// Copyright 2015 The Vanadium 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 main

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

	"v.io/jiri/jiri"
	"v.io/jiri/project"
	"v.io/jiri/runutil"
	"v.io/x/lib/cmdline"
)

var (
	// Flags for configuring project attributes for remote imports.
	flagImportName, flagImportPath, flagImportProtocol, flagImportRemoteBranch, flagImportRevision, flagImportRoot string
	// Flags for controlling the behavior of the command.
	flagImportOverwrite bool
	flagImportOut       string
)

func init() {
	cmdImport.Flags.StringVar(&flagImportName, "name", "", `The name of the remote manifest project, used to disambiguate manifest projects with the same remote.  Typically empty.`)
	cmdImport.Flags.StringVar(&flagImportPath, "path", "", `Path to store the manifest project locally.  Uses "manifest" if unspecified.`)
	cmdImport.Flags.StringVar(&flagImportProtocol, "protocol", "git", `The version control protocol used by the remote manifest project.`)
	cmdImport.Flags.StringVar(&flagImportRemoteBranch, "remote-branch", "master", `The branch of the remote manifest project to track.`)
	cmdImport.Flags.StringVar(&flagImportRevision, "revision", "HEAD", `The revision of the remote manifest project to reset to during "jiri update".`)
	cmdImport.Flags.StringVar(&flagImportRoot, "root", "", `Root to store the manifest project locally.`)

	cmdImport.Flags.BoolVar(&flagImportOverwrite, "overwrite", false, `Write a new .jiri_manifest file with the given specification.  If it already exists, the existing content will be ignored and the file will be overwritten.`)
	cmdImport.Flags.StringVar(&flagImportOut, "out", "", `The output file.  Uses $JIRI_ROOT/.jiri_manifest if unspecified.  Uses stdout if set to "-".`)
}

var cmdImport = &cmdline.Command{
	Runner: jiri.RunnerFunc(runImport),
	Name:   "import",
	Short:  "Adds imports to .jiri_manifest file",
	Long: `
Command "import" adds imports to the $JIRI_ROOT/.jiri_manifest file, which
specifies manifest information for the jiri tool.  The file is created if it
doesn't already exist, otherwise additional imports are added to the existing
file.

<manifest> specifies the manifest file to use.

[remote] optionally specifies the remote manifest repository.

If [remote] is not specified, a <fileimport> element is added to the manifest,
representing a local file import.  The manifest file may be an absolute path, or
relative to the current working directory.  The resulting path must be a
subdirectory of $JIRI_ROOT.

If [remote] is specified, an <import> element is added to the manifest,
representing a remote manifest import.  The remote manifest repository is
treated similar to regular projects; "jiri update" will update all remote
manifest repository projects before updating regular projects.  The manifest
file path is relative to the root directory of the remote import repository.

Example of a local file import:
  $ jiri import $JIRI_ROOT/path/to/manifest/file

Example of a remote manifest import:
  $ jiri import myfile https://foo.com/bar.git

Run "jiri help manifest" for details on manifests.
`,
	ArgsName: "<manifest> [remote]",
}

func runImport(jirix *jiri.X, args []string) error {
	if len(args) == 0 || len(args) > 2 {
		return jirix.UsageErrorf("wrong number of arguments")
	}
	// Initialize manifest.
	var manifest *project.Manifest
	if !flagImportOverwrite {
		m, err := project.ManifestFromFile(jirix, jirix.JiriManifestFile())
		if err != nil && !runutil.IsNotExist(err) {
			return err
		}
		manifest = m
	}
	if manifest == nil {
		manifest = &project.Manifest{}
	}
	// Add the local or remote import.
	if len(args) == 1 {
		// FileImport.File is relative to the directory containing the manifest
		// file; since the .jiri_manifest file is in JIRI_ROOT, that's what it
		// should be relative to.
		if _, err := os.Stat(args[0]); err != nil {
			return err
		}
		abs, err := filepath.Abs(args[0])
		if err != nil {
			return err
		}
		rel, err := filepath.Rel(jirix.Root, abs)
		if err != nil {
			return err
		}
		if strings.HasPrefix(rel, "..") {
			return fmt.Errorf("%s is not a subdirectory of JIRI_ROOT %s", abs, jirix.Root)
		}
		manifest.FileImports = append(manifest.FileImports, project.FileImport{
			File: rel,
		})
	} else {
		// There's not much error checking when writing the .jiri_manifest file;
		// errors will be reported when "jiri update" is run.
		manifest.Imports = append(manifest.Imports, project.Import{
			Manifest: args[0],
			Root:     flagImportRoot,
			Project: project.Project{
				Name:         flagImportName,
				Path:         flagImportPath,
				Protocol:     flagImportProtocol,
				Remote:       args[1],
				RemoteBranch: flagImportRemoteBranch,
				Revision:     flagImportRevision,
			},
		})
	}
	// Write output to stdout or file.
	outFile := flagImportOut
	if outFile == "" {
		outFile = jirix.JiriManifestFile()
	}
	if outFile == "-" {
		bytes, err := manifest.ToBytes()
		if err != nil {
			return err
		}
		_, err = os.Stdout.Write(bytes)
		return err
	}
	return manifest.ToFile(jirix, outFile)
}