golang/dep

// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package glock

import (
    "bufio"
    "fmt"
    "log"
    "os"
    "path/filepath"
    "strings"

    "github.com/golang/dep"
    "github.com/golang/dep/gps"
    "github.com/golang/dep/internal/importers/base"
    "github.com/pkg/errors"
)

const glockfile = "GLOCKFILE"

// Importer imports glock configuration into the dep configuration format.
type Importer struct {
    *base.Importer

    packages []glockPackage
}

// NewImporter for glock.
func NewImporter(logger *log.Logger, verbose bool, sm gps.SourceManager) *Importer {
    return &Importer{Importer: base.NewImporter(logger, verbose, sm)}
}

// Name of the importer.
func (g *Importer) Name() string {
    return "glock"
}

// HasDepMetadata checks if a directory contains config that the importer can handle.
func (g *Importer) HasDepMetadata(dir string) bool {
    path := filepath.Join(dir, glockfile)
    if _, err := os.Stat(path); err != nil {
        return false
    }

    return true
}

// Import the config found in the directory.
func (g *Importer) Import(dir string, pr gps.ProjectRoot) (*dep.Manifest, *dep.Lock, error) {
    err := g.load(dir)
    if err != nil {
        return nil, nil, err
    }

    m, l := g.convert(pr)
    return m, l, nil
}

type glockPackage struct {
    importPath string
    revision   string
}

func (g *Importer) load(projectDir string) error {
    g.Logger.Println("Detected glock configuration files...")
    path := filepath.Join(projectDir, glockfile)
    if g.Verbose {
        g.Logger.Printf("  Loading %s", path)
    }

    f, err := os.Open(path)
    if err != nil {
        return errors.Wrapf(err, "unable to open %s", path)
    }
    defer f.Close()

    scanner := bufio.NewScanner(f)
    for scanner.Scan() {
        pkg, err := parseGlockLine(scanner.Text())
        if err != nil {
            g.Logger.Printf("  Warning: Skipping line. Unable to parse: %s\n", err)
            continue
        }
        if pkg == nil {
            continue
        }
        g.packages = append(g.packages, *pkg)
    }

    if err := scanner.Err(); err != nil {
        g.Logger.Printf("  Warning: Ignoring errors found while parsing %s: %s\n", path, err)
    }

    return nil
}

func parseGlockLine(line string) (*glockPackage, error) {
    fields := strings.Fields(line)
    switch len(fields) {
    case 2: // Valid.
    case 0: // Skip empty lines.
        return nil, nil
    default:
        return nil, fmt.Errorf("invalid glock configuration: %s", line)
    }

    // Skip commands.
    if fields[0] == "cmd" {
        return nil, nil
    }
    return &glockPackage{
        importPath: fields[0],
        revision:   fields[1],
    }, nil
}

func (g *Importer) convert(pr gps.ProjectRoot) (*dep.Manifest, *dep.Lock) {
    g.Logger.Println("Converting from GLOCKFILE ...")

    packages := make([]base.ImportedPackage, 0, len(g.packages))
    for _, pkg := range g.packages {
        // Validate
        if pkg.importPath == "" {
            g.Logger.Println(
                "  Warning: Skipping project. Invalid glock configuration, import path is required",
            )
            continue
        }

        if pkg.revision == "" {
            // Do not add 'empty constraints' to the manifest. Solve will add to lock if required.
            g.Logger.Printf(
                "  Warning: Skipping import with empty constraints. "+
                    "The solve step will add the dependency to the lock if needed: %q\n",
                pkg.importPath,
            )
            continue
        }

        packages = append(packages, base.ImportedPackage{
            Name:     pkg.importPath,
            LockHint: pkg.revision,
        })
    }

    g.ImportPackages(packages, true)
    return g.Manifest, g.Lock
}