package main

import (
	"context"
	"fmt"
	"io"
	"os"
	"sync"

	"git.luzifer.io/luzifer/publish-vod/pkg/config"
	"git.luzifer.io/luzifer/publish-vod/pkg/uploader"
	"github.com/cheggaaa/pb/v3"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"

	"github.com/Luzifer/go_helpers/v2/str"
	"github.com/Luzifer/rconfig/v2"
)

var (
	cfg = struct {
		Config         string   `flag:"config,c" default:"config.yaml" description:"Configuration for the uploaders"`
		Limit          []string `flag:"limit,l" description:"Limit to certain uploader IDs"`
		LogLevel       string   `flag:"log-level" default:"info" description:"Log level (debug, info, warn, error, fatal)"`
		ValidateOnly   bool     `flag:"validate-only" default:"false" description:"Only execute validation and prepare functions, do not upload"`
		VersionAndExit bool     `flag:"version" default:"false" description:"Prints current version and exits"`
	}{}

	version = "dev"
)

func initApp() error {
	rconfig.AutoEnv(true)
	if err := rconfig.ParseAndValidate(&cfg); err != nil {
		return errors.Wrap(err, "parsing cli options")
	}

	if len(cfg.Limit) == 1 && cfg.Limit[0] == "" || len(cfg.Limit) == 0 {
		cfg.Limit = nil
	}

	l, err := logrus.ParseLevel(cfg.LogLevel)
	if err != nil {
		return errors.Wrap(err, "parsing log-level")
	}
	logrus.SetLevel(l)

	return nil
}

func main() {
	var err error
	if err = initApp(); err != nil {
		logrus.WithError(err).Fatal("initializing app")
	}

	if cfg.VersionAndExit {
		logrus.WithField("version", version).Info("publish-vod")
		os.Exit(0)
	}

	configFile, err := config.Load(cfg.Config)
	if err != nil {
		logrus.WithError(err).Fatal("loading config")
	}

	var (
		ctx = context.Background()
		wg  = new(sync.WaitGroup)
	)

	var (
		barPool       = pb.NewPool()
		longestPrefix int
	)

	if longestPrefix, err = preflight(ctx, configFile); err != nil {
		logrus.WithError(err).Fatal("executing preflight checks")
	}

	if cfg.ValidateOnly {
		return
	}

	if len(rconfig.Args()) < 2 { //nolint:gomnd
		logrus.Fatal("Usage: publish-vod <filename>")
	}

	if err = startUploads(ctx, rconfig.Args()[1], configFile, wg, barPool, longestPrefix); err != nil {
		logrus.WithError(err).Fatal("starting uploads")
	}

	if err = barPool.Start(); err != nil {
		logrus.WithError(err).Fatal("starting progressbars")
	}

	wg.Wait()

	if err = barPool.Stop(); err != nil {
		logrus.WithError(err).Fatal("stopping progressbars")
	}
}

func preflight(ctx context.Context, configFile config.File) (longestPrefix int, err error) {
	for id, c := range configFile.Uploaders {
		if cfg.Limit != nil && !str.StringInSlice(id, cfg.Limit) {
			continue
		}

		logrus.WithField("id", id).Info("validating config...")

		u := uploaderByName(c.Type)
		if u == nil {
			return longestPrefix, fmt.Errorf("unknown uploader %q", c.Type)
		}

		if err = u.ValidateConfig(c.Settings); err != nil {
			return longestPrefix, fmt.Errorf("validating config entry %q: %w", c.Name, err)
		}

		if err = u.Prepare(ctx, uploader.Opts{
			Name:   c.Name,
			Config: c.Settings,
		}); err != nil {
			return longestPrefix, fmt.Errorf("preparing uploader %q: %w", c.Name, err)
		}

		if l := len(c.Name); l > longestPrefix {
			longestPrefix = l
		}
	}

	return longestPrefix, nil
}

func startUploads(
	ctx context.Context,
	fileName string,
	configFile config.File,
	wg *sync.WaitGroup,
	barPool *pb.Pool,
	longestPrefix int,
) (err error) {
	f, err := os.Open(fileName) //#nosec G304 // Intended to open and upload arbitrary file
	if err != nil {
		return fmt.Errorf("opening VoD: %w", err)
	}
	defer f.Close() //nolint:errcheck // File is closed by process exit

	stat, err := f.Stat()
	if err != nil {
		return fmt.Errorf("getting VoD stat: %w", err)
	}

	for id := range configFile.Uploaders {
		if cfg.Limit != nil && !str.StringInSlice(id, cfg.Limit) {
			continue
		}

		logrus.WithField("id", id).Info("starting upload...")

		wg.Add(1)

		bar := pb.New64(stat.Size())
		bar.SetTemplate(pb.Full)
		barPool.Add(bar)

		go func(c config.UploaderConfig, bar *pb.ProgressBar) {
			defer wg.Done()

			bar.Set("prefix", fmt.Sprintf(fmt.Sprintf("%%-%ds", longestPrefix), c.Name))

			if err = uploaderByName(c.Type).UploadFile(ctx, uploader.Opts{
				Name:   c.Name,
				Config: c.Settings,

				Filename: fileName,
				Content:  io.NewSectionReader(f, 0, stat.Size()),
				Size:     stat.Size(),

				ProgressBar: bar,
				FinalMessage: func(format string, opts ...any) {
					bar.SetTemplate(pb.ProgressBarTemplate(fmt.Sprintf(`{{ string . "prefix" }} %s`, fmt.Sprintf(format, opts...))))
				},
			}); err != nil {
				bar.SetTemplate(pb.ProgressBarTemplate(fmt.Sprintf(`{{ string . "prefix" }} ERR: %s`, err)))
			}
		}(configFile.Uploaders[id], bar)
	}

	return nil
}