package main

import (
	"context"
	"fmt"
	"github.com/c2h5oh/datasize"
	"github.com/sethvargo/go-retry"
	log "github.com/sirupsen/logrus"
	"html/template"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"somegit.dev/ALHP/ALHP.GO/ent"
	"somegit.dev/ALHP/ALHP.GO/ent/dbpackage"
	"strings"
	"sync"
	"time"
)

const MaxUnknownBuilder = 2

type BuildManager struct {
	repoPurge    map[string]chan []*ProtoPackage
	repoAdd      map[string]chan []*ProtoPackage
	repoWG       *sync.WaitGroup
	alpmMutex    *sync.RWMutex
	building     []*ProtoPackage
	buildingLock *sync.RWMutex
	queueSignal  chan struct{}
}

func (b *BuildManager) refreshSRCINFOs(ctx context.Context, path string) error {
	pkgBuilds, err := Glob(path)
	if err != nil {
		return fmt.Errorf("error scanning for PKGBUILDs: %w", err)
	}

	wg := new(sync.WaitGroup)
	workerChan := make(chan string, runtime.NumCPU())

	for o := 0; o < runtime.NumCPU(); o++ {
		wg.Add(1)
		go b.SRCINFOWorker(ctx, workerChan, wg)
	}

	go func() {
		for _, pkgbuild := range pkgBuilds {
			workerChan <- pkgbuild
		}
		close(workerChan)
	}()

	wg.Wait()
	return nil
}

func (b *BuildManager) SRCINFOWorker(ctx context.Context, workIn chan string, wg *sync.WaitGroup) {
	defer wg.Done()
	for pkgbuild := range workIn {
		mPkgbuild := PKGBUILD(pkgbuild)
		if mPkgbuild.FullRepo() == "trunk" || !Contains(conf.Repos, mPkgbuild.Repo()) ||
			containsSubStr(mPkgbuild.FullRepo(), conf.Blacklist.Repo) {
			continue
		}

		for _, march := range conf.March {
			dbPkg, dbErr := db.DbPackage.Query().Where(
				dbpackage.And(
					dbpackage.Pkgbase(mPkgbuild.PkgBase()),
					dbpackage.RepositoryEQ(dbpackage.Repository(mPkgbuild.Repo())),
					dbpackage.March(march),
				),
			).Only(context.Background())

			if ent.IsNotFound(dbErr) {
				log.Debugf("[%s/%s] Package not found in database", mPkgbuild.Repo(), mPkgbuild.PkgBase())
			} else if dbErr != nil {
				log.Errorf("[%s/%s] Problem querying db for package: %v", mPkgbuild.Repo(), mPkgbuild.PkgBase(), dbErr)
			}

			// compare b3sum of PKGBUILD file to hash in database, only proceed if hash differs
			// reduces the amount of PKGBUILDs that need to be parsed with makepkg, which is _really_ slow, significantly
			b3s, err := b3sum(pkgbuild)
			if err != nil {
				log.Errorf("Error hashing PKGBUILD: %v", err)
			}

			if dbPkg != nil && b3s == dbPkg.Hash {
				log.Debugf("[%s/%s] Skipped: PKGBUILD hash matches db (%s)", mPkgbuild.Repo(), mPkgbuild.PkgBase(), b3s)
				continue
			} else if dbPkg != nil && b3s != dbPkg.Hash && dbPkg.SrcinfoHash != b3s {
				log.Debugf("[%s/%s] srcinfo cleared", mPkgbuild.Repo(), mPkgbuild.PkgBase())
				dbPkg = dbPkg.Update().ClearSrcinfo().SaveX(context.Background())
			}

			proto := &ProtoPackage{
				Pkgbuild:  pkgbuild,
				Pkgbase:   mPkgbuild.PkgBase(),
				Repo:      dbpackage.Repository(mPkgbuild.Repo()),
				March:     march,
				FullRepo:  mPkgbuild.Repo() + "-" + march,
				Hash:      b3s,
				DBPackage: dbPkg,
			}

			_, err = proto.isEligible(ctx)
			if err != nil {
				log.Infof("Unable to determine status for package %s: %v", proto.Pkgbase, err)
				b.repoPurge[proto.FullRepo] <- []*ProtoPackage{proto}
			} else if proto.DBPackage != nil {
				proto.DBPackage.Update().SetPkgbuild(proto.Pkgbuild).ExecX(ctx)
			}
		}
	}
}

func (b *BuildManager) buildQueue(queue []*ProtoPackage, ctx context.Context) error {
	var (
		doneQ         []*ProtoPackage
		doneQLock     = new(sync.RWMutex)
		unknownBuilds bool
		queueNoMatch  bool
	)

	for len(doneQ) != len(queue) {
		up := 0
		b.buildingLock.RLock()
		if (pkgList2MaxMem(b.building) < conf.Build.MemoryLimit && !unknownBuilds && !queueNoMatch) || (unknownBuilds && len(b.building) < MaxUnknownBuilder) {
			queueNoMatch = true
			b.buildingLock.RUnlock()
			for _, pkg := range queue {
				// check if package is already build
				doneQLock.RLock()
				if ContainsPkg(doneQ, pkg, true) {
					doneQLock.RUnlock()
					continue
				}
				doneQLock.RUnlock()

				// check if package is already building (we do not build packages from different marchs simultaneously)
				b.buildingLock.RLock()
				if ContainsPkg(b.building, pkg, false) {
					log.Debugf("[Q] skipped already building package %s->%s", pkg.FullRepo, pkg.Pkgbase)
					b.buildingLock.RUnlock()
					continue
				}
				b.buildingLock.RUnlock()

				// only check for memory on known-memory-builds
				// otherwise build them one-at-a-time
				// TODO: add initial compile mode for new repos
				if !unknownBuilds {
					// check if package has unknown memory usage
					if pkg.DBPackage.MaxRss == nil {
						log.Debugf("[Q] skipped unknown package %s->%s", pkg.FullRepo, pkg.Pkgbase)
						up++
						continue
					}

					// check if package can be built with current memory limit
					if datasize.ByteSize(*pkg.DBPackage.MaxRss)*datasize.KB > conf.Build.MemoryLimit {
						log.Warningf("[Q] %s->%s exeeds memory limit: %s->%s", pkg.FullRepo, pkg.Pkgbase,
							datasize.ByteSize(*pkg.DBPackage.MaxRss)*datasize.KB, conf.Build.MemoryLimit)
						doneQLock.Lock()
						doneQ = append(doneQ, pkg)
						doneQLock.Unlock()
						continue
					}

					b.buildingLock.RLock()
					currentMemLoad := pkgList2MaxMem(b.building)
					b.buildingLock.RUnlock()

					// check if package can be build right now
					if !unknownBuilds && currentMemLoad+(datasize.ByteSize(*pkg.DBPackage.MaxRss)*datasize.KB) > conf.Build.MemoryLimit {
						log.Debugf("[Q] skipped package with max_rss %s while load %s: %s->%s",
							datasize.ByteSize(*pkg.DBPackage.MaxRss)*datasize.KB, currentMemLoad, pkg.Pkgbase, pkg.March)
						continue
					}
				} else {
					b.buildingLock.RLock()
					if len(b.building) >= MaxUnknownBuilder {
						b.buildingLock.RUnlock()
						continue
					}
					b.buildingLock.RUnlock()
				}

				b.buildingLock.Lock()
				b.building = append(b.building, pkg)
				b.buildingLock.Unlock()
				queueNoMatch = false

				go func(pkg *ProtoPackage) {
					dur, err := pkg.build(ctx)
					if err != nil {
						log.Warningf("[Q] error building package %s->%s in %s: %s", pkg.FullRepo, pkg.Pkgbase, dur, err)
						b.repoPurge[pkg.FullRepo] <- []*ProtoPackage{pkg}
					} else {
						log.Infof("[Q] build successful: %s->%s (%s)", pkg.FullRepo, pkg.Pkgbase, dur)
					}
					doneQLock.Lock()
					b.buildingLock.Lock()
					doneQ = append(doneQ, pkg)

					for i := 0; i < len(b.building); i++ {
						if b.building[i].PkgbaseEquals(pkg, true) {
							b.building = append(b.building[:i], b.building[i+1:]...)
							break
						}
					}
					doneQLock.Unlock()
					b.buildingLock.Unlock()
					b.queueSignal <- struct{}{}
				}(pkg)
			}
		} else {
			log.Debugf("[Q] memory/build limit reached, waiting for package to finish...")
			b.buildingLock.RUnlock()
			<-b.queueSignal
			queueNoMatch = false
		}

		// if only unknown packages are left, enable unknown buildmode
		b.buildingLock.RLock()
		if up == len(queue)-(len(doneQ)+len(b.building)) {
			unknownBuilds = true
		}
		b.buildingLock.RUnlock()
	}
	return nil
}

func (b *BuildManager) htmlWorker(ctx context.Context) {
	type Pkg struct {
		Pkgbase              string
		Status               string
		Class                string
		Skip                 string
		Version              string
		Svn2GitVersion       string
		BuildDate            string
		BuildDuration        time.Duration
		BuildMemory          *string
		Checked              string
		Log                  string
		LTO                  bool
		LTOUnknown           bool
		LTODisabled          bool
		LTOAutoDisabled      bool
		DebugSym             bool
		DebugSymNotAvailable bool
		DebugSymUnknown      bool
	}

	type Repo struct {
		Name     string
		Packages []Pkg
	}

	type March struct {
		Name  string
		Repos []Repo
	}

	type tpl struct {
		March       []March
		Generated   string
		Latest      int
		Failed      int
		Skipped     int
		Queued      int
		LTOEnabled  int
		LTOUnknown  int
		LTODisabled int
	}

	for {
		gen := &tpl{}

		for _, march := range conf.March {
			addMarch := March{
				Name: march,
			}

			for _, repo := range conf.Repos {
				addRepo := Repo{
					Name: repo,
				}

				pkgs := db.DbPackage.Query().Order(ent.Asc(dbpackage.FieldPkgbase)).
					Where(dbpackage.MarchEQ(march), dbpackage.RepositoryEQ(dbpackage.Repository(repo))).AllX(ctx)

				for _, pkg := range pkgs {
					addPkg := Pkg{
						Pkgbase:        pkg.Pkgbase,
						Status:         strings.ToUpper(pkg.Status.String()),
						Class:          statusID2string(pkg.Status),
						Skip:           pkg.SkipReason,
						Version:        pkg.RepoVersion,
						Svn2GitVersion: pkg.Version,
					}

					if pkg.STime != nil && pkg.UTime != nil {
						addPkg.BuildDuration = time.Duration(*pkg.STime+*pkg.UTime) * time.Second
					}

					if !pkg.BuildTimeStart.IsZero() {
						addPkg.BuildDate = pkg.BuildTimeStart.UTC().Format(time.RFC1123)
					}

					if !pkg.Updated.IsZero() {
						addPkg.Checked = pkg.Updated.UTC().Format(time.RFC1123)
					}

					if pkg.Status == dbpackage.StatusFailed {
						addPkg.Log = fmt.Sprintf("%s/%s/%s.log", logDir, pkg.March, pkg.Pkgbase)
					}

					if pkg.MaxRss != nil {
						hrSize := (datasize.ByteSize(*pkg.MaxRss) * datasize.KB).HumanReadable()
						addPkg.BuildMemory = &hrSize
					}

					switch pkg.Lto {
					case dbpackage.LtoUnknown:
						if pkg.Status != dbpackage.StatusSkipped && pkg.Status != dbpackage.StatusFailed {
							addPkg.LTOUnknown = true
						}
					case dbpackage.LtoEnabled:
						addPkg.LTO = true
					case dbpackage.LtoDisabled:
						addPkg.LTODisabled = true
					case dbpackage.LtoAutoDisabled:
						addPkg.LTOAutoDisabled = true
					}

					switch pkg.DebugSymbols {
					case dbpackage.DebugSymbolsUnknown:
						if pkg.Status != dbpackage.StatusSkipped && pkg.Status != dbpackage.StatusFailed {
							addPkg.DebugSymUnknown = true
						}
					case dbpackage.DebugSymbolsAvailable:
						addPkg.DebugSym = true
					case dbpackage.DebugSymbolsNotAvailable:
						addPkg.DebugSymNotAvailable = true
					}

					addRepo.Packages = append(addRepo.Packages, addPkg)
				}
				addMarch.Repos = append(addMarch.Repos, addRepo)
			}
			gen.March = append(gen.March, addMarch)
		}

		gen.Generated = time.Now().UTC().Format(time.RFC1123)

		var v []struct {
			Status dbpackage.Status `json:"status"`
			Count  int              `json:"count"`
		}

		db.DbPackage.Query().GroupBy(dbpackage.FieldStatus).Aggregate(ent.Count()).ScanX(ctx, &v)

		for _, c := range v {
			switch c.Status {
			case dbpackage.StatusFailed:
				gen.Failed = c.Count
			case dbpackage.StatusSkipped:
				gen.Skipped = c.Count
			case dbpackage.StatusLatest:
				gen.Latest = c.Count
			case dbpackage.StatusQueued:
				gen.Queued = c.Count
			}
		}

		var v2 []struct {
			Status dbpackage.Lto `json:"lto"`
			Count  int           `json:"count"`
		}

		db.DbPackage.Query().Where(dbpackage.StatusNEQ(dbpackage.StatusSkipped)).
			GroupBy(dbpackage.FieldLto).Aggregate(ent.Count()).ScanX(ctx, &v2)

		for _, c := range v2 {
			switch c.Status {
			case dbpackage.LtoUnknown:
				gen.LTOUnknown = c.Count
			case dbpackage.LtoDisabled, dbpackage.LtoAutoDisabled:
				gen.LTODisabled += c.Count
			case dbpackage.LtoEnabled:
				gen.LTOEnabled = c.Count
			}
		}

		statusTpl, err := template.ParseFiles("tpl/packages.html")
		if err != nil {
			log.Warningf("[HTML] Error parsing template file: %v", err)
			continue
		}

		f, err := os.OpenFile(filepath.Join(conf.Basedir.Repo, "packages.html"), os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o644)
		if err != nil {
			log.Warningf("[HTML] Erro ropening output file: %v", err)
			continue
		}
		err = statusTpl.Execute(f, gen)
		if err != nil {
			log.Warningf("[HTML] Error filling template: %v", err)
		}
		_ = f.Close()

		time.Sleep(time.Minute * 5)
	}
}

func (b *BuildManager) repoWorker(repo string) {
	for {
		select {
		case pkgL := <-b.repoAdd[repo]:
			b.repoWG.Add(1)
			toAdd := make([]string, 0)
			for _, pkg := range pkgL {
				toAdd = append(toAdd, pkg.PkgFiles...)
			}

			args := []string{"-s", "-v", "-p", "-n", filepath.Join(conf.Basedir.Repo, repo, "os", conf.Arch, repo) + ".db.tar.xz"}
			args = append(args, toAdd...)
			cmd := exec.Command("repo-add", args...)
			res, err := cmd.CombinedOutput()
			log.Debug(string(res))
			if err != nil && cmd.ProcessState.ExitCode() != 1 {
				log.Panicf("%s while repo-add: %v", string(res), err)
			}

			for _, pkg := range pkgL {
				pkg.toDBPackage(true)
				if _, err := os.Stat(filepath.Join(conf.Basedir.Debug, pkg.March,
					pkg.DBPackage.Packages[0]+"-debug-"+pkg.Version+"-"+conf.Arch+".pkg.tar.zst")); err == nil {
					pkg.DBPackage = pkg.DBPackage.Update().
						SetStatus(dbpackage.StatusLatest).
						ClearSkipReason().
						SetDebugSymbols(dbpackage.DebugSymbolsAvailable).
						SetRepoVersion(pkg.Version).
						SetHash(pkg.Hash).
						SaveX(context.Background())
				} else {
					pkg.DBPackage = pkg.DBPackage.Update().
						SetStatus(dbpackage.StatusLatest).
						ClearSkipReason().
						SetDebugSymbols(dbpackage.DebugSymbolsNotAvailable).
						SetRepoVersion(pkg.Version).
						SetHash(pkg.Hash).
						SaveX(context.Background())
				}
			}

			cmd = exec.Command("paccache", "-rc", filepath.Join(conf.Basedir.Repo, repo, "os", conf.Arch), "-k", "1") //nolint:gosec
			res, err = cmd.CombinedOutput()
			log.Debug(string(res))
			if err != nil {
				log.Warningf("Error running paccache: %v", err)
			}
			err = updateLastUpdated()
			if err != nil {
				log.Warningf("Error updating lastupdate: %v", err)
			}
			b.repoWG.Done()
		case pkgL := <-b.repoPurge[repo]:
			for _, pkg := range pkgL {
				if _, err := os.Stat(filepath.Join(conf.Basedir.Repo, pkg.FullRepo, "os", conf.Arch, pkg.FullRepo) + ".db.tar.xz"); err != nil {
					continue
				}
				if len(pkg.PkgFiles) == 0 {
					if err := pkg.findPkgFiles(); err != nil {
						log.Warningf("[%s/%s] Unable to find files: %v", pkg.FullRepo, pkg.Pkgbase, err)
						continue
					} else if len(pkg.PkgFiles) == 0 {
						continue
					}
				}

				var realPkgs []string
				for _, filePath := range pkg.PkgFiles {
					if _, err := os.Stat(filePath); err == nil {
						realPkgs = append(realPkgs, Package(filePath).Name())
					}
				}

				if len(realPkgs) == 0 {
					continue
				}

				b.repoWG.Add(1)
				args := []string{"-s", "-v", filepath.Join(conf.Basedir.Repo, pkg.FullRepo, "os", conf.Arch, pkg.FullRepo) + ".db.tar.xz"}
				args = append(args, realPkgs...)
				cmd := exec.Command("repo-remove", args...)
				res, err := cmd.CombinedOutput()
				log.Debug(string(res))
				if err != nil && cmd.ProcessState.ExitCode() == 1 {
					log.Warningf("Error while deleting package %s: %s", pkg.Pkgbase, string(res))
				}

				if pkg.DBPackage != nil {
					_ = pkg.DBPackage.Update().ClearRepoVersion().ClearHash().Exec(context.Background())
				}

				for _, file := range pkg.PkgFiles {
					_ = os.Remove(file)
					_ = os.Remove(file + ".sig")
				}
				err = updateLastUpdated()
				if err != nil {
					log.Warningf("Error updating lastupdate: %v", err)
				}
				b.repoWG.Done()
			}
		}
	}
}

func (b *BuildManager) syncWorker(ctx context.Context) error {
	err := os.MkdirAll(filepath.Join(conf.Basedir.Work, upstreamDir), 0o755)
	if err != nil {
		log.Fatalf("Error creating upstream dir: %v", err)
	}

	for {
		for gitDir, gitURL := range conf.Svn2git {
			gitPath := filepath.Join(conf.Basedir.Work, upstreamDir, gitDir)

			if _, err := os.Stat(gitPath); os.IsNotExist(err) {
				cmd := exec.Command("git", "clone", "--depth=1", gitURL, gitPath)
				res, err := cmd.CombinedOutput()
				log.Debug(string(res))
				if err != nil {
					log.Fatalf("Error running git clone: %v", err)
				}
			} else if err == nil {
				cmd := exec.Command("git", "reset", "--hard")
				cmd.Dir = gitPath
				res, err := cmd.CombinedOutput()
				log.Debug(string(res))
				if err != nil {
					log.Fatalf("Error running git reset: %v", err)
				}

				cmd = exec.Command("git", "pull")
				cmd.Dir = gitPath
				res, err = cmd.CombinedOutput()
				log.Debug(string(res))
				if err != nil {
					log.Warningf("Failed to update git repo %s: %v", gitDir, err)
				}
			}
		}

		// housekeeping
		wg := new(sync.WaitGroup)
		for _, repo := range repos {
			wg.Add(1)
			splitRepo := strings.Split(repo, "-")
			repo := repo
			go func() {
				err := housekeeping(splitRepo[0], strings.Join(splitRepo[1:], "-"), wg)
				if err != nil {
					log.Warningf("[%s] housekeeping failed: %v", repo, err)
				}
			}()
		}
		wg.Wait()

		err := logHK()
		if err != nil {
			log.Warningf("log-housekeeping failed: %v", err)
		}

		// fetch updates between sync runs
		b.alpmMutex.Lock()
		err = alpmHandle.Release()
		if err != nil {
			log.Fatalf("Error releasing ALPM handle: %v", err)
		}

		if err := retry.Fibonacci(ctx, 1*time.Second, func(ctx context.Context) error {
			if err := setupChroot(); err != nil {
				log.Warningf("Unable to upgrade chroot, trying again later.")
				return retry.RetryableError(err)
			}
			return nil
		}); err != nil {
			log.Fatal(err)
		}

		alpmHandle, err = initALPM(filepath.Join(conf.Basedir.Work, chrootDir, pristineChroot),
			filepath.Join(conf.Basedir.Work, chrootDir, pristineChroot, "/var/lib/pacman"))
		if err != nil {
			log.Warningf("Error while ALPM-init: %v", err)
		}
		b.alpmMutex.Unlock()

		// do refreshSRCINFOs twice here
		// since MirrorLatest depends on the DB being correct, there can be packages queued which should not be queued,
		// so we check them twice to eliminate those.
		log.Debugf("generating build-queue for PKGBUILDs found in %s", filepath.Join(conf.Basedir.Work, upstreamDir, "/**/PKGBUILD"))
		err = b.refreshSRCINFOs(ctx, filepath.Join(conf.Basedir.Work, upstreamDir, "/**/PKGBUILD"))
		if err != nil {
			log.Fatalf("error refreshing PKGBUILDs: %v", err)
		}
		log.Debugf("regenerating build-queue for PKGBUILDs found in %s", filepath.Join(conf.Basedir.Work, upstreamDir, "/**/PKGBUILD"))
		err = b.refreshSRCINFOs(ctx, filepath.Join(conf.Basedir.Work, upstreamDir, "/**/PKGBUILD"))
		if err != nil {
			log.Fatalf("error refreshing PKGBUILDs: %v", err)
		}

		queue, err := genQueue()
		if err != nil {
			log.Warningf("Error building buildQueue: %v", err)
		} else {
			log.Debugf("buildQueue with %d items", len(queue))

			err = b.buildQueue(queue, ctx)
			if err != nil {
				return err
			}
		}

		if ctx.Err() == nil {
			for _, repo := range repos {
				err = movePackagesLive(repo)
				if err != nil {
					log.Errorf("[%s] Error moving packages live: %v", repo, err)
				}
			}
		} else {
			return ctx.Err()
		}

		log.Debugf("build-cycle finished")
		time.Sleep(time.Duration(*checkInterval) * time.Minute)
	}
}