash" {
		cmd, err := getLastCommand(args[4])
		if err != nil {
			return nil, fmt.Errorf("failed to build history entry: %w", err)
		}
		shouldBeSkipped, err := shouldSkipHiddenCommand(ctx, args[4])
		if err != nil {
			return nil, fmt.Errorf("failed to check if command was hidden: %w", err)
		}
		if shouldBeSkipped || strings.HasPrefix(cmd, " ") {
			// Don't save commands that start with a space
			return nil, nil
		}
		cmd, err = maybeSkipBashHistTimePrefix(cmd)
		if err != nil {
			return nil, err
		}
		entry.Command = cmd
	} else if shell == "zsh" || shell == "fish" {
		cmd := trimTrailingWhitespace(args[4])
		if strings.HasPrefix(cmd, " ") {
			// Don't save commands that start with a space
			return nil, nil
		}
		entry.Command = cmd
	} else {
		return nil, fmt.Errorf("tried to save a hishtory entry from an unsupported shell=%#v", shell)
	}
	if strings.TrimSpace(entry.Command) == "" {
		// Skip recording empty commands where the user just hits enter in their terminal
		return nil, nil
	}

	return entry, nil
}

func trimTrailingWhitespace(s string) string {
	return strings.TrimSuffix(strings.TrimSuffix(s, "\n"), " ")
}

func buildCustomColumns(ctx context.Context) (data.CustomColumns, error) {
	ccs := data.CustomColumns{}
	config := hctx.GetConf(ctx)
	for _, cc := range config.CustomColumns {
		cmd := exec.Command("bash", "-c", cc.ColumnCommand)
		var stdout bytes.Buffer
		cmd.Stdout = &stdout
		var stderr bytes.Buffer
		cmd.Stderr = &stderr
		err := cmd.Start()
		if err != nil {
			return nil, fmt.Errorf("failed to execute custom command named %v (stdout=%#v, stderr=%#v)", cc.ColumnName, stdout.String(), stderr.String())
		}
		err = cmd.Wait()
		if err != nil {
			// Log a warning, but don't crash. This way commands can exit with a different status and still work.
			hctx.GetLogger().Warnf("failed to execute custom command named %v (stdout=%#v, stderr=%#v)", cc.ColumnName, stdout.String(), stderr.String())
		}
		ccv := data.CustomColumn{
			Name: cc.ColumnName,
			Val:  strings.TrimSpace(stdout.String()),
		}
		ccs = append(ccs, ccv)
	}
	return ccs, nil
}

func buildRegexFromTimeFormat(timeFormat string) string {
	expectedRegex := ""
	lastCharWasPercent := false
	for _, char := range timeFormat {
		if lastCharWasPercent {
			if char == '%' {
				expectedRegex += regexp.QuoteMeta(string(char))
				lastCharWasPercent = false
				continue
			} else if char == 't' {
				expectedRegex += "\t"
			} else if char == 'F' {
				expectedRegex += buildRegexFromTimeFormat("%Y-%m-%d")
			} else if char == 'Y' {
				expectedRegex += "[0-9]{4}"
			} else if char == 'G' {
				expectedRegex += "[0-9]{4}"
			} else if char == 'g' {
				expectedRegex += "[0-9]{2}"
			} else if char == 'C' {
				expectedRegex += "[0-9]{2}"
			} else if char == 'u' || char == 'w' {
				expectedRegex += "[0-9]"
			} else if char == 'm' {
				expectedRegex += "[0-9]{2}"
			} else if char == 'd' {
				expectedRegex += "[0-9]{2}"
			} else if char == 'D' {
				expectedRegex += buildRegexFromTimeFormat("%m/%d/%y")
			} else if char == 'T' {
				expectedRegex += buildRegexFromTimeFormat("%H:%M:%S")
			} else if char == 'H' || char == 'I' || char == 'U' || char == 'V' || char == 'W' || char == 'y' || char == 'Y' {
				expectedRegex += "[0-9]{2}"
			} else if char == 'M' {
				expectedRegex += "[0-9]{2}"
			} else if char == 'j' {
				expectedRegex += "[0-9]{3}"
			} else if char == 'S' || char == 'm' {
				expectedRegex += "[0-9]{2}"
			} else if char == 'c' {
				// Note: Specific to the POSIX locale
				expectedRegex += buildRegexFromTimeFormat("%a %b %e %H:%M:%S %Y")
			} else if char == 'a' {
				// Note: Specific to the POSIX locale
				expectedRegex += "(Sun|Mon|Tue|Wed|Thu|Fri|Sat)"
			} else if char == 'b' || char == 'h' {
				// Note: Specific to the POSIX locale
				expectedRegex += "(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)"
			} else if char == 'e' || char == 'k' || char == 'l' {
				expectedRegex += "[0-9 ]{2}"
			} else if char == 'n' {
				expectedRegex += "\n"
			} else if char == 'p' {
				expectedRegex += "(AM|PM)"
			} else if char == 'P' {
				expectedRegex += "(am|pm)"
			} else if char == 's' {
				expectedRegex += "\\d+"
			} else if char == 'z' {
				expectedRegex += "[+-][0-9]{4}"
			} else if char == 'r' {
				expectedRegex += buildRegexFromTimeFormat("%I:%M:%S %p")
			} else if char == 'R' {
				expectedRegex += buildRegexFromTimeFormat("%H:%M")
			} else if char == 'x' {
				expectedRegex += buildRegexFromTimeFormat("%m/%d/%y")
			} else if char == 'X' {
				expectedRegex += buildRegexFromTimeFormat("%H:%M:%S")
			} else {
				panic(fmt.Sprintf("buildRegexFromTimeFormat doesn't support %%%v, please open a bug against github.com/ddworken/hishtory", string(char)))
			}
		} else if char != '%' {
			expectedRegex += regexp.QuoteMeta(string(char))
		}
		lastCharWasPercent = false
		if char == '%' {
			lastCharWasPercent = true
		}
	}
	return expectedRegex
}

func maybeSkipBashHistTimePrefix(cmdLine string) (string, error) {
	format := os.Getenv("HISTTIMEFORMAT")
	if format == "" {
		return cmdLine, nil
	}
	re, err := regexp.Compile("^" + buildRegexFromTimeFormat(format))
	if err != nil {
		return "", fmt.Errorf("failed to parse regex for HISTTIMEFORMAT variable: %w", err)
	}
	return re.ReplaceAllLiteralString(cmdLine, ""), nil
}

func parseCrossPlatformInt(data string) (int64, error) {
	data = strings.TrimSuffix(data, "N")
	return strconv.ParseInt(data, 10, 64)
}

func getLastCommand(history string) (string, error) {
	split := strings.SplitN(strings.TrimSpace(history), " ", 2)
	if len(split) <= 1 {
		return "", fmt.Errorf("got unexpected bash history line: %#v, please open a bug at github.com/ddworken/hishtory", history)
	}
	split = strings.SplitN(split[1], " ", 2)
	if len(split) <= 1 {
		return "", fmt.Errorf("got unexpected bash history line: %#v, please open a bug at github.com/ddworken/hishtory", history)
	}
	return split[1], nil
}

func shouldSkipHiddenCommand(ctx context.Context, historyLine string) (bool, error) {
	config := hctx.GetConf(ctx)
	if config.LastSavedHistoryLine == historyLine {
		return true, nil
	}
	config.LastSavedHistoryLine = historyLine
	err := hctx.SetConfig(config)
	if err != nil {
		return false, err
	}
	return false, nil
}

func getCwd(ctx context.Context) (string, string, error) {
	cwd, err := getCwdWithoutSubstitution()
	if err != nil {
		return "", "", fmt.Errorf("failed to get cwd for last command: %w", err)
	}
	homedir := hctx.GetHome(ctx)
	if cwd == homedir {
		return "~/", homedir, nil
	}
	if strings.HasPrefix(cwd, homedir) {
		return strings.Replace(cwd, homedir, "~", 1), homedir, nil
	}
	return cwd, homedir, nil
}

func getCwdWithoutSubstitution() (string, error) {
	cwd, err := os.Getwd()
	if err == nil {
		return cwd, nil
	}
	// Fall back to the syscall to see if that works, as an attempt to
	// fix github.com/ddworken/hishtory/issues/69
	if syscall.ImplementsGetwd {
		cwd, err = syscall.Getwd()
		if err == nil {
			return cwd, nil
		}
	}
	return "", err
}