1// Copyright 2019 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package cmd
6
7import (
8	"context"
9	"flag"
10	"fmt"
11	"io/ioutil"
12	"os"
13	"path/filepath"
14	"sort"
15
16	"golang.org/x/tools/internal/lsp/diff"
17	"golang.org/x/tools/internal/lsp/protocol"
18	"golang.org/x/tools/internal/lsp/source"
19	"golang.org/x/tools/internal/span"
20	"golang.org/x/tools/internal/tool"
21	errors "golang.org/x/xerrors"
22)
23
24// rename implements the rename verb for gopls.
25type rename struct {
26	Diff  bool `flag:"d" help:"display diffs instead of rewriting files"`
27	Write bool `flag:"w" help:"write result to (source) file instead of stdout"`
28
29	app *Application
30}
31
32func (r *rename) Name() string      { return "rename" }
33func (r *rename) Usage() string     { return "<position>" }
34func (r *rename) ShortHelp() string { return "rename selected identifier" }
35func (r *rename) DetailedHelp(f *flag.FlagSet) {
36	fmt.Fprint(f.Output(), `
37Example:
38
39  $ # 1-based location (:line:column or :#position) of the thing to change
40  $ gopls rename helper/helper.go:8:6
41  $ gopls rename helper/helper.go:#53
42
43	gopls rename flags are:
44`)
45	f.PrintDefaults()
46}
47
48// Run renames the specified identifier and either;
49// - if -w is specified, updates the file(s) in place;
50// - if -d is specified, prints out unified diffs of the changes; or
51// - otherwise, prints the new versions to stdout.
52func (r *rename) Run(ctx context.Context, args ...string) error {
53	if len(args) != 2 {
54		return tool.CommandLineErrorf("definition expects 2 arguments (position, new name)")
55	}
56	conn, err := r.app.connect(ctx)
57	if err != nil {
58		return err
59	}
60	defer conn.terminate(ctx)
61
62	from := span.Parse(args[0])
63	file := conn.AddFile(ctx, from.URI())
64	if file.err != nil {
65		return file.err
66	}
67	loc, err := file.mapper.Location(from)
68	if err != nil {
69		return err
70	}
71	p := protocol.RenameParams{
72		TextDocument: protocol.TextDocumentIdentifier{URI: loc.URI},
73		Position:     loc.Range.Start,
74		NewName:      args[1],
75	}
76	edit, err := conn.Rename(ctx, &p)
77	if err != nil {
78		return err
79	}
80	var orderedURIs []string
81	edits := map[span.URI][]protocol.TextEdit{}
82	for _, c := range edit.DocumentChanges {
83		uri := span.URI(c.TextDocument.URI)
84		edits[uri] = append(edits[uri], c.Edits...)
85		orderedURIs = append(orderedURIs, c.TextDocument.URI)
86	}
87	sort.Strings(orderedURIs)
88	changeCount := len(orderedURIs)
89
90	for _, u := range orderedURIs {
91		uri := span.URI(u)
92		cmdFile := conn.AddFile(ctx, uri)
93		filename := cmdFile.uri.Filename()
94
95		// convert LSP-style edits to []diff.TextEdit cuz Spans are handy
96		renameEdits, err := source.FromProtocolEdits(cmdFile.mapper, edits[uri])
97		if err != nil {
98			return errors.Errorf("%v: %v", edits, err)
99		}
100		newContent := diff.ApplyEdits(string(cmdFile.mapper.Content), renameEdits)
101
102		switch {
103		case r.Write:
104			fmt.Fprintln(os.Stderr, filename)
105			err := os.Rename(filename, filename+".orig")
106			if err != nil {
107				return errors.Errorf("%v: %v", edits, err)
108			}
109			ioutil.WriteFile(filename, []byte(newContent), 0644)
110		case r.Diff:
111			diffs := diff.ToUnified(filename+".orig", filename, string(cmdFile.mapper.Content), renameEdits)
112			fmt.Print(diffs)
113		default:
114			if len(orderedURIs) > 1 {
115				fmt.Printf("%s:\n", filepath.Base(filename))
116			}
117			fmt.Print(string(newContent))
118			if changeCount > 1 { // if this wasn't last change, print newline
119				fmt.Println()
120			}
121			changeCount -= 1
122		}
123	}
124	return nil
125}
126