// Copyright © 2017 Intel Corporation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package builder

import (
	"github.com/clearlinux/mixer-tools/log"
	"io/ioutil"
	"os"
	"path/filepath"
	"strconv"
	"strings"

	"github.com/clearlinux/mixer-tools/helpers"
	"github.com/pkg/errors"
)

// UpdateFormatVersion updates the builder.conf file with a new format version
func (b *Builder) UpdateFormatVersion(version string) error {
	b.State.Mix.Format = version

	return b.State.Save()
}

// CopyFullGroupsINI copies the initial ini file which has ALL bundle definitions
func (b *Builder) CopyFullGroupsINI() error {
	return helpers.CopyFile(filepath.Join(b.Config.Builder.ServerStateDir, "full_groups.ini"), filepath.Join(b.Config.Builder.ServerStateDir, "groups.ini"))
}

// RevertFullGroupsINI copies back the full ini to the manifest creator accounts for deleted bundles
func (b *Builder) RevertFullGroupsINI() error {
	return helpers.CopyFile(filepath.Join(b.Config.Builder.ServerStateDir, "groups.ini"), filepath.Join(b.Config.Builder.ServerStateDir, "full_groups.ini"))
}

// GetLastBuildVersion returns the version number of the most recent build
func (b *Builder) GetLastBuildVersion() (string, error) {
	var lastVer []byte
	var err error

	filename := filepath.Join(b.Config.Builder.ServerStateDir, "image/LAST_VER")
	if lastVer, err = ioutil.ReadFile(filename); os.IsNotExist(err) {
		return "", err
	}

	return strings.TrimSpace(string(lastVer)), nil
}

func (b *Builder) getLastBuildUpstreamVersion() (string, error) {
	lastMix, err := b.GetLastBuildVersion()
	if err != nil {
		return "", err
	}

	var lastVer []byte

	filename := filepath.Join(b.Config.Builder.ServerStateDir, "www", lastMix, "upstreamver")
	if lastVer, err = ioutil.ReadFile(filename); err != nil {
		return "", err
	}

	return strings.TrimSpace(string(lastVer)), nil
}

// getFormatForVersion returns the format for the provided local version
func (b *Builder) getFormatForVersion(version string) (string, error) {
	var format []byte
	var err error

	filename := filepath.Join(b.Config.Builder.ServerStateDir, "www", version, "format")
	if format, err = ioutil.ReadFile(filename); err != nil {
		return "", err
	}

	return strings.TrimSpace(string(format)), nil
}

// getLatestForFormat returns the latest local version for the provided format
func (b *Builder) getLatestForFormat(format string) (string, error) {
	var lastVer []byte
	var err error

	filename := filepath.Join(b.Config.Builder.ServerStateDir, "www/version", "format"+format, "latest")
	if lastVer, err = ioutil.ReadFile(filename); err != nil {
		return "", err
	}

	return strings.TrimSpace(string(lastVer)), nil
}

func (b *Builder) getLocalUpstreamVersion(version string) (string, error) {
	var localUpstreamVer []byte
	var err error

	filename := filepath.Join(b.Config.Builder.ServerStateDir, "www", version, "upstreamver")
	if localUpstreamVer, err = ioutil.ReadFile(filename); err != nil {
		return "", err
	}

	return strings.TrimSpace(string(localUpstreamVer)), nil
}

// StageMixForBump prepares the mix for the two format bumps required to pass an
// upstream format boundary. The current upstreamversion is saved in a temporary
// ".bump" file, and replaced with the latest version in the format range of the
// most recent build. This process is undone via UnstageMixFromBump.
func (b *Builder) stageMixForBump() error {
	vBFile := filepath.Join(b.Config.Builder.VersionPath, b.UpstreamVerFile+".bump")
	// bump file already exists; return early
	if _, err := os.Stat(vBFile); !os.IsNotExist(err) {
		return nil
	}

	version, err := b.getLastBuildUpstreamVersion()
	if err != nil {
		return err
	}
	_, _, latest, err := b.getUpstreamFormatRange(version)
	if err != nil {
		return err
	}
	latest += 10

	// Copy current upstreamversion to upstreamversion.bump
	vFile := filepath.Join(b.Config.Builder.VersionPath, b.UpstreamVerFile)
	if err := helpers.CopyFile(vBFile, vFile); err != nil {
		return err
	}

	// Set current upstreamversion to latest
	err = ioutil.WriteFile(vFile, []byte(strconv.FormatUint(uint64(latest), 10)), 0644)
	if err != nil {
		return err
	}

	// Load updated upstreamversion
	if err = b.ReadVersions(); err != nil {
		return err
	}
	return b.getUpstreamBundles()
}

// UnstageMixFromBump resets the upstreamversion file from the temporary ".bump"
// file, if it exists. This returns the user to their desired upstream version
// after having completed the upstream format boundary bump builds.
func (b *Builder) UnstageMixFromBump() error {
	vFile := filepath.Join(b.Config.Builder.VersionPath, b.UpstreamVerFile)
	vBFile := filepath.Join(b.Config.Builder.VersionPath, b.UpstreamVerFile+".bump")

	// No bump file; return early
	if _, err := os.Stat(vBFile); os.IsNotExist(err) {
		return nil
	}

	// Copy upstreamversion.bump to upstreamversion
	if err := helpers.CopyFile(vFile, vBFile); err != nil {
		return err
	}

	// Load updated upstreamversion
	if err := b.ReadVersions(); err != nil {
		return err
	}

	if err := b.getUpstreamBundles(); err != nil {
		return err
	}

	return os.Remove(vBFile)
}

// CheckBumpNeeded returns nil if it successfully deduces there is no format
// bump boundary being crossed.
func (b *Builder) CheckBumpNeeded(silent bool) (bool, error) {
	// Skip bump checks in offline mode
	if Offline {
		return false, nil
	}

	version, err := b.getLastBuildUpstreamVersion()
	if err != nil {
		if os.IsNotExist(err) {
			return false, nil
		}
		return false, err
	}

	// Check what format our last built version is part of
	oldVer, err := b.getUpstreamFormat(version)
	if err != nil {
		return false, err
	}
	// Check what format our to-be-built version is part of
	newVer, err := b.getUpstreamFormat(b.UpstreamVer)
	if err != nil {
		return false, err
	}

	// Check both formats are real numbers
	oldFmt, err := strconv.ParseUint(string(oldVer), 10, 32)
	if err != nil {
		return false, errors.New("Old format is not a number")
	}
	newFmt, err := strconv.ParseUint(string(newVer), 10, 32)
	if err != nil {
		return false, errors.New("Old format is not a number")
	}

	// We always need to perform a format bump if these are not equal
	if oldFmt != newFmt {
		// Stage the upstreamversion file for bump
		if err = b.stageMixForBump(); err != nil {
			return false, errors.Wrap(err, "Failed to stage mix for format bump")
		}

		format, first, latest, err := b.getUpstreamFormatRange(version)
		if err != nil {
			return false, err
		}
		// Don't print this if we have to loop a bunch of times to catch up on formats
		if !silent {
			log.Info(log.Mixer, "The upstream version for this build (%s) is outside the format range of your last mix "+
				"(format %s, upstream versions %d to %d). This build cannot be done until you complete an "+
				"upstream format build. Please run the following command to complete the format bump:\nmixer "+
				"build upstream-format\nOnce this has completed you can re-run this build you are attempting to create.\n"+
				"* Please note that if you are multiple format bumps behind, mixer will detect you are still behind and "+
				"re-run the command until the proper format is reached.",
				b.UpstreamVer, format, first, latest)
		}

		return true, nil
	}

	return false, nil
}