//
//  tank
//
//  Import and Playlist Daemon for autoradio project
//
//
//  Copyright (C) 2017-2018 Christian Pointner <equinox@helsinki.at>
//
//  This file is part of tank.
//
//  tank is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  any later version.
//
//  tank is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with tank. If not, see <http://www.gnu.org/licenses/>.
//

package v1

import (
	"encoding/json"
	"net/http"
	"net/url"
	"time"
	"context"

	"github.com/gorilla/mux"
	"gitlab.servus.at/autoradio/tank/importer"
	"gitlab.servus.at/autoradio/tank/store"
)

func (api *API) ListFilesOfGroup() http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		// TODO: implement pagination
		files, err := api.store.ListFiles(vars["group-id"])
		if err != nil {
			sendError(w, err)
			return
		}
		sendWebResponse(w, http.StatusOK, FilesListing{files})
	})
}

func (api *API) CreateFileForGroup() http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		request := &FileCreateRequest{}
		err := json.NewDecoder(r.Body).Decode(request)
		if err != nil {
			sendWebResponse(w, http.StatusBadRequest, ErrorResponse{Error: "error decoding request: " + err.Error()})
			return
		}
		if request.SourceURI == "" {
			sendWebResponse(w, http.StatusBadRequest, ErrorResponse{Error: "source-uri is mandatory"})
			return
		}
		srcURI, err := url.Parse(request.SourceURI)
		if err != nil {
			sendWebResponse(w, http.StatusBadRequest, ErrorResponse{Error: "source-uri is invalid: " + err.Error()})
			return
		}

		group := vars["group-id"]
		file := &store.File{}
		file.Source.URI = request.SourceURI
		if file, err = api.store.CreateFile(group, *file); err != nil {
			sendError(w, err)
			return
		}

		user := "anonymous" // TODO: get this from auth middleware
		refID := ""         // TODO: get this from query paremeter
		job, err := api.importer.CreateJob(group, file.ID, *srcURI, user, refID)
		if err != nil {
			// shall we remove the file here... thinking...
			sendError(w, err)
			return
		}
		if err = job.Start(context.Background(), 3 * time.Hour); err != nil { // TODO: hardcoded value
			// shall we remove the file here... thinking...
			sendError(w, err)
			return
		}
		sendWebResponse(w, http.StatusCreated, file)
	})
}

func (api *API) ReadFileOfGroup() http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		id, err := idFromString(vars["file-id"])
		if err != nil {
			sendWebResponse(w, http.StatusBadRequest, ErrorResponse{Error: "invalid file-id: " + err.Error()})
			return
		}
		file, err := api.store.GetFile(vars["group-id"], id)
		if err != nil {
			sendError(w, err)
			return
		}
		sendWebResponse(w, http.StatusOK, file)
	})
}

func (api *API) PatchFileOfGroup() http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		id, err := idFromString(vars["file-id"])
		if err != nil {
			sendWebResponse(w, http.StatusBadRequest, ErrorResponse{Error: "invalid file-id: " + err.Error()})
			return
		}
		data := make(map[string]interface{})
		if err = json.NewDecoder(r.Body).Decode(&data); err != nil {
			sendWebResponse(w, http.StatusBadRequest, ErrorResponse{Error: "error decoding request: " + err.Error()})
			return
		}
		// TODO: warn if data contains invalid/unknown keys
		// TODO: only allow this for successfully imported files...!?
		file, err := api.store.UpdateFileMetadata(vars["group-id"], id, data)
		if err != nil {
			sendError(w, err)
			return
		}
		sendWebResponse(w, http.StatusOK, file)
	})
}

func (api *API) DeleteFileOfGroup() http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		id, err := idFromString(vars["file-id"])
		if err != nil {
			sendWebResponse(w, http.StatusBadRequest, ErrorResponse{Error: "invalid file-id: " + err.Error()})
			return
		}
		if job, err := api.importer.GetJob(vars["group-id"], id); err != importer.ErrNotFound {
			job.Cancel()
		}
		if err = api.store.DeleteFile(vars["group-id"], id); err != nil {
			sendError(w, err)
			return
		}
		sendWebResponse(w, http.StatusNoContent, nil)
	})
}

func (api *API) ReadUsageOfFile() http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		vars := mux.Vars(r)
		id, err := idFromString(vars["file-id"])
		if err != nil {
			sendWebResponse(w, http.StatusBadRequest, ErrorResponse{Error: "invalid file-id: " + err.Error()})
			return
		}
		result := FileUsageListing{}
		if result.Usage.Playlists, err = api.store.GetFileUsage(vars["group-id"], id); err != nil {
			sendError(w, err)
			return
		}
		sendWebResponse(w, http.StatusOK, result)
	})
}