package action

import (
	"path/filepath"

	"github.com/Masterminds/glide/cfg"
	"github.com/Masterminds/glide/dependency"
	"github.com/Masterminds/glide/msg"
	gpath "github.com/Masterminds/glide/path"
	"github.com/Masterminds/glide/repo"
)

// Update updates repos and the lock file from the main glide yaml.
func Update(installer *repo.Installer, skipRecursive bool) {
	base := "."
	EnsureGopath()
	EnsureVendorDir()
	conf := EnsureConfig()

	installer.RootPackage = conf.Name

	// Delete unused packages
	if installer.DeleteUnused {
		dependency.DeleteUnused(conf)
	}

	// Try to check out the initial dependencies.
	if err := installer.Checkout(conf, false); err != nil {
		msg.Die("Failed to do initial checkout of config: %s", err)
	}

	// Set the versions for the initial dependencies so that resolved dependencies
	// are rooted in the correct version of the base.
	if err := repo.SetReference(conf); err != nil {
		msg.Die("Failed to set initial config references: %s", err)
	}

	// Prior to resolving dependencies we need to start working with a clone
	// of the conf because we'll be making real changes to it.
	confcopy := conf.Clone()

	if !skipRecursive {
		// Get all repos and update them.
		err := installer.Update(confcopy)
		if err != nil {
			msg.Die("Could not update packages: %s", err)
		}

		// TODO: There is no support here for importing Godeps, GPM, and GB files.
		// I think that all we really need to do now is hunt for these files, and then
		// roll their version numbers into the config file.

		// Set references. There may be no remaining references to set since the
		// installer set them as it went to make sure it parsed the right imports
		// from the right version of the package.
		msg.Info("Setting references for remaining imports")
		if err := repo.SetReference(confcopy); err != nil {
			msg.Error("Failed to set references: %s (Skip to cleanup)", err)
		}

		// Flatten
		// I don't think we need flatten anymore. The installer.Update logic should
		// find and install all of the necessary dependencies. And then the version
		// setting logic should correctly set versions.
		//
		// The edge case, which exist today (but innoculously) is where an older
		// version requires dependencies that a newer repo checkout does not
		// have. In that case, it seems that we may get to the point where we'd
		// have to run Update twice.
		msg.Warn("Flatten not implemented.")
	}
	// Vendored cleanup
	// VendoredCleanup. This should ONLY be run if UpdateVendored was specified.
	if installer.UpdateVendored {
		repo.VendoredCleanup(confcopy)
	}

	// Write glide.yaml (Why? Godeps/GPM/GB?)
	// I think we don't need to write a new Glide file because update should not
	// change anything important. It will just generate information about
	// transative dependencies, all of which belongs exclusively in the lock
	// file, not the glide.yaml file.
	// TODO(mattfarina): Detect when a new dependency has been added or removed
	// from the project. A removed dependency should warn and an added dependency
	// should be added to the glide.yaml file. See issue #193.

	if !skipRecursive {
		// Write lock
		hash, err := conf.Hash()
		if err != nil {
			msg.Die("Failed to generate config hash. Unable to generate lock file.")
		}
		lock := cfg.NewLockfile(confcopy.Imports, hash)
		if err := lock.WriteFile(filepath.Join(base, gpath.LockFile)); err != nil {
			msg.Error("Could not write lock file to %s: %s", base, err)
			return
		}

		msg.Info("Project relies on %d dependencies.", len(confcopy.Imports))
	} else {
		msg.Warn("Skipping lockfile generation because full dependency tree is not being calculated")
	}
}