package main

import (
	"bytes"
	"errors"
	"flag"
	"io"
	"log"
	"os"
	"path"
	"strings"

	"srs.epita.fr/fic-server/admin/sync"
	"srs.epita.fr/fic-server/libfic"
)

var OutputFormats = map[string]func(...string) (func(string) (io.WriteCloser, error), error){}

func exportThemeFiles(tdir string) (errs error) {
	theme, exceptions, err := sync.BuildTheme(sync.GlobalImporter, tdir)
	errs = errors.Join(errs, err)

	err = sync.SyncThemeFiles(sync.GlobalImporter, theme)
	if err != nil {
		errs = errors.Join(errs, err)
	}

	exercices, err := sync.GetExercices(sync.GlobalImporter, theme)
	if err != nil {
		log.Fatalf("Unable to list exercices for theme %q: %s", theme.Name, err)
	}

	dmap := map[int64]*fic.Exercice{}

	for i, edir := range exercices {
		log.Printf("In theme %s, doing exercice %d/%d: %s", tdir, i+1, len(exercices), edir)
		err = exportExerciceFiles(theme, edir, &dmap, exceptions)
		errs = errors.Join(errs, err)
	}

	return
}

func exportExerciceFiles(theme *fic.Theme, edir string, dmap *map[int64]*fic.Exercice, exceptions *sync.CheckExceptions) (errs error) {
	exercice, _, eid, exceptions, _, berrs := sync.BuildExercice(sync.GlobalImporter, theme, path.Join(theme.Path, edir), dmap, nil)
	errs = errors.Join(errs, berrs)

	if exercice != nil {
		paramsFiles, err := sync.GetExerciceFilesParams(sync.GlobalImporter, exercice)
		if err != nil {
			errs = errors.Join(errs, sync.NewChallengeTxtError(exercice, 0, err))
			return
		}

		_, err = sync.SyncExerciceFiles(sync.GlobalImporter, exercice, paramsFiles, func(fname string, digests map[string][]byte, filePath, origin string) (interface{}, error) {
			return nil, nil
		})
		errs = errors.Join(errs, err)

		if dmap != nil {
			(*dmap)[int64(eid)] = exercice
		}
	}
	return
}

type nopCloser struct {
	w io.Writer
}

func (nc *nopCloser) Close() error {
	return nil
}

func (nc *nopCloser) Write(p []byte) (int, error) {
	return nc.w.Write(p)
}

func NopCloser(w io.Writer) *nopCloser {
	return &nopCloser{w}
}

func writeFileToTar(dest string) (io.WriteCloser, error) {
	log.Println("import2Tar", dest)
	return NopCloser(bytes.NewBuffer([]byte{})), nil
}

func main() {
	cloudDAVBase := ""
	cloudUsername := "fic"
	cloudPassword := ""
	localImporterDirectory := ""

	// Read paremeters from environment
	if v, exists := os.LookupEnv("FICCLOUD_URL"); exists {
		cloudDAVBase = v
	}
	if v, exists := os.LookupEnv("FICCLOUD_USER"); exists {
		cloudUsername = v
	}
	if v, exists := os.LookupEnv("FICCLOUD_PASS"); exists {
		cloudPassword = v
	}

	// Read parameters from command line
	flag.StringVar(&localImporterDirectory, "localimport", localImporterDirectory,
		"Base directory where to find challenges files to import, local part")
	flag.StringVar(&cloudDAVBase, "clouddav", cloudDAVBase,
		"Base directory where to find challenges files to import, cloud part")
	flag.StringVar(&cloudUsername, "clouduser", cloudUsername, "Username used to sync")
	flag.StringVar(&cloudPassword, "cloudpass", cloudPassword, "Password used to sync")
	flag.BoolVar(&fic.OptionalDigest, "optionaldigest", fic.OptionalDigest, "Is the digest required when importing files?")
	flag.BoolVar(&fic.StrongDigest, "strongdigest", fic.StrongDigest, "Are BLAKE2b digests required or is SHA-1 good enough?")
	flag.Parse()

	// Do not display timestamp
	log.SetFlags(0)

	// Instantiate importer
	if localImporterDirectory != "" {
		sync.GlobalImporter = sync.LocalImporter{Base: localImporterDirectory, Symlink: false}
	} else if cloudDAVBase != "" {
		sync.GlobalImporter, _ = sync.NewCloudImporter(cloudDAVBase, cloudUsername, cloudPassword)
	}

	if sync.GlobalImporter == nil {
		log.Fatal("No importer configured!")
	}

	log.Println("Using", sync.GlobalImporter.Kind())

	// Configure destination
	if flag.NArg() < 1 {
		var formats []string

		for k := range OutputFormats {
			formats = append(formats, k)
		}

		log.Fatal("Please define wanted output format between [" + strings.Join(formats, " ") + "]")
	} else if outputFormat, ok := OutputFormats[flag.Arg(0)]; !ok {
		var formats []string

		for k := range OutputFormats {
			formats = append(formats, k)
		}

		log.Fatal("Please define wanted output format between [" + strings.Join(formats, " ") + "]")
	} else {
		fw, err := outputFormat(flag.Args()[1:]...)
		if err != nil {
			log.Fatal(err)
		} else if fw != nil {
			sync.SetWriteFileFunc(fw)
		}
	}

	themes, err := sync.GetThemesExtended(sync.GlobalImporter)
	if err != nil {
		log.Fatal(err)
	}

	hasError := false
	for i, tdir := range themes {
		log.Printf("Doing theme %d/%d: %s", i+1, len(themes), tdir)
		err = exportThemeFiles(tdir)
		if err != nil {
			hasError = true
			log.Println(err)
		}
	}

	if hasError {
		os.Exit(1)
	}
}