//  Copyright (c) 2014 Couchbase, Inc.
//  Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
//  except in compliance with the License. You may obtain a copy of the License at
//    http://www.apache.org/licenses/LICENSE-2.0
//  Unless required by applicable law or agreed to in writing, software distributed under the
//  License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
//  either express or implied. See the License for the specific language governing permissions
//  and limitations under the License.

package http

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"os"

	"github.com/blevesearch/bleve"
)

type CreateIndexHandler struct {
	basePath        string
	IndexNameLookup varLookupFunc
}

func NewCreateIndexHandler(basePath string) *CreateIndexHandler {
	return &CreateIndexHandler{
		basePath: basePath,
	}
}

func (h *CreateIndexHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	// find the name of the index to create
	var indexName string
	if h.IndexNameLookup != nil {
		indexName = h.IndexNameLookup(req)
	}
	if indexName == "" {
		showError(w, req, "index name is required", 400)
		return
	}

	indexMapping := bleve.NewIndexMapping()

	// read the request body
	requestBody, err := ioutil.ReadAll(req.Body)
	if err != nil {
		showError(w, req, fmt.Sprintf("error reading request body: %v", err), 400)
		return
	}

	// interpret request body as index mapping
	if len(requestBody) > 0 {
		err := json.Unmarshal(requestBody, &indexMapping)
		if err != nil {
			showError(w, req, fmt.Sprintf("error parsing index mapping: %v", err), 400)
			return
		}
	}

	newIndex, err := bleve.New(h.indexPath(indexName), indexMapping)
	if err != nil {
		showError(w, req, fmt.Sprintf("error creating index: %v", err), 500)
		return
	}
	newIndex.SetName(indexName)
	RegisterIndexName(indexName, newIndex)
	rv := struct {
		Status string `json:"status"`
	}{
		Status: "ok",
	}
	mustEncode(w, rv)
}

func (h *CreateIndexHandler) indexPath(name string) string {
	return h.basePath + string(os.PathSeparator) + name
}
