| 1 | // Command abono writes abono's starter pages into an app. |
| 2 | // |
| 3 | // abono pages -pkg <name> -dir <path> |
| 4 | // |
| 5 | // writes <path>/abono_pages.go, in package <name>, and the pages it |
| 6 | // renders, <path>/templates/abono/*.html. From then on they are the app's: |
| 7 | // committed, edited, translated. The command never overwrites a file. If |
| 8 | // any of them exists it writes nothing and lists the ones in the way; |
| 9 | // move them aside to start again. |
| 10 | package main |
| 11 | |
| 12 | import ( |
| 13 | "bytes" |
| 14 | "embed" |
| 15 | "errors" |
| 16 | "flag" |
| 17 | "fmt" |
| 18 | "go/format" |
| 19 | "go/token" |
| 20 | "io" |
| 21 | "io/fs" |
| 22 | "os" |
| 23 | "path" |
| 24 | "path/filepath" |
| 25 | "sort" |
| 26 | "strings" |
| 27 | ) |
| 28 | |
| 29 | //go:embed pages/*.tmpl |
| 30 | var sources embed.FS |
| 31 | |
| 32 | // packageLine is the line of abono_pages.go.tmpl that -pkg replaces. |
| 33 | const packageLine = "\npackage PKG\n" |
| 34 | |
| 35 | func main() { |
| 36 | os.Exit(run(os.Args[1:], os.Stdout, os.Stderr)) |
| 37 | } |
| 38 | |
| 39 | const usage = `usage: abono pages -pkg <name> -dir <path> |
| 40 | |
| 41 | Writes abono's starter pages into an app: <path>/abono_pages.go, in Go |
| 42 | package <name>, and <path>/templates/abono/*.html. Nothing is ever |
| 43 | overwritten: if any of those files exists, nothing is written. |
| 44 | ` |
| 45 | |
| 46 | // run is the command, for main and the tests: its exit code, 0 on |
| 47 | // success, 1 when it refused or failed, 2 for a usage mistake. |
| 48 | func run(args []string, stdout, stderr io.Writer) int { |
| 49 | if len(args) == 0 || args[0] != "pages" { |
| 50 | fmt.Fprint(stderr, usage) |
| 51 | return 2 |
| 52 | } |
| 53 | fset := flag.NewFlagSet("abono pages", flag.ContinueOnError) |
| 54 | fset.SetOutput(stderr) |
| 55 | fset.Usage = func() { fmt.Fprint(stderr, usage) } |
| 56 | pkg := fset.String("pkg", "", "the Go package abono_pages.go is in") |
| 57 | dir := fset.String("dir", "", "the directory to write into") |
| 58 | if err := fset.Parse(args[1:]); err != nil { |
| 59 | return 2 |
| 60 | } |
| 61 | switch { |
| 62 | case fset.NArg() > 0: |
| 63 | fmt.Fprintf(stderr, "abono pages: unexpected %q\n%s", fset.Arg(0), usage) |
| 64 | return 2 |
| 65 | case *pkg == "" || *dir == "": |
| 66 | fmt.Fprintf(stderr, "abono pages: -pkg and -dir are both required\n%s", usage) |
| 67 | return 2 |
| 68 | case !token.IsIdentifier(*pkg) || token.IsKeyword(*pkg): |
| 69 | fmt.Fprintf(stderr, "abono pages: -pkg %q is not a Go package name\n", *pkg) |
| 70 | return 2 |
| 71 | } |
| 72 | |
| 73 | files, err := pages(*pkg) |
| 74 | if err != nil { |
| 75 | fmt.Fprintf(stderr, "abono pages: %v\n", err) |
| 76 | return 1 |
| 77 | } |
| 78 | if err := write(*dir, files); err != nil { |
| 79 | fmt.Fprintf(stderr, "abono pages: %v\n", err) |
| 80 | return 1 |
| 81 | } |
| 82 | names := make([]string, 0, len(files)) |
| 83 | for name := range files { |
| 84 | names = append(names, name) |
| 85 | } |
| 86 | sort.Strings(names) |
| 87 | for _, name := range names { |
| 88 | fmt.Fprintf(stdout, "wrote %s\n", filepath.Join(*dir, filepath.FromSlash(name))) |
| 89 | } |
| 90 | return 0 |
| 91 | } |
| 92 | |
| 93 | // pages is every file to write, by its path under -dir: abono_pages.go |
| 94 | // in package pkg, and each page as it is embedded. |
| 95 | func pages(pkg string) (map[string][]byte, error) { |
| 96 | entries, err := fs.ReadDir(sources, "pages") |
| 97 | if err != nil { |
| 98 | return nil, err |
| 99 | } |
| 100 | files := map[string][]byte{} |
| 101 | for _, e := range entries { |
| 102 | src, err := fs.ReadFile(sources, "pages/"+e.Name()) |
| 103 | if err != nil { |
| 104 | return nil, err |
| 105 | } |
| 106 | name := strings.TrimSuffix(e.Name(), ".tmpl") |
| 107 | switch path.Ext(name) { |
| 108 | case ".go": |
| 109 | if bytes.Count(src, []byte(packageLine)) != 1 { |
| 110 | return nil, fmt.Errorf("%s: no %q line to set the package on", e.Name(), strings.TrimSpace(packageLine)) |
| 111 | } |
| 112 | src = bytes.Replace(src, []byte(packageLine), []byte("\npackage "+pkg+"\n"), 1) |
| 113 | if src, err = format.Source(src); err != nil { |
| 114 | return nil, fmt.Errorf("%s: %w", e.Name(), err) |
| 115 | } |
| 116 | case ".html": |
| 117 | name = "templates/abono/" + name |
| 118 | default: |
| 119 | return nil, fmt.Errorf("%s: not a page or Go source", e.Name()) |
| 120 | } |
| 121 | files[name] = src |
| 122 | } |
| 123 | return files, nil |
| 124 | } |
| 125 | |
| 126 | // write writes files under dir, or nothing at all if any is there |
| 127 | // already: the error names every one in the way. |
| 128 | func write(dir string, files map[string][]byte) error { |
| 129 | var there []string |
| 130 | for name := range files { |
| 131 | target := filepath.Join(dir, filepath.FromSlash(name)) |
| 132 | switch _, err := os.Lstat(target); { |
| 133 | case err == nil: |
| 134 | there = append(there, target) |
| 135 | case !errors.Is(err, fs.ErrNotExist): |
| 136 | return err |
| 137 | } |
| 138 | } |
| 139 | if len(there) > 0 { |
| 140 | sort.Strings(there) |
| 141 | return fmt.Errorf("these files exist, so nothing was written (the pages are yours once written; move these aside to write them again):\n %s", |
| 142 | strings.Join(there, "\n ")) |
| 143 | } |
| 144 | for name, body := range files { |
| 145 | target := filepath.Join(dir, filepath.FromSlash(name)) |
| 146 | if err := os.MkdirAll(filepath.Dir(target), 0o755); err != nil { |
| 147 | return err |
| 148 | } |
| 149 | // O_EXCL: a file that appeared since the check is still not |
| 150 | // overwritten. |
| 151 | f, err := os.OpenFile(target, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0o644) |
| 152 | if err != nil { |
| 153 | return err |
| 154 | } |
| 155 | _, err = f.Write(body) |
| 156 | if cerr := f.Close(); err == nil { |
| 157 | err = cerr |
| 158 | } |
| 159 | if err != nil { |
| 160 | return err |
| 161 | } |
| 162 | } |
| 163 | return nil |
| 164 | } |
| 165 | |
amadan