package service

import (
	"encoding/json"
	"fmt"
	"io"
	"io/fs"
	"net/http"
	"os"
	"path/filepath"
	"slices"
	"strings"

	"git.towk2.me/towk/makeshift/internal/archive"
	"git.towk2.me/towk/makeshift/internal/kwargs"
	makeshift "git.towk2.me/towk/makeshift/pkg"
	"git.towk2.me/towk/makeshift/pkg/storage"
	"git.towk2.me/towk/makeshift/pkg/util"
	"github.com/go-chi/chi/v5"
	"github.com/rs/zerolog/log"
)

func (s *Service) Download() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var (
			path         = s.PathForData() + strings.TrimPrefix(r.URL.Path, "/download")
			pluginKWArgs = chi.URLParam(r, "kwargs")
			pluginArgs   = strings.Split(r.URL.Query().Get("args"), ",")
			pluginNames  = strings.Split(r.URL.Query().Get("plugins"), ",")
			profileIDs   = strings.Split(r.URL.Query().Get("profiles"), ",")

			kw       *kwargs.KWArgs
			fileInfo os.FileInfo
			out      *os.File
			store    *storage.MemoryStorage = new(storage.MemoryStorage)
			hooks    []makeshift.Hook
			contents []byte
			errs     []error
			err      error
		)

		// parse the KWArgs from request
		kw.Set(pluginKWArgs)

		// initialize storage
		store.Init()
		store.SetKWArgs(kw)

		log.Debug().
			Str("path", path).
			Str("client_host", r.Host).
			Strs("plugins", pluginNames).
			Strs("profiles", profileIDs).
			Any("query", r.URL.Query()).
			Msg("Service.Download()")

		// prepare profiles
		errs = s.LoadProfiles(profileIDs, store, errs)
		if len(errs) > 0 {
			log.Error().
				Errs("errs", errs).
				Msg("errors occurred loading profiles")
			err = util.FormatErrors("failed to load plugins", "", errs)
			http.Error(w, err.Error(), http.StatusInternalServerError)
			errs = []error{}
		}

		// determine if path is directory, file, or exists
		if fileInfo, err = os.Stat(path); err == nil {
			if fileInfo.IsDir() {
				// get the final archive path
				archivePath := fmt.Sprintf("%s.tar.gz", path)

				log.Debug().
					Str("archive_path", archivePath).
					Str("type", "directory").
					Msg("Service.Download()")

				out, err = os.Create(archivePath)
				if err != nil {
					s.writeErrorResponse(w, fmt.Sprintf("failed to create named file: %v", err), http.StatusInternalServerError)
					return
				}

				// get a list of filenames to archive
				filenamesToArchive := []string{}
				filepath.WalkDir(path, func(path string, d fs.DirEntry, err error) error {
					if !d.IsDir() {
						filenamesToArchive = append(filenamesToArchive, path)
					}
					return nil
				})
				log.Debug().Strs("files", filenamesToArchive).Send()

				// prepare plugins
				hooks, errs = s.LoadPlugins(pluginNames, store, pluginArgs, errs)
				if len(errs) > 0 {
					log.Error().
						Errs("errs", errs).
						Msg("errors occurred loading plugins")
					err = util.FormatErrors("failed to load plugins", "", errs)
					http.Error(w, err.Error(), http.StatusInternalServerError)
					errs = []error{}
					return
				}

				// create an archive of the directory, run hooks, and download
				err = archive.Create(filenamesToArchive, out, hooks)
				if err != nil {
					s.writeErrorResponse(w, fmt.Sprintf("failed to create archive: %v", err.Error()), http.StatusInternalServerError)
					return
				}

				// load the final archive
				contents, err = os.ReadFile(archivePath)
				if err != nil {
					s.writeErrorResponse(w, fmt.Sprintf("failed to read archive contents: %v", err.Error()), http.StatusInternalServerError)
					return
				}

				// send the archive back as response
				w.Header().Add("FILETYPE", "archive")
				w.Write(contents)

				// clean up the temporary archive
				err = os.Remove(archivePath)
				if err != nil {
					log.Error().Err(err).Msg("failed to remove temporary archive")
					return
				}

			} else {
				// download individual file
				log.Debug().
					Str("type", "file").
					Msg("Service.Download()")

				contents, err = os.ReadFile(path)
				if err != nil {
					s.writeErrorResponse(w, fmt.Sprintf("failed to read file to download: %v", err), http.StatusInternalServerError)
					return
				}

				// prepare plugins
				store.Set("file", contents)
				hooks, errs = s.LoadPlugins(pluginNames, store, pluginArgs, errs)
				if len(errs) > 0 {
					log.Error().
						Errs("errs", errs).
						Msg("errors occurred loading plugins")
					err = util.FormatErrors("failed to load plugins", "", errs)
					http.Error(w, err.Error(), http.StatusInternalServerError)
					errs = []error{}
					return
				}
				if len(hooks) > 0 {
					// run pre-hooks to modify the contents of the file before archiving
					log.Debug().Int("hook_count", len(hooks)).Msg("running hooks")
					for _, hook := range hooks {
						log.Debug().Any("hook", map[string]any{
							"store": hook.Data,
							"args":  hook.Args,
							"plugin": map[string]string{
								"name":        hook.Plugin.Name(),
								"description": hook.Plugin.Description(),
								"version":     hook.Plugin.Version(),
							},
						}).Send()
						err = hook.Init()
						if err != nil {
							log.Error().
								Err(err).
								Str("plugin", hook.Plugin.Name()).
								Msg("failed to initialize plugin")
							continue
						}
						err = hook.Run()
						if err != nil {
							log.Error().
								Err(err).
								Str("plugin", hook.Plugin.Name()).
								Msg("failed to run plugin")
							continue
						}
						err = hook.Cleanup()
						if err != nil {
							log.Error().
								Err(err).
								Str("plugin", hook.Plugin.Name()).
								Msg("failed to cleanup plugin")
							continue
						}
					}

					// take the contents from the last hook and update files
					var (
						hook = hooks[len(hooks)-1]
						data any
					)
					data, err = hook.Data.Get("out")
					if err != nil {
						s.writeErrorResponse(w, fmt.Sprintf("failed to get data from hook: %v", err), http.StatusInternalServerError)
						return
					}

					// send processed (with plugins) file back as response
					w.Header().Add("FILETYPE", "file")
					w.Write(data.([]byte))
				} else {
					// send non-processed file back as response
					w.Header().Add("FILETYPE", "file")
					w.Write(contents)
				}

			}
		} else {
			s.writeErrorResponse(w, err.Error(), http.StatusBadRequest)
			return
		}
	}
}

func (s *Service) Upload() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var (
			path    = s.PathForData() + strings.TrimPrefix(r.URL.Path, "/upload")
			body    []byte
			dirpath string
			err     error
		)

		// show what we're uploading
		log.Debug().
			Str("path", path).
			Msg("Service.Upload()")

		// take the provided path and store the file contents
		dirpath = filepath.Dir(path)
		err = os.MkdirAll(dirpath, 0o777)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		// write file to disk
		body, err = io.ReadAll(r.Body)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		err = os.WriteFile(path, body, 0o777)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		w.WriteHeader(http.StatusOK)
	}
}

func (s *Service) List() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var (
			path    = s.PathForData() + strings.TrimPrefix(r.URL.Path, "/list")
			entries []string
			body    []byte
			err     error
		)

		// show what we're listing
		log.Debug().Str("path", path).Msg("Service.List()")

		// walk directory and show all entries "ls"
		err = filepath.WalkDir(path, func(path string, d fs.DirEntry, err error) error {
			if err != nil {
				return err
			}
			entries = append(entries, d.Name())
			return nil
		})
		if err != nil {
			switch err {
			case fs.ErrNotExist, fs.ErrInvalid:
				http.Error(w, "No such file or directory...", http.StatusBadRequest)
			case fs.ErrPermission:
				http.Error(w, "Invalid permissions...", http.StatusForbidden)
			default:
				http.Error(w, "Something went wrong (file or directory *probably* does not exist)...", http.StatusInternalServerError)
			}
			return
		}

		body, err = json.Marshal(entries)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		w.Write(body)
	}
}

func (s *Service) Delete() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var (
			path = s.PathForData() + strings.TrimPrefix(r.URL.Path, "/delete")
			err  error
		)

		err = os.RemoveAll(path)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		w.WriteHeader(http.StatusOK)
	}
}

func (s *Service) GetStatus(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	err := json.NewEncoder(w).Encode(map[string]any{
		"code":    http.StatusOK,
		"message": "The makeshift server is healthy",
	})
	if err != nil {
		fmt.Printf("failed to encode JSON response body: %v\n", err)
		return
	}
}

func (s *Service) LoadProfiles(profileIDs []string, store storage.KVStore, errs []error) []error {
	// check for special case profile ID (e.g. '*' or 'all')
	useAll := slices.ContainsFunc(profileIDs, func(profileID string) bool {
		return profileID == "*" || profileID == "all"
	})
	if useAll {
		var (
			dirpath  = s.PathForProfiles()
			profiles []*makeshift.Profile
			err      error
		)
		profiles, err = LoadProfilesFromDir(dirpath)
		if err != nil {
			errs = append(errs, err)
			return errs
		}
		store.Set("profiles", profiles)
		return nil
	}

	// load data from profiles into the data store
	var profiles = make(makeshift.ProfileMap, len(profileIDs))
	for i, profileID := range profileIDs {
		var (
			profilePath = s.PathForProfileWithID(profileID)
			profile     *makeshift.Profile
			err         error
		)
		if i > s.ProfilesMaxCount {
			log.Warn().Msg("max profiles count reached...stopping")
			return errs
		}
		if profileID == "" {
			log.Warn().Msg("profile ID is empty...skipping")
			continue
		}
		log.Debug().
			Str("id", profileID).
			Str("path", profilePath).
			Msg("load profile")
		profile, err = LoadProfileFromFile(profilePath)
		if err != nil {
			errs = append(errs, err)
			continue
		}
		profiles[profileID] = profile
	}
	store.Set("profiles", profiles)

	return errs
}

func (s *Service) LoadPlugins(pluginNames []string, store storage.KVStore, args []string, errs []error) ([]makeshift.Hook, []error) {
	// create hooks to run from provided plugins specified
	var hooks []makeshift.Hook
	for i, pluginName := range pluginNames {
		var (
			pluginPath string = s.PathForPluginWithName(pluginName)
			plugin     makeshift.Plugin
			err        error
		)
		if i > s.PluginsMaxCount {
			log.Warn().Msg("max plugins count reached or exceeded...stopping")
			return hooks, errs
		}
		if pluginName == "" {
			log.Warn().Msgf("no plugin name found with index %d...skipping", i)
			continue
		}
		log.Debug().
			Str("name", pluginName).
			Str("path", pluginPath).
			Msg("load plugin")

		// load the plugin from disk
		plugin, err = LoadPluginFromFile(pluginPath)
		if err != nil {
			errs = append(errs, err)
			continue
		}
		hooks = append(hooks, makeshift.Hook{
			Data:   store,
			Args:   args,
			Plugin: plugin,
		})
	}
	return hooks, errs
}