package main

import (
	"flag"
	"fmt"
	"path/filepath"

	"github.com/constabulary/gb/fileutils"

	"github.com/FiloSottile/gvt/gbvendor"
)

var (
	updateAll bool // update all dependencies
)

func addUpdateFlags(fs *flag.FlagSet) {
	fs.BoolVar(&updateAll, "all", false, "update all dependencies")
	fs.BoolVar(&insecure, "precaire", false, "allow the use of insecure protocols")
}

var cmdUpdate = &Command{
	Name:      "update",
	UsageLine: "update [ -all | importpath ]",
	Short:     "update a local dependency",
	Long: `update replaces the source with the latest available from the head of the fetched branch.

Updating from one copy of a dependency to another is ONLY possible when the
dependency was fetched by branch, without using -tag or -revision. It will be
updated to the HEAD of that branch, switching branches is not supported.

To update across branches, or from one tag/revision to another, you must first
use delete to remove the dependency, then fetch [ -tag | -revision | -branch ]
to replace it.

Flags:
	-all
		update all dependencies in the manifest.
	-precaire
		allow the use of insecure protocols.

`,
	Run: func(args []string) error {
		if len(args) != 1 && !updateAll {
			return fmt.Errorf("update: import path or -all flag is missing")
		} else if len(args) == 1 && updateAll {
			return fmt.Errorf("update: you cannot specify path and -all flag at once")
		}

		m, err := vendor.ReadManifest(manifestFile())
		if err != nil {
			return fmt.Errorf("could not load manifest: %v", err)
		}

		var dependencies []vendor.Dependency
		if updateAll {
			dependencies = make([]vendor.Dependency, len(m.Dependencies))
			copy(dependencies, m.Dependencies)
		} else {
			p := args[0]
			dependency, err := m.GetDependencyForImportpath(p)
			if err != nil {
				return fmt.Errorf("could not get dependency: %v", err)
			}
			dependencies = append(dependencies, dependency)
		}

		for _, d := range dependencies {
			err = m.RemoveDependency(d)
			if err != nil {
				return fmt.Errorf("dependency could not be deleted from manifest: %v", err)
			}

			repo, extra, err := vendor.DeduceRemoteRepo(d.Importpath, insecure)
			if err != nil {
				return fmt.Errorf("could not determine repository for import %q", d.Importpath)
			}

			wc, err := repo.Checkout(d.Branch, "", "")
			if err != nil {
				return err
			}

			rev, err := wc.Revision()
			if err != nil {
				return err
			}

			branch, err := wc.Branch()
			if err != nil {
				return err
			}

			dep := vendor.Dependency{
				Importpath: d.Importpath,
				Repository: repo.URL(),
				Revision:   rev,
				Branch:     branch,
				Path:       extra,
			}

			if err := fileutils.RemoveAll(filepath.Join(vendorDir(), filepath.FromSlash(d.Importpath))); err != nil {
				// TODO(dfc) need to apply vendor.cleanpath here to remove intermediate directories.
				return fmt.Errorf("dependency could not be deleted: %v", err)
			}

			dst := filepath.Join(vendorDir(), filepath.FromSlash(dep.Importpath))
			src := filepath.Join(wc.Dir(), dep.Path)

			if err := fileutils.Copypath(dst, src); err != nil {
				return err
			}

			if err := m.AddDependency(dep); err != nil {
				return err
			}

			if err := vendor.WriteManifest(manifestFile(), m); err != nil {
				return err
			}

			if err := wc.Destroy(); err != nil {
				return err
			}
		}

		return nil
	},
	AddFlags: addUpdateFlags,
}