package startup

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

	"github.com/go-skynet/LocalAI/embedded"
	"github.com/go-skynet/LocalAI/pkg/downloader"
	"github.com/go-skynet/LocalAI/pkg/gallery"
	"github.com/go-skynet/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 []gallery.Gallery, modelLibraryURL string, modelPath string, 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.LooksLikeURL(url):
			log.Debug().Msgf("[startup] resolved model to download: %s", url)

			// md5 of model name
			md5Name := utils.MD5(url)

			// check if file exists
			if _, e := os.Stat(filepath.Join(modelPath, md5Name)); errors.Is(e, os.ErrNotExist) {
				modelDefinitionFilePath := filepath.Join(modelPath, md5Name) + ".yaml"
				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)
				}
			}
		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)
				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 []gallery.Gallery, modelName, modelPath string, downloadStatus func(string, string, string, float64)) (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)
	if err != nil {
		return err, true
	}

	return nil, true
}