package startup

import (
	"errors"
	"fmt"
	"net/url"
	"os"
	"path/filepath"
	"strings"

	"github.com/mudler/LocalAI/core/config"
	"github.com/mudler/LocalAI/core/gallery"
	"github.com/mudler/LocalAI/embedded"
	"github.com/mudler/LocalAI/pkg/downloader"
	"github.com/mudler/LocalAI/pkg/utils"
	"github.com/rs/zerolog/log"
)

// InstallModels will preload models from the given list of URLs and galleries
// It will download the model if it is not already present in the model path
// It will also try to resolve if the model is an embedded model YAML configuration
func InstallModels(galleries []config.Gallery, modelLibraryURL string, modelPath string, enforceScan bool, downloadStatus func(string, string, string, float64), models ...string) error {
	// create an error that groups all errors
	var err error

	for _, url := range models {

		// As a best effort, try to resolve the model from the remote library
		// if it's not resolved we try with the other method below
		if modelLibraryURL != "" {
			lib, err := embedded.GetRemoteLibraryShorteners(modelLibraryURL, modelPath)
			if err == nil {
				if lib[url] != "" {
					log.Debug().Msgf("[startup] model configuration is defined remotely: %s (%s)", url, lib[url])
					url = lib[url]
				}
			}
		}

		url = embedded.ModelShortURL(url)
		switch {
		case embedded.ExistsInModelsLibrary(url):
			modelYAML, e := embedded.ResolveContent(url)
			// If we resolve something, just save it to disk and continue
			if e != nil {
				log.Error().Err(e).Msg("error resolving model content")
				err = errors.Join(err, e)
				continue
			}

			log.Debug().Msgf("[startup] resolved embedded model: %s", url)
			md5Name := utils.MD5(url)
			modelDefinitionFilePath := filepath.Join(modelPath, md5Name) + ".yaml"
			if e := os.WriteFile(modelDefinitionFilePath, modelYAML, 0600); err != nil {
				log.Error().Err(e).Str("filepath", modelDefinitionFilePath).Msg("error writing model definition")
				err = errors.Join(err, e)
			}
		case downloader.LooksLikeOCI(url):
			log.Debug().Msgf("[startup] resolved OCI model to download: %s", url)

			// convert OCI image name to a file name.
			ociName := strings.TrimPrefix(url, downloader.OCIPrefix)
			ociName = strings.TrimPrefix(ociName, downloader.OllamaPrefix)
			ociName = strings.ReplaceAll(ociName, "/", "__")
			ociName = strings.ReplaceAll(ociName, ":", "__")

			// check if file exists
			if _, e := os.Stat(filepath.Join(modelPath, ociName)); errors.Is(e, os.ErrNotExist) {
				modelDefinitionFilePath := filepath.Join(modelPath, ociName)
				e := downloader.DownloadFile(url, modelDefinitionFilePath, "", 0, 0, func(fileName, current, total string, percent float64) {
					utils.DisplayDownloadFunction(fileName, current, total, percent)
				})
				if e != nil {
					log.Error().Err(e).Str("url", url).Str("filepath", modelDefinitionFilePath).Msg("error downloading model")
					err = errors.Join(err, e)
				}
			}

			log.Info().Msgf("[startup] installed model from OCI repository: %s", ociName)
		case downloader.LooksLikeURL(url):
			log.Debug().Msgf("[startup] downloading %s", url)

			// Extract filename from URL
			fileName, e := filenameFromUrl(url)
			if e != nil || fileName == "" {
				fileName = utils.MD5(url)
				if strings.HasSuffix(url, ".yaml") || strings.HasSuffix(url, ".yml") {
					fileName = fileName + ".yaml"
				}
				log.Warn().Err(e).Str("url", url).Msg("error extracting filename from URL")
				//err = errors.Join(err, e)
				//continue
			}

			modelPath := filepath.Join(modelPath, fileName)

			if e := utils.VerifyPath(fileName, modelPath); e != nil {
				log.Error().Err(e).Str("filepath", modelPath).Msg("error verifying path")
				err = errors.Join(err, e)
				continue
			}

			// check if file exists
			if _, e := os.Stat(modelPath); errors.Is(e, os.ErrNotExist) {
				e := downloader.DownloadFile(url, modelPath, "", 0, 0, func(fileName, current, total string, percent float64) {
					utils.DisplayDownloadFunction(fileName, current, total, percent)
				})
				if e != nil {
					log.Error().Err(e).Str("url", url).Str("filepath", modelPath).Msg("error downloading model")
					err = errors.Join(err, e)
				}
			}
		default:
			if _, e := os.Stat(url); e == nil {
				log.Debug().Msgf("[startup] resolved local model: %s", url)
				// copy to modelPath
				md5Name := utils.MD5(url)

				modelYAML, e := os.ReadFile(url)
				if e != nil {
					log.Error().Err(e).Str("filepath", url).Msg("error reading model definition")
					err = errors.Join(err, e)
					continue
				}

				modelDefinitionFilePath := filepath.Join(modelPath, md5Name) + ".yaml"
				if e := os.WriteFile(modelDefinitionFilePath, modelYAML, 0600); e != nil {
					log.Error().Err(err).Str("filepath", modelDefinitionFilePath).Msg("error loading model: %s")
					err = errors.Join(err, e)
				}
			} else {
				// Check if it's a model gallery, or print a warning
				e, found := installModel(galleries, url, modelPath, downloadStatus, enforceScan)
				if e != nil && found {
					log.Error().Err(err).Msgf("[startup] failed installing model '%s'", url)
					err = errors.Join(err, e)
				} else if !found {
					log.Warn().Msgf("[startup] failed resolving model '%s'", url)
					err = errors.Join(err, fmt.Errorf("failed resolving model '%s'", url))
				}
			}
		}
	}
	return err
}

func installModel(galleries []config.Gallery, modelName, modelPath string, downloadStatus func(string, string, string, float64), enforceScan bool) (error, bool) {
	models, err := gallery.AvailableGalleryModels(galleries, modelPath)
	if err != nil {
		return err, false
	}

	model := gallery.FindModel(models, modelName, modelPath)
	if model == nil {
		return err, false
	}

	if downloadStatus == nil {
		downloadStatus = utils.DisplayDownloadFunction
	}

	log.Info().Str("model", modelName).Str("license", model.License).Msg("installing model")
	err = gallery.InstallModelFromGallery(galleries, modelName, modelPath, gallery.GalleryModel{}, downloadStatus, enforceScan)
	if err != nil {
		return err, true
	}

	return nil, true
}

func filenameFromUrl(urlstr string) (string, error) {
	// strip anything after @
	if strings.Contains(urlstr, "@") {
		urlstr = strings.Split(urlstr, "@")[0]
	}

	u, err := url.Parse(urlstr)
	if err != nil {
		return "", fmt.Errorf("error due to parsing url: %w", err)
	}
	x, err := url.QueryUnescape(u.EscapedPath())
	if err != nil {
		return "", fmt.Errorf("error due to escaping: %w", err)
	}
	return filepath.Base(x), nil
}