package gitpb

// An app to submit patches for the 30 GO GUI repos

import (
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"time"

	"go.wit.com/lib/cobol"
	"go.wit.com/log"
	"google.golang.org/protobuf/types/known/timestamppb"
)

func (repo *Repo) Mtime(fname string) *time.Time {
	var fileTime *time.Time
	tmp, err := repo.statMtime(fname)
	fileTime = &tmp
	if err != nil {
		log.Info("MTime got err", err)
		return nil
	}
	return fileTime
}

func (repo *Repo) statMtime(filename string) (time.Time, error) {
	pathf := filepath.Join(repo.FullPath, filename)
	statf, err := os.Stat(pathf)
	if err == nil {
		return statf.ModTime(), nil
	}
	log.Log(WARN, "Mtime() os.Stat() error", pathf, err)
	return time.Now(), err
}

func (repo *Repo) changedDir() bool {
	fname := ".git"
	fileTime := repo.Mtime(fname)
	if fileTime == nil {
		// .git doesn't exist. something is wrong. rescan this repo
		return true
	}
	mtime := timestamppb.New(*fileTime)
	pbtime := repo.Times.MtimeDir
	if pbtime == nil { // this can happen?
		repo.Times.MtimeDir = mtime
		return true
	}
	if (pbtime.Seconds == mtime.Seconds) && (pbtime.Nanos == mtime.Nanos) {
		return false
	}
	dur := mtime.AsTime().Sub(pbtime.AsTime())
	repo.StateChange = fmt.Sprintf("%s changed %s", fname, cobol.FormatDuration(dur))
	repo.Times.MtimeDir = mtime
	return true
}

func (repo *Repo) didFileChange(fname string, pbtime *timestamppb.Timestamp) bool {
	fileTime := repo.Mtime(fname)
	if fileTime == nil {
		repo.StateChange = fmt.Sprintf("%s missing", fname)
		return true
	}
	mtime := timestamppb.New(*fileTime)
	if pbtime == nil {
		repo.StateChange = fmt.Sprintf("%s mtime never recorded", fname)
		return true
	}
	if (pbtime.Seconds == mtime.Seconds) && (pbtime.Nanos == mtime.Nanos) {
		// it's the same!
		return false
	}
	dur := mtime.AsTime().Sub(pbtime.AsTime())
	repo.StateChange = fmt.Sprintf("%s mtime changed %s", fname, cobol.FormatDuration(dur))
	// need to reload from the filesystem
	return true
}

// boo. I'm not good at golang. this should use reflect. I'm bad. my code is bad. boo this man. you're cool, I'm outta here
// make this work right someday
func (repo *Repo) updateMtime(fname string, pbname string) bool {
	fileTime := repo.Mtime(fname)
	if fileTime == nil {
		// .git/HEAD doesn't exist. something is wrong. rescan this repo
		return true
	}
	mtime := timestamppb.New(*fileTime)
	pbtime := repo.Times.MtimeHead
	if pbtime == nil { // this can happen?
		repo.Times.MtimeHead = mtime
		return true
	}
	switch pbname {
	case "MtimeHead":
		if pbtime == nil { // this can happen?
			repo.Times.MtimeHead = mtime
			return true
		}
	default:
	}
	if (pbtime.Seconds == mtime.Seconds) && (pbtime.Nanos == mtime.Nanos) {
		return false
	}
	dur := mtime.AsTime().Sub(pbtime.AsTime())
	repo.StateChange = fmt.Sprintf("%s changed %s", fname, cobol.FormatDuration(dur))
	repo.Times.MtimeHead = mtime
	return true
}

func (repo *Repo) changedHead() bool {
	fname := ".git/HEAD"
	fileTime := repo.Mtime(fname)
	if fileTime == nil {
		// .git/HEAD doesn't exist. something is wrong. rescan this repo
		return true
	}
	mtime := timestamppb.New(*fileTime)
	pbtime := repo.Times.MtimeHead
	if pbtime == nil { // this can happen?
		repo.Times.MtimeHead = mtime
		return true
	}

	if (pbtime.Seconds == mtime.Seconds) && (pbtime.Nanos == mtime.Nanos) {
		return false
	}
	dur := mtime.AsTime().Sub(pbtime.AsTime())
	repo.StateChange = fmt.Sprintf("%s changed %s", fname, cobol.FormatDuration(dur))
	repo.Times.MtimeHead = mtime
	return true
}

// check the mtime of the .git/config file
func (repo *Repo) changedConfig() bool {
	fname := ".git/config"
	fileTime := repo.Mtime(fname)
	if fileTime == nil {
		// .git/config doesn't exist. something is wrong!
		log.Info("gitpb .git/config is missing", repo.GetGoPath())
		return false
	}
	mtime := timestamppb.New(*fileTime)
	pbtime := repo.Times.MtimeConfig
	if pbtime == nil { // this can happen?
		repo.Times.MtimeConfig = mtime
		return true
	}

	if (pbtime.Seconds == mtime.Seconds) && (pbtime.Nanos == mtime.Nanos) {
		return false
	}
	dur := mtime.AsTime().Sub(pbtime.AsTime())
	repo.StateChange = fmt.Sprintf("%s changed %s", fname, cobol.FormatDuration(dur))
	repo.Times.MtimeConfig = mtime
	return true
}

func (repo *Repo) changedIndex() bool {
	fname := ".git/index"
	fileTime := repo.Mtime(fname)
	if fileTime == nil {
		// .git/index doesn't exist. something is wrong. rescan this repo
		return true
	}
	mtime := timestamppb.New(*fileTime)
	pbtime := repo.Times.MtimeIndex
	if pbtime == nil { // this can happen?
		repo.Times.MtimeIndex = mtime
		return true
	}
	if (pbtime.Seconds == mtime.Seconds) && (pbtime.Nanos == mtime.Nanos) {
		return false
	}
	dur := mtime.AsTime().Sub(pbtime.AsTime())
	repo.StateChange = fmt.Sprintf("%s changed %s", fname, cobol.FormatDuration(dur))
	repo.Times.MtimeIndex = mtime
	return true
}

func (repo *Repo) reloadMtimes() bool {
	var changed bool
	if repo.Times == nil {
		repo.Times = new(GitTimes)
		log.Info(repo.FullPath, "repo.Times were nil")
	}

	if repo.changedHead() {
		changed = true
	}
	if repo.changedIndex() {
		changed = true
	}
	if repo.changedConfig() {
		changed = true
	}
	if repo.changedDir() {
		// changed = true
	}

	return changed
}

// also checks .git which seems to change *a lot*
// this might work immediately after git checkout
func (repo *Repo) DidRepoChangeDir() error {
	if repo.Times == nil {
		repo.Times = new(GitTimes)
	}
	if repo.didFileChange(".git/HEAD", repo.Times.MtimeHead) {
		return log.Errorf(".git/HEAD changed")
	}
	if repo.didFileChange(".git/index", repo.Times.MtimeIndex) {
		repo.StateChange += "jwc"
		return log.Errorf(".git/index changed")
	}
	if repo.didFileChange(".git/config", repo.Times.MtimeConfig) {
		return log.Errorf(".git/config changed")
	}
	if repo.didFileChange(".git", repo.Times.MtimeDir) {
		// todo: do something with CheckDirty()
		return log.Errorf(".git changed")
	}
	if repo.Times.LastUpdate == nil {
		log.Info("repo.Reload() was never run")
		return log.Errorf("Reload() ran for the first time")
	} else {
		if repo.Times.LastUpdate.Seconds < repo.Times.MtimeHead.Seconds {
			log.Info("SHOULD RUN Reload() here", repo.Times.MtimeHead.Seconds-repo.Times.LastUpdate.Seconds, "secs diff")
			return log.Errorf("Reload() time skew on .git/HEAD")
		}
	}
	// log.Info("DidRepoChange() is false", repo.FullPath)
	return nil
}

func (repo *Repo) DidRepoChange() error {
	if repo.Times == nil {
		repo.Times = new(GitTimes)
	}
	if repo.didFileChange(".git/HEAD", repo.Times.MtimeHead) {
		return log.Errorf(".git/HEAD changed")
	}
	if repo.didFileChange(".git/index", repo.Times.MtimeIndex) {
		repo.StateChange += "jwc2"
		return log.Errorf(".git/index changed")
	}
	if repo.didFileChange(".git/config", repo.Times.MtimeConfig) {
		return log.Errorf(".git/config changed")
	}
	if repo.didFileChange(".git", repo.Times.MtimeDir) {
		// todo: do something with CheckDirty()
		// return true
	}
	if repo.Times.LastUpdate == nil {
		log.Info("repo.Reload() was never run")
		return log.Errorf("Reload() ran for the first time")
	} else {
		if repo.Times.LastUpdate.Seconds < repo.Times.MtimeHead.Seconds {
			log.Info("SHOULD RUN Reload() here", repo.Times.MtimeHead.Seconds-repo.Times.LastUpdate.Seconds, "secs diff")
			return log.Errorf("Reload() time skew on .git/HEAD")
		}
	}
	// log.Info("DidRepoChange() is false", repo.FullPath)
	return nil
}

func (all *Repos) ScanAllMtimesVerbose() (string, error) {
	var count int
	var anyerr error
	for r := range all.IterAll() {
		var err error
		var ok bool
		if count < 10 {
			// only show output for the first 10 repos
			ok, err = r.didRepoChangeVerbose()
		} else {
			err = r.DidRepoChange()
		}
		if err != nil {
			log.Info(r.Namespace, err)
		}
		if (err != nil) || ok {
			// means there was output
			anyerr = err
			count += 1
		}
	}
	if anyerr != nil {
		all.Save()
	}
	return "looked into mtime changes", anyerr
}

func (r *Repo) didRepoChangeVerbose() (bool, error) {
	var output bool
	if r.Times == nil {
		r.Times = new(GitTimes)
		log.Info("repo.Reload() was never run")
		output = true
		// means this is going to populate the mtimes for the first time
		// todo: make sure the whole thing gets saved
	} else {
		if r.Times.LastUpdate != nil {
			lastupdate := r.Times.LastUpdate.AsTime()
			dur := time.Since(lastupdate)
			if dur < 5*time.Minute {
				log.Info("repo.ReloadMtime() was was last run", cobol.FormatDuration(dur), r.Namespace)
				output = true
			}
		} else {
			log.Info("repo.ReloadMtime() LastUpdate == nil", r.Namespace)
			output = true
		}
	}
	if r.didFileChange(".git/HEAD", r.Times.MtimeHead) {
		r.RunVerbose([]string{"ls", "-l", ".git/HEAD"})
		output = true
		return output, errors.New(".git/HEAD changed")
	}
	if r.didFileChange(".git/index", r.Times.MtimeIndex) {
		r.StateChange += "jwc2"
		r.RunVerbose([]string{"ls", "-l", ".git/index"})
		output = true
		return output, errors.New(".git/index changed")
	}
	if r.didFileChange(".git/config", r.Times.MtimeConfig) {
		r.RunVerbose([]string{"ls", "-l", ".git/config"})
		output = true
		return output, errors.New(".git/config changed")
	}
	if r.didFileChange(".git", r.Times.MtimeDir) {
		if r.Times.MtimeDir != nil {
			lastupdate := r.Times.LastUpdate.AsTime()
			dur := time.Since(lastupdate)
			if dur < 5*time.Minute {
				log.Info("repo.ReloadMtime() MtimeDir last run", cobol.FormatDuration(dur), r.Namespace)
				r.RunVerbose([]string{"ls", "-l", ".git", "-d"})
				output = true
			}
		} else {
		}
		// todo: do something with CheckDirty()
		// return true
	}
	if r.Times.LastUpdate == nil {
		log.Info("r.Reload() was never run")
		output = true
		return output, errors.New("Reload() ran for the first time")
	} else {
		if r.Times.LastUpdate.Seconds < r.Times.MtimeHead.Seconds {
			log.Info("SHOULD RUN Reload() here", r.Times.MtimeHead.Seconds-r.Times.LastUpdate.Seconds, "secs diff")
			output = true
			return output, errors.New("Reload() time skew on .git/HEAD")
		}
	}
	// nothing changed. All mtimes being monitored are old
	return output, nil
}