github.com/freetocompute/snapd@v0.0.0-20210618182524-2fb355d72fd9/cmd/snap/last.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2017 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     9   *
    10   * This program is distributed in the hope that it will be useful,
    11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   * GNU General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package main
    21  
    22  import (
    23  	"errors"
    24  	"fmt"
    25  
    26  	"github.com/snapcore/snapd/client"
    27  	"github.com/snapcore/snapd/i18n"
    28  )
    29  
    30  type changeIDMixin struct {
    31  	clientMixin
    32  	LastChangeType string `long:"last"`
    33  	Positional     struct {
    34  		ID changeID `positional-arg-name:"<id>"`
    35  	} `positional-args:"yes"`
    36  }
    37  
    38  var changeIDMixinOptDesc = mixinDescs{
    39  	// TRANSLATORS: This should not start with a lowercase letter.
    40  	"last": i18n.G("Select last change of given type (install, refresh, remove, try, auto-refresh, etc.). A question mark at the end of the type means to do nothing (instead of returning an error) if no change of the given type is found. Note the question mark could need protecting from the shell."),
    41  }
    42  
    43  var changeIDMixinArgDesc = []argDesc{{
    44  	// TRANSLATORS: This needs to begin with < and end with >
    45  	name: i18n.G("<change-id>"),
    46  	// TRANSLATORS: This should not start with a lowercase letter.
    47  	desc: i18n.G("Change ID"),
    48  }}
    49  
    50  // should not be user-visible, but keep it clear and polite because mistakes happen
    51  var noChangeFoundOK = errors.New("no change found but that's ok")
    52  
    53  func (l *changeIDMixin) GetChangeID() (string, error) {
    54  	if l.Positional.ID == "" && l.LastChangeType == "" {
    55  		return "", fmt.Errorf(i18n.G("please provide change ID or type with --last=<type>"))
    56  	}
    57  
    58  	if l.Positional.ID != "" {
    59  		if l.LastChangeType != "" {
    60  			return "", fmt.Errorf(i18n.G("cannot use change ID and type together"))
    61  		}
    62  
    63  		return string(l.Positional.ID), nil
    64  	}
    65  
    66  	cli := l.client
    67  	// note that at this point we know l.LastChangeType != ""
    68  	kind := l.LastChangeType
    69  	optional := false
    70  	if l := len(kind) - 1; kind[l] == '?' {
    71  		optional = true
    72  		kind = kind[:l]
    73  	}
    74  	// our internal change types use "-snap" postfix but let user skip it and use short form.
    75  	if kind == "refresh" || kind == "install" || kind == "remove" || kind == "connect" || kind == "disconnect" || kind == "configure" || kind == "try" {
    76  		kind += "-snap"
    77  	}
    78  	changes, err := queryChanges(cli, &client.ChangesOptions{Selector: client.ChangesAll})
    79  	if err != nil {
    80  		return "", err
    81  	}
    82  	if len(changes) == 0 {
    83  		if optional {
    84  			return "", noChangeFoundOK
    85  		}
    86  		return "", fmt.Errorf(i18n.G("no changes found"))
    87  	}
    88  	chg := findLatestChangeByKind(changes, kind)
    89  	if chg == nil {
    90  		if optional {
    91  			return "", noChangeFoundOK
    92  		}
    93  		return "", fmt.Errorf(i18n.G("no changes of type %q found"), l.LastChangeType)
    94  	}
    95  
    96  	return chg.ID, nil
    97  }
    98  
    99  func findLatestChangeByKind(changes []*client.Change, kind string) (latest *client.Change) {
   100  	for _, chg := range changes {
   101  		if chg.Kind == kind && (latest == nil || latest.SpawnTime.Before(chg.SpawnTime)) {
   102  			latest = chg
   103  		}
   104  	}
   105  	return latest
   106  }